Header gasket

[ArtemisI6]

Doing a port/polish on a '78 200ci head. I want to gasket match the exhaust ports, but I'm divided about which gasket I should match to.

For the time being, and due to budget limits, we're going to have to use the stock exhaust manifold. Eventually that's going to be upgraded - probably to CI's dual-out header. I don't want to match to a different gasket, then move to the header, and CI's "improved design" header gasket and find that the ports once again don't match the gasket as well as they can. I am not porting the head twice, either. So, I'm not sure what to do here. Could I use the CI header gasket with a manifold, and just cut out the 3/4 divider part of the gasket (I'm not putting in the port divider) and then just buy a new header-style gasket when I switch to a header? Or are the gaskets close enough to each other in sizing that if I port according to a manifold gasket, my worries in regards to later switching to a header/header gasket are not a problem?

I hope I'm not being too confusing here. If I am, I can try to explain it in a different way.

 

[ArtemisI6]

Anyone? Someone's got to have some info to help me. Really I guess what I'm asking is how much does CI's header gasket different from a typical exhaust manifold gasket, and which one would you use as a port matching guide, if you were only going to port it once?

 

[64 200 ranchero]

id think it would work fine, i just got a ci gasket, if you cut out the large port side it should work

 

[JackFish]

I wouldn't cut the custom CI header gasket, if I understand you correctly. Save it for it's intended purpose.
The stock gasket sets are so cheap on ebay, you could find some replacements there, maybe even a "lot".
http://cgi.ebay.com/ebaymotors/FORD-2-4 ... 33640438a9

 

[Gene Fiore]

This is just my 2cents, but I would not gasket match exhaust ports. I'm no expert but the difference in size between the port and most exhaust gaskets, header or otherwise, is pretty big on these motors. I think you would lose too much velocity in the exhaust flow by doing that. I would just smooth the inside of the ports but leave the size basically the same. I had my head ported by a professional and this is what they did. Maybe someone with more extensive knowledge in this area will chime in.

 

[AzCoupe]

I agree with Gene..... the gains, if any, are so minimal that it just isn't worth the time or money.

 

[MustangSix]

Most darn gaskets would lead you to try and make the ports wider. No gain at all from that exercise. What the exhaust ports need is more height, but there's not a lot of metal left to make any big improvements.

You'll get about 80% of the gains you're going to get by doing a lot of work under the valve. Blend the bowls, get rid of the ridges, and do some work on the guide. There are also some lumps in the roof of the exhaust ports on some heads that can be safely ground away. Then work the valves by backcutting them, doing a three or even five angle valve job, and cutting the seat to about .050" max to open the available area under the valve. YOu can pick up a little by reliving the chamber walls too.

By the time you pay to do all that, you would have done far better to just buy an alloy head from Mike.....

 

[ArtemisI6]

Can't even come close to affording an aluminum head... the owner of the car is my 23 year old girlfriend working three jobs to pay student loans, a car payment, and other bills in addition to trying to have a car hobby. This is only a slightly above-stock build, and we're on the second year of trying to finish it. We're keeping the '78 head we got with this motor, but since a mild port/polish by me won't cost her anything, we're going to do that. I personally would like it if she had a valve job done, but I don't see that happening due to the cost. Anything that I can do at home without expensive equipment, we're doing, but anything expensive requiring a machine shop that isn't essential has to be avoided unfortunately. If it was my motor I'd put more into machining and parts cost, but she has different priorities than me.

Anyway, I guess I won't bother doing port matching, and instead concentrate on polishing and cleaning up the bowls and areas behind the valves. Thanks again for the advice, guys.

 

[JackFish]