Is it easiest to just remove the pistons with the jugs on a Ztu?

[molinegb]

On MM diesels gasket thickness is reduced on block and head to incresse compression. Better starting. R/z don't have much compression to start with.

 

[T.R.K.]

FYI: I re-ringed a R once and it knocked like crazy. Alan knows what he is talking about.

 

[molinegb]

FYI: I re-ringed a R once and it knocked like crazy. Alan knows what he is talking about.

Done lots and never had issue with top rings, Did one yesterday.

 

[Alan K]

Done lots and never had issue with top rings, Did one yesterday.

Guess you got lucky. Using Z blocks on an R will work ok, but not using R blocks on a Z.

 

[JOCCO]

Guess you got lucky. Using Z blocks on an R will work ok, but not using R blocks on a Z.

Oh god you have messed with me now. I thought they were interchangeable. Same bore thought the stroke was different 185 vrs 165 engine. I am talking ZTE and r. What did I miss? I Realize za zb is different.

 

[Alan K]

Oh god you have messed with me now. I thought they were interchangeable. Same bore thought the stroke was different 185 vrs 165 engine. I am talking ZTE and r. What did I miss? I Realize za zb is different.

Yes, that is correct. R had a shorter stroke, ZA-ZBs were longer stroke. Just that the piston travel is different where the ring groove ends up being a different stroke. If you remove the ring groove you are fine, but hard to do on a blind hole block.

 

[JOCCO]

Yes, that is correct. R had a shorter stroke, ZA-ZBs were longer stroke. Just that the piston travel is different where the ring groove ends up being a different stroke. If you remove the ring groove you are fine, but hard to do on a blind hole block.

Ok but za zb had center bearing on crankshaft ztu and r did not. Basically two different engines. Also 206 cube inch.

 

[JOCCO]

Yes, that is correct. R had a shorter stroke, ZA-ZBs were longer stroke. Just that the piston travel is different where the ring groove ends up being a different stroke. If you remove the ring groove you are fine, but hard to do on a blind hole block.

I still stand behind what I said earlier if you have that much of a ring grove you have a lot of taper on the bore and technically need a rebore. Yes old school wisdom was rings could take up to .10 thousands but that is a cheap crude repair. Much Like cutting down .10 thousands rings to fit.

 

[molinegb]

I still stand behind what I said earlier if you have that much of a ring grove you have a lot of taper on the bore and technically need a rebore. Yes old school wisdom was rings could take up to .10 thousands but that is a cheap crude repair. Much Like cutting down .10 thousands rings to fit.

Measured R ZT ZA original pistons have on shelf. All measure 5/16" from top ring to top of piston. No difference on any far as clearance.

 

[Alan K]

I still stand behind what I said earlier if you have that much of a ring grove you have a lot of taper on the bore and technically need a rebore. Yes old school wisdom was rings could take up to .10 thousands but that is a cheap crude repair. Much Like cutting down .10 thousands rings to fit.

.008 cylinder taper was the maximum on the ZA engines. If you can find a place to bore them out redoing them is fine, but.... finding a place to do that now days isn't as easy as it used to be. Those places are few and far between. That is why most people just do a re-ring job on them since they aren't farming with them anymore or have very little use.
The R / Z engines had variations but are still the same style engine.
There used to be ridge reamers for the R / Z blocks but they are long gone.