Cure Heat Soak - Intake Block Off Plate

Block off plates on intake manifolds shouldn’t be hard, right?? Well there are some details to think about and even if you get the wrong gasket set, theres a few things you can do to make sure you have the right set up for your engine.

#intakemanifold #blockoff #heatsoak

[Redlines]

Your explanation and clever way of blocking the exhaust from going into the Intake Manifold is genius. Good explanation and video. These are the kind of videos that help an individual step through and understand a subject matter. Great Video.

[stevebrown]

I like this channel, working on an old 350 truck. Had to go thur everything, rolling restoration over years. Problems everywhere, watching your videos has really helped. Thank you

[mikef-gidg]

I did the exact thing many many years ago, I lost the set that came with the gaskets, and I made some up. I worked great. I have been restricting the cross over more and more over the years, especially with stock intakes, with no issues at all. These engines don't get run with freezing temps out side anyway. I have recently modified several aluminum and iron factory intakes to resemble performer type intakes, and have eliminated the cross over entirely. For my mild performance SBC engines, I think it will work out fine. I going for the stock looking performance sleeper look. Time will tell.

[zumintroy]

The heat crossover is used to heat the floor of the intake manifold so that any liquid fuel that has separated from the mixture will be vaporized. This becomes more of a problem as the air temperature gets colder than 50 deg F.

[Driven_Dragon]

I love Gasgacinch! I use it on both sides of any fuel related gasket. Never have ANY vacuum leaks EVER. Best insurance and makes the gaskets reusable as well.

[oantech]

I only use Felpro blue gaskets. I throw out the front and rear rubber rail gaskets and run a 1/4" bead of "The Right Stuff" form a gasket on each rail. Let it sit for 15 minutes and drop the intake in place and tighten it up. A perfect seal and no oil seepage. I also find it necessary to re-torque the intake after initial run-in only with aluminum intakes for whatever reason. I have had water leak into the combustion chamber and show up at the tail pipe before re-torque. This is from years of Chevrolet experience. I hope it helps someone.

[jameshoneyc]

Some guys are welding theirs closed. I think I'll do this less permanent and a lot easier. Thanks for the video.

[jacobsabian]

i used an old license plate cut the exact same way and used rtv to keep it stuck to the gasket on installation 👍

[seanjohnson]

Used stainless steel shim cut to fit and copper rtv to close off the heat cross over from the stock heads to my new edelbrock performer intake manifold on my 390fe. Not sure how much it helps with horsepower but living in Southern California it can't hurt.

[xexdsr]

I've cut up a beer can once and it worked pretty good

[robertclymer]

hello again! Could you please tell me how thick the piece of aluminum was from the Jasco Acetone can? I see you check with your micrometers but you didn't say. Would really appreciate the thickness please. Really appreciate it. I am ready to install my permormer rpm on my 460 big block in the next day or so. Cheers from Motown.

[robertclymer]

Good Stuff! Was not aware of this Mod, but I am now. Thanks for sharing! Blessings from Motown.

[IronHorseGarage]

This is some great information!!! Keep it coming!!!

[hotrodray]

It's also for prevention of carburetor venturi ice. Remember the exhaust manifold flapper valve? But heating the carb also happens in the summer
Remember the exhaust manifold heated snorkels on the air filters? That helped too.

[stephenvanvliet]

I’ve seen a few of your videos. Always great job explaining what’s going on. This video speaks to the exact question I have right now. I have a pretty stock 350 sbc, maybe a mild cam in there (not sure exactly) with original heads that have the crossover port. I bought the airgap intake manifold and the AVS2 carburetor. The intake as you probably know does not have the port. I’ve gotten a few answers here. Edelbrock told me I can use their gasket and simply cut out the perforated box and just let the crossover port blow straight into the aluminum blocked off material on the intake. I currently have the felpro 1204 gasket that has the metal blocking. Which I believe is what you refer to in this video. Can you simply provide your opinion towards my plan that I would be good with original head with open crossover to 1204 feltpro with blocked off metal square, sandwiched under the airgap with no port?

[briang]

You should add a little disclaimer that if your running a hot air or divorced style carb choke, that you cannot eliminate the crossover or the choke will never work properly. But I understand that 95% of people with these old school engines are either using an electric choke, manual choke or no choke at all so for those folks it doesnt matter but there are still guys, my self included that still have a divorced choke system which I think works well and in the mid to late 70s there were alot of "hot air" style chokes where a steel tube was placed in the cross over amd air would be pulled through that heated tube and warm the choke spring so for those applications a heat cross over is necessary.

[larryboyer]

To be clear you have the block off on the side that will be against the head, and the side with the striping to the intake manifold, correct??

[jamesharrison]

Heat crossover has nothing to do with leaded vs unleaded but as you said it's there to help vaporize the incoming fuel for better distribution to all cylinders. Of course the alcohol will vaporize faster than the gas but not enough to affect performance.
When you begin to block off the crossover is in racing applications

[larryburns]

If not in cold climate use felpro 1204

[paulrivas]

I just used a two block off plates and the dry fitted the intake and it’s not sitting flush. Is that gonna be an issue or would it sit flush once I tighten it down?