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TR2/3/3A Piston Slap đź‘‹

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HighAltitudeTR3

HighAltitudeTR3

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Yeah... piston Slap. I've got it. It usually fades a bit when the engine is warm. Only one that pesky #4 cylinder. Can you guys please tell me what I need to know about this on these engines? Just weighing a few options here.
 
Well. It usually means your engine is worn out. Use thicker oil and run it until you are set for a rebuild.
 
In my limited experience piston slap is not a common complaint with these engines although that dos not rule it out. On the other hand, my Subaru Forester has slapped away alarmingly when cold for the past 230,000 miles, so John's suggestion to drive it may be a good one.
Valve train noise will often go away when warm also, so make sure you positively rule out that possibility.
Also, again in my limited experience, piston slap is usually caused by a fault in the piston. If it is, it's not that hard to replace one and new pistons are probably available, depending on size, although you might have to buy a set. If compression, oil consumption, oil leakage and oil pressure are acceptable, I might consider that option.
Tom
 
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Thanks Tom and John.

oil pressure is good and so is compression. I replaced the rod bearings recently so I know that it's not that. The noise will stop when I pull the 4th wire. Piston clearance is pretty much the only thing I hadn't checked when the engine was open.

I have another few few weeks of driving here and will probably line my self up for a rebuild in the spring. Is this liners and Pistons? I know the crank is good, cam seems fine, but will double check and if it's bad, I will probably just replace with a new one.
 
It can be annoying and worrisome to the owner, but usually not harmful. If it's not an inherent condition it was probably brought on by heat expansion of the piston causing scuffing of the piston skirt and a looser fit.
A loose wrist pin makes a similar sound.
 
Thank you poolboy, that is kind of what I read online. I did check to see if I had play in the wrist pin but didn't notice any. (But I'm not an expert by any means). I guess I'll drive it until it snows or breaks, whichever comes first.

Anyone get the 89mm Pistons from Moss??
 
I think if I were you and it depends on if you got the head rebuilt and the rocker shaft when things were apart???., I would give it go and pull the head and pull the liners buy some new 87mm or even 86 if you can find a deal then clean everything out good and go for it --and you could get by for maybe 600 or 700. The other way is more inclusive when you pull the engine and trans and do the clutch and crank and timing chain ect ect and it usually cost 2000.00 before you are done. I must admit it sounds more like a wrist pin from here because you would have seen the scaring of piston slap.
steve
 
Since you just had it apart, you know what is involved. Taking #4 piston out is not all that hard and will take the guessing out of the diagnosis. It seems a bit of overkill to plan on a complete rebuild on the basis of a ticking at #4 when all else seem fine. My opinion anyway.
Tom
 
TomMull said:
Since you just had it apart, you know what is involved. Taking #4 piston out is not all that hard and will take the guessing out of the diagnosis. It seems a bit of overkill to plan on a complete rebuild on the basis of a ticking at #4 when all else seem fine. My opinion anyway.
Tom
Click to expand...

Normally I would agree...but it appears he's already had to do half a rebuild, and it keeps increasing. The pan's been off at least twice this month. At some point you are best off just pulling the motor and going through the whole thing. At the first thread concerning the knocking noise...I had this motor pegged as just plum wore out.
 
I agree with both of you. I don't want to chase noises forever though. Replacing one piston vs replacing all of them isn't the bulk of the work in this job. I also have a local guy who has done in back in the 80's and he just mentioned he needs a new set. So I'll sit in on his and help out and he'll guide me a bit on mine.

In terms of a wrist pin, I think the noise would get worse when the engine warmed up. Regardless of wrist pin and piston Slap, the cylinders while not super warm are tired, so I might as well get it all done.
 
When I bought my old TR-3 in 1977, the engine sounded like bells when first started. I got to reading up on it, and the liners were designed to be rotated 90° to deal with piston slap. Not a cure, but you could kick the can down the road.
 
In racing classes that only allowed very stock engines, we used to clearance these engines all the way out to about 0.010" clearance and they ticked when cold but were quiet once warmed up.

Lotus Cortina engines came that way from the factory! Don't sweat it. In the good old days you'd get the skirts knurled (a temporary remedy) but you really don't need to bother.
 
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