For those who have a 40/34 large valve race head, what are you using for the head pipe gaskets since the exhaust ports are larger than stock?

Thanks.

Scooby

 

scoob, get some ron woods copper gaskets and port match them. i think hpr even uses the same gaskets.

and you know the stock ones just smash and block you exhaust.

 

What gasket? Hope that answers your question. My head pipes have also been opened up to match my ports.

 

same thing with my XR's, I run a stock copper with an initial smash at build, then remove headpipe right away and file or port to match and then never replace until another head change, no problem with leaking, multiple tear-downs is not an issue unless your using different headpipe set-ups, and if you do mostly will still seal without problems.

XR

 

Does anyone have any evidence that it makes more power to port match your head pipe?.........or is it just an assumption?

 

I got alot better torque curve after than before, HP pulled longer and harder too. Worked on mine anyway.

 

Boy for someone that claims they know so much you sure don't know anything as far as I am concerned. Its simple if your exhaust port is bigger then your head pipe opening then your going to have some restriction. 8 times out of 10 I have had to port the opening on headers to get the same flow numbers on a flow bench when using a test header to flow heads. I am also talking about automotive heads here and not some puny single, But the concept is the exact same. So now go assume something else, Like who can I pay now........[img]i/expressions/face-icon-small-tongue.gif[/img]

 

watch out tj he will come on here and say he knew that and he wanted to make shure that everyone else did[img]i/expressions/face-icon-small-smile.gif[/img]

oh nut im just giving ya some crap, lol

 

First, I don't understand the basis for your hostility. It is actually a legitimate question. Your comparison between multi-cylinder engines and single cylinder engines is flawed. They are not the same at all. I am not going to attack your knowledge base as you did mine because I am sure you know quite a bit about how automotive engines work. I was under the impression that we were discussing the DS650 motor.

Second, a flow bench only tells you part of the story on a single cylinder. More flow through the head does not necessarily make more power. If you want to know CFM and some limited velocity indicators, flow testing is great but on a single cylinder if you want to make more power.......cylinder pressure is where it is at. More exhaust port flow is not necessarily what you want.

Third, Crazypainter had a good answer and I would expect it from him because he probably tested this on Alky.........which any exhaust port restriction will cost him much more than a gas motor. He is right by the way. I bet he actually could tell by the seat of the pants to.

Fourth, my question was not whether the restriction helps or hurts, the question was if anyone had actually tested this theory on a DS motor or if this was merely an assumption. As you know the internet is full of ideas but not all of them are good information that has been verified. Conventional wisdom is a poor excuse for passing on untested theories, imho.

Fifth, on a big valve DS head, if the exhaust header gaskets restrict flow on a properly ported exhaust side of the head they will hurt performance. But, if the exhaust ports are over done, the restriction will actually be a net benefit by helping to band-aid a bad port job.............Oh yeah, I forgot to mention it will only effect a N/A gas motor by an amount too small to accurately guage on a dyno.

Lastly, I have another question since we are on the subject.........How should the exhaust ports change in a turbo charged single cylinder application as compared to N/A? Gas or Alky? Don't just focus on the head flow............there is also the pressure on the front side of the turbo to.

Why don't you lay down your sword for a minute, AMD and think about how this works and if there is any merit to what I am suggesting........

 

Shmee - That is ok, I can take it. [img]i/expressions/face-icon-small-smile.gif[/img]


Btw, there is no "H" in sure... [img]i/expressions/face-icon-small-blush.gif[/img] lol Wow, I guess I can dish it out to [img]i/expressions/face-icon-small-wink.gif[/img] [img]i/expressions/face-icon-small-smile.gif[/img] lol