How do u Block off a Heat riser Cross over......
Le Mans Master
Joined: Jul 2001
Posts: 9,622
Likes: 16
From: absecon nj
Re: How do u Block off a Heat riser Cross over...... (Alwyn678)
i make up little metal inserts that fit in the gasket to block it off,cant be too thick or intake wont seal..they do make intake gaskets with block offs in them too.
Le Mans Master
Joined: Dec 2000
Posts: 7,245
Likes: 4
Re: How do u Block off a Heat riser Cross over...... (Alwyn678)
Years ago you could buy intake gaskets (for big block at least) with a metal insert already in them to block the crossover.
Maybe you still can.
Maybe you still can.
Melting Slicks
Joined: Apr 2001
Posts: 3,399
Likes: 278
From: Olmsted Falls, Ohio
Re: How do u Block off a Heat riser Cross over...... (Alwyn678)
Use intake gaskets that have the port(s) blocked off. You will not be able to use a Hot Air choke, EGR, or the Heat Riser valve if you are required to do so.
If you take off the manifold look into getting a lifter valley baffle to stop the hot oil from splashing against the bottom of the manifold.
I'm curious as to why you need to cool down the carb more than the insulator spacer will do. Are you getting a lot of fuel boiling or what? What is the underhood temp? Have you checked it to see how hot it is under there? Maybe something else is happening to make the carb hot...
Just noticed your other posts.... Since you are talking about the '74 (I think) you could open up the cowl induction door (take it out) so that air flows all the time. I tried this with my stock air cleaner assy for a while and then switched to an open style air cleaner. Now I just let the engine air flow out past the cowl. My engine compartment is a lot cooler than it was before. Sure the carb is sucking in some of that warm air, but in the long run, all things considered, I think it's a reasonable tradeoff.
[Modified by KenSny, 5:53 PM 10/26/2001]
If you take off the manifold look into getting a lifter valley baffle to stop the hot oil from splashing against the bottom of the manifold.
I'm curious as to why you need to cool down the carb more than the insulator spacer will do. Are you getting a lot of fuel boiling or what? What is the underhood temp? Have you checked it to see how hot it is under there? Maybe something else is happening to make the carb hot...
Just noticed your other posts.... Since you are talking about the '74 (I think) you could open up the cowl induction door (take it out) so that air flows all the time. I tried this with my stock air cleaner assy for a while and then switched to an open style air cleaner. Now I just let the engine air flow out past the cowl. My engine compartment is a lot cooler than it was before. Sure the carb is sucking in some of that warm air, but in the long run, all things considered, I think it's a reasonable tradeoff.
[Modified by KenSny, 5:53 PM 10/26/2001]
Safety Car
Joined: Apr 2001
Posts: 4,795
Likes: 1
From: Regina Saskatchewan, Canada.
Re: How do u Block off a Heat riser Cross over...... (Alwyn678)
I have been using the special gaskets for some time now. The Fel-Pro number is 1204 for a small block chev. Your local parts store should be able to special order them for you since they probably don't keep them in stock. Or maybe try a speed shop.
Racer
Joined: Sep 2000
Posts: 287
Likes: 0
From: Wildwood IL
Re: How do u Block off a Heat riser Cross over...... (jerryp58)
Jerry, I'd say zippo. With the heat riser removed, all the exhaust will flow right out the exhaust pipe. I didn't remove my heat riser or actuator. I simply reversed the check valve on the vacuum line between the carb and tvs so the valve never closes. Looks all stock, just doesn't work like stock! hehehe
:cheers:
:cheers:
Racer
Joined: Oct 1999
Posts: 329
Likes: 1
From: Richmond VA
Re: How do u Block off a Heat riser Cross over...... (trs77)
I have made the block off piece by cutting up a beer can and using a little RTV to hold it in place with a regular gasket. The metal is thin enough not to affect the seal.
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Melting Slicks
Joined: Apr 2001
Posts: 3,399
Likes: 278
From: Olmsted Falls, Ohio
Re: How do u Block off a Heat riser Cross over...... (trs77)
Jerry, I'd say zippo. With the heat riser removed, all the exhaust will flow right out the exhaust pipe.
Safety Car
Joined: Apr 2001
Posts: 4,795
Likes: 1
From: Regina Saskatchewan, Canada.
Re: How do u Block off a Heat riser Cross over...... (Alwyn678)
Something else to consider is what we up here call "icing a carb". You do need some heat and I was told it's possible to ice one even in the summer. I wouldn't know the difference though because it's never happened to me and all my carbs have ran so damn rich that they'll start it any weather.
Melting Slicks
Joined: Apr 2001
Posts: 3,399
Likes: 278
From: Olmsted Falls, Ohio
Re: How do u Block off a Heat riser Cross over...... (Stingy74)
Stingy74 - Actually, that is the real purpose of the crossover in the intake manifold - to help warmup and get the car out of rich mode sooner so that the emissions will be cleaner.
