Engine: Intake block off

[57transtar guy]

Anyone ever use the custom Hells Gate Hot Rod intake flanges sold on eBay and what have you experienced? Looking for pros and con's to blocking the center ports if my intake.

[sals54]

As you are in AZ, you should have nothing but good results in blocking off the center ports. Your generally warm climate is going to work well without the added heat of the exhaust gasses passing under the carb. Especially with this cr*ppy new gas. I live in Sacramento CA and its normally decent weather here, so I run with the ports blocked off and the choke plate in the permanent open position.

[Mike Van Veghten]

Coupla things -

1. The Hells Gate (like most others), do not have the proper port entry angle. These "aren't" Chevys, Chryslers or Fords..! I even pointed that out to them many months ago. They didn't seem to care that they were wrong.
If you want to build your own manifold, a better flange is needed.

2. As Sal says, blocking the crossover will not be a problem here in the west. If you lived in a colder climate, then yes, you may loose some early morning performance, but not in AZ, CA, NV.
Just a thin piece of stainless steel stuck in there against the manifold (both sides) will work fine.

Mike

[57transtar guy]

Thanks guys!

Just a small piece of stainless steel to cover the openings of both sides will do the trick? I was afraid of not being able to create a proper seal!

Any other suggestions before I do this? Use silicon? New gaskets? Gasket above and below? Just want to make sure I get it right

[Mike Van Veghten]

New composit gasket, one each side.
Do not use the steel stamped gasket. Whatever normal sealent you normally use. With composit gaskets, you really don't need a sealent though. I never use any.
With the .015"/,02" thick stainless on the manifold side of the gasket, no other gasket is required.

Mike

[PackardV8]

Yes, as usual, MVV is correct. Those flanges would only be useful for making a fairgrounds cruiser "look at me" intake. The 90-degree angle is all wrong for a maximum performance intake.

No, fabricating a good-looking-good-science steel intake is way, way more complicated and difficult than most would think. There are several feet of welds, all which have to be air-tight and ground for appearance and some joints want to be where it's impossible to weld.

jack vines

[Paul Keller]

Re: Mike's suggestion to use a composite (rather than steel "shim" gasket) - Will that match-up the ports with a steel ("shim") head gasket?
(I prefer the composite, but have always been told to use the same type on the intake as on the head to keep the ports aligned)
Paul TK

[StudeRich]

If you have not seriously surfaced the block or the heads there should be plenty of wiggle room in the Intake Manifold to head fit to seal just fine using either thick or thin on either one.

[57transtar guy]

I ordered the composite gaskets from Chuck Collins and when they come in I will cut a couple pieces of stainless steel for the center ports. They go on both the right and left side if the carb?

Also, I am removing my electric choke and installing a manual. Thoughts?

[Mike Van Veghten]

As I noted...on both the left and right side of the manifold/head crossover port.
One on the left side, between the gasket and the intake manifold.
One on the right side, between the gasket and the intake manifold.

If you plan on using "tin" snips to cut the stainless, make sure you clean/remove all burrs, and make sure the material is mostly flat. As in, no sharp bends, wrinkles. It needs to be about 1/4" to 3/8" larger than the port opening on each side.

Mike

[PackardV8]

What you'll notice with the crossover blocked off and the electric choke is it pulls off fast idle way sooner than the old stove choke. It will start just as well, but in cold, damp climates, it will not give fast idle long enough for the engine to warm up.

In most parts of AZ most months of the year, you probably never need a choke/fast idle anyway. Manual chokes are fine in theory, but in practice most of us forget to push them back in until way down the road at the first traffic light, we notice the fast idle.

jack vines

[Tom Bredehoft]

I used the stainless stock to block off my exhaust passage. After about 3 months, maybe 100 miles. I pulled the manifold and there was half a cup of water in it. Condensation. I drilled a 1/4 in hole in each of the stainless plates, and had no further trouble.

[jerezstude]

We take a different approach to blocking off crossover with great success. Using an old cast iron frying pan and torch we melt used pistons and fill crossover. Has totally resolved boiling gas out of carb and vapor lock. JerryKurtz

[57transtar guy]

I'm too much of a novice to try that!!!

I will stick to the stainless plates that I plan on cutting with a blade and flattening with a press.