Thread: I can't decide what engine to build....need advice

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I'm trying to put together a new engine for my '35 chevrolet. First off I drive the car a good bit and I usually make a 1000 mile round trip every year to pigeon forge on this car and I'd like to start going on more trips to to nats and such in the future, so I need it dependable. I've got a set of world products sportsman II's I've been hanging on to and a set of '69 186 castings on the 355 in the car now. I've got a 350 4 bolt block that'll clean up on .040, a '509 400 2 bolt block that'll clean up on .040, and 4 bolt 400 that is shot and I've got 8 sleeves to put it back standard. I'll build Either a 383 or a 400 and either way I'll be buying a rotating assembly so the money will be the same either way. I'd like to get as much power as possible so I'm leaning toward the 400 but I'm wooried about keeping it cool. I've got a Custom Auto Radiator 5 row radiator, not aluminum, Cooling components/walker electric fan and shroud, Edelbrock water pump, high flow 180 deg. thermostat, and I've got my headers wrapped and the pipes wrapped back to about the front seats. I've invested around $1200 in the cooling system. The car got up to around 210 idling in traffic last summer with the sending unit mounted in the head which is a little hotter than the intake. I'll be moving it to the intake on the new engine. I have since installed the edelbrock water pump and wrapped the exhaust so it shouldn't get quite that hot now. Going down the road it runs around 170 with the 180 thermostat. I want to build the 400 and if I do I'll pay close attention to the steam holes and try every trick I can find to help keep it cool, but something inside tells me to build the 383/385? Of course I'll be trying to get the quench right and the dynamic compression around 8:1. I have no personal experience with a 400 I've just heard horror stories. What would you do?

Throw all that away----get a Dart SHP block , build it with a 3.875 crank and 4.125 bore use AFR heads and geta a cam for the driving that you do---you can end up with 427 cid

For lots of driving? I'd go with an LS1 and forget the old stuff. Even in stock form the technology is way ahead of the old small block design. The potential for power add ons is much more advanced, too.

I can't afford any of that right now.....I started a new job this year. Automotive Service Technology instructor at Elba High School. I'm at the bottom of the pay scale as this is my first year and I'm still working in my shop in the evenings to make ends meet. I would love to upgrade but I have no choice, the engine has to be replaced, and I have to stick with the old stuff at this time. I'm only looking for 375-450 hp with a little driveability, on the ragged edge of course, and using parts I already have and my access to machine shop equiptment. I should be able to keep it under $1500 for the whole build or I can buy a $1500 block??? I can see that in my future with a pair of turbos tucked under the front fenders but that's dreaming at this point. 383 or 400? I know the sportsman II's are old technology but I traded a $100 running 305 for them.......they fit my budget.

Attaboy Jerry, pull out all the stops and go big or go home, huh?

35chevy, the 400 2-bolt block has better integrity in the crankcase than the 400 4-bolt. Once you start putting some horsepower into the 4-bolt, the webbing pulls out of the block and you run over the crank. Start your build with the 509 block would be my suggestion. In my opinion, the 400 has gotten an undeserved bad rap for overheating. I'm thinkin' that this crap was started by some dunderhead who bolted 350 heads onto his 400 without drillin' 'em for steam holes and the motor spit out the head gaskets due to localized hot spots at the edge of the bore. Either that or it rattled like a can full of marbles from detonation for the same reason. They'll cool as well as any other SBC if you pay attention to detail and it sounds like you are on that page. The late, great Smokey Yunick said that the thin limit on cylinder walls is about 0.135". Under that thickness, the skidding of the rings on the walls transfers vibes to the water jacket side of the cylinder and separates air bubbles from the cooling water. These air bubbles cling to the water jacket wall, preventing cooling water from getting to the wall to carry away heat and you have a problem. Over 0.135", there is enough mass in the walls to quell the vibes and prevent this problem. Smokey used to cut blocks apart, install glass windows and run the motor so that he could observe what was going on inside, so I pretty much take anything he has written as gospel. And yes, he said the rings SKID up and down the bore, they don't glide smoothly like you might think.

Here are the instructions for drilling steam holes in your SII heads....
http://www.gregsengine.com/350to400.htm

And a cooling system checklist that you may find helpful....
http://www.crankshaftcoalition.com/w...cooling_system

If you'll post the converter and rear gear you're going to use, I'll run up a DynoSim dyno pull for the 400 with SII heads and help you with component selection. Also, the kind of cam you want to run, solid flat tappet, hydraulic flat tappet, solid roller or hydraulic roller. Also, please tell me whether you want a choppy idle, some rump-rump or dead smooth. By the way, another item that has gotten an undeserved bad rap is solid flat tappet cams. You do not have to adjust valves every week like some throttleheads might have you believe. I suspect that twice an year would be a Lord's plenty and you would probably find 'em measuring the same after the cam gets settled in. Personally, I just LUUUUUUV the sound of solids ticking.

Oh, tha ain't all the stops----I also would use his 2 bolt 400 block, but I'd put angle bolt main caps on it. But I'd use the SHP block before I put 8 sleeves in a 4 bolt 400 sbc.

Originally Posted by jerry clayton

Oh, tha ain't all the stops----I also would use his 2 bolt 400 block, but I'd put angle bolt main caps on it. But I'd use the SHP block before I put 8 sleeves in a 4 bolt 400 sbc.

Agreed.....

Here's what I'm thinking. '509 block .040, keith black's w/ 18cc d-cups, 5.7 rods, heads are 72cc, static compression should be around 9.5:1. Might have to mill the heads a little and play with head gasket thickness to get dynamic compression and quench right. I'm thinking flat tappet solid lifter cam. I have a 700r4 with around a 2600-2800 stall and the current gears are 3.08's but I'm building another rear and I have a set of 3.55's, 3.73's and 4.10's to choose from, I am leaning toward the 3.55's. I have 28" tires and I like to run aroung 80 on the interstate. 3.73's would probably be the lowest....of course I'll use what fits the engine combination best. I have power brakes also and I have a vacuum reserve canister. Idle quality.....The Lousier the better, it's a Hotrod Let me know if yo need any other info to run that dynosim for me, thanks.

408 SBC Low RPM Grunt motor. 415 HP, 475 FT/LBS. (For cruisin' and gettin' out of the way )
We're gonna use World Sportsman II heads on this motor, 'cause we've got 'em. They're not the best choice to make horsepower, but for a cruise motor and makin' torque, they ain't that bad. Thing is, they don't flow as well as some other heads you could use on this motor, so trying to prop them up with more static compression ratio and more cam to try to make a horsepower motor is fruitless. Better to optimize what you have to work with and make good torque, then use a gear to take advantage of it. I went to several sources to find some "real" flow figures for these heads. Brzezinski has flowed a bunch of 'em on a SF600 and averaged 'em out, so I went with their figures. I just don't trust figures from the manufacturer as much as I do from an independent company that has no axe to grind. On the DynoSim, these heads stall and nose over at 5000, so I optimized the cam to use this to advantage and make a torque motor out of it. By the way, I tried 11 different cams before I found the one I liked for this build. One of them made 460 ft/lbs at 2000 rpm's, but the hp was nothing to write home about.

Sportsman II flow figures from Brzezinski:
0.100" 64 60
0.200" 130 107
0.300" 186 126
0.400" 214 139
0.500" 230 147
0.600" 233 148

Block: 400 CID Chevy, casting 509, bored +0.040". In my opinion, it is detonation and/or rpm's that kills parts. With this build, I would be totally comfortable using the 2-bolt main caps as is. Nominal block deck height on a virgin block is +/- 9.025". The stack of parts used in this build is 9.008". Most available 400 gaskets will be around 0.040" compressed, so you would want to cut the block decks about 0.017" to zero deck to generate a 0.040" squish with a 0.040" gasket. Or you could cut the decks 0.012" for a piston deck height of 0.005" and use a 0.040" gasket for a squish of 0.045". Your choice. Measure very carefully before cutting anything.

Crank: 400 Chevy, 3.750"

Rods: 5.7" rod of your choice. Since this will be a low-rpm build, I might just use production 350 rods with ARP bolts and the big end re-sized and grind the head of the bolts for cam clearance. Scat I-beam capscrew rods will not have any clearance issues at the cam.

Pistons: 18cc D-Cup Hypereutectic, Keith Black #KB147+040, 1.433 compression height, 5/64, 5/64, 3/16 rings. If necessary grind rod bolt heads for .030" clearance at camshaft. Grind block at pan rail if .030" clearance is not present. Check stock rod balance pad-to-piston clearance, underside of piston. Pay careful attention to ring end gap information from KB. If I have to use a dish piston, I like the KB's because of the D-Cup configuration on the crown. It leaves a generous flat pad on the crown to mate up with the underside of the cylinder head to generate excellent squish.

Heads: World Products Sportsman II cast iron. 200cc intake runners, 72cc chambers, 2.02" intake valves, 1.60" exhaust valves. I suspect you could help these heads out considerably by doing a little bowl blending, precision 5-angle job on the seats and a couple of shallower cuts on the backsides of the valves. I don't know this for a fact, I'm just thinking out loud.

Intake manifold: Dual-plane, high-rise such as the Edelbrock RPM, Weiand Stealth or Professional Products Typhoon.

Carburetor: Vacuum-secondaries 650 CFM of your choice. This motor made a little more hp and torque with an 800, but the driveability (throttle response) and fuel mileage would probably discourage me from using it. If we used heads that flowed better, then yes, definitely I would use the 800.

Headers: Long-tube, equal-length headers of your choice. With this motor, it's a toss-up between 1 5/8 and 1 3/4 primary size. Use what you have. 1 1/2" long-tubes or shorties will be down 38 hp and 41 ft/lbs on this motor combination.

Rocker arms. I used 1.5 rockers for this build. It is said by some that you can pick up 15-20 hp by using full roller rockers over stamped steel ones because of the reduced friction. It is also said that full rollers will lower oil temperature and that makes sense to me. My DynoSim makes no distinction between them, so I can't change that part of the build. I figured you already have 1.5's, so I didn't want to spend any of your money. I did use 1.6's on the sim just to see what would happen. 1.6's will pick up 4 hp and 6 ft/lbs. Hardly worth the trouble and/or expense, taking into account the additional stress generated at the lobe/lifter interface.

Camshaft: CompCams solid, flat tappet, installed advanced 2 degrees. This motor with this cam (advanced 2 degrees) at this static compression ratio should run detonation-free on 87 octane swill as long as the motor is built with a 0.035" to 0.045" squish and the ignition timing is optimized. I might use a 2-piece front cover on this build so that I could try different offset bushings on the cam dowel pin, advancing it and retarding it to tweak the motor after I got a good feel for the baseline power. Some will say that if you have to advance or retard the cam, you've chosen the wrong cam. I don't agree with that. Usually, you can't find cams with only 2 to 4 degrees difference between them from the same manufacturer, so you use the cam that comes closest to what you want the motor to do and tweak it a couple degrees either way to get what you want. That's my take on it anyway. Use extreme caution on the valve springs with a flat tappet cam. You don't necessarily have to use a Comp cam, but you should talk with the tech guys at whatever grinder you choose to make absolutely certain you're using the correct valve springs on your heads for the cam used. The springs that Comp recommends for this cam are shown on this cam card.....
http://www.compcams.com/Cam_Specs/Ca...?csid=220&sb=0

Static compression ratio: 9.42:1
Dynamic compression ratio: 8.00:1

RPM HP TQ
2000 158 414
2500 198 417
3000 252 441
3500 312 468
4000 361 475
4500 394 460
5000 415 436
5500 371 454

I might be thinking of using a little taller gear with this motor than I would with another build that makes more hp at higher rpm's. 3000 r's with the 3.08 gear and a 28" tire makes 81 mph by my calculations. This would put the converter past stall and deliver 441 ft/lbs to the pinion. Oops, just went back and read that you have a 700R4. I believe the OD on that box is 0.7, is that right?

WOW!!! Before I go any further, I must say this is the most awesome website I've ever found. A lot of sites offer very little help. You guys are awesome. That is almost exactly the engine comination I was looking at. I think the horsepower and torque numbers are very respectable for a streetrod. Heck, a lot of rods don't have half that much power. Couple of things.....I already have the performer RPM, the 981-16 springs required for the 282s cam so I'm well on my way to having all the parts. My headers are 1 5/8 block huggers. I'm sure the headers will hurt a little but I plan to upgrade to longtube at some point. I have already welded the flanges around the outside of the tubes and port matched them to the exhaust ports of the heads in an effort to get all I can out of them.. The heads have a 5 angle valve job, stainless valves w/ undercut stems and I believe a 30 deg. back cut. After much research, I tapered the guides and polished the ports, but I did not significantly alter the port shape. I was a little surprised at the flow numbers, they are a little low compared most. Nosing over at 5000 is also a surprise, though I do understand these are by no means new technology. The 700r4 does have a .7 overdrive and I have a lockup converter. 3.55's would put me at 2387 rpm at 80 mph and 3.73's would put me at 2508 rpm. WOW, 475 ft/lb's of tourque through a 3.06 first gear and 3.73's I better start thinking about a new rear suspension Thanks for your help, I really appreciate it. That's a lot of info!

You're welcome. I enjoy doing this stuff. You'll make more power than what was shown, because the heads will flow better than what I used in the DynoSim, but it's better in my opinion to show it conservative and be overwhelmed with the actual results than it is to anticipate something fantastic and possibly be disappointed with the actual results.

Check out this link here...the guy builds a 500hp engine for a little over $5000.00
http://www.hotrod.com/projectbuild/h...d/outcome.html

This cam is gonna want a lot of initial ignition timing and the heads will probably want somewhere around 36 total. Use 20 at the crank and 16 centrifugal. Use manifold vacuum for the vacuum advance cannister. If the motor is hard to get cranking speed up when you go to start it because of the 20 initial at the crank, install a momentary button on the dash to kill ignition voltage to the coil while you get the motor spinning, then release the button.

Not knowing your level of expertise, I'll link Isky's tutorial for installing the cam and degreeing the damper. Use either a fully degreed damper or find TDC on your stock damper and use a timing tape on it so you can properly ignition time the motor once it's together.
http://www.iskycams.com/camshaft.php

Advancing the cam 2 degrees will change the figures shown on the cam card. Intake centerline will be at 104 degrees ATDC, exhaust centerline will be at 116 degrees BTDC and timing events will be 37/65/77/25 @ 0.015" cam lift.

So, 20 degrees initial and 36 degrees total? All in by what rpm?

Originally Posted by 35chevy

So, 20 degrees initial and 36 degrees total? All in by what rpm?

I might start at 2800 and change springs up or down to change it a couple hundred r's and see what happens. Edited my post above. Go back and see. You can, of course, use a crank gear with the advance on it, but then it's not so easy to change the cam timing later. Using an offset dowel and 2-piece timing cover makes it easier.

There is a rodder on another forum (whose opinion I respect) who advocates setting the ignition timing at the crank at 36 and locking out the centrifugal. I've never done it, but he says it'll wake the motor up and that you don't need a curve with a loose converter anyway. Sorta makes sense to me, depending on the stall rpm's. But then I was thinkin' that if you had the converter locked up and were under a moderate load at.....say.....2000 rpm's, I don't think the motor would like it much.