I’ve done some searching on this but came up with very little good information…

What is common practice when it comes to lightening a Honda crank (namely the TypeR crank)?

As I understand a full out knife edge can reduce reliability; however I also read that removing 4-5lbs can be done without concern (assuming everything is done right).

What are people’s thoughts/experiences with this?

Thanks,
Doug

 

i did one for my last engine. put 4100 miles on it this last season with no problems. weighed 34.195 lbs stock and 29.4 lbs when i was done.
obviously magnaflux it and check for straightness before you spend your time doing all this.
balanced, tapped, cleaned and plugged oil holes, heat-treated and micro-polished.
this is a 89mm crankshaft.

 

does it rev higher or faster??

 

yah it revved pretty freely.

 

where did you send the crank out to?
what was their cost?

 

i did the lightening myself. a local machine shop balanced it for me for $75, and i had it heat-treated at another local place for $50.

 

i know castello/kms and a few others also offer this service
the heat treatment is a must right?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lohatch &raquo;</TD></TR><TR><TD CLASS="quote">i did one for my last engine. put 4100 miles on it this last season with no problems. weighed 34.195 lbs stock and 29.4 lbs when i was done.
obviously magnaflux it and check for straightness before you spend your time doing all this.
balanced, tapped, cleaned and plugged oil holes, heat-treated and micro-polished.
this is a 89mm crankshaft.






</TD></TR></TABLE>

looks like you do great machine work

 

you just used a regular lathe right?

 

yep

 

i wish i had access to a lathe and alot of other tools and machine equipment.
either way i am wondering do you have to heat treat the crank after you lighten it.
i thought that you compermise the harding process only when when you weld?

 

well you are not heating it above its eutectic temperature when you turn it, so the only other reason i could see for heat treating would be to relieve stress. other than that, it might be a good idea to peen the fillets on the crank, as well as where you machined.