Well finally built and ***embled and off to the dyno on monday at 9am hope she turns some good numbers.....
It has 30 over pistons, custom ground lunati cam and porting. Should be good for 415hp and 525 foot lbs. Of torque.
A stock 1970 472 was rated at 375 HP stock in my Motors manual. Don't know how accurate the rating was though.
yeah they rated them high. The true dynoing of a stock motor was 300hp. and 400.foot lbs. of torque. so it didnt do too bad.
If you don't mind me asking ,how much do you have in the engine build?What type of pistons?Those are some pretty good real world numbers.Ought to be fun.
read a few yrs ago that a 70 stock 472 caddy was dyno at 360 .hp.hope so, i got one sittin in the floor.but my book says 375. id settle for 36o thou.
I have a 500 Caddy on the stand waiting for a mild buildup. I got a case of the stupids and tossed the stock rods out years ago. Needs rods & pistons before I can start the build.
How about some pics? I have a +.030 1970 472 (now a 478) in my avatar F-100. Custom cam, big valves (2.19/1.89), intake & headers...runs just fine
Well I have a kit I bought from MTS they are really nice guys and I tried to keep it as reasonable as i could. (remember it is a totally different monster than a 350) so between the kit, which includes a custom cam by lunati, lifters and springs, a gasket kit, a high volume oil pump,timing chain set, and i had to get 30 over pistons because the cylinders were out of round .09 to .12 so that hurt a bit but all that was 1400.00. then the block needed the engine work turned crank (it was good and only needed a polish. heads dissasembled and re done with springs and shaved the guides and hot tanked and the block maged, line bore check and cleaned and bored 30 over, pistons put on the rods, and the most time was drilling out the heads where the manifold bolts broke (8) of those, all that was 1200. Then all the bolt on items. The nice part was i got them all at auto zone for about 400. Trust me going all the way down to nothing and building it up ****ED. and just a bit of info make sure you are postive about the carb i tried 5 quadrajets and could not get them to adjust right without rebuilding them, so after 2 days on the dyno and 400 for a holley carb and 700 for the dyno, which I could have only been on for a couple of hours had I had a good carb I am into this thig for 4000.00 which isnt really to bad but i thought different was cool but I was like "What the hell did I do".......ps im glad i went to the dyno guy because putting that much money into a motor and not having it set up right, i could have leaned it out or had it so rich that it would or could have destroyed itself and then I really would have been SOL. so hope this helped but it did make some nice numbers.<VAR id=yiv345814494yui-ie-cursor></VAR>
Interesting. My 472 is 10:1 compression, Sig Erson cam, stock intake and Quadrajet, mildly ported heads and intake (with advice from MTS), stock manifolds. I would say you don't have enough carb, seems like it'd pull a little more than that. Brian
That's the reason I asked Brian... I have a stock 70' model 472 in my '55 Caddy, runs out great but like everyone else I'm always looking to improve things. Mine has the stock Q-jet which is OK but with the typical sloppy throttle shafts. Trying to decide which way to go on the carb. I've been doing a lot of research, plugged the numbers into several CFM calculators, even talked to the Holley and Edelbrock guys at the HRR in Bowling Green. I don't know whether it's due to the 4400 RPM redline or what but the numbers I'm coming up with (and what the techs told me) are right around 600 cfm or less. I know the Quadrajets these engines came with are rated at 750-800 cfm but Q-jets by design have small primarys and much larger secondarys and supposedly only flow what's needed... I've got both a good Edelbrock 600 as well as a 750 in need of a rebuild - I'm thinking of sticking the 600 on first and seeing how it does, This is no hot rod but I do want decent power. Of course another couple of MPG wouldn't hurt my feelings either. On the trip to Indy I averaged about 12-13 doing 60-65. If I can get that number up around 15 I'll be more than happy.
If you want some good reading do a search for Bad Seed Chevette,hot Rod mag did a buildup of a 500 in a chevette & it was good reading,they keep adding stuff,different carbs,put 472 heads on which raised comp to 12-1 if I remember,I think it was April 2000 You can download off their site. HTH
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