Speedracer

Greetings,

Two questions

1. If you were to repair a crank with a spun #5 bearing, who would you use?

2. Does anyone have a used std/std 3.2 or 3.3 crank that they would be willing to sell?

Thanks
GG

turbobrat930

armundo at CCR ( custom crankshaft repair) he is in CA.... The only one I would trust.

schnele

Why risk such an important part, a new one is less than a rebuild if the repaired one fails.

Bruce Eyring

I agree about Armando at CCR. He did my crank in August of 2003 and 110,000 miles latter it's just perfect. Mine is a 1988 930....spun a rod bearing...result of using synthetic oil...now 110,000 miles on Armando's crank thanks to Castrol 20-50 regular old oil. Last phone I had for Armando was 650.364.1747 and address was 650 Broadway Unit #4 Redwood City, Cal. 94063. If this is wrong...Jerry Wood would probably know.

purplehaze.

Armando just did mine after a spun bearing. Phenomenal guy!

I believe if it was your #5, that means oil starvation. Talk with him about why and potential solutions.

I also went down to 2" Nascar bearings, additional oil passage in the center main journal....

New address:

Armando Ayala
Custom Crank Repair CCR
612 South Railroad Ave
San Mateo, CA
94401
650-364-1747

Good luck!

Glenn

Matt O.

Whoa. Spun bearing because of synthetic? Is that fact or opinion or anger or what? This is the first I've heard NOT to use synthetic on a Porsche engine (besides the whole miles/leaking issue).

Please elaborate.

-Matt

jim dorociak

Armando did a crankshaft for me, he is slow, but crank was better than new. Jim

timc1018

Are there issues with the #5? Or could it be low oil, trash in oil, high temps, abusive driving, or other user related issues. Never heard of any design problems relating to the Rod Bearings in these engines.

Tim

purplehaze.

It was the #3 rod bearing for me. Basically, the first one in the flow of oil from the pump, from the rear of the crank to the front. When trash gets in, it hits that first rod, then goes to the next one forward. Damage is worse on the first impacted one, as the trash was there longest.

I'm not fully sure why the #5 one means starvation, but others here can tell you - as well as Armando. I believe that's why he (and many others) suggest an additional oil hole in the crank in the middle main journal. I even had my middle main bearing slotted, thanks to Bill Rudtner.

"Normal" driving with these cars can yield several hundred thousand miles on stock rod bearings. Given the oil is changed, kept cool, at the proper levels, etc.

I track my car, but nothing over 6800-7000 rpm. Several race shops recommend replacing the rod bearings every 40 hours when running high rpms. You try and "catch" them when they start to wear, before they spin. That frequency can drop down to 60, then 80 based on rpm's and oil temp. There are several posts that discuss it (See the one on 2" Nascar bearings in Pelican's Engine Rebuilding Forum).

Glenn

AngM018

You can no longer buy 930 cranks new.

I had some scratches that they couldnt polish out. I did it through EBS who shipped it out to someone else. I was told it would be ok for a street car with little racing, but if it was a racing application then it wouldnt last long. Basically they welded, polished, then re-balanced it.

You may also want to consider a 964 crank. not sure what all it will take, but people on here would be able to tell you.

Geoffrey

If the engine is not revved past 7000rpm, then there is not an oiling issue on #2 and #5 rod bearings and the crankshaft does not need to be cross drilled, even in a track environment. Above that, and the older cranks may have oiling issues and the common solution is to cross drill the center main bearing to allow additional oiling to #2 and #5.

Glenn, there is a problem with factory bearings, we have experienced premature wear and no longer use them. There are a better race bearing available in the same size as stock as well as slightly over or under to allow you to blueprint the clearances and provide for different specifications, especially if it is a racing engine. They cost 2x stock bearings, but I'll never use stock bearings again.

purplehaze.

Geoffrey,

Good to know. Thanks.

I did look into the better bearings you mentioned (Smart Racing Products). Unfortunately they were not available for the 3.3, just the 3.2 and 3.6. I would have bought them. Too many posts about inferior stock bearings to use them again.

Bruce Eyring

talk to some of the old timers that have been around 930's forever...they'll tell you not to use synthetic...they told me that too...but of course I knew more than they did...and a turned rod insert was the result.. but..since most 930's are driven only a couple of thousand miles a year because they've been screwed with so much...or "performance enhanced" or "performance upgraded" to a dead stop...and synthetic oil in a 930 engine is part of coming to a dead stop. Who do you want to believe..a guy who goes 2000 miles a year...50% of that on a tow truck...or someone who drives a 930 20,000 miles a year...year after year.?

AngM018

Now having a 930 that grew up on Castrol, I have had to put a stop to it. A LOT of oils out there now have upgraded so much that they will destroy these old engines before they do their lubricating duties. I now ship in Brad Penn, and if I cant get my hands on it in time, I have a case of Diesel oil (rotax) sitting on the shelf. Even then I make my own special blend...

Geoffrey

Glenn, some of the information you have doesn't make sense. The 3.2 Carrera, 3.3 Turbo, and 3.6 964 all have the same size crankshaft journals where the rod bearing journal should be 54.971 - 54.990mm.