Motor Deconstruction and Assembly Tips, Tricks, and Processes List

[Moto-Mucci]

It seems like every experienced wrencher has their own special tips, tricks, and processes they've found over the years that help the ease of motor reassembly and longevity.

I thought this would be an interesting and informative thread to create for anyone undertaking a rebuild (as I currently am) - mild to massive.

We'll see how this goes. Hopefully we can get a good list going of tips and processes, along with some Do's and Don'ts for people to reference.

Contribute at will and I'll add it. if you disagree with any of them for some reason please post up why.

The List:
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[Kershaw]

i tore down my old block. but it was scrap so i didnt rebuild it.

but for taking apart an engine, its quite easy: just keep removing nuts and bolts.

i had the long block down to the just the block. without pistons, without crank, without anything, etc. in about 1.5 hours.

[jlevie]

After tearing the engine down, measure each cylinder at multiple points looking to see is there is taper or out of round that exceeds spec. Measure each crank journal at multiple points to check for wear that exceeds specs. Understand that these measurements are to be to a tenth of an inch.

If the block passes test, have the cylinders honed and at the least use new rings. It is much better to use use pistons as the ring groves are probably worn. If the crank passes, it needs to be polished before reassembly and the matching bearings used. Correct bearing clearance is 1/10 per inch of journal. The connecting rods need to be rebuilt with new bushings reamed & honed to fit the wrist pins.

The head & valves will certainly need to be ground and new seals installed. New valve guides may be needed and the cam may need to be replaced or brought back into spec. The head may need to be surfaced. If badly worn, the rockers should be replaced. Valve springs need to be tested to see if any are soft and require replacement.

Use new rod and main bearing bolts and new head bolts. DO NOT hot tank the block. Doing so will probably destroy the intermediate shaft bearings, which are NLA. Elbow grease and solvent will get the block clean. Oil passages must be rodded out and blown clean. Use a new oil pump and relief valve.

[Jean]

Intermediate shaft bearings are an m20 thing only correct?

[dirtysix]

Clean clean clean.

[Farbin Kaiber]

I suggest bagging individual components fasteners in labeled zip-loc bags. It will save a ton of time, also I suggest a notebook and schematics/diagrams that work for your specific mindset on the project.

And, label, label, label.

[SpecM]

^ add to that a digital camera. Take pics of every step + record the notes

[Moto-Mucci]

Intermediate shaft bearings aren't NLA. I just picked up a set and had them installed after getting the block hot tanked. I'll try to grab the part number.

But yes, don't hot tank the block unless you have replacment bearings Id say.

[dandrewg]

Here's a good thread on the intermediate shaft bearings, second post down http://www.e30tech.com/forum/showthr...441#post597441 , I just ordered a pair Tuesday

[DTM190]

Dont skimp on assembly lube is my best advice, get the best you can