NZConvertible

I'm swapping an S5 turbo onto my 'vert, so I'm replacing all the exhaust gaskets. Because I've ported the manifold and turbine housing and am making a downpipe with a custom backplate, I've had the turbo-manifold and turbo-downpipe gaskets made by a specialist gasket maker. Since these can be made for much less than Mazda charges, I'm getting them to make the engine-manifold gasket too. I'd like to use a genuine gasket as a pattern, but haven't been able to get hold of a spare one. I could just make a pattern off the manifold but from the photos on the Mazdatrix and RB sites it looks like the exhaust port holes on the gasket are quite a bit bigger than the manifold ports, and I'd like to mimic that on my gasket to allow for a bit more porting if possible. I was hoping one of you guys could scan one and post it up for me. I'd be really grateful.

RotaryEvolution

iTrader: (30)

just make sure he uses the right materials, there is a reason the oem gaskets are so expensive. i tried playing with copper, though the melting point should have stood up to the heat it did not, mainly because of the backpressure pushing on the gasket as well. i have used copper on V8 headers with good results but in turbo applications it would have to be a high grade steel or ceramic.

NZConvertible

I'll get some photos tomorrow of what I've already got. It's a sandwich construction like the OEM gaskets with copper lining on the inside edge. I don't know how they do it for the price. I haven't used these yet, but a mechanic mate of mine has had the same place make many exhaust gaskets for customer cars and had no problems.

RotaryEvolution

iTrader: (30)

yep but this is a rotary after all.

Rotary_Knight

iTrader: (4)

Found this on mazdatrix.....

HAILERS

This shows the side facing the rotor housings.

This one is used and a gonna get used again and again and again til it leaks. BUT, I will offer it up for sale for the generous sum of one hundred fifty USA dollars. Remember, it's a proven gasket.....humor.

IF there is something that needs measurement, just ask. But you have one. So, maybe this isn't what you want. You want a series five gasket scanned? Or???

EDITED.....EDITED.....EDITED......FOR GROSS ERRORS. Wait a half hour and real measurements will be shown. I kinda goofed up with the calipers.

HAILERS

A little better
The hole in the gasket is quite a bit larger than the exaust port hole.

Tell you what. I just picked up a gasket that I assumed was turbo. Maybe I need to go compare other gaskets I have laying about. Not in the next few hours though. Much later.

stevej88na

I bet 5.95mm is 5.95 inches!

HAILERS

5.95????? He's from downunder and won't notice. humor

Here's a manifold sitting on top of a gasket. Gasket gotum large hole.

RotaryEvolution

iTrader: (30)

the one you pictured is of a TII block to manifold gasket Hailers, the n/a gasket still has the same dimensions but it is a mesh style gasket instead of the solid steel surface appearance.

and i can get these gaskets for $65 from Atkins for OEM, they are pricey but it's not like they are that bad and are going to break your wallet. is spending 2 hours dealing with a machine shop really worth all that hassle?

NZConvertible

Dude, you're a legend. That's exactly what I was hoping for. Thanks very much for that.

Yeah that's what I thought, so the next question is how big are the exhaust ports in relation to the manifold ports? The manifold ports are also a bit oval. If there's a reducing step at the manifold entrance then I'd like to deal to it. I've already port-matched the turbine housing and manifold (as well as widened the ports a bit) so I'd like to do the same here if possible. Also, is there any reason why I shouldn't just get two small gaskets made like the FD's, rather than one big one? It'd probably be cheaper.

Some of those cars were rotaries.

I can get one from Mazda for NZ$85 (~US$60), but it'll cost me ~NZ$30 (~US$21) to have this made. I don't really need to get this one custom made like I did with the others, but I like that fact that I can get a quality gasket for nearly a third of the price. I don't really consider this a hassle, and when I had the other gaskets made I hardly spent any longer there than I would've ordering it from Mazda. Two hours? I think I was there for ten minutes discussing it with him, and I learnt some stuff about gaskets and other products they sell at the same time. You don't get that at Mazda.

HAILERS

Some of what you want is here. Some isn't.

I don't have a spare TURBO housing to scan. They're on a engine.

But the sleeves are the same diameter as the NONTURBO one in the jpg that's attached.

It's a little difficult to measure the inner diameter of the exaust ports on the housings. If needed I might measure them. But you know the inner part of the sleeve is tapered? Slanted? Ain't prefectly round so to speak.

NZConvertible

That's great, that tells me what I wanted to know. The width of the manifold ports is about the same as the width of the exhasut port, but the height is less, so there's a step at the top and bottom which I guess could cause turbulence. I'm going to take those steps out by making the manifold ports circular.

I've scaled your first photo of the gasket on a photocopier to make it into a perfect template. I'll get that underway on Monday. Thanks again!

Here are the gaskets I've already had made. Note the copper lining in the inside edge.

NZConvertible

Here's what I've done to the manifold. The engine-side ports should now be pretty close to the shape and size of the engine's exhaust ports. The turbo-side ports have been widened, and matching work done to the turbine housing (as well as wastegate porting).

HAILERS

The question is in the attached jpg I've no depth perception online.

NZConvertible

Nope, it's a perfectly flat surface. It's just marks left behind by the original gasket, which has much bigger holes. The lighting makes the openings look different sizes too, but they're the same.

NZConvertible

Okay, here's the finished product. It cost NZ$36 (~US$25) and it turned out I didn't even need the template because they had one in stock!

stevej88na

Looks good! $25 for a one-off is a deal too.

HAILERS

*******Also, is there any reason why I shouldn't just get two small gaskets made like the FD's, rather than one big one? It'd probably be cheaper.
************************************************** **********************

That's a good question, because when you look at the price, just one of the FD cost73.50 and you need two. But the second gen cost only 59 bucks USA.

Seems a FD owner would get a saw out and cut a second gen gasket out and save serious money. Soooooooo........there must be a serious difference somewhere in the exaust ports b/t the two engines. Got me as to what.

NZConvertible

I saw that crazy FD price. I really hope that's for a pair...

HAILERS

$73.48 EA.

http://www.mazdatrix.com/getprice.as...m=13-4610-N3A1