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Discussion Starter #1
Just took on a project for my neighbor. Restoring the engine for a 1965 GTA with Twin Plug head. I have been a High Performance Engine Machinist since '84 (recently retired). This is the first engine I've been involved with an engine that has removable "wet" cylinder sleeves. My quandary now is regarding the condition of the sleeves.

The neighbor has a "Build Sheet" from the last owner showing it was done 10 yrs ago. Compression is stated as being 12:1, using Domed JE forged pistons. This car's life was spent as a rally car, and will be gently used as such again. The engine seemed to have lost it's "punch" shortly after purchase. Leaking down the cylinders as follows;

#1- 12%
#2- 21%
#3- 32%
#4- 12%

Leakage mostly was noted from crankcase, indicating ring seal, although I suspected a head gasket failure at first. Upon removing the head (which was the hardest head removal I've ever encountered) there was no signs of gasket failure (Victor Reinz composition gasket). The sleeves had a copper O-ring installed that barely contacted the O.D. of the gasket fire fire. The head had been cut for an O-ring, but none were installed.

After removing the pistons/rods and removing the rings to check end gaps, it was obvious that the top ring had lost a lot of tension likely due to over heating. The gap measured .016" for top, and .024" for 2nd. The pistons appear to be in great shape dimensionally and we would like to reuse with new Total Seal rings. Piston/wall clearance is somewhat large and the bore tapered and out-of-round. We are looking at having LA Sleeve supply new sleeves, honed by them to fit the pistons. LA Sleeve could not provide an answer to my MAIN questions.

Here's were I need input from experts here. What relationship should there be between the deck surface of the crankcase and the top of the sleeve, considering the high compression of this package ??? Currently the top of sleeve is at the same height as the block deck. A friend that has experience with diesel applications feels that the sleeve should protrude .003-.004" above the block deck. Is there a generally accepted dimension for this concern as related to this engine ??? I'm also assuming that the O-ring situation is NOT OEM. Is there any book out there that we could purchase as a guide to any peculiarities of this engine ???

THANKS in advance for and kind input !!!

Joe
 

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Richard Jemison
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The factory spec for the liners without the o-rings in place is .002"
The factory race prep for the liners and head was simply a "V" groove in the liner and head for the fire ring to migrate into when torqued. Torque on the head should be about 10% higher than factory spec with high compression builds.
Doubled "O" rings might be a bit much for the fire rings to accommodate.
Look at the top side of the gasket, the grooves should be accomplishing the same function and preventing any fire ring migration or leakage.
Fire rings are smaller(narrower) in modern gaskets than the old versions.
 

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Discussion Starter #3
Thank You Richard !

The V-groove concept is something I've never heard of. I'd like to see a picture some time. Maybe LA Sleeve has some input about that. Yes, it does seem like the sleeve/head O-ring grooves were cut with a wider fire ring in mind. Thanks for the torque increase idea.
 

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Compression is stated as being 12:1, using Domed JE forged pistons. This car's life was spent as a rally car, and will be gently used as such again.
Rally car? That's a lot of compression for pump fuel ... likely to need at the very least some race fuel in the mix ... if you are running California pump fuel (91) it won't like more than 10.5:1 ... otherwise you will be retarding timing.
 

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Discussion Starter #5
This is a race only situation. The car will be trailered, and fed nothing but high octane fuel or AV gas.
 

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Richard Jemison
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The grooves are described in Stction 1 / Detail, page 2, issue 1, of the Competition Advisory Service. A Red 3 ring notebook publication from the early `70s (`71?) by the Alfa Owners Club which had the most usable of the Technical information from Don Black`s Alfa Romeo Competition Referance hand book.
That publication mentioned the grooving of the heads & liners as well under Detail for 1600 / GTA
The specs for the grooves on a 1600 were were on a 84.5 mm center to center, groove width 0.8mm and depth 0.5mm side angles 84 degrees.
 
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