CLASS RACER FORUM - View Single Post - Spark Plug Heat ranges, what gains have you made?

Stan Weiss · 09-02-2021, 07:05 AM

When you add wrist pin offset a number of thinks happen. The piston and the crank rod journal are not ATDC and BBDC at the same time. Now based on which way you have the offset decides if piston TDC is before or after crank rod journal TDC. Another thing that happens is all 4 cycle are not long 90 degrees each. 2 become less and 2 become more. Again which 2 do what is based on where the offset was placed.The is also a very very small change in stroke and displacement. (For inline engines where you can move / offset the crank center line these can be larger).

Stan

09-02-2021, 07:05 AM	#28
Stan Weiss Senior Member Join Date: Apr 2020 Location: Phila, PA Posts: 793 Likes: 0 Liked 733 Times in 384 Posts	Re: Spark Plug Heat ranges, what gains have you made? When you add wrist pin offset a number of thinks happen. The piston and the crank rod journal are not ATDC and BBDC at the same time. Now based on which way you have the offset decides if piston TDC is before or after crank rod journal TDC. Another thing that happens is all 4 cycle are not long 90 degrees each. 2 become less and 2 become more. Again which 2 do what is based on where the offset was placed.The is also a very very small change in stroke and displacement. (For inline engines where you can move / offset the crank center line these can be larger). Stan Attached Thumbnails Last edited by Stan Weiss; 09-02-2021 at 08:07 AM. Reason: Added Graph