Author Topic: clearancing for 5 mil crank (Read 4175 times)

31aford · « **on:** February 22, 2014, 03:49:57 PM »

Do I need to clearance the upper crankcase for 5 mil stoked rod clearance?

C-Leigh Racing · « **Reply #1 on:** February 22, 2014, 04:47:49 PM »

Oh yes, specially with a non clearanced rod big end. You'll need to trench them as well.
Now if the rod would have been one of the Pro-x clearanced rods from ESR, you could get away with just a lite clean up on the trenching, but work would still need to be done in the upper part of the cases to clear the top part of the rod.
Even a + 4 ESR crank with the clearanced rod, the top part of the cases need clearanced.
Easy way to see how much, take the crank & a right side case & slip the crank in, then put an old piston on & old cylinder just so the rod will run up & down the center, then you can see how much needs to be removed.
You might not be able to do this though with the + 5 & unclearanced rod.
Looking at those two pics, I'm guessing you cant rotate the crank ??.
Neil

31aford · « **Reply #2 on:** February 22, 2014, 04:55:45 PM »

That is with the old crank in the case. The new crank is from esr.

udontknowme · « **Reply #3 on:** February 23, 2014, 10:49:25 AM »

ya put the crank in each half with the cylinder and piston then rotate it to see where the clearance issues are. you dont need much. i would think .020" is plenty but thats your call. if you can get your desired clearance all from the trench and still have sufficient meat in that area then you can leave the rod untouched. i prefer to leave the rod at full thickness but thats just me

if alot of material needs to be removed youll want a experienced machine shop to do it. if theres just a couple high spots you can do it with hand tools like a dremel

C-Leigh Racing · « **Reply #4 on:** February 24, 2014, 12:41:37 PM »

Ok, the ESR stroker cranks, suppose to have a clearanced rod, but even with those you'll have to dress up the top part of the cases. Shouldnt need to trench the cases though.
Neil

31aford · « **Reply #5 on:** February 24, 2014, 10:09:22 PM »

Got the crank in just had to clearance a small amount on the top corners. Should be dune ready in a couple weeks. Thanks for the tip on inserting crank with cylinder and old piston.

udontknowme · « **Reply #6 on:** February 24, 2014, 11:19:36 PM »

did ya get all them metals shavings in the bearings :chuncky: