Shortened crankshaft

W

WFOorBUST

Member
I had noticed a hand full of stickers with just a nut holding the flywheel on and does not have the 2 or so inches hanging out like on others. Do they cut the cranks down now or is that an aftermarket crank?
 
new style cranks all that way. old style a few get cut off. Have to mount pull cranker on engine with new style.
 
I use a hack saw then use a bench grinder to put a nice finish to it. I use 5/8-18 Grade 8 nuts for starter nuts. Been doing it for years with no issue at all.
 
WFOorBUST said:
And that's legal in stock classes.
Click to expand...

I'd have to check the wka book but I don't believe the starter nut is a tech item.. I've never had anyone say anything about it at the two tracks where we races. Maybe someone else has a manual handy and can confirm that.. Not sure where mine is lol
 
Years ago we always cut the end of the crank almost flush to the threaded end for modified classes.The reason was with the end being short it was less likely to be snapped of in case of a side impact collision.Keep in mind the nerf bars were on little short bars and side panels weren't used at that time.The shafts have been cut short to accept the pull starter for nearly 20 years or more now.
 
Yea, we've cut them short for probably 20 years now as well. I use a band saw and cut it right at the end of the threads. I just cut a crank short in a customer rebuild this week. Use a 15/16" socket on your elec. starter. Much lighter (and closer balanced) than sticking that extended starter nut on the end of the crank.


-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cuts
www.CarlsonMotorsports.com
Celebrating 25 years of service to the karting industry
765-339-4407
bcarlson@CarlsonMotorsports.com
 
We cut off most of our cranks also but we did dyno test an engine with the starter ratchet on, left the engine on the dyno, cut the crank off, installed a nut versus the ratchet, redynoed the engine with the same identical results. That engine was not affected at all with the ratchet removed. I'll admit I was sure it would make a difference but that shows I didn't have a clue.
 
luckie, did you pull down on your runs, or use an acceleration dyno? Just curious.

For small plate stuff and momentum tracks, I've found the extra weight on the flywheel (heavy flywheel as well) helped kinetic energy. For sprint tracks and tight cornered ovals where you are lifting, the lighter flywheel combination worked better. We also tested this with a variety of clutches back in the day when the push for small lightweight clutches was the in thing.

For all the difference it made, my own personal engines all have the cranks cut short for elec start. The convenience is worth it to me. :)
 
Carrying an electric start for a stock flathead, that must be a mini lite because the ol colman I have is no where near convenient vs a puller.
 
Mini lite is the only way to go lol I start all mine with an electric starter while everyone else on the grid sits there and pulls and pulls!
 
When you are a old man like I am you don't want to do any hand Cranking, I didn't want too when I was younger either! Good Heart Attack FUEL.
 
Let's no try to split hairs. It doesn't make a durned bit of difference whether or not the hand crank or exterior starter is used.
Get it started and race.
 
You must log in or register to reply here.
Back
Top