I have a rare-ish turbo (IHI VJ23, not going on a Miata) that I need a manifold to turbo and downpipe gasket for. I have modeled them up off of the turbine housing in Fusion 360, 3D printed to check the fitment, and I'm ready to send out the files to sendcutsend.com to get made from 304 stainless.

The manifold (cast) and turbine housing flange surfaces are flat without any abnormalities, and the downpipe I'm making will have the flange machined flat after welding.

What thickness on the gaskets would you recommend for this purpose? Different material a better choice on this?

Thanks for your input!

 

I'd highly recommend not running a gasket on either. If both surfaces are planed flat (which can easily be DIY'd if things are apart), they will seal. Just put a touch of grease on them when you tighten them up and the grease will carbon up and seal any minor imperfections. I've been running my kraken/2860 setup like this for the last 5 years, 20,000+ miles, and countless trackdays.

 

Thanks for posting, that's some really good results! I have read about this in my research but fear with my luck Id get a leak. I was actually considering this but looked into cost of getting these gaskets made from 304 and its surprisingly cheap, around 15 bucks for both depending the thickness of course. Then that ole "piece of mind thing" lmao

The manifold and turbine housing flanges are flat as I can tell, but might could use a touchup if I do go that route.

 

If you get a nice piece of glass, pretty thick like 1/2" if possible, you can contact glue some 400 grit to it and resurface the flanges. You gotta pull the studs out of the manifold though. If the parts aren't on the car I'd recommend this even if you do go with a gasket.

 

If you insist on a gasket, why 304 stainless? I'd try the .040 copper.

 

+1 for sand flat & smear grease

 

I can get the studs out, everything is on the bench. If I can manage getting something like thick glass as you mention, I may just give it a shot.


Just from research really I guess 304 seemed more of a common material for those. I did see copper as well, but just getting different thickness recommended for gaskets overall. Looking to get a better idea of what would be a common type replacement in a situation where a custom gasket is needed (or not!) Sadly also about $25 each in .040" copper to make.


I have the OEM manifold gasket, but its too messed up for reuse. It is MLS like most. I do know the OEM downpipe gasket is a solid, one thickness steel, just not sure what that is. I need to stop playing with these old OEM turbos that have zero replacement parts LOL

 

Jay Precision Machine in NorCal and resurface it for you. He is the only spot in the bay who was willing to resurface a turbo/manifold for me.
You must run NO gasket. No question.

 

Only this every time.

 

Thank you all for the input, much appreciated