I am in the midst of my first head gasket replacement job ever. '86 22re 4Runner. Got the top end gasket set from engnblder and have been cleaning my mating surfaces as I go during reassembly. Head is back on and come to realize that the old remnants of the exhaust gasket are really fused to the mating surface of the header. I guess the high temps basically welded them together. Is this common?

I have soaked the whole thing in pb blaster and whacked at it a bunch with a hammer and flathead screwdriver trying to break this stuff loose, no dice. Eventually I took a dremel to it with a cutoff wheel and tried to cut this stuff away down to what appears to be its original shape. I see no difference in the types of metal, leading me to question whether this is actually the way the header is made.

It seems to me like this header should have raised portions that fit through the gasket holes, allowing the exhaust to pass through without actual direct contact with the gasket, which seems like a good idea.

The problem here is that these raised portions of the header mating surface will not fit into the pear-shaped holes in the new gasket, so I am left with a 1/8" space between the gasket and the flat surface of the header. If I take the header out of the truck, I will try to basically resurface it with a grinder until only the pear-shaped parts that are black with exhaust residue are raised. Then they should fit neatly through the gasket and I think I will have a solid seal.

OR - Is the header mating surface supposed to be flat? In that case I will remove it from the truck and have a machinist mill the whole surface flat.

Can anyone tell me where this header came from? My best guess from my research is that it is a pacesetter header. My research also tells me that this is a dumb cheap "upgrade" and it is much better to stick with the stock cast manifold and go to 2.25" pipes. I am on a budget, no Thorley, etc.

So what is my best option here? Try to make use of this crappy header or spend $100-150 on a stock cast manifold and just do my 2.25" pipe upgrade now? Keep in mind I am on a tight budget.

Thanks for you help.

Pics:

Here's a good shot of the header, can you confirm if this is an old pacesetter?





Here's the situation with the mating surface, you can see my attempts at dremeling some of this crap away on the number 1 cylinder port:





And, why it don't work! :

 

I'm pretty sure my header mating surface is flat. I have a trail gear, and haven't installed it so I'll check to make sure. I also have the stock manifold sitting on the shelf. If you go that route, I'll sell it cheap.

 

Yep, my header is a flat surface.

 

I think thats a home made / custom header you got there. The raised portions were meant to increase pressure on a different sytle of gasket. Probably just like a Mr Gasket type from back in the day.

 

Thanks for the input there folks. Any recommendations on how to proceed? Should I cinch that header right up against the new stock gasket? I suppose I don't have to worry about it unless it develops a leak. Badlander, may send you a pm about that stock manifold in a week if things don't work out.

 

I wonder is there a gasket made for that header

If that is indeed a gasket a little gasket stripper and sharp putty knife should get those old pieces off.

To me it looks like cobbled together header made by hand.

I have found headers pretty much a big pain over the years except on full race vehicles

 

if you mount the bare header onto the head, do those raised portions fit into the head? they might have been put there to increase the strength in the face area, because it's a weak spot on these headers.

i hope that you don't have a smog inspection in chicago, because the egr port is blocked on those headers... the o2 sensor is only monitoring one cylinder there, instead of an average of all 4 cylinders.

you should be able to get a stock 22re exhaust manifold for next to nothing, i would go that route... and when that stock exhaust manifold gasket blows out, get a remflex gasket.

 

Thanks for the input all. Badlander pmed about your extra Mani.

 

My Doug Thorley header is the same way. It is not meant to be used with the factory Toyota gasket.

You need this type http://www.summitracing.com/parts/DTE-9542?seid=srese2.

 

Thanks; that was the gasket he needs to get.

 

I slapped everything back together with the header as is and the stock gasket. So far no leaks. The flange of the header is bent slightly towards the head under pressure from the bolts, but it appears the raised portions get increased clamping and seal well. Thanks again for your input everyone. I will continue to run the exhaust like this.