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AA 2056 cylinder to case faces Normal?

Posted: Wed Dec 04, 2019 2:01 am
by Gnasha
I was mating the barrel faces to a decked case. I notice the landing face on the barrel is small very small in comparision to the face on the case.

I have attached some photos showing measurements to show there is 1mm or 0.04" landing face on the barrel, this excludes the chamfer on the deck face.

All the other measurments are spot on incl ring gaps piston clearance etc

I'm aware there is little or no pressure in the crankcase, however I do have concerns.

I was thinking of boring old VW barrels to suit the AA pistons???

Has anybody seen this before on after market barrells?

thanks fo rreading
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Re: AA 2056 cylinder to case faces Normal?

Posted: Thu Dec 05, 2019 7:03 pm
by Clatter
This is normal.
Big bore cylinders for one thing.
Another is that some might use large studs.

There's those with type 1s who have to grind clearance for their head studs.
You should see how small a set of 94s with 10mm head studs can get - like nothing left!

This is one of the very few places most all builders will use an aggressive sealant - like RTV/silicone.

A thin smear of RTV, and you're good to go. ;-)

Re: AA 2056 cylinder to case faces Normal?

Posted: Fri Dec 06, 2019 1:04 am
by Gnasha
Arrrrh I though the name was familiar, I remember the junk build topic, sublime, learnt so much from that.

Thank you for your response (the only one) it has reasured me some what. However, I have sourced a set of 039 101 301 C and was going to have them machined to suit the AA pistons.

When you say aggressive, do you mean from a resistance point of view? do you have a recommended RTV for this issue?

Thanks again.

Re: AA 2056 cylinder to case faces Normal?

Posted: Fri Dec 06, 2019 9:05 am
by twodollardoug
Yamabond 4

Re: AA 2056 cylinder to case faces Normal?

Posted: Fri Dec 06, 2019 10:23 am
by Clatter
Ultra Grey

Re: AA 2056 cylinder to case faces Normal?

Posted: Fri Dec 06, 2019 11:07 am
by Gnasha
Thank you Clatter and 2$. Much appreciated.