To rebuild or not to rebuild this old engine?

[TYMinColton]

Hi, again,

Thanks to all of you who have weighed-in on my ford 881 diesel engine rebuild project to this point (spanning a couple of threads). The question that remains is whether it would be worth my time and $$$$ to do the following: Grind the valves, Hone the cylinders (flex, 3-stone), Re-ring the pistons, and put her back together. IMHO, an overhaul is just too expensive, but I'd also hate to throw away good money doing a half-a** job.

Here are the basic facts:
1. Valve grinding. Estimated cost $100-300, depending upon whether valve guides need to be replaced. (reasonable and probably a must given the condition of the valves.)

2. Piston rings. Cost $65. (No brainer.)

3. Cylinders

(Option A). Overhaul. Three different engine shops have recommended reboring and starting over (no surprise ). We're talking like $650 for the overhaul kit, and $80-300 to rebore and clean-up. (Just not an option - too much $$$$. This option = scrap-heap or possibly a buyer.)

(Option B). Hone the cylinders (possibly Sunnen) and/or clean with flex hone or three-stone hone. (cheap, but a solution?)

Seriously, do I have any chance of getting away with honing, re-ringing, grinding the valves and putting her back together? Given that this will probably cost me $200-300 I'd like some idea of my odds here . . . . clearly these high compression engines are really finicky . . . and the last thing I need is to spend a bunch of cash and still have an engine that won't run .

Thanks again for your opinions and suggestions - it's been a really hard decision to make and it's starting to keep me up at night
- Pete

 

[Soundguy]

If you can hone and still be in tolerance, and get the valves cleaned up.. go for it.. it will be cheap.. and as you said.. it's eaither that, scrap it or sell it right.

lots of people do 'quickie' "upper" or "lower" rebuilds.. IE.. valve job and rings.. or just slipping in new bearing shells.. etc... to get buy..

All depends on just how bad she is.. etc.

You already know you won't get the full benefit as from a full rebuild.. nor the price tag either. The labor, and time of the rebuild is what is at risk of being 'wasted'

soundguy

 

[Kernopelli]

I missed your earlier posts but have you checked the cylinders for out-of-round and gouges? That would be my deciding factor on honing to an oversize. If they aren't too bad, I don't know why cleaning them up wouldn't be fine. I have done this before on an old 2 cylinder engine using my drill press and a Sunnen hone w/ fine stones. I borrowed a ball type flex hone and cross hatched it to finish it up and was able to keep everything within the upper end of standard specs. I purchased .010 rings and filed them down to get correct ring gap. Ground the valves myself the old fashion way...takes awhile but it's cheap. Worked out great and the satisfaction of doing it myself was more than worth it.

 

[TYMinColton]

I missed your earlier posts but have you checked the cylinders for out-of-round and gouges?

Cylinders don't appear to have any obvious gouges (and no ridge), but I haven't checked yet for out of roundness. Can I do this with a cheap micrometer?

I have done this before on an old 2 cylinder engine using my drill press and a Sunnen hone w/ fine stones. I borrowed a ball type flex hone and cross hatched it to finish it up and was able to keep everything within the upper end of standard specs.

-Sunnen hone has been recommended several times, but now I'm beginning to realize that this isn't necessarily referring to the "machine" itself that hones ($$$$ can't rent), but rather to the hone itself. Need to do a little more research to find out where to rent/buy one.

I purchased .010 rings and filed them down to get correct ring gap.

My engine was overhauled to .02 oversized. I know I can buy a set of .03 oversized rings. Sounds like you're suggesting that I could just buy oversized, place them in the cylinder, measure the gap, and file them down to spec? If I've got this right, really good idea! If not, still probably a good idea, but I need more info .

Ground the valves myself the old fashion way...takes awhile but it's cheap.

How? Angle grinder in a vice? Lathe? I've seen this done with a proper machine, but never "the old fashion way". Is there an easy way to check to see whether the valves are seating properly?

Worked out great and the satisfaction of doing it myself was more than worth it.

I really like the way you operate - my kind of guy.
Thanks a ton
Pete

 

[Kernopelli]

Cylinders don't appear to have any obvious gouges (and no ridge), but I haven't checked yet for out of roundness. Can I do this with a cheap micrometer?


-Sunnen hone has been recommended several times, but now I'm beginning to realize that this isn't necessarily referring to the "machine" itself that hones ($$$$ can't rent), but rather to the hone itself. Need to do a little more research to find out where to rent/buy one.


My engine was overhauled to .02 oversized. I know I can buy a set of .03 oversized rings. Sounds like you're suggesting that I could just buy oversized, place them in the cylinder, measure the gap, and file them down to spec? If I've got this right, really good idea! If not, still probably a good idea, but I need more info .


How? Angle grinder in a vice? Lathe? I've seen this done with a proper machine, but never "the old fashion way". Is there an easy way to check to see whether the valves are seating properly?


I really like the way you operate - my kind of guy.
Thanks a ton
Pete

To check the roundness, you really need a bore gauge to get accurate figures.

Yes, Sunnen makes machines but the hone I am referring to was a 2 stone set up. The stones are changeable with varying grit and the hone can expand and lock to a specific diameter. Available used on ebay if you can't find one and a little pricey new.

Yes on buying .030 rings and filing them down to correct gap.

Grinding the valves I used lapping compound and a suction cup style tool($3-$4). You hold the top of the valve with the "suction cup on a handle" and put compound between the valve and the seat. I put the end of the tool in a cordless drill instead of rolling it between my hands to spin it. I just ground and ground (and ground)! until I felt certain I had a uniform seat. Extremely "shade tree mechanic" level stuff but it worked very well.

 

[RobJ]

That one valve seat looks a little rough, might or might not clean up. Clover Compound in the green cans is what's used.

I'd rebuild what you have considering the age of the tractor. Then keep the PM up on it real good. It looks like its missed some in its lifetime.

Rob

 

[Soundguy]

Daryl beat me to it.. but yeah.. hand lapping.. usually gets the seat and valve fairly decent.. and is great for your forearms!

soundguy

 

[TYMinColton]

Daryl beat me to it.. but yeah.. hand lapping.. usually gets the seat and valve fairly decent.. and is great for your forearms!

soundguy

You guys are too funny! I've actually been looking for a good forearm workout - all this running around lately . Already have one of those suction cup lappy thingys (and a cordless ), so should be good to go.

Working on tracking down a cylinder gauge and then a Sunnen hone to rent. Sounds like these will be next steps for her road to recovery.

Daryl,

Extremely "shade tree mechanic" level stuff but it worked very well. [Quote/]
This may sound stupid, but about 4 months ago I was actually trying to sell this ford tractor to guy named "bud" who had an e-mail address with "shadetreemechanic" in the name. Too weird, or ironic, or something. Not an expression I've heard. He was apparently into rebuilding old tractors and wanted a diesel from the 01 series. Needless to say he never got back to me . . . would have been his for $500.

Thanks again Fellas your insights are very much appreciated.
Pete

 

[Kernopelli]

[Quote/]
This may sound stupid, but about 4 months ago I was actually trying to sell this ford tractor to guy named "bud" who had an e-mail address with "shadetreemechanic" in the name. Too weird, or ironic, or something. Not an expression I've heard. [/QUOTE]

Growing up in S. Illinois, I wish I had a dollar for every time I saw someone with their old beater parked under a tree in the yard working on it. The more affluent in town had a big oak tree with a good limb that was parallel to the ground...they would hook a come-along to it and pull engines. I was probably 18 yrs old before I saw a cherry picker or gantry crane, heck...a chain hoist for that matter.
Makes me smile/warm fuzzies just thinking about it.

Back to valve grinding. One trick I have used is to shine a light either under or over the valve and look from the other side. If you can see light any place between the valve and the seat.....get busy pumping up those forearms.

 

[Soundguy]

I just rebuilt the hyd cover in my 660 after blowing a couple orings out.. I used a 12v wench witht he cable thrown over a barn rafter to help pull the cover.. I installed eye bolts into the seat bolt holes to lif tit... Not quite 'swinging from a tree' but close..

soundguy