Obviously a reground crank is not as "good" as an original just as a line-bored case is not as good as a new one...but how much is too much? I've been told any more than 40-over on the case is too much for a street motor. How 'bout the crank? Is it as critical to oil pressure and such on the main and rod journals as cutting the case is? I noticed no-one (retailer) sells any more than 20-under cranks, so maybe that is an indication. Just curious what negative impacts a reground crank offers.
-Cosmo
Re-ground crank question
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britegreenVWSB
- Posts: 637
- Joined: Thu Apr 11, 2002 1:01 am
Re-ground crank question
A second under crank will give just as good a life as an unground crank. When you get to the 3rd cut you are getting into "grey" area, and anything more than this the crank would make a nice center piece on your coffee table. If I was in a pinch I'd use a .040" undersized crank in a stock motor, but never in any performance application. Does the phrase "rubber crankshaft" mean anything to you? =)
TG
TG
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PEPPE
- Posts: 763
- Joined: Tue Jun 12, 2001 12:01 am
Re-ground crank question
i've seen that 0.10 under give the same service as new or STD
0.20 is good for a mild engine, and it shows about 10-20% more wear than STD or 0.10.
0.30 and over last about the half.
it is common for a STD or 0.10 under cranks to outlive 2 sets of bearings, over that the bearings lasts as the crank.
I use 0.30 and down for stock low power engines or for "want o be cheap" people helping this with bigger oil pumps
Peppe
0.20 is good for a mild engine, and it shows about 10-20% more wear than STD or 0.10.
0.30 and over last about the half.
it is common for a STD or 0.10 under cranks to outlive 2 sets of bearings, over that the bearings lasts as the crank.
I use 0.30 and down for stock low power engines or for "want o be cheap" people helping this with bigger oil pumps
Peppe