I am swithcing to the edelbrock headers for a tpi car that has the bigger y pipe, I don't thnk that vavle is going to fit anymore, can I just disconnected it? it is onthe pas side and has avavle that opens and close to help warm the car up. Thanks

P.S anything I have to do to remove it? thanks

What are the pros and cons of removing it?

 

What ya got there is called a heat riser. It blocks off the exhaust on one side of the engine, which forces it to the other side, via special passages through the heads/intake.

You can remove it, but allot of folk go a step further and also install block off plates between the intake and heads, so exhaust doesn't still back up into there. Hotter intake doesn't help performance.

 

Yea, but if its more street driven than anything else, I wouldn't block off the heat to the intake. It does help driveability and fuel economy somewhat. Go ahead and take out the valve in the exhaust though.

 

If you're putting headers on, that valve will come out with them. It's vaccume driven so don't forget to plug that line when you pull it. I pulled mine on my 84 T/A that's carbureted and I don't really notice any difference. Doesn't affect driveability or mpg that I can tell. I may have to look to see if there is something that I need to block off so I don't get uneeded exhaust fumes in my car.

 

As general info: The part in question is the EFE valve (early fuel evaporation, IIRC), used on carbed cars only. TPI cars simply incorporated a spacer in the valve's place.

JamesC

 

So I won't really miss it is what you're saying. Good to know. The original poster mentioned he had a TPI Car...what part then would he be talking about?

 

BLACK Z can correct me if I'm wrong. I think he has a carbed car but is purchasing the TPI version of the headers because of the larger Y-pipe. A TPI car doesn't have the EFE valve, only a spacer (essentially the valve without the butterfly).

JamesC

 

To plug the crossovers I would have to pull the intake correct?there would be no more warm air in there after I remove the vavle then if the vavle was still in place right? thanks

 

How many lines come on the EFE can I just plug them? What happens if I leave them un plugged? thanks

P.S where do the lines connect to?

 

The EFE valve is operated by the TVS (Thermal Vacuum Switch) in the thermostat housing, I think. Anyway there'll be a vac line on the EFE valve from the TVS. Plug the line at the EFE valve and see what happens.

No EFE when cold:

Engine may stumble and stall during warm-up
Engine takes longer time to warm up
Choke may heat up and be off before engine is warm

By the way, I seem to recall that this system didn't function particularly well as time passed: the valve would seize because it's never serviced and the passage under the manifold would become clogged. So, shoot, you may notice no difference in driveabiity at all.

JamesC

 

I didn't notice any passages that I needed to block off. Where would they be if I had to? I've been digging and looking with my flash light but can't find anything that it might have gone to.

 

Check this link for a better idea of how the system works:

https://www.thirdgen.org/forums/exha...ht=passage+EFE

JamesC

 

Is there any pros/cons of plugging the passages on the intake? is it worth pulling hte intake to do this after I take the vavle off the exhaust?
My vavle works fine I replaced a few years ago, and my motor is new the so the pass are open.Why would the choe kick off sooner now, wouldn't stay on longer now that the heat is not being forced though the intake?

 

Think of an air gap intake. less heat in the intake is better. That could be the best ticket. Get an aftermarket intake without them holes. Intake will still block em off.

But Yes to block them passages you gotta remove the intake.

Guy just use 1in wide by 1/8 thick steel stock from any hardware store. You file and feather the edges till they sort of fit into the head hole flush. Then the intake holds them in place tight. Or that is how I have seen it done. Looks very clean and nice. Almost like GM planed it that way. They also feed the EGR on the intake if you got one, I think???

Though there is epoxy block filling material you can get. Some times when ya build and enigne ya gotta fill any un-needed parts of the block with a cement like stuff that makes it strong like them holes were never there.

One tip, if your not replacing the stock manifold its near impossiable to remove that valve. The valve to head flange is smooth, only the valve end has the right circle ring for the Y pipe. Though the vavle is easy to gut. That is what I did to mine. Cut the valve out and welded the shaft holes up.

 

That is the problem James but by default they shut once the car is off and about 90% of the time stick closed or only half open. which does hinder things a tad.

 

Leave it out.