Engine: CASO dilemma: Rings and bearings vs bore it and new pistons, etc. ?

[garyash]

I keep staring at the '63 OHV 6 block I pulled out of the Wagonaire Standard. The engine has 65,000 miles on it but sat for 20 years. I got it unstuck and took the head off. I found one stuck valve and its pushrod was bent. The valve freed up with some penetrating oil and a few light taps with a mallet. The pushrod is toast, but I have a set of pushrods from another engine.

I checked the cylinder bores. Remarkably, they weren't rusty or scored. They measure about .002" over at the bottom and .007" over at the tops (side to side direction). All the bores were marked for .0005" over initially. The temptation to just put in new rings and bearings is gnawing at me. On the other hand, I have it apart this far and who knows what will be found on the lower end and cam bearings. Should I just ring it myself with new main bearings or go whole hog and haul it to the engine shop? [They speak Studebaker there.] The head needs to go to the shop anyway for crack checking and a full valve job. I'm looking for long-term reliability, not speed.

[63 R2 Hawk]

Back in the "good old days", I "rebuilt" several of my driver Ford & Chevy sb motors with measurably tapered and worn bores. Reamed the ridge, honed & slapped new rings on the original pistons, reground the cranks with new bearings , new cam bearings and put many additional miles on them without problems, no excessive oil consumption or piston slap. In those days I didn't have the money for boring, new pistons, etc, just needed to fix my get-to-work car. Maybe I was just very lucky? I've had more problems with motors that had a complete overhaul by a known quality machine shop- piston slap, oil consumption, etc. I was curious about your bore measurements though, most older motors I've worked on exhibit more wear at the bottom of the bore than at the top?

[gordr]

Gary, I think you want to look at the pistons. The OHV six has a reputation of being hard on pistons. If the ring grooves are badly worn, or the skirts show signs of cracking or having worn undersize, a simple re-ring won't do it.

I have torn down quite a few OHV six engines, and if it turns out that you need a few pistons, I might have some that match. Yours for the postage if you can use them.

[PackardV8]

most older motors I've worked on exhibit more wear at the bottom of the bore than at the top?

That would be a most unusual condition. Because of the pressure of compression and heat of combustion, 99.9% of cylinders are worn three times as much at the very top of ring travel; Gary's .002" at the bottom and .007" at the top is typical. Thus usually the ridge at the top and not at the bottom.

Back in the bad old days, I patched up my share of junk and ran it successfully. Today, not so much.

jack vines

[Jim B PEI]

Please refresh my memory... one year of the OHV is very hard on pistons --63, right?--and another year is much better--64, right?--due to the piston (skirt) design? Or is it the other way around?

[jclary]

Back in the bad old days, I patched up my share of junk and ran it successfully. Today, not so much.

jack vines

I think the statement above is a result of a condition we often find ourselves in our youth...the exuberance of youth coupled with a lack of funds. As we age and build at least a rudimentary bank account, wisdom, and hopefully an ego tempered by experience...we learn to value "peace of mind" over bragging about how cheap we accomplished something.

Better to do a thorough evaluation and rebuild accordingly than to patch it together and have that nagging hunch that you might have missed something.

When I was young, I'd walk or hitch-hike miles to get home for a chain and buddy to drag a broke down vehicle back home to fix it myself. Now...I hate even more, the idea of having to pay a tow-truck the price of a rebuild just to load me up on a roll-back and haul the thing back home.

[SN-60]

To: garyash,---Hi Gary! Don't throw rocks at Me....but how about converting to a sweet little 259? You'll have 'forever' dependability, good gas mileage, and the extra power You might need when Your hauling extra
Straight-Eight engines home for the Indy Car!

[irish]

Gary, I think you want to look at the pistons. The OHV six has a reputation of being hard on pistons. If the ring grooves are badly worn, or the skirts show signs of cracking or having worn undersize, a simple re-ring won't do it.

I have torn down quite a few OHV six engines, and if it turns out that you need a few pistons, I might have some that match. Yours for the postage if you can use them.

I build diesel engines by trade, after you follow the advice quoted above, if everything checks out re-ringing your engine will probably add at least half the mileage it has already traveled (if it's at 65k you should get 40k more without problems). If that's good enough for you then just re-ring it, if it isn't rebore it. Personally considering how most of us drive these cars today I would just re-ring it if the pistons are good.

Joe

[Kdancy]

To me-- if you are planning on selling it down the road, do the job right and put new pistons and rings in it. The next owner will greatly appreciate it!
If it were mine, I'd put a 259 in-----

[JohnM15]

To get to the root of the matter is that you can't decide and wanted our input. Here is my input:

I would sit down with a cup of Joe and write down the tradeoffs:

Your time
Shop cost
Parts cost
Desired reliability
...

Seems to me you will have to pull the lower end bearings to know enough. If your going to pull apart that much, I would do the whole nine yards, or maybe eight yards...

[Bob Andrews]

Gary- remember what you've got. Just being objective, it's not a highly valuable car. And, you're not doing a show car, right?

If I had it, I'd clean the pan, do the head, maybe a timing gear, and be done. You'll still hit the important goals, same as a full rebuild- saved, driving, usable.

Of course, knowing you I would have assumed you would be doing an all-out show build, but seeing that you asked, I say go econo. Or is that CASO??

[(S)]

We overhauled a 259 once the cheap way it had .004 and .005. on the two largest cylinders. By the time we honed it we figured it lost another .001 or .002 so it was pushing .007 the outer limit according to the shop manual.

The engine looks beautiful, every nut and bolt detailed, and everything is new - it has been several years now-- the engine does'nt even leak oil. When I hit the key it turns over and starts the second revolution! It runs like a scared, SMOKING, jackrabbit.

I'll never recomend this, and never do it again in my shop.