Piston / rebuild question

[No Pvmt]

I'm doing a rebuild on my `04 D2 and recently bought some used pistons. My OEM pistons have H41 stamped on them and the others have H42 stamped and are in “marginal” condition (they came from `04 D2?); they seem to measure out the same… but are they, will they be okay to put in and why the different stamping? I would hate for them to cause other issues or is my builder being overly cautious? Please advise...

Thank you

 

[helievacpilot]

If I were going through the trouble of a re-build, the last thing I would use is used pistons in "marginal" condition.

 

[No Pvmt]

Agreed, however this is my plight with this vehicle at this time.

 

[Roving Beetle]

Wow. Sorry to hear this.

The pistons are from a supposedly reasonable (I forget the exact) miles '04 - I bought the motor from Will Tillery.

What's marginal? Not trying to be an ass at all, just curious.

You needed 3 and paid for three, I sent six. Are they all marginal?

Again - hard to not sound like I'm upset, I'm much more upset they may not be what you need. I'm happy to refund the $$ in full if you'd like.

Doug

 

[No Pvmt]

Doug, I wanted to be fair to you and didn’t want to list you as my source due to not seeing the pistons myself. My mechanic (that’s doing the build) claims they’re “Marginal” (baked oil). He was also concerned that they have different stamps on them (H41 vs H42).
…“Rick, cleaned most of the pistons for a set of 8, As previously stated I will measure rings on the pistons and the pistons in the bores per factory procedure and will reject any that don't meet specs. But caution you that because of the difference of the stamping H41 and H42 from the replacement ones I can't guarantee they are identical as no research has turned up what that stamping means. As the replacements are used and marginal in my opinion I will proceed as long as you are OK with this and reply agreeing that you understand. For my part I will follow factory engine rebuild procedures to ensure the highest quality for you rebuild”….. Mechanic
I asked him to clean them up and pick the best three of six. Is he just being overly cautious and trying to cover his back-end? I don’t see the difference being that I’m using five of my own pistons that in turn would make them “marginal” as well. I’m trying to see if you and others of the craft have any input as to his concern regarding the stamping. I do appreciate your offering and do look forward to doing business with you again.
Best,
Rick

 

[Roving Beetle]

I saw they had in my opinion very normal oil staining or "baking" as he called it.

Sounds like a good mechanic but in all honesty I think he's covering his butt. Understandable for sure.

There was no evidence of scoring in the block bores, no broken rings, no wrist pin movement noticed and no "hot spots" or deformation or pitting that I saw on the pistons. I think they are fine. That said I'm not an "expert" however I've rebuilt plenty of motors and I am Yanmar marine diesel trained and certified.... I'd use them with new rings and bearings of course.

As for the numbers - my *guess* is it means very little given how often rover seems to stamp different numbers on stuff and change batches mid year etc. But maybe it means something?
Let me know if you'd like $$ back. No worries.

Cheers
Doug

 

[sedat]

since when has oil stains resulted in a metal part being unfit for service? Every Rover EVER would be unfit under that statement.

if they mic out the same and weigh the same, hell with it, throw em in and run it, chances are it'll be better than anything that was built by LR at that time anyway.

Find another shop and soak the fuckers in diesel or your favorite cleaner.