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Checking and preparing a remanufactured engine.
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Author:  peeeot [ Mon Oct 06, 2014 2:48 pm ]
Post subject:  Checking and preparing a remanufactured engine.
Hello,

I just purchased a remanufactured 225 to install in place of my Scamp's original engine, which had crankshaft damage to do consuming the #6 rod bearing. The engine that I bought has been in storage for at least 5 years since remanufacture. I am looking for some advice on how to proceed with preparing this engine for installation.

For example, should I remove main bearing caps and rod caps to apply fresh break-in lube? Should I redo the rear main seal? Retorque any bolts?

The work on the engine looks good to me except that the connecting rods are not installed in order. That shouldn't matter, right?

Thanks in advance for your input!
Author:  nuttyprof [ Mon Oct 06, 2014 5:20 pm ]
Post subject: 
The rod caps need to be on the correct rods, as long as they are it shouldn't matter the order. (if the pistons and rod bearings are new)
Author:  nm9stheham [ Tue Oct 07, 2014 5:33 am ]
Post subject: 
I guess my main concerns would be:
1) Rust on any cylinder wall; if not treated for that at the factory, the rust could be extensive. I would put some WD40 in each bore and let it set for a while, so I could rotate the crank OK. Then borrow a borescope and carefully and thoroughly look down in each cylinder for rust.
2) No lube left on bearings. I would pull the pan and rework fresh oil under each bearing cap. See 4 below.
3) Check for cam lube
4) Pre-oiling would be nice but have never myself read any way to do that for a /6. Perhaps one could pressureize light oil through a temp plug in the oil pressure sensor port.
5) Can't think of any need to re-torque anything at this point unless one just wants that for a check.
Author:  peeeot [ Fri Oct 10, 2014 10:15 am ]
Post subject: 
Thank you for your responses so far.

This engine was not fully assembled at purchase; the only gaskets installed are the head gasket and the rear main seal. I don't see a lick of rust anywhere but I have decided to go ahead and disassemble the engine and put fresh lube everywhere. That way I can check things out as well. The engine is not under warranty so it's not like I'm going to void it by going back in.

I plan to use assembly lube on all the bearing surfaces, lifters, and valve stems. I gather that the cylinder walls should have a bare minimum application of light motor oil. I want to use break-in lube on the cam, which is dry (I already removed it and the lifters, which appear to be new).

A couple of questions:

1. The camshaft shares the same markings as the one from the old engine. Its wear surfaces look fresh, but I have to assume it is an original cam. I plan to check the lobe height with a caliper. Is it common practice to reuse camshafts on stock rebuilds? Any reason I should replace it, assuming lobes measure out evenly?

2. I intend to put the rods back in order. Since the engine hasn't been started, that shouldn't be a problem right?

3. I expect to find cast iron rings on the pistons. Would it give me longer engine life to buy a set of chrome rings to install, since the cyls have been machined and honed?
Author:  WagonsRcool [ Fri Oct 10, 2014 8:44 pm ]
Post subject: 
1) If there's no visible wear on the cam lobes AND you're ok with the performance of a stock cam then there's no reason not to reuse it.

2)Assuming that all pistons/bores/connecting rod bearings are the same size then it shouldn't matter which rod is in which cylinder- they're only marked so that each rod cap stays with its rod. (if it'll help you sleep better at night then by all means, put them in order :wink: )

3) I would definitely step up to better rings; moly, chrome, or whatever floats your boat. The cheap "rebuilder" iron rings can/will wear the bore fairly quickly.

I'd also look at the valve stem seals- it likely has the "old school" cheap poly-acrylate umbrella seals that will harden & fail in a couple years. There are better materials & designs available.

Work a small amount of petroleum jelly into the oil pump rotors- this will help them seal & prime during start-up.
Author:  nm9stheham [ Sat Oct 11, 2014 6:39 am ]
Post subject: 
Cam lobe wear-in is pretty easy to spot; there will be varying shiny surfaces across the lobe peak. For a full blown re-man operation, where everthing is pulled apart and parts processed separately, the cam would have to be tossed as there is no way in creation to keep each lifter matched with it particular cam and with the exact same lobe.

Since you are there, check each lifter to be sure there is a convex surface across the cam contact face.

BTW, I only lube bearings (and everthing exepct cylinders, rings and pistons, with synthetic engine oil or a mix of oil and moly break-in lube. Don't put synthetic on the cylinder walls and rings and don't break in the engine with synthetic oil.

Good deal on the no rust; that is very good news. Great suggestion above on the better rings IMO. And you can always swap rods around; the only touchy area would be for a balanced engine where rod&pistons assmeblies are paired. But I would not expect that here.
Author:  DusterIdiot [ Sat Oct 11, 2014 8:59 am ]
Post subject:  Just remember
Quote:
3) I would definitely step up to better rings; moly, chrome, or whatever floats your boat. The cheap "rebuilder" iron rings can/will wear the bore fairly quickly.
Exactly but take into account that if the bores were honed for iron, and you go moly the bores need to be refinished with a finer grit for that style of ring.
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