What engine do I have

[60RIDER]

Hi guys, I have a '60 pan with original cases, bought it already stroked, had it since '98, been rebuilt twice. No one can tell me exactly what I have, even my engine builder, he'll say 'well its about......'. Anyway it has 1978 S&S stroker flywheels with new S&S rods,got new S&S pistons 92-2906 which say 'use for 4-5/8,4.3/4 or 5" stroke, but I don't use any stroker plates. I thought anything over 1/4" stroke needed stroker plates. It's got STD Pan heads with shovel ports, unmodified. Stock OEM replacement cylinders. I'm trying to find out my stroke, and compression ratio. Can anyone lead me down the right path?
thanks 60rider

[65flh5326]

It most likely has 4 5/8 stroke with stock bore cylinders it would be a 89"
Sounds like an early S&S conversion. The mechanic would have to be around 50yrs old to know, Ha Ha.
With the pistons described the stroker plates would be required on the longer strokes.

Don

[sleeper]

If you know the bore & stroke you can use this calculator
http://www.truettandosborn.com/calculator.htm
To give U exact cu in's & cc's.
If U indeed have 4 5/8" stroke, It's kind'a unlikely to have stock bore unless they are NOS cylinders or superlo-miles.
To check stroke; remove spark plugs & use a drinking straw.(plastic) put it in the plug hole & slowly roll the motor till you get TDC=top Dead Center & mark the straw at that position, then slowly roll the motor till you hit BDC= Bottom Dead Center, any further movement would result in the straw coming back up.
Anyway at BDC mark the straw as you did at TDC, & remove it & measure the distance between the 2 marks. That IS your stroke..... ;D (fine point marker is nice)

[Larry49EL]

Just make sure you use a long enough straw