Repalcement parts for a rebuild

[scoll911]

I'm rebuilding an engine which has about 1,400 miles. I reviewed the list of parts to be replaced in the engine rebuild book. Considering the engine was rebuilt 1,400 miles ago, do I need to replace all of parts on the list? Obviously I will replace all gaskets, but what about rod bolts and some of the othe hardware?

P.S., I rebuilding because it looks like a rod bearing is bad

[Jim Sims]

Rod bolts are a one time use item (the torque specified takes them into the plastic range); they can only safely be tightened once. Keep the old rod bolts to check your bearing clearances with plasti-gage. Also the flywheel to crankshaft mounting screws are one time use items. In addition, if you pull out the oil pump I'd replace the nut locking tabs. Cheers, Jim

[snowman]

Rod bearings do not go bad for no reason at 1,400 miles.

Try to find out WHY that rod bearing went bad. A lot of grit? maybe someone bead blasted the case? Check the crank throw dimensions very carfully. IF there is damage to the surface of the crank it might need to be reground and re tuftrited. Check the oil clearence using plasti-guage.

All I can suggest is if you do not find a reason keep looking. There MUST be a reason. If after you look at everything and you do not find a reason check back in this forum and tell us what you did find or not. Maybe someone can suggest where to look next. There is NO black magic here. It may come down to not finding a definite answer. If it does, then you must do everything, I mean everything possible to check everything on reassembly. These steps can be outlined if you do not find anything.

[scoll911]

Before the first rebuild the engine was in pretty bad shape. I had to replace the crank and P/Cs, I guessing there must have been some grit left in the oil lines some how. The case was not bead blasted, I took everything to a very good porsche machine shop in CA.

Speaking of machine shops -- Does anyone know of a good machine shop in Albuquerque?

[snowman]

One thing the machine shops do NOT do is clean. You must thoroughly clean anything they do, brush, brush and clean clean and clean again. Use Tide (I don't know why its just what the experts say) and hot water for the final cleaning.

[ChrisBennet]

I just want to add to the good advice Jack gave you.
If the previous failure broke up the rod bearing, those bits could end up anywhere just waiting to come loose and plug an oil passage. Whenever a motor "blows up" you need to clean the whole oil system. BTDT. This involves sending the oil coolers out for ultrasonic cleaning, cleaning the oil lines and thermostats and removing the oil gallery plugs and cleaning the inside of the case. It's a huge job.

Having bought a "perfect" crank that was far from perfect, I now trust no one and measure everything myself.

The sort of troubles you are experiencing are why I came to this conclusion:
"I don't think of it as experience so much as accumulated remorse."
good luck,
Chris

[Doug Zielke]

Originally posted by snowman
One thing the machine shops do NOT do is clean. You must thoroughly clean anything they do.....

Except, perhaps, Competition Engineering.
Everything they sent me back, was perfectly clean, properly packaged, and obviously handled with great care and attention.

[Wayne 962]

Machine shops clean, but as I stated in the book, you need to keep cleaning even more. The chemical wash that Walt (Competition Engineering) did on my case was good, but there was still a lot of grit and grime left in there. Lack of cleaning is probably the number one contributor to engine oil leaks and eventual failure...

-Wayne

[snowman]

I second that.