Torque specs for 59AB with 8BA crank

B

bosscat28

Member
On a 59AB block with an 8BA crank with insert rod bearings
Should I use torque specs for the 59AB mains 80 - 90 ft/lbs
& 8BA torque specs for the rods? 45-50 ft/lbs

Mains per Mac Van Pelts page
32-48 V8 - 80-90 ft/lbs
49-53 V8 - 95-105 ft/lbs

Rods per Mac
32-48 V8 - 40-45 ft/lbs (self locking)
49-53 V8 - 45-50 ft/lbs
 
I believe main bearing studs are torqued to 80 ft lb, with bolts they're torqued to 100 ft lb
 
On this subject,
Is this a pretty straightforward swap? Any other modifications required? Which oil pump, etc.
Thanks
 
The torque is always for the bolt or stud so it follows the type of block or con rod used and fasteners used for that block or con rod.
 
Last edited:
RalphM said:
On this subject,
Is this a pretty straightforward swap? Any other modifications required? Which oil pump, etc.
Thanks
Click to expand...

Depends on what cam you use. If you use a 59A cam you will have to use a 59A cam drive gear on the front of the 8BA crank. If you use an 8BA camshaft, you will have to convert to the 8BA distributor and timing cover.
 
Thank you,
I know crank/cam gears are different, I would probably stick with the earlier gears. So do the crank bearings need to be 59A style?
 
RalphM said:
Thank you,
I know crank/cam gears are different, I would probably stick with the earlier gears. So do the crank bearings need to be 59A style?
Click to expand...

The mains are the same for both the 59A and 8BA, but the rod bearings are different. The 59A has full floating rod bearings that spin where as the 8BA has insert non spinning bearings (which are what all modern engines use). You have to use the 8BA rods with the 8BA crankshaft too.
 
Brian is correct. Use the bearings originally designed for that particular block no matter what crankshaft.
 
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