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Figure 8 survey results

To: fot@autox.team.net
Subject: Figure 8 survey results
From: "Jack W. Drews" <vinttr4@geneseo.net>
Date: Mon, 03 Mar 2003 20:01:24 -0600
Thanks for everybody who responded to the question regarding type of 
sealant, if any, you use on the figure 8's. Here are the results:

Permatex non-hardening - 3
Hylomar - 2
Yamabond
Copperkote
Gaskacinch
Blue RTV
Spray, brand unknown (Mordy's magic goo, I think)
loctite 510 or 563

The reason I asked the question is as follows.

I always use a sealer, too. I'm uneasy about putting 40 year old parts 
together metal to metal and expecting them to seal. However, I've found 
that every sealant that I've tried has changed the liner protrusion, no 
matter how thinly it was spread. It seems that the biggest problem in 
building these engines is getting a perfect head seal. I assemble dry, 
measure protrusion, and then use figure 8's of whatever thickness is needed 
to give the proper protrusion, and I shoot for less than the factory spec 
-- I try for .003. However, when I assemble dry, then use sealant, it 
increases protrusion. I have even recorded protrusion at assembly time with 
goo on the gaskets, and then recorded the protrusion again when the engine 
is disassembled. I find that it doesn't all squish out. The change in 
protrusion seems to last.

I'm going to do my engine again, and am considering alternatives. I might 
take the sealant thickness into account when setting the liner protrusion. 
Or maybe I'll decrease protrusion to help the seal at the water jacket 
openings and rely on the o-ring to seal the combustion chambers. Any more 
comments?

uncle jack

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