Are 315 runners to large for a 454?
 

I have used the Edelbrock Ovals with 290’s with good results. I was looking at a pair of used Edelbrocks in the SWAMP Column with rectangular ports with 315 runner. I plan on building another pair of 496’s and turning them 5,000 to 5,200 RPMs, but might put them on a current 454 that currently has head problems.:eek:

Thoughts on bolting them on either 454 or 496?

Well, I will tell you that I am using the 315cc AFR cnc ported heads on my naturally aspirated 565cid engines with small hyd roller cams and great success....runs up to 5600rpm and makes about 670ft lbs of torque @4400rpm....and that is just with a smaller cam profile....pushes my 32' A/T so far at 94mph GPS, with flat water, full tanks of fuel.

You'd need a hefty cam to make those heads work at speed. With your plan to only run up to 5000rpm, there really is no point as those heads will only just start to provide bennefit over the lge oval ports at aroun 4700 anyway. If your lge oval port heads already have big valves and similar cc combustion chamber, there really is no point changing them out. They'll make more power in your range.
The only plus would be if the heads you have now have small valves in them and big chambers, the Edelbrock heads should have the 2.19" & 1.88" valves with about 118cc chambers I think, that would help make power over the ovals between 3000 and 5000 but the large runners will make you stumble for power down low IMO.

Good luck though!

I believe the Edelbrock Marine Ovals have 110cc's, so the bigger chambers will lower compression also.

They also have 2.5 1.9 valves on the marine version.
Yes I think I will pass, just checking.

I need some heads:mad:

AFR has a new 265/290 "roval" that has just been released that should be awsome for 454-540 marine motors. These heads will really perform with even moderate lift cams. Imagine, a 525hp motor with a 600 hour top end. AFR (and evidently Jim Valako) understand the big time benifits of high velocity ports.

Hey Jim,
I recently bought a couple of sets of Dart Pro 1's (310) for my 496's. I was looking at everything between 290 and 310 runners. Both Jim V. and Dean G. recommended them for my application. Cubic inch and your cam selection as well as desired RPM's will pretty much determine what size your going to altimately end up with. Certainly the smaller runners would work better with a 454 however if you can get a good enough deal on them go for it. You'll at least be ahead of the game for your future builds. Be sure and email me if your interested in the Pro 1's. I have a good source for you as well as inexpensive.
john
[email protected]

I would certainly of entertained the thought of these also. Somehow I overlooked them.

they would kill bottom to mid range power to much..

Don't the big rect port open chamber heads have 118cc chambers?

My Vortec's have 105cc closed chambers, I know that much. I thought the rect ports were open 118s?

I might be totally wrong though, my wife tells me that all the time! :drink: