Help Identifying Mahle Piston/Cylinders

[Arctic Rat]

Hi Everyone,

Some of you may have seen I posted what I thought was a 2.5 short block for sale. What I have is confusion.

I removed a head/cylinder and found MAHLE 90ZN2 W6 cylinder. I believed this to be a 90mm Nikisil jug? As I had a 2nd motor with the same Mahle part that had 90mm pistons (RS 8.5:1) After posting what I believed was a 2.2 that someone had put 2.7 piston/cylinders on. A fellow Pelican noticed the piston was not the correct shape for the RS low comp piston. In my enthusiasm with what I though I had found I did not notice this.

I pulled a 2nd head/cylinder so I could remove a piston. Here is were I am lost in Mahle part#'s. What I removed is a Mahle 84V51? by part number and by measurement this is an 84mm piston?

Finally my question:

WHAT AM I MISSING WITH THIS? HOW DO 84MM PISTON AND 90MM JUGS WORK TOGETHER?

Is the Mahle part number 90ZN2 just a casting number and the bore could be anything?

Thank You for any help you can give. Some pics of what I have.

Joe D

[911hutch]

You are referencing the MAHLE casting number of your cylinders. Measure your cylinders... you will find they are in fact 84mm. MAHLE used the same casting number for the cylinders regardless of bore size for a number of years....... Your cylinders are not 90mm regardless of the casting number on your cylinders.

[targa72e]

The piston should be a 2.2 E 84mm Mahle 84v51. The current and later replacement P&C sets for the 2.4 L engines moved away from Biral and started using Nikasil. Probably use the same casting as for 2.7 and only bore to 84mm. Also heads do not look like they have the chamfer needed when using 90mm bore.

john

[Arctic Rat]

911hutch and John,

Thank you for the clarification. I indeed measured the cylinder and they are as you say 84mm. So I have a T case with upgraded 2.2E piston and cylinders?

Thanks again
Joe D