exhaust gaskets

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MK
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Re: exhaust gaskets

#16 Post by MK » Sat Nov 19, 2016 7:07 am

My guess would be that the 44.5 mm is pretty equal to a 1.75 inch tube raw material.
When trying to manufacture fittings for my DIY RD350 and RD500 pipes, I ended up in using standard stuff to save excessive machining.
Jolly Moto offers the flanges as a spare part and the RD350 part fits the RD500.

That's the Jolly flanges (25-30 Eur each)
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Bye
Martin

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kpke
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Re: exhaust gaskets

#17 Post by kpke » Sat Nov 19, 2016 10:52 pm

Nice work there MK!

Well, I might try this for between the cylinders and manifolds.

I'm going to do a little heat testing first to see how this material holds up.

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https://www.youtube.com/c/KensGarage1

1985 RZ500 (R6 suspension & body work)

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two-stroke-brit
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Re: exhaust gaskets

#18 Post by two-stroke-brit » Sun Nov 20, 2016 9:17 pm

harbor freight do a cheap hole punch set that will make for nice clean stud holes.
and a round hole is less prone to tearing.
She might not be pretty but always a fun ride !!

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Re: exhaust gaskets

#19 Post by kpke » Mon Nov 21, 2016 12:09 pm

Thanks for that tip two-stroke-brit!

My silicone gasket heat test consisted of taking a piece of the scrap material and putting a propane torch to it, starting far away and getting closer and closer. The material held up quite well. At one point it lit on fire. But even after that it is still pliable.

So I went ahead with assembling the lower chambers on to the cylinders using the homemade high temp silicone gaskets. And of course high temp RTV for the slip fit of the chambers into the flanges.

I do see that due to the durometer of the gasket material (technical term; it's a little squishy) it tried to squish out a bit when tightening the flange nuts. But I don't think too much at all. It appears that plenty of material was captured in there to seal it up. I will find out.

The RTV is curing. I will start it up probably tomorrow giving it a full 2 day cure.

Since I am optimistic on the outcome of this little experiment :idea: , I went ahead and fully assembled the bike. I need to ride it to the dirt bag challenge in two weeks. :cool:
Ken's Garage YouTube Channel :smt023
https://www.youtube.com/c/KensGarage1

1985 RZ500 (R6 suspension & body work)

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Speed Freak
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Re: exhaust gaskets

#20 Post by Speed Freak » Mon Nov 21, 2016 4:44 pm

Ok, with this flange design I think it`s better to try filling it with RTV if you dont want to make new flanges.
Correct sealing material for this application is graphite based sealing material like this:
http://www.klinger.co.at/pages/en/produ ... ph2000.php" onclick="window.open(this.href);return false;
The Yamaha seals are also made out of this material.
I would leave the original gasket in to avoid big diameter steps between cylinder and pipe.

HT silicone is ok for up to ~250°C, exhaust gas temperatures can go up into the range of ~700°C.
Flange temperature will be lower due to water/air cooling but maybe on pipe side still critical for Silicone.
The O-ring of my jolly moto pipe on the NSR125 did not work long, after 2 weeks it was brittle and started leaking again after I replaced it.

Good luck :smt023
My bikes:
RD500 YPVS 1GE
RD350 YPVS 31K 1985
Honda CBR 1000 RR SC57
Yamaha R1 RN04

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kpke
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Re: exhaust gaskets

#21 Post by kpke » Mon Nov 21, 2016 8:28 pm

Thanks. I'll keep my fingers crossed.

I did leave the Yamaha crush gaskets in when I assembled the flanges to the cylinders.

The next ride for this bike is scheduled for Sunday, 12/4/16.

I'll keep you posted on the results of the experiment.

Someday the bike may make it to Turfrey’s shop for some new pipes/flanges/silencers. :smt007 Need to save my pennies.
Ken's Garage YouTube Channel :smt023
https://www.youtube.com/c/KensGarage1

1985 RZ500 (R6 suspension & body work)

MK
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Re: exhaust gaskets

#22 Post by MK » Tue Nov 22, 2016 8:00 am

The stock Jolly O-Rings are standard EPDM or NBR.
Cheap but not heat resistant at all.

I replaced them by Viton rings. They last better, but also get a flat side where they touch the pipes.
Bye
Martin

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Re: exhaust gaskets

#23 Post by Speed Freak » Tue Nov 22, 2016 9:27 am

I replaced the O-Ring by a RD350 - problem solved, exhaust isn`t leaking anymore and it has a lot more power now :mrgreen:
My bikes:
RD500 YPVS 1GE
RD350 YPVS 31K 1985
Honda CBR 1000 RR SC57
Yamaha R1 RN04

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kpke
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Re: exhaust gaskets

#24 Post by kpke » Tue Nov 22, 2016 11:22 pm

After 2 1/2 day cure I started the bike and things look very promising.

Rode it around the 'hood and checked gaskets/RTV and no evidence of any leakage.

After the next big ride in a couple of weeks if all is good I'll do the same process to the uppers.
Ken's Garage YouTube Channel :smt023
https://www.youtube.com/c/KensGarage1

1985 RZ500 (R6 suspension & body work)

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two-stroke-brit
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Re: exhaust gaskets

#25 Post by two-stroke-brit » Wed Nov 23, 2016 8:46 pm

kpke wrote:After 2 1/2 day cure I started the bike and things look very promising.

Rode it around the 'hood and checked gaskets/RTV and no evidence of any leakage.

After the next big ride in a couple of weeks if all is good I'll do the same process to the uppers.
fingers crossed. :smt023
She might not be pretty but always a fun ride !!

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kpke
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Re: exhaust gaskets

#26 Post by kpke » Sat Dec 10, 2016 11:15 am

So far so good. After about 100 mile ride last Sunday there is no evidence of any exhaust spooge coming out.

The silicone gaskets are not discolored.

I am calling this a win.

Next I will do the uppers with the same process. They are currently spooging a bit.
Ken's Garage YouTube Channel :smt023
https://www.youtube.com/c/KensGarage1

1985 RZ500 (R6 suspension & body work)

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