SBC mileage

Hi,
I am recently retired and trying to realize a dream of a Model A street roadster. So far I have a title, a repro frame, a Magnum 4" drop front end with econo brake kit, a 74 Maverick 8" rear and a 76 Corvette 2-bolt 350 V8 (80K miles) along with a recently rebuilt TH350 (no lockup) with a B&M shift kit and new clutches. I have searched the Internet for anything I can find on the 350 V8 and I am disappointed to find that power requires high compression and that requires 92 octane fuel! I do not want to spend more than about $1600 on the engine but I want a low rpm torque cam for mileage and able to use 87 or 89 octane fuel and as near a 300 HP as possible. I really like the Comp Cam XE250 cam, but the best deal from Manufacturers Wharehouse only offers Melling cams and the MTC-1 seems to have too long a total duration for economy. The question is can I find a way for under $1600 to get an engine with low rpm torque (2.79 rear gear!). I have a set of good, bare 461 heads but with 62 cc chamber, I can't find a short block that will yield something near 9:1 C.R. What kind of mileage can I expect with a 9.1 CR, Melling MTC-1 cam and cheap rams-horn exhaust manifold; I have a cast iron intake and a useable Q-jet carb. The Magoo 29 claims 18 mpg with a 3.08 rear and a hi-po 327, can I find a way to get 20 mpg? I look forward to expert communication.

Don Shillady

I have a 383 stroker with t-5, and 3.42 gears in my 34 Ford 3 window, Weighs 2150 lbs, gets 17 driving easy, which I did once, just to check the mileage. 300 hp on regular gas, turbo 350 trans, and good mileage seems like a reach. Maybe a 4x4 high torque cam will make it feel like 300?

Well thanks for some replies. It looks like I can expect 16 mpg so I will have to opt for lower compression to favor 87/89 octane fuel. One other idea/question is about Rhoads lifters. What is the collective experience on variable lifters? Can I use say a Comp Cam XE270 for high rpm HP and then have a 258 degree cam at low speed? Japanese high tech engines now use variable lifters even though U.S. street rodders have had Rhoads and Crane variable lifters for years. Are variable lifters noisy? Does use of a high volume oil pump spoil the effect so that one should use a stock oil pump with variable lifters? Why don't more rodders use variable lifters? The bottom line is: can variable lifters help mileage AND keep high rpm HP?

Don Shillady:LOL:

Well thanks for the welcome. I apologize for some long posts, but I tend to be a motor-mouth and after lecturing for 33 years I am able talk about any subject for 75 minutes! Today has been a beautiful day! Yesterday I received my TCI 4-bar kit for my 2.79 Maverick rear and today I found a friendly welder who did a great job for a very reasonable fee. Mr. Gary Dye of "Best Welding" is a bit remote but a friendly "Harley Man" with a neat MIG welder. He is down on Route 460 just off of I-295, east of Petersburg VA and asked that I advertise him a bit for rodders in the mid-Atlantic region. He is right next to the Mid-Atlantic VW Garage with an impressive number of junk VWs to choose from. Anyway, I guess I am a bit over my head in discussions with Brickman and Richard/TechInspector1 regarding squish. Briefly I have learned that probably I can increase the mileage of my roadster (SBC350/TH350/2.79:1 Maverick rear) with a short duration cam AND I CAN RUN HIGH COMPRESSION IF THE SQUISH SPACE IS SMALL. Richard's suggested 0.035" clearance seems tight to me but the good news is that by using a Felpro head gasket with 0.015" compressed thickness and a standard deck height of 0.025" the squish space should be 0.040". I am reluctant to go all the way to 11:1 C.R. but I can now hope that with tight squish space I might even be able to run 89 octane with a 9.1 C.R.???? With my "Copper Parachute" retirement package I probably will choose a low end crate motor from Automotive Warehouse in Charlotte and trade in my '76 Corvette two-bolt 350 for a 4-bolt 9.1 CR engine. The only problem is that they only sell Melling cams and so I will have to choose from their standard cams. Well I note that the original Model-A engine made 42 HP at 2200 rpm and used a 3.78:1 rear with 21"/19" tires and achieved 20 mpg. While a 260 HP 350 with a short duration cam might not deserve "He He He", at about five times the original HP it ought to deserve a "He He" and maybe I can crack the 20 mpg barrier and still cruise at 70 mph running only about 2200 rpm. I am amazed to find this forum when I had so many questions. It is really a GREAT FORUM with a lot of collected expertise and I am glad to have found it. If I can keep up the fast pace of construction I might be on the road by next summer and realize a life long dream of owning a Model A roadster? I hope to become just an assembler but running the brake lines look like the next challenge. This is progress report rather than a question, but I might ask other roadster owners with coil-spring rear suspension how to choose among the three holes in the shock mount. The obvious answer is probably to use the middle hole first and see how it sits? I like the "down hill" stance so I may end up jacking it up in the top hole but I guess it depends on tire size.

Best Wishes,
Don Shillady
Retired Scientist/teenage rodder

Streets,

Thanks for your reply. Well so far no pictures. All there is a is a Brookville frame, Magnum 4" drop front end with sping and disk brakes and as of yesterday the 8" Maverick rear with TCI brackets welded, sanded and painted black (according to Henry Ford). I still have to bolt in the Vega steering box and the cross-steering setup. Walking around the VW junkyard during the welding yesterday I noted how much smaller almost every part is; expecially the main drive spline. Still I am reminded that on quite a few occasions I was able to pull a VW engine by removing just four bolts and using a floor jack to lower the engine. Since there was almost no sheet metal on my 1600 cc Dune Buggy I only had to disconnect the electrical wires and fuel line to drop the engine! Well I guess I will have to buy a "cherry picker" to install the combined SBC350/TH350. I don't know yet if I will buy a Heritage or a Bebops body but both use the combined fenders and floor all in one piece and both fit the Brookville frame that I have with the rear arch behind the rear instead of over the rear. I don't see any sense buying the body until I get a rolling chassis. On my budget and taste from '50s memories, my goal can be seen on the Heritage body website showing plain steel wheels with baby moon caps and an Ididit steering column. For some reason steel wheels and baby moon caps on a '29 really "sends me"; maybe something in my brain from age 17 is still in there! I am willing to accept the razzing from this group because I have already learned a lot and I finally found a place to get expert answers. There are going to be a lot more questions, but maybe other readers can learn along with me. Back to the main issue, if the Magoo '29 reported 18 mpg with a 3.08 rear and a hi-po 327 should I not expect 18-19 mpg on the highway with a 9.1 CR 350 and a MTC-1 cam (similar to Edelbrock Performer-plus cam; NOT exactly a short duration cam!) with a 2.79 rear gear? Well there may a lot of compromises along the way to getting a roadster that runs, but let's not forget the main goal of having a roadster that runs! I will try to get this forum an end-of-summer picture of the chassis, but I doubt if I can get the body on this year? Maybe I will just buff the fiberglass and run it black for a while???

Best Wishes,
Don Shillady
:)

Techinspector1,

Thanks for the Elgin Cam address and the other site on lobe separation. The cam you cite has less lift and duration than the stock 350 cam, but I guess 3-5 mpg has to come from somewhere. From the tight lobe separation it might be a mistake to add 1.6 rockers on the intake valves? I am still digesting your claim regarding the squish and 11:1 CR. I have played with the automatic C.R. calculator from Cambellenterprise.com and the PAW catalog and there are several possibilities ranging from flat top pistons to 22 cc dish pistons to use my old 461 double-hump heads and various gaskets to achieve C.R. from 8.8 to 10.7. Then again I could buy a low end crate motor with 9.1 C.R. and replace the cam. I still like the Comp Cams XE-250 which is also marketed by Elgin. However, my first choice would be a Holley-Lunati "Avenger Truck Cam", 253/265 adv. dur., 204/216 @0.050", 112/107 lobe sep. with 0.427"/0.454" at the valve because it has higher lift and the claim is that it will operate with stock springs. You bring up a deep issue in "hot rod philosophy" as to what are we trying to do? I had hoped that I could use a medium range cam with Rhoads lifters to get BOTH mileage at low rpm and occasional "performance" at higher rpm. So far no one says the Rhoads lifters are worth anything but clicking noise, so I am back to the choice of MPG OR PERFORMANCE, not both. Thus I would prefer the Avenger Truck cam or the Elgin 5870 (their second cam). How sure are you that if I were to use 0.025" deck and 0.015" gasket (0.040" squish) with 10.7:1 I would be able to use 92 octane pump gas without detonation? If so I may build up my present block rather than trade it in, otherwise I will just order a crate engine with 9.1 CR and swap in the Holley Avenger Truck cam. You are the expert!

Don Shillady

Richard,

Thanks for your prompt reply. I get the message about small squish for high C.R. but as a former/retired scientist HOW/WHY does it work? Maybe the small squish volume prevents buildup of carbon deposits which form hot spots? What is your explanation as to why the small squish prevents detonation?

Don Shillady

Richard/All:

Well "magic" is not a good answer for me but there is a pretty good answer from Speed-O-Motive at:

http://www.speedomotive.com/Building%20Tips.htm

Apparently for squish between 0.035" and 0.060" the gas is squeezed sideways to create TURBULENCE that reduces detonation. In addition, if the piston comes close to the underside of the slightly cooler head, some cooling of the piston occurs, again reducing detonation. Also no benefit seems to show up if the squish is more than 0.080" but 0.060" might be needed to allow for rod stretching at high rpm (>6000). This answers my question that 0.025" deck + 0.015" gasket = 0.040" squish would work and be a little safer than 0.035". In addition I have learned from Richard that he thinks any cam with more than 200 degrees duration at 0.050" lift will degrade mpg. Thus my search for the ultimate cam now looks like GM part No. 3896929, the original 300 HP cam for the SBC 327. The duration of this cam at 0.050" is listed as 195/202 with lifts of 0.390/0.410 I/X. This cam fits Richard's formula for mileage and if I can get 300 HP with this cam in a 350, that is enough for me just cruising and telling myself I am getting 300 HP, although I think I will add an Edelbrock Performer intake and ceramic-coated short tubular headers. Well Richard is the expert with a little help from Speed-O-Motive and I have learned a lot. What a Forum!!!!!

Best Wishes,
Don Shillady
Retired Scientist/teenage rodder
;)

Street/Tech1:

No offense intended. It does make one ask what is the intended purpose of the car. I recall I did annoy some of my science colleagues by asking Why, Why, Why? I have little or no intention of bracket racing, although many on this Forum are interested in some form of racing. Thus I am just interested in "brisk performance" with reasonable mpg. Richard was the only one to respond about how to improve mileage, but I do not want to go to extreme measures like high pressure tires and keeping my eye on a vacuum gauge or other measures which can lead to extreme high mpg in an impractical way. Thus I am glad for the information Richard has provided and the additional info from Speed-O-Motive cited above. My "worst nightmare" is the first Tech Inspection of my car at a Street Rod event, which I recognize is necessary but there are so many parts in a complete buildup that I will have to go through Virginia State Inspection just to get on the road and then a Street Rod Tech Inspection so maybe they will find flaws that need fixing right away. Well again I know now how to plan for good quench/squish to achieve higher C.R. which leads to higher power and better fuel efficiency and Richard's 200 degree duration limit for mileage. The 300 HP 327 cam does indeed look good now for cruising. I hope that when I get the car on the road I will be able to travel and meet some of the folks on this forum. Thanks again.

Don Shillady
Retired Scientist/teen rodder

Richard/Tech1,

Thank you VERY MUCH! You read my mind regarding lock washers. All the stuff from TCI has NyLok nuts and I wondered about them. Actually on the four-bar bolts I would rather have cotter pins, but clearly lock washers on anything that rotates will not work very long. Back to my cam obsession. I take it that your recommendation of the VERY short duration cam with 184/194 @0.050" ASSUMES the small squish/quench volume we have been discussing. I checked the Melling catalog again and they have the same cam as well as a replica of the 327 300 HP cam. I don't know the C.R. of the 300 HP 327 but I assume it was pretty high, maybe 10.5:1; I know the 327 350 HP SBC had 11:1 C.R. Since I am mainly flirting with the Automotive Warehouse people in Charlotte and they sell only Melling cams, I now can specify several of the cams we have discussed. Getting back to "what am I trying to do?", I want a little more performance than the stock cam (260/268 @0.006", 194/202 @0.050", 0.383/0.401 w 1.5 rockers), so what about trying to recreate the 327 300HP with the 350 block? If I can't see potential for more performance than stock, I will probably go with the 327 300 HP cam. If I use the 184/194 cam will I get better mpg AND more low rpm torque? The description of "poor" performance above 4000 rpm does not sit well with me and I guess if I have to wimp out and take the well worn path to performance at 16 mpg I may do that. Are you saying that the very short cam improves torque up to 4000 rpm? Thanks again, it is great to be able to chat with experts on this Forum.

Best Wishes,
Don Shillady
Retired Scientist/teen rodder

Richard/Tech1,

Well I have indeed learned a lot about high compression related to the SBC and I do not want to annoy you. Within the limit of your patience, I will ask one last question. According to the Speedway catalog, Rhoads lifters reduce duration by 10-15 degrees and lift at the valve by 0.020-0.030". You have hinted that they do work while others have responded on another thread that they just make clicking noise. Therefore my (last and also first) is what cam specifications would be within range of the variability of Rhoads lifters to achieve BOTH fuel economy below 2500 rpm but still allow performancement in the 4500 rpm range. Thinking over what rodders want it is to be "slick" beyond the average family sedan,and yes I do want BOTH mileage and performance. Since I now realize the Melling MTC-1 cam is almost the same as the Edelbrock performer with specifications: (I/E)

278/288 @0.006", 204/214 @0.050" lift and 0.420"/0.443" at the valve

Or should a shorter duration cam be used? I would expect the Rhoads lifters would effect the 0.006" duration more than the 0.050" duration. Assuming I can put up with the clicking noise, does that hurt the longevity of the lifters?

Thanks a lot for your previous helpful comments.

Don Shillady
Retired Scientist/teen rodder

Techinspector1,

Putting aside the discussion of the optimum mpg/performance cam, let's get back to the question of lockwashers. I have assembled the TCI four bar assemblies with the bolts just finger tight. The bolts came with nylon locks instead of lockwashers. My question is which side of the nut goes to the outside? Is the nylon supposed to be on the inside and be crushed to a lock? Or is the nylon supposed to be on the outside? IT is much easier to start the nut and put the nylon on the outside. This is a simple question, but I want to get it right.

Don Shillady

Street is Neat!
Thanks for the quick reply, I should have waited for your reply but I paid for the call to Calif. and got the same answer from the TCI Customer Service. Next time I'll just sit here and save the cost of the phone call (NOT an 800 No.!). For interested listeners, there is another point about the rear four bar. There is a heavy 1/4" oval plate that fits over the two bolts on each side as a reinforcement to maintain the spacing between the upper and lower bolt. I did not know how to phrase a question about that here and that is why I called TCI. I suppose on a 9" rear with a 400 HP setup there might be a chance of bending or wrinkling the rear mount brackets, but on my 8" rear and only a 250-300 HP motor those plates placed on the outer part of the rear brackets should be more than adequate to keep the rear aligned without "drag twist". Streets I am pleased that you take an interest in my roadster, I guess there is a responsibility with a classic roadster to do it right so I'll probably have more questions as I build.

Best Wishes,
Don Shillady
Retired Scientist/teen rodder

SBC Mileage?????

Today I spent some money on brief phone (non-800) chats with Tech people at Crane Cams and at Speedway Motors, the main two sources of variable hydraulic lifters. The guy at Crane was really sharp on their many products, but had never heard of using their "Fast Bleed Lifters" or "High Intensity Lifters" for low rpm torque or for added mileage. The Tech guy at Speedway Motors was more open to the idea that the Rhoads lifters add low rpm torque and that it could lead to more mileage, but said that with a SBC350 it would be tough to get above 18 mpg. Well, I know I have already disagreed with some experts on this forum but for my money I am probably going to try the Rhoads lifters with a Melling MTC-1 cam which is a very close approximation of an Edelbrock Performer plus cam. If (??) the Rhoads lifters take about 12 degrees off the 0.006" lift of the MTC-1 it should be a very good torque cam in the low rpm range (nobody seems to know at what rpm the lifters will pump up fully, it depends on the oil used and the condition of the oil pump) and at higher rpm (4000 ?) I should get the full benefit of the longer duration just like a Performer Plus cam. My wife says that she will not mind the clicking of the lifters if it means more mpg so I guess I am working toward "doing the experiment" with:

SBC 350, medium valves 1.95/1.55 in 76 cc heads but with 0.015" steel shim gasket and decked block for squish/quench of about 0.035"-0.040". The cam will be a MTC-1 with Rhoads lifters. The car will be about 2500 lb. (Model-A roadster + us) with a TH350 and 2.79:1 rear from a '74 Maverick (8"). The engine will have short tubular headers and turbo mufflers.

With no intention of offending anyone here I have had to thrash out what I want, namely performance AND mileage! The Tech guy at Speedway said circle track racers use Rhoads lifters to gain low rpm torque while using long duration cams for speed on the straightaways so I think I am on the right track except that I am looking at a lower rpm range where the lifters pump up for a smaller cam. Unfortunately I probably will not know if this works until next summer since I am just assembling the chassis, but if anyone tries this before then I would like to know the results. Who knows, maybe gas will be over $3.00/gallon by then?

Best Wishes,
Don Shillady
Retired Scientist/teen rodder

Well I guess I am talking to myself because hot rods are by nature performance machines, usually without regard for mpg. Anyway TechInspector1/Richard suggested a short duration cam and I guess I "ticked" him off :LOL: discussing Rhoads lifters. Anyway, I have continued to study the situation as the time approaches to purchase a crate engine this Summer. Here is a comparison of some similar cams mainly so Tech1 knows I am still thinking.

Cam Adv Dur. I/E 0.050 Dur. I/E Valve Lift I/E LCL I/E

Elgin 5911, recommended by TechInspector1
260/270 184/194 0.368/0.398 104/104

GM-Crane Part No. 12353914, Lo Speed, Hi Torque
180/194 0.378/0.401

Mellling 22108 (Probable Choice) *****
260/270 184/194 0.368/0.398 104/104

Holley Truck Avenger, Lunati 90350LUN
253/265 204/216 0.427/0.454 107/112?

Corvette 327 300 HP
195/202 0.390/0.410

Melling MTC-1 ( the same as Edelbrock Performer Plus)
278/288 204/214 0.420/0.443 107/117

CompCams XE250
250/260 206/212 0.432/0.444 106/110


It is clear that small changes in the cam can make large differences in performance and mpg. The claim of the Elgin 5911 is an increase of 3-5 mpg. In addition, it is my understanding that if I purchase a crate engine fom Automotive Maufacturers in Charlotte I must use a Melling cam and the 22108 appears to be identical to the Elgin 5911 and maybe that is the way to get 20 mpg with a SBC 350 and still have fast 0-60 mph acceleration, by sacrificing higher mph needed for short 1/4 mile times. As TechInspector1 says, for light-to-light acceleration one needs high torque and maybe the Melling 22108 is the way to get BOTH
traffic light performance and highway mileage. Anyway, if I think I need more torque I can add 1.6 ratio rockers later without changing the cam! Sorry about another long post, but as the price of gas goes up this topic may become more relevant!

Best Wishes,
Don Shillady
Retired Scientist/teen rodder

Well thanks for the added tip on the Streetmaster manifold, I am not familiar with that manifold but I recognize the need for high velocity intake at low rpm; is the Streetmaster available new? What got me thinking was finding the Crane cam with a GM part No. with an even shorter intake duration of 180 degrees, so the Elgin 5911 has longer duration than the Crane cam! I am glad you are not offended because you are a source of a lot of valuable knowledge. I checked with the Automotive Warehouse folks in Charlotte and they do already use the 0.035"-0.040" quench/squish in their 9:1 C.R. crate motor and they say I should be able to use 89 octane gas for sure and maybe even 87 octane with the quench effect. They seem to offer reasonable custom features in the engines they build so I will hold them to a 0.040" squish and then pick the Melling 22108 and if that is too tame I will add 1.6 ratio rockers for a little more lift at the valve. You are only slightly younger than me and I am pushing within my economic limit to get my roadster built while I can still enjoy it, but the price of gas may continue to go up while I build!

Best wishes,
Don Shillady/teen rodder

ok- Don,
Tech hit it on his next to last response. I think that you have forgotten about cam phasing at the higher rpms. You have to make this up with improved intake runners & a "balenced" exhaust porting.
Also kill the overlap & you will get it.

I am sorry that I don't understand the last concept about cam phasing at higher rpms. Please explain more, I am learning fast. I did wonder about valve clearance with 1.6 ratio rockers and flat top (eyebrow) pistons and close squish/quench. Regarding the manifold, I will try a Streetmaster if I can get one and I still have an original iron 4 bbl manifold. With relatively low prices for an Edelbrock Peformer that would be available if needed. To make my question clearer, I am using a 2.79:1 rear ratio and probably 15" rear tires so as far as I can tell I will be running at about 2100 rpm at 70 mph on the Interstate and on local country roads I expect to be limited to 50-55 mph, unless the 2100 pound '29 has exceptional handling, so again I will be running at less than 2000 rpm in high gear. The only worry is the performance in low and second gear with the TH350 and stock converter. I am hoping that there will be jack rabbit torque at the light or for downshifts leading to sportscar 0-60 mph times (6 seconds or better?). It would appear that with a low rpm cam and intake, 1/4 mile times will be terriblly slow. However, I must consider my age, reflexes at my age and the fact that I am still working off "points" on my Va License from previous "frisky behavior" and it takes a few years to work off those points. If I can occasionally smoke the tires in low and get 0-60 mph in 6 seconds as well as have passing torque at 70 mph along with 20 mpg, I'll stay with the low cam and small intake. If I need "more" I can upgrade to 1.6 ratio rockers and a Edelbrock Performer intake. In any case I will use short tubular headers for "looks" as well as some added torque.

Thanks for valuable Tech Advice,
Don Shillady
Retired Scientist/teen rodder

OK- now that I've read thru the whole thread I can see that you've got the fever.
Being from Va. for 30+ years I understand the need to behave on the road.....so- don't get caught up in all the hype. Your roadster at 2100 lbs. with a crate 327, and even with those gears will have GREAT low end pull. Get yourself an Allison torque converter ( the are used for R.V.'s ) for a couple of hundred bucks.
Maybe change those rear gears to at least 3:08's.
If you want to get a Sealed Power 262 cam for it and that will give you a little bump.....you won't need much more than that if you expect to keep it rubber side down anyway, and you should still be in the mid twenty's range on fuel.

Good Luck....Let us know how it comes out....Jim

P.S.
If it get's too confusing for ya call Luther the roofer at Roofing Supply on Hull St.....he can help you too. He's got one of everything down there.

Jim,
Thanks for the encouragement. To make things interesting I am only about a mile from a State Trooper HQ and here you can be sure to see at least one Trooper car anytime I venture out on Rt. 1 or I-95! I only know of one other roadster down in Smithfield, a Brookville steel body, but I have not visited him yet. On the other hand I am only one block from the Harley Davidson Agency on Rt. 1 so maybe they get all the Trooper attention? Originally I just wanted to add a "3/4 cam" like the MTC-1 (Performer) to a rebuilt engine and have a good street car, but that seems to lead to about 16 mpg and I hoped to get up to 20 mpg with prices being what they are. As you say maybe there is enough torque to have good performance even if I sacrifice the top end and the Streetmaster should be a beast up to 2500 rpm. I guess you mean that at higher rpm the open chamber single-plane intake will experience "pulse conflict" or something where the intake pulse demand starts to rob one cylinder from another. Well I don't know at what rpm that starts, but maybe the high rear gear and light vehicle weight will work with the short cam and low end intake, we will see. Looking over the sports cars 0-60 times, maybe I can hope for 4 sec and some day try the 1/8 mile drags. Does anyone out there have a copy or a reference to the 1974 Motor Trend article on the Streetmaster debut by Edelbrock? Years ago when I was working on a '40 Ford convertible I got to know a number of the Early Ford enthusiasts in central Va, but now with a Chevy drive line I have to start all over since they generally frown on Chevy-in-Ford combinations. All I can say is that I still have a good set of crank and rods from a '49-51" Merc but after I bought three flathead blocks and found them cracked I gave up on flatheads and a SBC has an easy 240 HP where you would have to do a lot of expensive work to get a flathead up to 240 HP, so I will have to cultivate some new friends.

Best Wishes,
Don Shillady
Retired Scientist/teen rooder

I used to live on Norfolk street there just across from the school, there are still a few of us around, but there are just as many carpetbaggers around there too.
Don't listen to what everybody wants you to run - it's your rod.
Old Luther down on Hull is the one that can really help you so that you don't get knocked in the head so much by all the scam artist's, and so called friends with "just what you need" in their garage.
Good Luck with your project, Let us know how it turns out.

Jim

TechInspector1/Richard:

I have left you alone for a while, but I have taken a Summer job to buy a low end crate motor and the time is approaching to make the deal final. The cam you recommended (Elgin 5911) appears to be identical to a GM/Crane cam and the same specs are available as a Melling cam which means it is available through the company that will build my engine. The Crane description describes the performance as "brute torque" between 500-3000 rpm. I have calculated car speed with my 2.79:1 rear ratio and the gears in the TH350 and all the speeds available up to 3000 rpm are acceptably high in all three gears with 14" or 15" tires. My question is whether the torque between 500-1000 rpm is useful with a standard torque converter? Because this cam has LESS LIFT than the stock cam as well as shorter duration I find it difficult to believe there would be a performance enhancement as well as mileage increase. If this is so then for speeds up to say 85 mph this would be/is (?) a "wonder cam" when used with a stiff rear gear. Can you cite any knowledge of actual use of this cam?

The engine specs. will be:

4.040" bore, block decked and thin gaskets used to give 0.035" squish.

76 cc heads with flat top eybrow pistons for 9:1 Comp. Ratio

Edelbrock Performer dual plane manifold

Rochester Quadrajet 4 bbl (initially)

1 5/8" tubular headers

Elgin 5911 cam

The compromise cam is the grind Elgin calls #5870 ????

Don Shillady
Retired Scientist/teen rodder

Well here is an update on this idea which maybe most of you don't want to think about. I have learned from this Forum that a number of the members are serious drag racers with impressive cars and I admit I am over my head there since I am only interested in a "resto-rod" '29 Ford roadster. After the 2/4-bolt debate I decided that the 2-bolt is plenty strong enough for my needs and I went ahead with rebuilding a 0.030" over 2-bolt 350 with "882" 76 cc heads (shaved) and flat top pistons for a compression ratio of about 8.7:1. I really debated the use of a 184/194 @0.050" cam as suggested by Tech1 but the torque range only goes to 3200 rpm using the Crane version of this cam (Crane No. 10008) and if I decide to change the rear gear from 2.79:1 later to say 3.55:1 that will not be enough rpm, so I chose instead the Crane cam No. 10010 which is a 194/204 @0.050" "torque cam with specs just slightly hotter (longer duration by a few degrees) than the 300 HP Corvette cam for 350 SBC and a torque range of 1000-4200 rpm. This should still give pretty good mileage (18 mpg?) with the 2.79:1 rear and if I get disgusted with low gear bog I can change the rear ratio later without changing the cam. With a simple 0.040" gasket and 0.025" deck I will not worry about octane and hope to run 87. My machinist (2-bolt Butler) will measure the deck for me after the pistons are in and maybe I will chose to use a thinner head gasket, but I really do not want to risk a leak and "hydraulicing". Thus at the end after using new rods and new valve guides with a 3-angle valve job I will just have a rebuilt 355 SBC with a torque cam with a torque range of 1000-4200 rpm, which should be good to about 90 mph in second gear with 15" tires and the 2.79:1 rear if there is enough torque to push the full fendered car through the air at that speed. Anyway that cam will allow me to upgrade the rear ratio later if needed/wanted and I will never know what mileage I might have gotten with the 184/194@0.050" cam. Maybe it doesn't matter anyway if I only drive the car on weekends! I will still use the Performer intake and the Quadrajet 4 bbl carb. Now here is a question. In the thread on H.P. versus Torque an article in Car Craft was cited and it says that for under 300 H.P. 1 1/2" diameter primary header tubes will help torque. Any opinions on header tubing diameter?
Now here is the CONTROVERSY! See the Washington Post Writers Group Syndicated column by Ellen Goodman entitled "Hybrid Owners Laugh All the Way to the Pump". I know you don't want to read it and neither do I but I have always enjoyed Ellen Goodman's columns until now as being politically sensible. She is bragging in that column about her new Prius which gets 60 mpg! I think when you cost it out you don't really save any money buying an expensive Hybrid even though the mileage is good. In addition, you and I are mainly interested in the rush of acceleraton from a big engine in a small car, BUT (!!!) there are a lot of people out there in the population who ARE interested in higher mileage and the price of gas! I have seen a few Prius two-door sedans on I-95 every day commuting and they usually stay in the right lane and I have not observed any burst of speed from them in passing so I am guessing they are quite slow, BUT (!) they are coming and we need to recognize this fact so I would rather hear a few encouraging words about how to get higher mileage AND TORQUE from a standard engine like the SBC OR (!!) maybe we ought to be talking about the Buick V6? This is a sobering thought to the little boy/girl inside of each of us who would just like to "go fast" but we ought not to talk down to engineering principles that will/can improve mileage. Well if you get a chance to read the Ellen Goodman column, I hope you will think about ways to build "torque/mileage" motors so maybe (?) we can have acceleration AND mileage???? Also I would like to know if I use 1 1/2" headers instead of 1 5/8" headers, will that help torque below 4300 rpm in a SBC? Allow me to say thanks for a LOT of good advice from a number of you in planning for my mild SBC and other helpful comments.

Don Shillady
Retired Scientist/teen rodder

Don,
I gave you the combo for that in our first thread of discussion- you didn't listen to it then, so why should I bother to repeat myself?
882 heads are garbage, throw them away and use a quality set of heads. Those have a factory flaw in the intake runner design and flow for crap. your performance, as well as mileage will suffer.
If your going to run those heads than there will be no differance if you run 11/2 or 1 5/8 or any at all. Your worried about exhaust flow from a set of heads that are worthless for flow.

Jim/Hambiskit,

I appreciate your interest and thanks for your comments. I recently had a surprise tax bill after we paid off our house and now there is no escrow withholding, so I had to pay a pretty large lump sum of property taxes and I had to scale down the engine rebuild. I am using an article "Low-Buck Small-Block Buildup" from HOT ROD magazine, December 1995. Although they used a PAW 280 cam, they got 303.3 H.P., corrected, at 5000 rpm on a dyno using rebuilt 882 heads so I am hoping that I will have about 240 H.P. at 4200 rpm (guestimate). Their engine had a torque peak at 3750 rpm of 362 ft. lb. with 9:1 C.R. With my slightly lower C.R. of about 8.7:1 (we may cc one cylinder chamber to get a better idea of my C.R.) I may get 330 ft. lb.?? Anyway, I know the 882 ports were deliberately restricted for mileage in 1976, but let me try them and maybe in the future I will opt to buy better heads. For now I will be content to try 240 H.P. in a light body for a while and gradually make improvements. Thanks for your interest.

Don Shillady
Retired Scientist/teen rodder

With a small block Don - the power IS IN THE HEADS , if you have to run them for now then they are better than nothing I guess. I don't think that your going to be happy with that combo your putting togather.
OK, here it is again, 350 bored 30 over block,
307, or 327 steel crank,
327pistons & rods @ 4030
262H cam from Crane
461 or 441 heads- full port & polish
Edelbrock Torker Intake - ported
Holley 750 cfm w/1" spacer
1 5/8 Hedman headers, or better
283 solid damper
Cloyes hex-adjust timing set w/button

If you shop around, and do the assy. yourself, total cost of this build is less than 1500.00, INCLUDING the machine work. This combo will produce around 450 hp, with about 480 ft. lbs. of torque. With stock compression @ 9.5: 1 you can still run pump gas, and if you keep your foot out of it, you will get around 28 mpg.
The differance is the stroke & crossover, this is a Can-Am set-up for the cafe racers in the 60's. It works really good.

LOL- you know you aren't right , don't ya?
Just a little to the left??

Well it's nice to know I have some friends out there who care! I am not going to tell you my tax bill and I would not be surprised if Streets' is larger. One thing the younger members may not know is that once you are off a payroll with deductions you have to pay the IRS Quarterly Estimated Taxes as well as local property taxes (it was an unwelcome surprise to me!). Although my tax is probably less that for Streets, it did make a dent in my engine plans. Today Joe Bultler cc'd one of my rebuilt heads and got 75 cc after a slight shave and the pistons are in and the deck turned out to be 0.016" so I could still use a thin head gasket to get higher compression as well as more quench. So far I have not figured out the volume of the double eyebrows in the cast pistons, one guy says 7 cc and another says 4 cc. That makes the final compression with a 0.040" gasket as either 8.8 or 9.0 to 1. For Richard/Tech1 I was hoping he would say some really great things about the performance of the 184/194 @0.050" cam but it looked to me that I might end up in second gear a lot more with the mileage cam and as I said if I ever upgrade the rear to a 3.55 that cam really would be a limiting factor. No I do not plan to do 90 mph in second gear, but with a 2.79:1 rear gear I might want to hold it in second for an on ramp. I am selling my 461 heads because of the lack of accessory bolt bosses and high compression and I think I will end up with something like the Goodwrench Universal 350 which is rated at 240 H.P. with headers and a Performer intake. At least Jim/Hambiskit partially answered my question about primary header diameter and I will go with the 1 5/8". I note that the 350 in the Dec. 1995 Hot Rod article "Low-Buck Small-Block Buildup" used 1 3/4" diameter headers and their cam was 280/290 adv. duration with 0.443"/0.465" lift at the valve from PAW compared to my Crane 10010 cam with 260/270 adv. duration and only 0.398"/0.420" valve lift, but as Hambiskit says and as confirmed by flow graphs I have seen for the 882 heads, most of the flow increase is over by about 0.400" valve lift anyway and so I will end up with about 240 H.P. but hopefully good torque to pull the 2.79:1 rear. Anyway you can see from just the few comments you have made how different a person's goals can be and I am content that I did as well as I can for the bucks required. If Streets got 18 mpg with a 383 SBC and a 2.79 rear gear (when the blower was off) and the Magoo '29 roadster got 18 mpg with a hi-po 327 and a 3.08 gear, I think I can hope for 18 mpg with a 2.79 gear and while that is still low compared to a hybrid Prius, it compares favorably to one young man I talked to with a 350 SBC driving a two-speed Power Glide who informed me he was geting about 12 mpg! I HAVE learned a lot from your comments, thanks.

Don Shillady
Retired Scientist/teen rodder

Don, What do you want for those heads? Have they been fluxed? Are they a matching set? Are they complete? If so then if the price is right I will buy them from you. Let me know - ok? Also- are you on Norfolk Street?

The 461 heads are in Butler's shop looking for a circle track buyer, but I have said before on this Forum that the first $150 takes them. They are matched and have been pressure checked recently and found to have no cracks. The intake seats have been cut for 2.02 intake valves and I have over $200 in them so far but if you are visiting Richmond or want to pay the freight I can send them for $150 plus shipping costs. I am just six miles south of Ashland along Route 1, but maybe shipping them is easier, although expensive?

Don Shillady
Retired Scientist/teen rodder

Don,
I have friends that live on Norfolk Street....let me call them & see if they will pick them up for me. They are nice people that have a local biz. there....I'll let you know in the next day or two...ok?

OK Hambiskit, I will retrieve them from the machine shop as they are not sold there yet. My address and phone number are in the phone book. I have learned a lot about SBC engines and I guess if I were starting over I would take a good look at a 327 where those heads would be a better fit, but for me the C.R. is too high on the 350 block for current gas prices. If it comes to a close call as to who gets them I will respond to the first $150, so don't wait too long.

Don Shillady
Retired Scientist/teen rodder

Thanks, I will call them tomorrow. It's too late there now.

Hambiskit,

I settled accounts with Joe Butler today at his machine shop and he already had a guy put a $50 deposit on the 461 heads two weeks ago, but still owes the other $100. I have not been contacted by your folks so the way it stands is that if they want those heads for you they can just take the money to Joe's Machine Shop at 514 Myrtle Street (in the back of a white building with a church sign in the front) in Ashland and pick them up there. As of now whoever brings the $150 first gets the heads and if your folks are first, Joe will refund the $50 to the other guy.

Don Shillady
Retired Scientis/teen rodder

Maybe this thread is the place to ask this question. Now that I am locked in for a while to a mild 350 with a street torque cam and a 2.79 rear gear, I am wondering whether to trade/sell my rebuilt TH350 transmission for an R700. People and articles tell me that the TH350 is more reliable than the R700, but of course the limit to only three speeds and the fact that I have the early non-lockup TH350 leads to lower mileage for two reasons. Assuming I keep the 2.79 rear gear, what about the change to optional planetary gears on the TH350? The low gear will only change from 2.52 to 2.70 and the gears are expensive so is it worth the change? The good part of that idea is that high gear remains 1.00 so the 2.79 ratio is still available for cruising mileage.
My rough calculations indicate that If I keep the 2.79 rear gear and add the lower ratio planetary gear, the new low gear will be what it would be if I had a 3.00 rear gear, not a great improvement, but still some better performance while retaining the high gear mileage. Any comments from someone who has tried the lower ratio planetary gears in a TH350?

Don Shillady
Retired Scientist/teen rodder

Richard/Tech1,

Back to this issue I have looked at a number of the 700R4 deals and I have several questions. First check out the site for the '94 Corvette getting 18/25 mpg:

http://www.corvettesbyrickdaniel.com...ETTESPECS.html

I note they get 0-60 in less than 5 sec with 350 H.P. and a 700R4 and a 2.73:1 rear. Admittedly the aerodynamics of a '29 Ford roadster cannot compare to the sleek shape of a "Vette, but the '29 is lighter by almost 1000 pounds so the 0-60 time could be comparable with a 300 H.P. SBC and a 700R4 with a 2.79:1 rear. I may be able to swing the finances for a 700R4 in the near future due to a real estate deal but the old question arises about how to handle the electronic lockup. What is a simple way to hook up a 700R4? Also I was interested in your comment about a "manual valve body". After shifting 4-speeds in VWs and a MG midget for many years I would not mind shifting a manual valve body if it is easy, but so far it seems like the idea is to have a ratchet shifter which might be quite stiff. Is it possible to use a Loktar shifter with a manual valve body in an easy manner just as if it were a manual 4-speed without a clutch? Thus can you answer if it is easy to make a 700R4 manually controlled without a computer or use a manual valve body which is easy to use in the usual gear-rowing fashion common with a true manual 4-speed?

Don Shillady
Retired Scientist/teen rodder

Well just to keep the thread going I will mention that yesterday my family attended the Va State Fair in Richmond and I had a chance to look over the stealth Camaro of one of the local counties (Henrico). It is an unmarked maroon 2002 Camaro with a lot of internal gadgets including a PC. The thing of interest is that their sign advertised the car as their 159 mph cruiser with a LS1 engine and a automatic 4 speed. The main feature of interest is that it has only a short stub antenna externally but both forward and backward looking radar with the ability to pick out the fastest vehicle from a pack. Chatting with the officer, he admitted he had only taken the car up to 131 mph and the 159 mph number may be only due to the highest reading on the speedometer dial. But, assuming a 0.7 overdrive gear in my roadster with a 2.79 rear ratio and 735/75/15 rear tires I calculate a theoretical top speed of 197 mph at 4500 rpm! Clearly with 1929 full fenders and a square top I suppose anything over 100 mph would be difficult as well as illegal on the street with a Model-A roadster. I imagine the wind buffeting at high speed in a Model-A would be severe (based on memories) so I am only interested in the 70-80 mph range for "passing" on the Interstates. I looked up the LS1 350 specs and see that the bore is less at only 3.900" but with a longer stroke than my old '76 350. Also as noted above in the 2004 Corvette site the Corvette uses a 2.73 ratio rear with the automatic 4-speed and 0.7 overdrive. The question is when I run the calculation for my tires with a 700R4 0.7 overdrive and my engine, the rpm comes out around 1500 at 70 mph. The question is whether the car will actually run at that low rpm with the non-aerodynamic roadster body and will I have to change the rear to a lower ratio say 3.55? This is just a conversation piece, but I wonder how those 0.7 overdrives can run in the 60-80 mph range with such low rpms and is this only possible with the greater torque of the LS1? On the other hand with lockup in the 4th gear and the automatic making the decision when to shift I guess it works great for a slick body, but will it work easily for a roadster body? Maybe tinkering with the shift point for the OD gear will be necessary?

Don Shillady
Retired Scientist/teen rodder

Don,

My 93 Vette had 2.73'3 (w/ a 700/R4 & 300 HP LT-1)), and I ran all day at about 1850 rpm at 70 mph. I got 29 mpg on my first trip with it. I didn't like the lack of balls on the low end, so I changed out to 3.55's. My mileage on the road is still about 24, and 19 in town. With the lock-up, the trans run very cool.

I'm setting up my '34 with 3.73's and a R4 from Bowtie Overdrives. I spent several hours on the phone with the owner, and he knows more about OD transmissions than anyone I ever met. His transmissions are all run in a mule before he ships them out. He also (for a small price) sends a pressure and temp gauge with the transmission, and guides you through the installation.

After driving a Vette for 8 years, I wouldn't want a manual valve body either. The stock setup works just fine. You can downshift or hold it in gear as you wish.

Richard and Henry, Thanks for excellent answers! It looks like I should be able to purchase a 700R4 soon and maybe later change the rear. For sure the low gear of 3.06 on the 700R4 should be a lot better than the 2.52 gear of the TH350 even with the 2.79 ratio rear and I will have to evaluate the weight factor since the roadster should be lighter than the Vette by 500-800 pounds. It is great to learn from your actual experience!

Don Shillady
Retired Scientist/teen rodder

[QUOTE]Originally posted by Don Shillady
Richard and Henry, Thanks for excellent answers! It looks like I should be able to purchase a 700R4 soon and maybe later change the rear. For sure the low gear of 3.06 on the 700R4 should be a lot better than the 2.52 gear of the TH350 even with the 2.79 ratio rear and I will have to evaluate the weight factor since the roadster should be lighter than the Vette by 500-800 pounds. It is great to learn from your actual experience!

Don Shillady
Retired Scientist/teen rodder [/QUOTE


im running the 700r4 trans in my truck with a 410 gear and other than the overdrive i dont like it. ive changed the trans twice, the valvebody a couple times, used dif. stages of shift kits and its eather to hard with the kit or to soft without the shift kit. cant seam to get it right.:confused: don if you will tell joe butler, mike said hi. he used manage one of my shops in richmond a few yrs ago and i hadnt heard from him in awhile. thanks:p