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TR2/3/3A TR3 pistons and liners

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TFB

Jedi Knight
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Im pulling my liners and pistons to try and resolve head gasket issues due to 0 liner protrusion,
First copper composit installed by previous owners shop went 22k until major blowout.
Replacement Moss copper composit only lasted 2k.I was hoping for another 20K
I then installed a racerorations Stainless and composit and ARP head bolt kit and it leaked after 1k

Liners are 86mm JRF with 25k,piston are 4 ring,two oil .155 one piece and two .062 comp.
Liner top to figure 8 flange is4.4483,protusion with 17-18thou (measured after removal)copper 8 gaskets was 0.
Thickest gaskets seem to be .021 from rimmer.
So it looks like Rimmers .021 copper would get me to .003 protusion which is still on the low end and I still need correct rings..
Option 2 is a new liner set if the flange to top is longer than my 4.4483.I dont know original dimension.
Any thoughts on currently available 86mm liner sets appreciated,or does it make sense to go 87mm.
Thanks
Tom

.
 
Thanks Bob.I considered this the last couple times I had the head off but after going to the effort to pull theliners I am hoping just to get things fitting right,
I remember Randalls posts on the subject back when I was building the car about 10-13 years ago,along with all his other great first hand info.
Tom
 
Could a prior owner have had the block decked with the liners in place? Seems like your options are taking liners, FO8 gaskets and block to a machinist so as to allow calculation of how much the block (sans liners) needs to be decked to restore protrusion. Or take a flyer on new liners. Before doing so, I would get the provider to give you measurement from bottom flange to top of liner to compare to what you have. As for diameter, I don't think it makes any difference.
Bob
 
Other option is extra thick figure of eight gaskets, or double them. I think Rimmer brothers sells the extra thick, I also recomend the head gasket from bpnorthwest.com that has silicone beads around all the holes and bolts.
Last time we bought a sleeve/piston set, we bought 87mm. The only thing I was disappointed with was the rings. They were pre-sized and were at the maximum gap. I would rather the rings be just above the minimum gap.
 
Thanks Bob,I have taken the measurements and need to gain .005.Most likely the replacemet liners are off.
I would like to know the original dimension for the liner top to the flange.My 4.483 seems an odd number(added an extra 4 in op)
I will call Moss and see if they can give me number,but was also hoping somebody knew the original measurement.
Tom
Jerry said:
Other option is extra thick figure of eight gaskets, or double them. I think Rimmer brothers sells the extra thick, I also recomend the head gasket from bpnorthwest.com that has silicone beads around all the holes and bolts.
Last time we bought a sleeve/piston set, we bought 87mm. The only thing I was disappointed with was the rings. They were pre-sized and were at the maximum gap. I would rather the rings be just above the minimum gap.
Click to expand...
Thanks Jerry.Yes,Revington,not rimmers that I put in op,
lists .021 in alum or copper as thickest and also seems to have the best price on 86mm set(420vs most other 580) although they dont give much other info.
Theroadsterfactory is the only one to list manufacturers name,County 87mm.
Tom
 
TFB, Are you sure you don't have another issue. There are other things that might cause your failures, for example, Is your cooling system up to the task. The cooling systems are marginal even when working well, particularly so in hot weather.

In my admittedly limited experience, as long as the liner height is positive, consistent and close at least to specs, they will work. Not that you shouldn't try for perfection, just my observation. (If I remember correctly, which is not always the case, the steel FO8's were available in several thicknesses in the past. No help now though). I always use the copper ones, which I'm told actually compress very little and so do raise the liners a bit.

Here are some expert considerations on FO8s from Mick Edwards (Motorsport Mickey) on another forum: FO*s

The 4 ring pistons are tractor technology, in my opinion. I'm not sure they are still available even in 86 mm size. I've been happy with the 87s.

Tom
 
The problem sounds like it is getting worse. I am in Tom’s court that it could be something else, like a crack maybe in a bolt hole or something. I am not sure how to test for cracks in a block or head, so I would probably try to find someone who knows, and they are hard to find these days. I have seen cracks where the oil and water did not mix.

steve
 
Thanks Tom and Steve,
I may have something else but the car has never overheated,and I started with a fresh rebuilt shortblock,r from previous owners shop.
Although the head appears straight ,my machinists precision straight edge is only a foot long,and I dont want to take the time to set it up in my milling machine and index it so I am going to have it skimmed and vacuum checked.It appears to have already had .015 taken off.
I am leaning towards ordering the 86mm set from Moss and will see how things fit
Moss is a little more expensive with no sale but they have always been really good for any return issues,and they have everything else I need.
Tom,what head gasket did you use with the 87mm?
Tom
 
TFB said:
Thanks Tom and Steve,
I may have something else but the car has never overheated,and I started with a fresh rebuilt shortblock,r from previous owners shop.
Although the head appears straight ,my machinists precision straight edge is only a foot long,and I dont want to take the time to set it up in my milling machine and index it so I am going to have it skimmed and vacuum checked.It appears to have already had .015 taken off.
I am leaning towards ordering the 86mm set from Moss and will see how things fit
Moss is a little more expensive with no sale but they have always been really good for any return issues,and they have everything else I need.
Tom,what head gasket did you use with the 87mm?
Tom
Click to expand...
I used a Payen gasket from an old Payen head set. Nothing special at the time but pricey today.
Tom
 
For what it's worth, the liners for the last two engines I built were 4.486 and 4.487. The copper gaskets supplied with the gasket set were 19-20 mils, after the copious burrs were removed. The dimension from the top of the block to the mounting flange should be 4.500; one of mine was 4.497-4.498, obviously had a couple mils taken off it, but the other was right at 4.500.

I'd hate to have to buy a new piston and liner set just for a few mils. Before that, I'd either get the block shaved a couple mils or make my own gaskets. It can be done.
 
TFB, I checked my left over stuff and found 2 copper FO8s that measure just over .020. PM if you could use them.

Sarastro, Yes I've heard of people making the FO8s. Beyond my ability though.

Tom
 
Thanks Steve for those measurements which would work for my block.
I ordered the 86mm 3 ring from Moss so I will see how things fit up.
Atlhough the 4 ring with 2 one piece oil rings are probably not ideal for preformance I was suprised how pristine the bores and pistons were after about 25kmiles,with the pistons having no wear,not even any skirt scuffing.I think the lower ring helps keep the piston centered.
Thanks Tom M for that generous offer.I will send a pm tomorrow,heading out for lunch with the kids.

Happy Fathers day to the Dads,
Tom
 
when we were racing it was SOP to use Cometic head gaskets, they will build to your spec for a fair price.
Mad dog
 
Thanks for all the replies.
I took my head to my long time speed shop and because I measured the piston skirt clearance of the new 86mm set at .0025 at the top and about ,001-.0015 on the bottom ,I am going to have them fit the pistons,rather than do it myself with my ridgid cylinder hone or send them back.
They confirmed with a bore gauge the taper and clearances.
I also got a surprise when removing the old wrist pins and two broken rings and a chunk of ring land fell on the bench.This was #4 cylinder and must have happened on the first major gasket blowout.
Special thanks to Tom Mull who is graciously sending me .021 8 gaskets so making progress.
Tom
 
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