txboater

This may be the stupid question of the week, but I have ot ask it.

I found a heck of a deal on an aluminum intake and carb for my 454/502 re-power.

The issue at hand is the aluminum intake is rectangular port and the heads are oval ported.

Is it viable to use a rectangular port intake on an oval port head?

I can imagine there would be some flow disruption, but will it be enough to not make the swap?

If this is a no go- anyone need a nice Merc aluminum intake off a 502?

Thanks all!

RAC

cobra marty

Not the best results with rect manifold and oval heads. Have seen oval manifold and rest heads with decient results.

H2Xmark

save your money, not worth the trouble and vacuum leaks

blue thunder

I did a similar post to this a while back, only more along the lines of what Cabra Marty said. I decided to make a match set. I don't think it will work at all with rect intake and oval heads. Simple plumbing (physics actually) says you want the greatest restriction at the point of use for optimum control. In the case of an engine this is the intake valve. Unless the heads have huge cfm oval ports, you will kill fuel mix velocity and therefore kill performance. That is if it will work with no vacuum or water leaks at all.

BT

FloridianSon

Big ports are built to screem and go fast with high rpm's but large oval ports will outperform them up to 6500rpm.This is what I did this time around, new 502 from runsnew took off the big heads and put on the merlin oval port heads,they came with 2.25 intake and 1.88 exhaust.Left the stock pistons in 8.75cr and have the Holley 300-42 oval port intake.The cam I put in was high performance chevy replacement from the zz502-502 at 224in. 234ex. dur. .527in. .544 ex.lift 110 LSA and installed at 110*what I hope I have done is put together a motor that will be great on the cruse,4000rpm and turn a little bigger prop on my bravo 1 and can burn any fuel and with a little luck should make me the power I am looking for at 5200-5500rpm.This is no race boat but if I was getting 64 solid on GPS with my old 454 mag and the new motor should maybe 100hp more if I get a solid 70 on GPS and can cruse all day at 50 on GPS and turn 4000-4500 then I have what I am looking for.I do not want to worry about the high test gas crap that you need with the high CR that some people run and spinning that motor up so high.I do think it would have been cheaper to wipple now that I have come allmost to the end and have seen the cost and what hp I got for it but that is another motor all together.Hope this was not to much and to answer your question Dennis Moore's book says you can do it with the holly 300-42 intake!

blue thunder

Florida... I think you did good without the wipple. I started shooting for reliability first and performance second. You should have much better long term reliability with what you did (steda the whipple) and reasonably good performance. Hope it jells for ya!

BT