2N engine evaluation: no sleeves!

Got the engine up on a stand yesterday and started measuring things. The crankshaft is stamped .010, the journals are smooth and it plastigages .002 to .003. The camshaft looks like new. That's the good part.

But wait...there are NO SLEEVES at all in this engine. The pistons were running in the bare block. I'm not sure how big a problem this is.

More information: the pistons are 3.265 diameter (.080 oversize?) They have 4 rings and they have a dome shape on top.

The bores measure 3.271 to 3.272 at the bottom and 3.276 to 3.280 at the top. So I'm looking at .002 to .004 out of round and .005 to .007 taper. MARGINAL according to my FO-4.

My question:I'm on a real tight budget, can I get by with just a hone and re-ring...or do I need to get the block bored out for .090 sleeves and new pistons?

some people wanted to cheat a few CI out and pull sleeves and run OS pistons bare inthe block.

depends on actual conditions if you can re-ring and go.. etc..

Gussy........many early thin sleeve 9N-2N's had their sheetmetal sleeves pulled so they could run 1940 Mercury pistons for more horsepower. Unfortunately, the "cure" is NEW CASTIRON sleeves and pistons. Yes, you will haffta "bore" yer block; this is a common engine machine shop procedure. Castiron wears better for chrome rings. BTW, Ford specs: 90-psi min (dry) NEW rebuilt engine is about 125-psi. ........Dell

If money is a consideration, I would run the engine as-is unless there is a problem such as burning oil or low power capability......It is not clear what operating history is.

(quoted from post at 16:07:57 11/30/12) Got the engine up on a stand yesterday and started measuring things. The crankshaft is stamped .010, the journals are smooth and it plastigages .002 to .003. The camshaft looks like new. That's the good part.

But wait...there are NO SLEEVES at all in this engine. The pistons were running in the bare block. I'm not sure how big a problem this is.

More information: the pistons are 3.265 diameter (.080 oversize?) They have 4 rings and they have a dome shape on top.

The bores measure 3.271 to 3.272 at the bottom and 3.276 to 3.280 at the top. So I'm looking at .002 to .004 out of round and .005 to .007 taper. MARGINAL according to my FO-4.

My question:I'm on a real tight budget, can I get by with just a hone and re-ring...or do I need to get the block bored out for .090 sleeves and new pistons?

Click to expand...

A set of sleeves, rings, and pistons is $160 - pretty modest in my book. The bigger question is the cost to rebore the block and the prices quoted on here vary substantially. I would figure a MINIMUM of $25 per hole and that may be optimistic depending on your location.

I've been on "real tight budgets" or so I thought when I was younger and I have honed and knurled, and re-ringed a few engines to avoid paying the price for boring and new parts. Never seemed to last real long or run real good and I usually wound up doing it over and doing it "right" in short order.

I'm sure that makes you feel real good but I'm afraid it's pretty accurate given your numbers which I don't think even make the MARGINAL threshold. It is a low RPM, low compression, low power flathead so it will run longer with things looser than most but it's a short term stop gap at best. How long before you are off your very tight budget and flush enough to bore and sleeve it and how long can you expect it to hold together without boring and sleeves. Are all you looking for is enough to get you through to summer or does it have to go a couple years? What situation is it going to leave you in if it craps in a 3-4 months? That would seem to be the question because if you are really using it it WILL need to be bored and sleeved in the not too distant future.

TOH

My question:I'm on a real tight budget, can I get by with just a hone and re-ring...or do I need to get the block bored out for .090 sleeves and new pistons?

Click to expand...

My first question would be why did you take it apart ? Was is smoking / using oil ?

Second question would be what do you plan to do with it ?

Technically you can rering it but it is on the edge of the scale . Hastings claims .012 tapper but I hate to think of the rings expanding and contracting that much on each stroke . If you are selling it or don't plan on using it much , you might get out cheap .

Usable oversized pistons can be sold to help recoup some of the cost . I have custom bored blocks to tightly fit used oversized pistons .

Weakest link in my opinion is the oil pump , spend the money to get it rebuilt tightly .

Ken:
I got this tractor from an estate. I saw the PO bushhogging with it a few times 20+ years ago, it seemed to have plenty of power and it certainly wasn't smoking. (I didn't get a chance to observe the oil pressure) Winter of '92, the PO parked it in a shed on his place...the following spring it wouldn't run, so he just walked away and there it sat until I pulled it out of the shed and opened up the engine.
I found one of the exhaust valves was firmly stuck open...no doubt the cause of the twenty-years-ago troubles.
I'll use this tractor to mow a 50'x 2000' strip in our pasture...maybe 6 times per year.

Gustafson what do you have for a airplane? iam flying a champ out of a 1000 ft srip hear. thanks bob

TOH:
Thanks for the opinion, that's exactly the kind of feedback I'm looking for.

Interesting, isn't it, when we're younger we live on a "tight budget", in middle age the money seems to flow more easily, then we get older and find ourselves, AGAIN, back on a strict budget...But I suppose that's just the cycle of life.

Anyway, of course, I'd like to do a first class overhaul, but this tractor project is being financed by retirement savings and whatever I can squeek out of my social security check. And that means I'm not going to be able to do everything perfectly, I'll have to cut some cornors somewhere. So I'd sure value your opinion on how to proceed in this situation.

The wife tells me I can spend $700 on this thing. So I guess a better question would be: what's the most I can do for $700?

Hi Bob:
It's a 1947 Taylorcraft BC12-D. Bought it wrecked in '04, rebuilt it over 8 year period.

1000' strip sounds a little snug even for a champ. But great fun I'm sure!

(quoted from post at 11:46:11 12/01/12) TOH:
Thanks for the opinion, that's exactly the kind of feedback I'm looking for.

Interesting, isn't it, when we're younger we live on a "tight budget", in middle age the money seems to flow more easily, then we get older and find ourselves, AGAIN, back on a strict budget...But I suppose that's just the cycle of life.

Anyway, of course, I'd like to do a first class overhaul, but this tractor project is being financed by retirement savings and whatever I can squeek out of my social security check. And that means I'm not going to be able to do everything perfectly, I'll have to cut some cornors somewhere. So I'd sure value your opinion on how to proceed in this situation.

The wife tells me I can spend $700 on this thing. So I guess a better question would be: what's the most I can do for $700?

Click to expand...

I wouldn't call $700 shoestring tight ;-) But given your description of your budget and intended use I'd start by freeing it up, slap a fresh set of rings in it, bolt it back together, change the fluids and take it out for a test run. If it will pull and spin the mower you need for your airstrip I'd call it good to go for the time being and move on.

If it lacks power or makes worrisome noises that you can reliably identify as piston related then pull the engine and resleeve it:

Sleeve and piston kit - $160.
Boring - 4@500 - $200.
Miscellaneous bits - $140.

That's $500. If that $700 budget isn't coming out of the grand kid's lunch money you might just skip the first phase, speed past GO, and deposit $500 in the tractor. All of that presumes the lower end is not in need of attention which you really won't know for sure until you get it started.

TOH