Switching from efi to carb, which intake should I use?
 

Well guys, I'm leaving my area of knowledge, and switching from efi to carbs. Which intake would best suit my needs? Here's the engine spec's 502, AFR 315's, 8.75-1 compression, crane 741 cam.
I really need something with brass inserts in the water passages, unless I go with closed cooling. But I'm not sure I'm going to bother with the closed cooling, I would rather just get an intake with brass. I will also need a 4150 base, going off of what the carb shop is reccomending.

I guess I better explain that I'm not switching to carbs because the efi is a pain in the azz or anything, It's simply a money issue. I'm building a twin to the motor in my Velocity and putting them both in the Powerplay. So buying 2 harnesses/computers, 1 more intake/throttle body/injectors, ect. it will be way more affordable to just switch both to carbs.

Thanks,
Frank

My opinion is Edlebrock air gap or a Dart

Gotta be a single plane. Dart and World Merlin come in marine versions.

with a 741 and 315's, both too big, with 8.75:1 that's why I'm saying dual plane.

I spin the motors up to approx 5600. Will that limit my selection to a single plane? Or are the Rpm Air Gaps still a viable option?

An air gap will still be fine at 5600rpms. The dart will probably make more hp above 5000rpms.

Do they make an Air Gap with brass inserts? I went with the Merlin intake on my 502 and have been happy. Just be careful with what intake gaskets you use- the gasket they recommend has a larger water passage opening than the brass insert on the intake. Unfortunately I learned that the hard way...

I'm a little confused. Why do you think you need brass inserts if you're running aluminum heads?

Exactly,

I have a similar setup and run Edelbrock Victor Jr. for the 4150 Holley's. Picked up 10 hp over dart that was on the stock carb 500hp. A 1" spacer will pick up a few more hp.

Spend the money and put closed loop cooling.

The heads are hard anodized in all the water passages, and exterior. Your right, I don't have to have brass inserts, but it would be one less thing for me to worry about. I guess I could have the intake hard anodized also.

My thought is , I have never heard of heads getting so corroded that they leak, but I've seen it happen on intakes alot.

Thanks,
Frank

Why not have the intake hard anodized like the heads? It wouldn't stop it but slow it down. That way you do have a better selection of intakes.

Dart 6200 or Check out CP's sale!




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i LEFT A POST ON GD if you want to go check it out I have had DART SINGLE PLANES one for 7yrs and one for 12yrs in saltwater only just flush it out, but check my post in gd:D

If you run in salt water you need to pm me and lets talk about head corrosion, anodizing or not. The corrosion problem is caused by using a gen 6 block with gen 4 heads (AFR 305s) and the way the head gasket seats on the block. Been there done that got a $1000 welding bill for the repairs. Bob Madara, RMBuilder can also describe the issue so call him if needed. I will try and post some pics if I can find them.

Well that sells me on closed cooling! I guess it would be worth the extra few dollars.

I run in bracish water, but I get a good fresh water flush when I come home up the river.

Thanks,
Frank

call me 337-540-8228

1 year old AFR 305 with anodized water passages

WOW! That's scary! I wonder if it's a problem with the different metals. Cometics vs aluminum heads vs steel block.

Frank you will love closed cooling. A few yrs ago played with a 502 with several intakes/hydr. cam combos on a dyno and ended up with 620hp/592#' at 5500 with KE's exhaust. Ended up with a Brodix HVH intake and were using bolt on Canfield heads. Also had 9.5:1 compression. You should be able to do the same if not better. Good luck!

The block has triangular/oblong water passages. The AFR heads have round water passages which are smaller than the water passages on the block. The head gasket is built to allow the gen iv style heads to be bolted to a gen vi block. So the head gasket seals around the oblong passage because it is bigger than the hole in the head. This allows salt water to get between the head and the head gasket in the part of the gasket that did not seal and causes the corrosion. You can see the outline of the head gasket seal in the above picture.