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Engine basics => Engine set up tips => Topic started by: Annette Elmore on November 01, 2006, 03:44:59 AM

Title: Bushing conrods!
Post by: Annette Elmore on November 01, 2006, 03:44:59 AM

Anyone give me advice in bushing conrods - I've just bought a Unimat lathe/mill and wonder whether it can do the job?

I'm going to use it for making muffler adaptors and venturis - but my flying buddy asked if it'd do for bushing conrods.

Tony

Title: Re: Bushing conrods!
Post by: Jimmy R. Jacobs on November 01, 2006, 09:34:31 AM

  Yes you can , but you will need to build a jig to hold conrods . Do not try to hold in vise.

                                            Jim

Title: Re: Bushing conrods!
Post by: phil c on November 02, 2006, 06:44:31 AM

Be prepared to experiment with the fit in the rod and the fit on the crankpin.  Both have to be right.  The ideal way to do it is to calculate the hoop stress in the part when an oversized bushing is pressed in.  It's easy, in these small sizes, to press in a bushing that almost tears the big end apart, so it is just waiting to break in use.

I only did this once on a major engine redesign.  Ended up fitting the crankpin too tight and the bushing eventually spun in the rod. 

Title: Re: Bushing conrods!
Post by: Dave Rolley on November 02, 2006, 09:05:05 AM

It might be easier to make a new rod from scratch using a modern metal like 7068 aluminum.

http://www.go-cl.se/dye-rods.html

Dave