scottyp99

Hi guys, I have a question that doesn't pertain specifically to Corvettes, but there are some very smart experienced people on this forum, so here I am asking. Ready? Here we go!

I have an Edelbrock 2101 intake manifold, which has a port height of 1.88". I am planning to install a set of aluminum heads that have an intake port height of 2.06". I am concerned about the amount of "meat" around the manifold port that there will be to seal against the head. The difference between 1.88" and 2.06" is .180". That's about 3/16". The amount of "meat" around the manifold port is not a whole lot more than 3/16". What I am wondering is if that .180" difference will all be at the top of the port, or evenly distributed between the top and bottom. In other words, will the top of the intake manifold port be .180" lower than the top the intake port on the head, or will it be .090" lower at the top and .090" higher at the bottom? Also, would a thicker gasket help raise the intake relative to the head just a tiny bit? Say, a .120" thick gasket as opposed to a .060" gasket? Be advised that the intake manifold is on the engine right now and cannot be easily compared to the head using the intake gasket, or anything like that. Thanks for any input on this issue,

Scotty

68post

You are correct in your assumption on port sizing, should be smaller at top and bottom. The thick gasket where it's not needed will raise the intake causing it to also be high on the china walls and possible slight binding some in the bolt holes, and raising the distributor ever so slightly.
You need an RPM Performer or an appropriate Weiand instead, (doesn't need to be an "Air-Gap"), or just as well - have yours port matched and ported. A porter can tell you if it can be made to fit without welding.
IMO - you'll be loosing some benefit of larger runner head by using a too small unported intake.

Jebbysan

You will need to buy a 1205 gasket to compare the sizes.......put the 1205 on the head and line it up with the bolt holes....now put it on the intake and do the same thing.....does the gasket cover everything?
The .180 being split top and bottom is ideal.....but in the real world forget it......
If the intake is lower or higher than the larger port.....find another intake to use.

Jebby

REELAV8R

You could just port match the 2101 if you want them to match.
The intake port being smaller than the head port is better than the other way around. It also makes intake reversion more difficult. But it can also cause some fuel fallout from the intake charge when transitioning from the intake to the head.

I ported the snot out of my 2101. There is a lot of meat to work with.

scottyp99

I have read a couple of articles about engine builds using these heads with an Edelbrock Performer RPM, which has a 1.92" high port, and nothing was mentioned about any problems, so I think I'm just not gonna worry about it for now. Thanks for the input, though.

Scotty

REELAV8R

"Building" an engine, IMO, is more than bolting parts together. It's about getting them to work well together and that may take some mods.
Bolting parts together... is assembling an engine.
Sure they will work, why wouldn't they, barring manufacture or quality defects? Will they work well?...That's the question.

BOOT77

Depends on exact parts assembled. Sometimes the small port intakes fit/cover the larger head ports and sometimes they don't. I used a 2101 performer and action plus 8004 intakes on Sportsman II heads, where others have claimed theirs would not fit. That's also why I like air-gap or vortec type intakes, they have a straight flange top edge. I modded a vortec intake because the heads have vortec ports w/o the vortec bolt pattern. But if i wanted to use a nonair gap shorter intake I'd prob do the same since they are cheaper and better than the 2101, still not sure how much exactly shorter than a regular RPM, wish I had one to compare.