Need Guidance: Forgot to Mark Liners During Engine Disassembly

If you’re boring to the next or larger oversize piston, then cylinder location does not matter.

 

So does he think liners are custom made to fit specific places and orientation in a specific block? It only matters if the old pistons were to be reused.
When assembled new they grabbed 8 liners at random, stuck them in the block at random and used them with their matching pistons. You have wisely decided not to do that so put them in without O rings and make sure protrusion is withing specs and ignore the ignorant advisor.

A torque plate is best but the factory never did it that way.

 

You should be able to check for roundness within factory spec after boring/honing. My machinist had to make a fixture to stop the walls of the liner from expanding when honing.


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Shouldn't "worry too much" about it?

Why ANY worry?

 

If you bore the original liners don’t they have a special surface treatment that is very thin so after boring/honing do you have to retreat the liners
To the original hardness?

 

As far as I know the liners on my engine (‘75 GT4) had no coating. Later models may have had nikasil coatings.


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2 valves all used iron liners.

 

You must be talking about the Nikasil coating they have on the four valves engine.

 

When I pull the liners out for a rebuild I dont mark them until I've cleaned them and prepared everything for the machine shop. I randomly engrave them 1-8 or 1-12 on the flat of the flange and tell the machine shop to put the number to the front of the block when he refinishes them. All that matters is what hole they are in when they get machined. I give him a head gasket and my torque plate.

Obviously it doesn't need to be done that way because Ferrari never did but when I see the difference using a dial bore gauge with and without the plate I cant do it without using the plate. I also found that if you 180 the sleeve the reading changes and it changes from hole to hole in the block if you move them around.

 

Holes refers to the 8 holes in block that the sleeves go into. Mark them (the sleeves) 1-8 and make sure they get machined in those specific holes and put them back in those holes when you assemble the engine. Thats what I do but you can do it however you wish.

 

No I think what he is saying is that if you are going to bore/hone the liners in the block then mark the liners for each hole and their orientation so that when you finally reassemble you put them back in exactly the same holes in the same orientation.


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Depends on how round and straight they are when you put them in the block and put a torque plate on it. You wont know if you don't check. What fixture was used to do your sleeves? What did Ferrari use?

 

This is my plate, I use it on the V8's rather than make another one with 4 holes. Same thickness as the head itself.

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To find someone with a torque plate for another engine with the same bore size, bore spacing and head stud pattern would be a long shot.

It might be possible to torque the head on and measure from underneath if you want to check. I have a new head gasket I reuse just for the torque plates. One thing I can tell you is it wont be as straight or as round is if you had used the plate and no way to correct that (if it needs correcting) without buying another set of pistons. A race engine shop would know that the method used on yours isn't as good as what he does to the race engines he builds and no doubt has an assortment of plates hanging on the wall for engines he caters to.

 

Page B12 of the shop manual has the spec for liner taper to not exceed 0.010 - 0.015mm. This can be measured with a dial bore gauge.

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No, the third paragraph lists ovalization and taper limits.


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