BB mod - worth doing?

[John G.]

Re: BB mod - worth doing?

Joe -

I think I wouldn't bother - here's the result of an amateur clearancing the bottom of a cylinder bore for rod clearance on a 383; bye-bye block.

Just as a point of information: Was the excessive clearance grinding on this block the result of trying to obtain enough clearance for passage of the connecting rod nut? .. Should cap style (bolt only) connecting rods have been used in this application?. Would it have made a difference?

A huge disappointment in losing the block.........but..........can it be saved?

http://www.lincolnelectric.com/knowl...ronpreheat.asp

[Joe C.]

Re: BB mod - worth doing?

Just as a point of information: Was the excessive clearance grinding on this block the result of trying to obtain enough clearance for passage of the connecting rod nut? .. Should cap style (bolt only) connecting rods have been used in this application?. Would it have made a difference?

A huge disappointment in losing the block.........but..........can it be saved?

http://www.lincolnelectric.com/knowl...ronpreheat.asp

Yes it would have.
Many aftermarket manufacturers go a step further than this. They offer CR's (called "stroker" rods) with specially designed shoulders for the cap screws, which cause even less interference with the crankshaft webs in the block. Some clearancing is sometimes still needed, but nowhere NEAR the amount shown in John's reference photo!!!!

[Chris E.]

Re: BB mod - worth doing?

However, I've never seen a PV include an idle vacuum check.

I was wondering the same thing......

[Duke W.]

Re: BB mod - worth doing?

the best improvement to a 427 engine is to install a 454 rotating assy as the .250 longer stroke makes for a lot more torque.

Does the aftermarket offer an internally balanced 454 crank?

Theoretically, all other things equal, a 454 will pull a little more vacuum at the same idle speed as a 427. Idle vacuum is not measured during PV, but then a good PV judge should be able to tell from engine idle characteristic/quality whether the camshaft is OE or something close in terms of overlap, which is a primary factor in idle characteristic/quality.

Duke

[Clem Z.]

Re: BB mod - worth doing?

Does the aftermarket offer an internally balanced 454 crank?

Theoretically, all other things equal, a 454 will pull a little more vacuum at the same idle speed as a 427. Idle vacuum is not measured during PV, but then a good PV judge should be able to tell from engine idle characteristic/quality whether the camshaft is OE or something close in terms of overlap, which is a primary factor in idle characteristic/quality.

Duke

just add heavy metal to the stock crank and use a 427 damper and flywheel