372/385 Hybrid

[wcorey]

This was homelite410 idea as well. I may end up there ...who knows. ..

Sorry to side track your build…

If your thinking 390 crank then maybe the more practical answer is to stroke the 372 crank, as you do have a mill to do it.

The 12-13mm wrist pin issue should be easy to resolve with adapter caps/bushings, I could spin you up a pair if needed.

To fit the wider 390 bolt pattern on to the 372 case...
Unless the bolt pattern is big enough from one to the other that there's no overlap, I'd guess that the cases would need to be built up with a bit of welding rather than an adapter plate.
Might result in some added crankcase volume as well.

 

[Mattyo]

Sorry to side track your build…

If your thinking 390 crank then maybe the more practical answer is to stroke the 372 crank, as you do have a mill to do it.



huh? stroke a 372 crank? lengthen it? it would involve splitting it, and welding, not mill .. no?



The 12-13mm wrist pin issue should be easy to resolve with adapter caps/bushings, I could spin you up a pair if needed.


AWESOME... good to know thanks!



To fit the wider 390 bolt pattern on to the 372 case...
Unless the bolt pattern is big enough from one to the other that there's no overlap, I'd guess that the cases would need to be built up with a bit of welding rather than an adapter plate.
Might result in some added crankcase volume as well.

I don't know if the case is AL or Mag... weld to Mag? I dunno... not me though. I'm ok with my mig, but not sure about my ability to weld anything else.

 

[Mattyo]

somehow my comments ended up IN your quote... please have a look inside your quote, my comments should be obvious

 

[Mattyo]

just so everyone doesn't think I've disappeared, I bought some aluminum plate of different thicknesses at the local scrap place, to use as riser plates.

I still need to actually stick the case on the mill and mill it...haven't done that yet, no time plus I need to build a jig to hold it better in the vice. plus I have the CT GTG this weekend sapping all my free time

 

[Mattyo]

Finally had some time to do some milling!

Milled a junk chassis as an experiment

The idea is to put an aftermarket 54mm 046 jug on...because it's the biggest mm jug available the takes a piston with a wrist pin that will fit the 372 crank.

So to accommodate the taller jug...I removed .373



Too tight against the clutch side...I did not have to remove so much material ...among other issues.

I still won't have a seal at the transfer ramps...so I needed to remove enough for an aluminum adapter plate ... .235 ...that is the thickness that I seemed to need. 3/16 or so.



Lots of issues to overcome. I'll evaluate the whole thing soon and post my findings....still might be possible.