Large journal crank

[neal1980]

Does anyone know if its possible to machine a large journal 4.6 crank in to a small journal 3.9 block?

I have 4.6 internals lying around and small journal stuff seems quite rare to find..

Cheers

[chassis 33]

Yes it is, the other option is to bore out the 3.9 journals to take the larger setup, however I think this is only possible on the "intermediate" blocks, which have the bosses for cross bolting but aren't actually cross bolted. However I might be talking out of my arse on that last point.

Best bet is to speak to your preferred engine expert, John Eales, V8D, RPi etc etc

Regards
Iain

[cre]

Hi,

Your block can be bored on the main line to take a large journal crank without problems.

Jamie

[chassis 33]

Oops, yes, Jamie is another who will give you the answers you need!!! Sorry Jamie!!!

Regards
Iain

[boosted Ls1]

cre said:

Hi,

Your block can be bored on the main line to take a large journal crank without problems.

Jamie

Probably a fair bit cheaper to bore then to grind. That said there may be more likely hood of error and screwing the block up. You'll also have to mill in bearing location slots unless you use pins.

Boosted.