Need Guidance: Forgot to Mark Liners During Engine Disassembly

Hey fellow Ferrari enthusiasts,

I'm reaching out to seek some guidance as I'm finally in the process of reassembling my engine, but I've hit a snag. During the disassembly process, I realized that I forgot to mark the liners, specifically indicating which position from all 8 cylinders they correspond to. Now, I'm a bit concerned about whether this oversight could potentially cause any issues down the road.

I've consulted with two other mechanics about this matter, and I've received conflicting opinions. One mechanic assured me that it's not a significant issue and that I shouldn't worry too much about it, especially since I was about to purchase two brand new liners and use stock pistons, but decided against it and decided to bore out the current liners and purchase a set of Wossner pistons, so if I had to swap out the liners, two of them would have definitely not been "appropriate" for the engine. However, the other mechanic expressed concern, suggesting that it could be problematic since the liners might not sit perfectly parallel without proper marking.

Given this discrepancy in opinions, I'm turning to this knowledgeable community for advice. Has anyone encountered a similar situation before, or does anyone have insights into whether not marking the liners could indeed pose a problem during reassembly? I want to ensure that everything is done correctly to avoid any potential issues with my engine in the future. Furthermore, are their certain steps I should follow when re-assembling the liners to make sure they are true.

Any guidance or suggestions would be greatly appreciated. Thanks in advance for your help!

 

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

 

Thanks for your clarification, a fellow member on here said the same exact thing.

Would it make a difference if we bored and honed them out of the block? They were bored and honed individually out of the block as the book suggests, but I recently came to understand that in the ideal world they should be honed in the block using a torque plate on the block with the cylinders in place.

 

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.

 

Thanks already did that, instaleld without the O rings and tomorrow I'll have the engine shop measure the portrusion for me.

 

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.

 

What do you mean exactly by this? What do you mean mark the hole they are in? Any reason why you do it?

 

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.

 

So the holes in the block where also machined to mstch the liners? Is this purely for potrusion?

 

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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Thanks for the clarification however mine were bored and honed OUTSIDE the block as the book suggests. Would you recommend that I rehon them inside the block?

 

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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Thats my question/concern, how can I check the roundness? I believe Ferrari allows up right around .0005-.0008 in liner distortion based on another Fchatter I am discussin this with.

The machinist I used had to create a Jig specifically for them to be able to bore/hone them. I have confidence in this machinisist since all the drag racing and racing groups tend to use their services but I want to be 101% sure that everything is correct prior to assembly.

In terms of Torque plates are there any other engines which possibly match with this? Possibly Alfas/Fiats?

 

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.

 

It might be partially my fault since I wanted to do everything as the manual suggested.

is there a tool I can use to measure if everything is ok?

and if hypothetically he has a torque plate to fit my engine, will it make a difference if I rehone or no?

 

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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Are you referring to the protrusion? 0.01 to 0.05?

 

No, the third paragraph lists ovalization and taper limits.


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