Hi Hamber's Looking for some been there done that tips for wringing some extra power out of a 331 Cadillac V8. I am about to start a full resto of a '49 Caddy and although I want to keep it as close to original as possible in most areas, I am looking at some suggestions for tweaking the 331. From what I have seen, there is not a huge amount to do. I am definitely not interested in dropping in a 350 crate, I want old school and a modest increase on the standard 160HP. Seen some nice dual carb set ups and read about some dizzy changes and cam grinds. Any other suggestions? Cheers
I know that snieders will grind you a 331 cam for like 175 i think, you can also get isky cam/lifter kits on ebay. Also check out this thread for more info...http://www.jalopyjournal.com/forum/showthread.php?t=8282&highlight=331+cadillac+tech
Higher comp pistons and some later 331 heads will help. Down fall of later heads you lose the center bolt valve covers.
Just get some later heads and a four barrel carb. and manifold and you will vastly improve the H.P. on that '49 engine.
A 6-71 will put a bit of pep in your step. It'll fit under the hood of a 49. It'll look stock on the out side and you can always take it off if it scares ya.
Thanks all for your tips,..maybe not so much for KrisKustomPaint and the 6-71 tip! Sounds like there are a few easy options there, nice. Sounds like they way to go. Thanks again Cheers
As suggested, a fresh regrind on the cam can add a bunch of power but don't go too big unless you also bump the compression. And, with any regrind, you will need either adjustable rockers or adjustable pushrods. If you need help with the cam or pushrods just send a note. .
Marcus's Post (copied) on my website http://hotrodcaddy.com/?p=17 Probably the ONLY online copy of "Hot Rod Deluxe"'s article on the Cadillac 390 (also on my site) http://hotrodcaddy.com/?p=139 And of course teh most extensive picture gallery of Cadillac 331/365/390 speed parts on the Internet (Guess where? YEP!) http://www.hotrodcaddy.com/speed_parts.htm That's a good start! Charles
If you want to keep it 'period correct' and not go so crazy with mods as to effect normal drivability, maybe look for a Paxton or McCullough supercharger for it. Back in the early and mid-50's Paxton/McCullough offered bolt-on supercharger kits for most cars of the day, including Cadillacs. If you can find one of the more common factory units for a Ford, Studebaker or even a Kaiser and could fabricate your own mounting brackets and pulley assembly etc., you could probably recreate (or do a pretty reasonable facsimile at least) of the aftermarket kit they offered for the Cadillac V8. Since in *stock form*, they only put out about 5 or 6 lbs. boost it would still be compatible with the stock compression cast pistons - but that's still enough boost to give solid 40% horsepower increase over stock. Mart3406 ========================
Thanks all, and no worries Kris I knew you were stirring and I had a chuckle about it. Would definitely be cool! Thanks Mart - I didnt know about the Paxtons in that era - thought they were more a 60's Mustang thing but very interesting. I do like a blower, however for the '49 think nothing would be cooler than a set of carbs on a dual or tripple manifold. (Thanks in part after seeing them on your site Charles!) I found both your sites looking for info on Caddies and dual carb set ups. I was looking for the buy it now tab on a few of them!!!! Thanks 73rr I did read that about the grind/resulting potential probs. Dont plan on going too crazy. I am thinking a cam grind and some 390 heads with a twin or tripple carb set up like on the '58 era Chevs
On your website, you say "Basically a 390 is a bored out 331 and 390′s cant be bored out that far." Does this mean my 331 (or any) may take a 4" bore?
The Jalopy Journal
