Pontiac 400 Stroked to 407 Engine Spec Sheet (correct numbers) Input / Advice Wanted

Ok so first I appologise for screwing up the first build sheet posted I was working on, so after noting to self not to have more than 1 engines notes written down in front of me at one time here is the correct spec sheet for a potential build up of a 77' Pontiac 400. Right now were in the initial stages of looking to take the ole gal and put a fire under the seat. I know pushing a 77' cast 500HP+ is not a good idea so no I don't want to go that far. However that being said I would like some input into potential tweaking of the numbers with maybe a slightly different setup. I punched these numbers in for the estimated HP/TQ which are estimates only. I do know paper is one thing dyno is another. So hopefully i didn't make any errors this time since I did make sure and only had one motors notes out at one time! Thanks in advance for any pointers or input. I would like to boost or maintain the HP/TQ estimates while bringing down the compression to around 9.5-9.7:1 if possible. It is also a goal to keep cost within reason so no im not even going to ask for the cheapo buildup ideas, cheap = more cost down the road.


Pontiac 400 (6.6 liter) 1967-1979
Cubic Inch Displacement 405.8ci +.030 Over Stock Bore W/ 10:1 Compression on Pump Gas. All balancing to within .1 Gram Tolerance

BLOCK: Cast Steel Crank W/ Performance Balance
Pistons H Series Premium Forged Flat Top
Bore 4.150 (+.030 Over)
Stroke 3.750
Main Journal 3.00
Rod Journal 2.250
Connecting Rods:
Forged 6.625 H-Beam W/ 3/8” Cap Screws
Piston to Deck .030 Head Gasket .039”
Piston Dished -5.00cc Flat Top Valve Relief Cut
HEADS: *note final number based on port & polish gasket matched job
Compression Ratio W/ 72 cc Combustion Chamber 10:1
Edelbrock D Port Performer (Bare)
72cc Combustion Chamber
Intake Runner Volume 204cc
Exhaust Runner Volume 145cc
Intake Valve 2.11
Exhaust Valve 1.66
Valve Spring Diameter 1.46” 120 lbs @ 1.800 Installed Height
Cam:
Cam #Magnum 51-240-4 292H
RPM Range 2500-6500
*Required 3000 Stall 9.5:1 Compression *minimum compression ratio
Advance Duration Degrees 292 Int 292 Exh
Lobe Separation 110 Degrees
Centerline 106 Degrees
Valve Lift .501 Int .501 Exh @.50 In Lift
Valve Timing @ .006 Lift
Exhaust Closes 32 ATDC Opens 80 BTDC
Intake Opens 40 BTDC Closes 72 ATDC
Gross Lift (1.65:1 Ratio Rockers) .411 Int .446 Exh
Gross Lift (1.50:1 Ratio Rockers) .374 Int .406 Exh
Intake Manifold
Edlebrock Performer RPM Series
1500-6500 RPM
Carburetion:
Holley 0-4779C 750 CFM Double Pumper
Estimated Numbers
405.8 ci Displacement
452.79 HP @ 6600 RPM 466.07 Ft Lbs Tq @ 4337 RPM(@ Flywheel)
Engine CFM 801
Volumetric Efficiency 103.07%
Compression Ratio 10.01:1
Estimated Wheel HP Based on Upgraded Transmission 369.94 HP
Octane Rating 90

many build use the bbc H beam rod 990 pin and 2200 rods size if you go with a crank. l would lose the stock crank its not realy a stroker till it gets some arm last one i built to 495 . i like to run roller cams most all builds as well

Yeah I know its not technically a stroker. Its how the rotating assembly is sold. I do like your idea though. I read a couple tech sheets about doing the bottom end like your post. All good stuff

not much about it realy scat crank PEP rods I beam rods 6800 and a icon pistons i made up stroker kits with parts i like to used . that is base off of past history with who i deal with . 4.500 crank drops right in the milodon road race pan fits nicely the windage tray may need to be trimed abit and use the mildon tray kit .most time making things fit was dealing with the dip stick guide tube that bolts on the main cap need some fab work to make sure it not bending the dip stick and not reading oil or hitting the counter weights on the crank . roller cam is the only way to go . my own numbers that Erson cams custome grind . Erson roller cam all cores it this time are 4/7 swap for the pontiac built many with and with out the 4/7 swap lower HP and Tq under 700hp and offer more then hp the fire order cuts down on crank flexs helps the engine run cooler .HP and TQ numbers you may not see the gain but still nice to get any ways the custom core cam and custom grind is not any more added to cost . if you go roller you will have to cut out baffle out of valley cover as it hits the roller cam lifter bodys and you will have to reroute your PCV to valve cover .it can not stay in valley pan if the baffler is cut out for the roller lifters

I don't think I have ever (or at least seldom) written, But I, like Pat, do a lot of this type stuff---and your choice of a 400 block ( with the smaller)(altho bigger than most engines) is the best choice Pontiac to use as The 455 block has even bigger main sizes---and with the stroker cranks with the Chev bearing sizes out there are good candidates for moveing up the cubes to the upper 4xx's-


Not only does the 455 have much bigger mains for the bearing size but that makes the distance fron main bore to cam bor shorter and easier to split------

yep well i would of did the 400 block ended up with the customers 455 that i made a 495 very very big mains but as now bigger in CID it may help him keep it under the 6500 + side of the rpms last time i talked to him he could not hook it in any gear on the road

Yeah the customer wants to keep the numbers matching aspect of the car but wants significant amount of gains in HP. I do think we can achieve what he wants through a good solid upgrade to the original spec but do more through the drive train. Right now I'm just spec'ng it out more for budget . Still gotta keep in mind machine shop costs and my labor on assembly. I've heard a lot of negative things about the #X heads so really thinking need to look at good options there. Course if it were me I'd just pickup a good crate motor to drop in and save the original #'s engine. But to each their own..I can do all the fab work for what's been mentioned so that's no issue either. Just looking at different setups to achieve a motor that will get him what he wants which is neck snapping torque and haul ass HP . I haven't done a whole lot of Pontiac build ups so appreciate the advice on their quirks. I'm working on my own 455 Buick engine right now for my 36' coupe so new quirks I'm learning on that motor too with its poor oiling issues in the bottom end. I may just post up what I've got so far . Its gunna be a real mover in that lil coupe all said n done compared to that inline 8 it had haha . I just didn't want to approach the 400 as I would with a Chevy since I've read a lot of subtle differences in the setup of the block

Quote:

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Originally Posted by pat mccarthy

many build use the bbc H beam rod 990 pin and 2200 rods size if you go with a crank. l would lose the stock crank its not realy a stroker till it gets some arm last one i built to 495 . i like to run roller cams most all builds as well

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Yeah I've looked at that option and looks like with a trip to the machine shop its really no issues. Blocks gotta go there anyways.

well any stock iron pontiac head is going to roller cam is hard to get the set up on the valve springs that will not pass coil bind ..as for guys with number block s i done more then one and not just chevys every one wants more power out of there muscle car with pump gas .the only thing it can do is move up the cid of the engine move to a roller cam to get the power they want to see out of there car . most all the time the engine cam be put back to stock

I commonly suggest putting the original numbers matching STUFF on the shelf for safe keeping and built a replica to beat the hell out of---that way if you do have something split apart in a catiscrpic manner you haven't killed the value of your ORIGINAL package??????????


But also, in those deals I don't recommend an engine of another make/model because of all the accessories, exhaust, etc------you can still show your Poncho at a Pontiac DAY WITHOUT ALL THE SNUBBERS turning there backs on you---------


and probably valve seat, valve spring, rocker geometry are biggest concerns along with the roller cam /modern day oils issues




Also OSK, I didn't realize that you had recently opened a SHOP?

all good points on numbers stuff jerry. i do spend some time talking about this to the customer if they do want a block thats not numbers that fine .BUT some guys want there number engines and i do not spend more time on this as then needed or tell the guy thats wants the number engine built up not to do it. i see it no sense pissing a guy off and spending his money to the find the guy thats will build his number block has for the chevy in chevy . chevy in the pontiac deal well i have one and the next guy wants it back to stock has abit of work in front of him as the car was not pass warranty before the 389 pack it up then a 400 did not fair much better . so the l88 427 was not a option on the gto but did fit fine dad had it this way it s goning to stay this way till they throw dirt on me

I understand what your saying and where your coming from Pat-------------------


It just seems that here OSK got on here presenting some numbers and such, asking for drtails and opinions and in reality he was fishing for info to pass on to a propestive customer of his business he has formed but he doesn't have any machining equipment to do the work any way-nothing wrong with that, just a little questionable----------??

i hear you.... i will pass on what i was thinking has last time......well ...i had to sit in the corner till i learned how to play better with other s

Yes I did finally launch this last year mainly doing sheet metal fab & customizing. We also do old school speed equipment setups. As far as in house machining capabilities were just not there yet. I have been doing engine work on the side for many years but on the poncho motors I've read just so many different things I thought it best to get a real opinion not some blogger looking to get followers. Were just a small shop that's growing and are getting set to move into a larger facility. Which will allow me to finally bring in more equipment. I do understand where your coming from Jerry just understand I'm always looking to learn something new. I did post my setup though to begin with as how I want to build the motor based on what I know. If there is a better way I'm all ears

Quote:

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Originally Posted by jerry clayton

I commonly suggest putting the original numbers matching STUFF on the shelf for safe keeping and built a replica to beat the hell out of---that way if you do have something split apart in a catiscrpic manner you haven't killed the value of your ORIGINAL package??????????


But also, in those deals I don't recommend an engine of another make/model because of all the accessories, exhaust, etc------you can still show your Poncho at a Pontiac DAY WITHOUT ALL THE SNUBBERS turning there backs on you---------


and probably valve seat, valve spring, rocker geometry are biggest concerns along with the roller cam /modern day oils issues




Also OSK, I didn't realize that you had recently opened a SHOP?

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Also yes I am pushing hard to get him to leave the original engine alone. I'd much rather go find another 400 to build and convince him to just store the numbers matching. I always try to side with what's best for the car first customer second. I decided awhile back I'm tired of working for others. Its much better working for myself!

Good luck on your new shop!!! I was self-employed most of my working years, and most of the time I had a jerk for a boss!!!!:LOL::LOL::LOL: It's a lot of extra work and is a constant learning process! Taxes, insurance, and regulations can often be tougher to deal with then the most irate customer you ever had nightmares about!!!

Just a suggestion, until you have the equipment and knowledge to do all the engine machining and assembly, I'd leave it up to a competent engine shop.....Main reason being that if you touch the engine last, guess who the customer is going to hold responsible for any problems with the engine??? I never thought it a good idea to warranty someone else's work!!!! I much preferred to let the customer do his own dealing on an engine, I was willing to make some suggestions and answer questions, but that's about it.!!!!! IMO a new business is going to have enough start up difficulties and expense without assuming the liability for someone else's work!!!!

Good luck on the new venture!

Quote:

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Originally Posted by Dave Severson

Good luck on your new shop!!! I was self-employed most of my working years, and most of the time I had a jerk for a boss!!!!:LOL::LOL::LOL: It's a lot of extra work and is a constant learning process! Taxes, insurance, and regulations can often be tougher to deal with then the most irate customer you ever had nightmares about!!!

Just a suggestion, until you have the equipment and knowledge to do all the engine machining and assembly, I'd leave it up to a competent engine shop.....Main reason being that if you touch the engine last, guess who the customer is going to hold responsible for any problems with the engine??? I never thought it a good idea to warranty someone else's work!!!! I much preferred to let the customer do his own dealing on an engine, I was willing to make some suggestions and answer questions, but that's about it.!!!!! IMO a new business is going to have enough start up difficulties and expense without assuming the liability for someone else's work!!!!

Good luck on the new venture!

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Appreciate all the info. Its been a lot of squeezing this first year. Where to invest money in where not to. Which stuff to buy n not get burned the usual. Thing is I hate out sourcing work on stuff I'm perfectly capable of doing in house. I do have the background and equipment to take care of the assembly. I didn't just decide one day to toss my hat in the ring n start building motors ;) that said I don't have the facility yet in order to do the machining in house. Were a one man band here and very limited space . Course that's exactly why we gotta move. I need a bigger space cause I do have clients who want work done but I'm just fresh out ta room for any other equipment . I don't want to build one of them mega shops either I really wanna stay small and focus on the quality not quantity. I like working from home as it is now and don't want to get into a situation with land lords and all that noise. Maybe pickup up a couple guys along the way but never more than 4. It'll be a tough one to swallow to not do any motor building . I've always taken pride in my attention to detail. But if the risk vs reward isn't there I can set ego aside until we're fully capable of doing everything in house. I sure do appreciate the insight . Just a guy wanting to continue building a solid reputation n put a lil food on the table. Wife n I sacrificed quite a bit last couple years so hopefully we can keep growing as more people get exposed to my work. Thanks again Dave you gave me a lot to think about. -Tony

Pat and I can't talk about EGOs--------------------------

I got a whole lot of respect for you guys and your experience . Just love sitting around talking motors and learning new ways of doing things. Took me a long time before the ole flathead guys started coming around that'd open up about trick setups. Just wanna contribute to keeping this hot rod world alive!

i do not know in your parts but here were i am at machine shop hourly rate is as much the same as 1989 .but the cost of the machines even used are more . cost of tooling . cost of insurance cost of losse and liability . here in mi they have what they call milk run that state license and show you as having and moving haz wast . then the cost of moving it out and getting the wast to a safe state and matter thats good in Mi. i had to stop cleaning blocks .heads .cranks tin .for a friend who sells online hard to find pontiac engins. at the time it looked like ok money .till i work it out on paper . no machine work was done and soon foud out there no money in cleaning part with what i have for equipment it.s just the evil part of the deal stuff needs to be clean to machine it. a bake n shake set up is very:D nice nothing but dust and hi heat burns off the bad stuff but many of them set up ampro are over 20.000 used .to pay that machine off is a hell of a of of 350 chevys much the same with bore bars like my rottler F2B i love it . but they sell used for 7000.to 10.000 that s a hell of alot of bore jobs . well mine busted in the spring of the year .so then i started looking for parts to fix it then some one to service it. every one has died or stop fixing engine machines.but will sell you a new cnc machine . so now i know way more about a fixing rottler boring bar then last year that much go,s with every machine i own . evey machine . i seen cnc machine that you could put 3 parts on and line bore all parts with a tooling set up . but then you have to ask your self how long is it going to take to pay it off will it make money . i would of never got in to the engine machine deal but was the last card i had to play would of stop at valve epuipment and just built engines .it is a very hard bussness around here .. very over rated it has to be way more then money or your never going to like it

Yeah machines cost money. I'm really kicking myself for not buying the last opportunity I had to buy a mill machine w/ vertical head & more cutting heads than I could count. It was from the 40's? I think. But family friend owned a machine shop was giving me a deal at $1500. There was somewhere around 40-50k in heads. I just didn't have the space to put it. I told him I'd be kicking myself within two years for not buying it. Could've done anything I could imagine on it. Was a Boeing machine so lifetime of aircraft tolerances and maintenance. Oh well there's still a lot to get at the new place before worrying about getting machine tools. I've always sent out my bottom ends for machine service n done my own assembly. I'll just need to check out Washington states laws of liability a lil further before I decide if its best to outsource or do things the way of how is always done it for myself or friends on the side . A lot for me to think about Pat.

I been telling myself and others that I have a flat head ford and a 392 hemi that I want to machine for myself and then I'm planning on selling off my equipment---I'll keep a mill, bandsaw, welder, etc but want to get rid of the other stuff as I don't want to move it when we leave this area---------The cleaning/chemical disposal issues are out of this world-------


However---I can buy core blocks that are baked, and machine them which is all labor except for the cost of the core--I pay taxes on the core so I don't have to deal with the state for sales taxes-if someone wants to do Summit/Jegs, fine---no shipping or taxes for me to deal with--------


I find that more and more rare type set ups are coming to me because I know the history of combo and don't just go .030 over if it only needs .005------and I don't machine off any stamped numbers that need to be on there-------


About the only surface that doesn't get machined is the oil pan rails and front cover and bell housing mountings------

Yeah with this move were doing now to get setup into a bigger place has been pretty hectic trying to prep the house & keep business moving . My customers actually a big car nut and we've talked about maybe teaming up on this 77' and doing a road track type car. Course if not he's still a very good client and been chomping at the bit to do an engine for him. Just not sure what the disposal fees would be if I did expand into the machine side but I can always call that family friend. He did just retire and sold off his machine shop so might just pick his brain. Kinda thinking of sticking with the fab side of it now that I'm hearing the horrors of disposal fees n state licencing. I can't paint so that's a given for outsource or interior the rest I can do but as I'm a certified welder I even checked into chassis building but even that's got outrageous fees . Funny how the cost of living goes up but yet welder's who were around for the big boom of pipeline building in the 60's n 70's tell me their wages and now making less per hour but paying 4x the cost in doors n fuel. Makes a guy really pay attention . This is exactly why I don't want to get too big. Just a good solid honest shop doing quality work. Given I do specialize in tig on specialty metals like chromoly n aluminum there's race guys always breaking stuff that want stuff repaired. I've been real cautious of chasing money and keeping a pretty level head about this. Not my first business but at 36 now I'm a lot more educated and a lot more willing to listen than at 19 haha.

I can tell you guys that here in the Pacific northwest I know of only a couple guys I'd tryst to do machine work on a flathead engine or nailhead. But them guys are pushing up there in the years. Just wondering who's going to take over when their gone

oh i save you the time if they have a good lawer they can sue you not a hell of alot you can do about my lawer tells me . know some guys that been down that road . i try like hell to make customers happy some you can not so i try to pass on some if i get the feeling that i could never do any thing that would work. as for mills that mill may of worked. but buying a mill that is setup to do just engines they have tooling and set ups for fast floor to floor time . i have a milled that i milled chevy heads on my J head brigport and cut seat.s for flat heads but never did the job as good as the storm vulcan or the berco with a PCD cutter . i still use the j head mill on the heads and use it to reface the ex side of some heads if they are all chewed out from rust drill and tap .cut pistons added a key ways on cranks many other thing that would be the first machine i would buy

Oh I hear ya. I've passed on guys who I just didn't have a good feeling on. So hard in a day where people are so sue happy. Kinda makes a guy think that the only way to make a living is be some shiesty lawyer lol. Such a sad world we live in have to pass up customers cause of a bad gut feeling their only out to make a buck off a law suit

A good deal for you would be building custom stainless exhaust headers for show cars and hot rods plus the underneath work-even tho you can buy nice headers fo most apps, the underneath out the back stuff is often screwed up--------


and at one time I had 4 bridgeports---could leave them set up for angles on different jobs while still having at least one to bore holes--------

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Originally Posted by jerry clayton

A good deal for you would be building custom stainless exhaust headers for show cars and hot rods plus the underneath work-even tho you can buy nice headers fo most apps, the underneath out the back stuff is often screwed up--------


and at one time I had 4 bridgeports---could leave them set up for angles on different jobs while still having at least one to bore holes--------

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small hole i use the small engine bore head on the rottler bores nice small hole have a big face plate and bored rods under .002/001.5 then take to size on the sunnen rod hone save on arms had like 12 sets of bbc rods to do have it all setup still pain in the ass

Yeah I'm talking to a couple race teams about doing some stuff for them. I'm looking at a parts line for some very nice stuff all chromoly all fully tig welded. I see a lot of "chromoly" after market parts but are only in reality partially chromoly. And the welds are kinda iffy from looking closely at them. But stainless exhaust yeah that's definitely something to look into. Heck I wanted it for my own hot rod when she's all wrapped up. And do have a supplier that can provide most any engine out there the flanges they do in house. I can order the per cuts in sny thing I want to buy. Real nice guys to work with. Course if I had my own equipment I already have a guy lined up that wants to get in here with me so might just have to do some pricing after we net our house sale money n just figure out what's what on the market and continue to stay in a speciality niche with our parts line which something I'm expanding into with some of our bolt aftermarket street / strip parts. Carroll Shelby's words of wisdom still echo in my ears. Said he never made near as much money building cars as he did building the parts . I will continue to do my homework. Never made a decision without thinking of all the variables. Course just kinda off the cuff I'm already setup for the welding so tube shark would be about the biggest expense for getting the exhaust started. Guys are giving me so much to think about for what areas to expand into and its appreciated . Really just frustrated right now with how tiny the current shop is and turning away clients . Really past chomping at the bit to get into the new facility.

I sure don't wanna come off as chasing rabbits with all the good ideas but as we are expanding and looking into other areas to expand into the hot rod market with. Probably more so in the way of a good parts line geared towards street/strip applications but I do also want to get at least one show car done for next season to showcase those parts on and have the means to turn them out as orders come in. Like I said were just too limited on space right now but the times come to sell our place and find a sutible location to be able to expand into doing more work and more work is always good thing.

good luck... i know guys here in this town that can go toe to toe with any one out there. you name paint . welding. fab. engines . and there could be new guy that i do not know .but the thing is there not much going on around here as i see it less i am getting old and blind i hope your a young man sounds like to will have alot on the plate

Its definitely a lot on the plate right now. At least after we can get moved can sit down and finalize some major purchases and just build. Trying to get a house prepped for sale with a newborn boy well that's more challenging than any fab work I've done lol