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steelcomp was here
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26,526 Posts
Discussion Starter #1
502 gen6, 1071, GM crank, ~10-12# boost, yada yada.
Comments?





 

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!%@#$
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508 Posts
looks good. possibly a season or two on the bearings.
Mag and polish the crank, new bearings and oil pump and enjoy the summer.

But there are no pics of the bore, rings, and piston tops. If they look the same than you might be all good.

Question, what are the limits of a GM crank, when I built my engine I was planning on 10-12lbs boost and was told I must buy a good crank. Ended up with 13lbs boost and each rebuild it checks out good.
 

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steelcomp was here
Joined
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26,526 Posts
Discussion Starter #6
looks good. possibly a season or two on the bearings.
Mag and polish the crank, new bearings and oil pump and enjoy the summer.

But there are no pics of the bore, rings, and piston tops. If they look the same than you might be all good.

Question, what are the limits of a GM crank, when I built my engine I was planning on 10-12lbs boost and was told I must buy a good crank. Ended up with 13lbs boost and each rebuild it checks out good.
Actually there's not supposed to be more than four or five hours of run time since a new set of rings and bearings.
Bore is glazed...rings never sealed evident by the amount of oil in the intake ports and intake. Cam was also in at 108*.



Tune up was self explanitory. Tops of the pistons have way too much carbon for a blower engine with this few hours on it.



I don't know what to expect from stock GM forged cranks. Someone spent a little time on this one deburring and blending some sharp edges. It's ground .011 under, and within .0003 all the way around.
 

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just a ski boat with bark
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2,811 Posts
What are the mounts attached to the inside of the valley for?



Darrell.

For the two extra head bolts or studs on each head that help clamp the head gasket on that long open stretch on those 2 cylinders on a factory BBC.
 
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