blownz

I was wondering your opinion on wether or not to keep the heat riser on a 78 Pace Vette with a L-82 in it. I have added Edlebrock Alum Heads and intake. I also am in the process of installing the McJack headers. The Vette will reside in Fla. I have also changed the cam to a Comp grind that Johns Corvette Service recommended.

speedreed8

i got rid of mine (79 L82) i considered it a flow restrictor. may help the engine warm up faster. but i didnt need it. the body of it is still in place used only as a spacer.,. because of the length of the exhaust pipe. i removed the shaft / butterfly, welded up the ends. I havent missed it at all.....

PeteZO6

I assume you mean the valve on the passenger exhaust manifold that closes when the engine is cold and forces exhaust gases through the intake to warm the incoming charge. With the headers, doesn't it go away?
I have aluminum L-98 heads with no exhaust crossover. Also aluminum intake. On cool mornings here in Northern California it's a bit cold blooded until the engine is well warmed up. As long as I don't give it too much gas too fast, it's fine. If i gas it too much it coughs and stumbles a second then gets going.
In Florida I don't think you will have a problem. We're enthusiasts, and a bit of nursing a car along until it's warm isn't a big deal, where your grandma or great uncle might not have the patience for it. Just my thoughts.

Pete

7t9l82

im in florida and i don't even have a choke. for that matter, i didn't have one in northern virginia (fairfax county).

Skid*MARK

We made a custom one from stainless that is open, looks just like the stock exhaust flange pattern, It is going on a 67 big block with side pipes, we are useing the Mc Jacks headers also that replace the manifolds and hook to the factory side exhaust, had to have the spacer in there for the proper fit, just did not want a rusty cast iron block hooked to the nice looking headers, also had a custom set of free flowing side pipes built to let the 489 stroker breath.
one good advantage of having a full machine shop at our desposal.

7T1vette

You won't need it in Florida...

scottyp99

When I was a kid, that part fell under the category "I don't know what it is, so get rid of it."

The aluminum intake manifold will allow heat to be transferred to the carb a little better, so I don't think you'll miss the exhaust cross-over, as long as you are using an electric choke.

Scott

Brcmpbl

I live in Atlantic Canada and I replaced mine with a spacer and it works fine until I put it away for the winter (next week probably).

7T1vette

Now, if I lived in Canada and wanted to drive in the winter (on the good days, of course), I would definitely keep the heat riser and/or install an electric choke [on a carbed engine].

Paul L

Old Wives' Tale. Back in the day it was believed that it promoted rust-out of the right muffler owing to all exhaust heat being directed to the left side on start-up and a short period thereafter.

ezobens

The valve is worthless if your motor has aftermarket heads (or intake) that has the heat crossover provision removed/blocked anyway-
I believe Corvette Central (among others) sells a replacement spacer that is open and fills the void left when removing the valve.

gcusmano74

IMHO, once you are using an aluminum manifold, you don't need the heat riser. The aluminum heats up much faster than cast iron. Besides, didn't we all just spend a bunch of money and time on a free flowing exhaust system? Why would we choke off one side of it?

Mod75

Right/wrong, i tack welded mine open, manual choke

springer89

You should go ahead and install Edelbrock heat insulator gasket. My hot starts improved dramatically after I did


http://www.edelblog.com/tech-tips/resolving-heat-soak/