M50 VS S50 How do you know?

[White325is]

I know there is a VIN on the back of the head to tell what car they came from.
Is there any special number in the VIN that tells what motor it is?

[Farbin Kaiber]

Third alpha should be an S for S50/2 or an A if it is an M50/2

[White325is]

Thanks, Just found this also..

"Driver side on block just above where the oil dip stick tube enters the oil pan. There will be a group of stamped numbers (not casting numbers). if the lower number starts with 2.5 - it is a 2.5 liter block. If it has 3.0 it is a 95 3 liter block, and like wise if it has 3.2 it is a 3.2 lter block. Hope this helps!"

[7pilot]

The number on the back of the head is a sticker, so it comes off relatively easily if there is a heavy leak .
It will be stripped off if the head has been in a hot tank.
I have not bothered to see the the casting nos on the head are decipherable.

m

[lifeiskaos]

Thanks, Just found this also..

Every 24v engine i've seen has this. It'll say 25, 28, 30, 32 etc for engine size. That's the best way to tell if you have a 2.5l s50 or not :???:

[JGood]

Do you have the engine in your possession, so you can tear it apart, etc...?

s52 has a longer stroke, right? Could you put a long wooden dowel in the spark plug hole and measure the travel while turning the engine by hand? Compare to an m50, or just do the math to see what it should be.

The cams don't need measured, you can see the difference in duration with your eyes, just gotta pull the valve cover.

What about checking the injectors?

[Dominic49]

i always just used a dowel and measure the difference in stroke