Crankshaft measurement

smithi created the topic: Crankshaft measurement

Hi all...
Please help me understand how to identify and to measure the crank stroke of a crank that is not installed in a motor. Also there is no markings on crank.
#25812
Attachments:

Please Log in or Create an account to join the conversation.

Hot Rods replied the topic: Crankshaft measurement

That appears to be a CY full circle stuffed crank. An easy way to tell the stroke is to use a caliper to measure from the edge of the rod big end pin ( nearest the shaft ) to the edge of the shaft diameter ( not on any radius at the counterweight ). If that measures .120", that is a stock 28mm. stroke. If it measures .140", that is +1mm ( 29 mm. ) stroke. If it measures .160", that is +2mm ( 30mm. ) stroke. These measurements are very close approximations, as it's difficult to tell the exact edge of the rod pin. The metric measurement would be 3, 3.5, and 4mm respectively.
#25813

Please Log in or Create an account to join the conversation.

Jd267 replied the topic: Crankshaft measurement

Can you explain this a little better I'm trying to figure the stroke of a tiger king crank I have that is either 28.6mm or 28.8mm , in my 290 with stock base gasket I have 15 thousandths . I don't think the crank is 28.6mm stroke
#25879

Please Log in or Create an account to join the conversation.

Hot Rods replied the topic: Crankshaft measurement

Using a dial caliper, measure from the outside of the shaft ( nearest the rod ) to the center point of the rod pin, and add 6mm ( half the shaft diameter = .2362" ). Take that total and multiply by 2. That is your stroke. "Inches" is more accurate, and can be converted to mm.
#25880

Please Log in or Create an account to join the conversation.

Time to create page: 0.411 seconds

Who's Online

TodayToday2468
YesterdayYesterday3494
Guests : 43
Now Online

User Login

Mailbox

You are not logged in.

Mailing List

captcha 
© 2015 Modelgasboats.com. All Rights Reserved.