piston and liner kits

[TomMull]

Are the Mahle piston and liner kits worth the extra money- more than double the “County” sets? Are there other alternatives? Thanks. Tom

 

[DougF]

Personally, I would spend the extra money. Check around to see if you can get a better price for the same or comparable items.

With the cost of an engine rebuild what it is, I wouldn't scrimp on internal parts. I'm not saying that County brand is of questionable quality, I just want the best I can buy to reduce the risk of failure. Also, with the higher price could come better machining tolerances.

 

[TR3driver]

OTOH, there was a thread recently (different board) about the Mahle pistons being substantially heavier (like 50% more) than others.

"County" is a repackager, they don't make any parts themselves and frequently switch manufacturers. They've certainly had quality problems in the past, but I've not heard anything bad about them in recent years. Plus I've used some really cheap pistons & liners in the past (including a set that was returned to JC Whitney for being mismatched sizes) and never had a problem that I attributed to the quality of pistons & liners.

So I'd say it comes down to a conversation between you & your pocketbook. Assume, just for the sake of argument, that the County liners will only last 80,000 miles and the Mahle for 150,000 (actually, I believe Mahle only makes pistons, the liners are from someone else) ... then figure out what the chances are that you will still care in 75,000 miles AND not have some other reason to tear the engine down

Personally, I went with the forged pistons from BFE, which I believe he has custom-made by Venolia (pistons) and LA Sleeve (liners). But I'm planning to get a bit more grunt from this motor (and maybe even experiment with supercharging later on), so I wouldn't suggest the extra cost for everyone.

Also, someone posted recently that they were getting the Mahle set from Germany for quite a bit less than TRF is asking. You might check into that.

Yet another option is only buying pistons and having your old liners bored oversize. Joe Alexander at ARE is a fan of this method, and can help with having your liners bored. Last time I did the math, it did result in a significant cost savings.

"You get what you pay for" is a warning, not a promise ...

 

[TomMull]

Thanks Randall. You've put some perspective on this. It's doubtful that I have 80000 sidescreen miles let in me and I certainly don't want to pay extra to add to the weight of the pistons. From what I can glean, the "County" pistons are made in the Far East, consequently the low price, which may or may not reflect in quality. The rings and liners in Europe. It's good to hear of no complaints of County sets lately.
From my limited experience, I've had no trouble with either the pistons nor the liners but with rings. During my last rebuild, many years ago, I broke a new (one piece) oil ring and bought an aftermarket set (3piece) and installed only that one ring. That cylinder was oily ever since. (I think I staggered and measured the gaps and got them in right but hat was a long time ago. I think Don Elliott said somewhere that he had ring seating issues too.
By the way, I know of ARE but not BFE, not that I have any need for custom forged pistons. Tom

 

[TR4nut]

I put in Mahle pistons in my 3A - I'm impressed with the quality, the weight issue is more of a racer thing I believe at high RPMs. But I bought them a few years ago at not much premium to County brand so unless you can get them discounted its much harder to justify the added cost.

 

[TR3driver]

By the way, I know of ARE but not BFE, not that I have any need for custom forged pistons. Tom

BFE is British Frame and Engine, a small supplier of mostly racing parts for Triumphs. Ken Gillanders runs it from his spare bedroom near Los Angeles "mostly as a favor to my racing friends". But he is an ex-Triumph dealer mechanic and has been around racing Triumphs since the early 50s.

He has a web site at https://www.britishframeandengine.com/ but I don't think it's been updated since it was created, and it certainly doesn't list all the parts he has (or can get). Usually it's best to call him; he doesn't do much on the computer but he loves to talk. (Ask him about his TR2 drag racing trophies)

 

[Don Elliott]

I bought my piston rings and liners as a matched kit diectly from Peter hepworth in North Yorkshire. I have 4 rings on these pistons. The racing guys like the Hepilite kits. I drove 94,000 miles and used 1 quart of 20W50 oil every 600 miles. That was the issue. In 2007, I rebiult the engine and the engine re-build shop owner whom I have known for years told me I needed to replace the rings as there had been "blow-by" pressurising the sump (oil pan) causing the oil to get forced out the down-pipe below the fuel pump.

I had him hone the bores and put in new rings I bought directly from Hastings in Michigan. Since then I have been using Castrol 10W30 for 11,000 miles and have never needed to top up any oil between oil changes (3000 miles) during four summers of driving.

I am very pleased and since it was mu friendly neighbour you assembled the engine for me, I can only assume that the bores of the liners had not been honed before assembly in 1989.

 

[TomMull]

Thanks all. I take from this that I'm probably sacrificing some quality with I don't need with the County set so I think I'll go for price. Randall Thanks for the BCF link. I'll bookmark it. Don, did your car have the 4 ring pistons originally? Tom

 

[TR3driver]

I had him hone the bores and put in new rings I bought directly from Hastings in Michigan.

Just for clarity, that is frequently all that is required. If the bores are not worn out or damaged in some way, you don't need to replace the liners. Ditto the pistons.

And unless you can see that they have already been honed, I would suggest always honing before installation, even for new liners. The honing process, when properly done, helps the rings both seat quickly and last longer.
https://www.hastingsmfg.com/ServiceTips/cylinder_bore_refinishing.htm

A stone-type hone will work, but my preference is for the brush type (aka Flex-Hone).

 

[prb51]

I had him hone the bores and put in new rings I bought directly from Hastings in Michigan.

Just for clarity, that is frequently all that is required. If the bores are not worn out or damaged in some way, you don't need to replace the liners. Ditto the pistons.

And unless you can see that they have already been honed, I would suggest always honing before installation, even for new liners. The honing process, when properly done, helps the rings both seat quickly and last longer.
https://www.hastingsmfg.com/ServiceTips/cylinder_bore_refinishing.htm

A stone-type hone will work, but my preference is for the brush type (aka Flex-Hone).

For what it's worth: We had a local Brit that owned/operated a Brit car service shop "Coventry Motors". He's left the business sadly, age. He apprenticed in the motor shop at Coventry working on TR3's. He told me "Don't replace the liners, pull 'em out, turn 'em a quarter, hone 'em and go". He said the get a tad oblong from running but turning them that 1/4 deals with that. Never tried it but that's what he told me.

 

[TomMull]

Turning them 1/4 is in the literature somewhere and I've considered it. Thanks for reminding me as I'll consider it again. Tom

 

[Don Elliott]

Tom - I believe that my original pistons had three rings as all TRs left the factory like that. When I was doing the restoration of my 1958 TR3A from 1987 to 1990, I wanted to keep everything "as original" and the only set I could find with the original bore (1991 cc) was the kit from Hepolite and these pistons happen to have 4 rings. When I spoke to Peter Hepworth himself, he told me that he thought he could find a set (his last set for 1991 cc) down in the basement and that I should call him back the next day. I did and the deal was done. When I got the set, the rings happened to have 4 rings per piston.

The piston you see above is one of that set with zero wear after 94,000 miles on them. The rings are from the new Hastings kit. Yes, that piston and the others have been cleaned a bit. The bores of the liners were worn with a slight wear taper of 0,0005" from end to end - virtually like new. Since my neighbour put it all together, he was very careful and balanced each set of pistons and con-rods to have equal weights. But I was in the Far East on business for three weeks and never noticed if the liners had been honed or not.

At 94,000 miles, I too rotated the liners 90 degrees because the side to side force of the pistons and con-rods would now be running in the areas in the bores where there would be no-wear. I've been pleased with the results I have had for the last 3 summers (11,000 miles) with Castrol 10W30 and 4 oz. of ZDDP per oil change.

Two days ago, I put the TR away for the winter. But I managed to drive it ove 300 miles in the past three weeks.