Wisconsin TFD cylinder bore question.

[Dave41A]

I'm working on a Wisconsin TFD for my NH66 baler. I bought the baler at auction several years ago and have baled for maybe 5 years with it. Anyway, the engine has some severe oil leaks and is hard to start, so I thought I would tear it down and do at least a re-ring, hone, and new gaskets throughout. I am not looking for a restoration, just a better running engine.

Before ordering rings I made the following measurements on cylinders 1 and 2, both in-line with and across the crankshaft:

Cyl 1, with crankshaft: Top 3.2718, Middle 3.2693, Bottom 3.2681
Cyl 1, across crankshaft: Top 3.2719, Mid 3.2709, Bottom 3.2681

Cyl2, with crankshaft: Top 3.2725, Mid 3.2711, Bottom 3.2692
Cyl2, across crankshaft: Top 3.2739, Mid 3.2639, Bottom 3.2687

My first guess is this looks like a 0.020 overbore. Is anyone familiar with the tolerances for these engines? Am I due for a 0.030 overbore?

I looked at posting in "stationary engines," but decided to start here to at least some ideas.

Thanks in advance,
Dave

 

[Dave41A]

re-posted at "stationary engines" to see if anyone there has insight.

Wisconsin TFD bore question

I started at "Implement" alley but am re-posting here to see if this can get a different set of eyes. I'm working on a Wisconsin TFD for my NH66 baler. I bought the baler at auction several years ago and have baled for maybe 5 years with it. Anyway, the engine has some severe oil leaks and is...

forums.yesterdaystractors.com

 

[Fritz Maurer]

Find a long feeler gauge set (ribbons) and see what the actual piston/cylinder wall clearance is. If you can pull a .006 through there, that’s a little on the loose side, but would be ok for the steady medium speed of a baler.

On the other hand…. small engine parts have become much more reasonable in recent years, with the increased aftermarket manufacturing ( which is your only recourse with Wisconsin anyway). Being that this sounds like your front line baler, and since you have the engine apart anyway, I would personally go for the next overbore and not have to worry about your current dimensions. If your machine shop gets the parts , all this guesswork is eradicated.

 

[Mike(NEOhio)]

I have a set of .020 oversize rings if that will help. I rebuilt a TJD that was so worn it had to go to .020 and mistakenly ordered two sets thinking the set is for one cylinder. Check the parts list and see if they will work. This set will also go in a THD with four rings.

 

[Mike(NEOhio)]

I have a pdf of the service manual for TE and TF. l can email it to you. The D only signifies Stellite exhaust valves. Do what Fritz said. Manual says piston skirt to cylinder clearance is .004 to .0045 but that's new. Recommends rebore at over .005 wear but does not give a bore size or skirt diameter for new.

 

[Dave41A]

Mike and Fritz: Thanks for the responses. I'll check with a feeler gage and post back with what I find. I'd love to get that pdf if you can send it.

 

[Mike(NEOhio)]

Mike and Fritz: Thanks for the responses. I'll check with a feeler gage and post back with what I find. I'd love to get that pdf if you can send it.

Here ya go. I guess the new system allows attaching pdf. The old one didn't.

 

[Dave41A]

Mike: Awesome! Thanks for sharing that with me.

 

[Dave41A]

I have a pdf of the service manual for TE and TF. l can email it to you. The D only signifies Stellite exhaust valves. Do what Fritz said. Manual says piston skirt to cylinder clearance is .004 to .0045 but that's new. Recommends rebore at over .005 wear but does not give a bore size or skirt diameter for new.

Mike: For one piston, a 0.005 feeler gauge is a tight fit, but for the other I can go all the way to 0.008 and it still withdraws.
The piston shows significant wear on the skirt.

My worst bore is 0.0039 oversize. That's nearly the 0.004 'like new' right there. Ring gaps are all over 0.025.

I'll look into if a 0.030 overbore can be done economically. Pistons & rings add to the price. I may end up going with a "predator" engine when I'm all done.

Thanks again for the manual. Dave