Cylinder Marking Confusion?

[TxSquash]

I'm trying to figure out what I've got in my 78'SC 3.0. I've got the heads off, but I can't figure out who the P/C maker is. I've read that if you have Alusil you should not separate the P/C. You should leave the piston in the cylinders if your not going to replace them. Where as if you have Nikasil you can separate them and even hone and replace the rings. So I'd like to know, because I can see it would be easier to pull the cylinders to remove the piston heads.

Henry Schmidt in 2004 post said "The easy way to tell Alusil from Nikasil is that Nikasil is magnetic."

Well here is the confusion. The outside of the cylinder is non/magnetic, but the inside of the cylinder wall is magnetic. So I think I have Mahle Nikasil P&C's.

I couldn't get a decent photo so I used one off the board. My markings are exactly the same except the numbers are different. Mine are 703 over the same M marking in the photo, and 058 undre the M. Then there is a 0, and a triangle with a 5 in it.

Sorry for the long post,... but this is my first time.
Thanks
Doug

[dcriss]

Hi Doug,

Yes, the INSIDE of the cylinder in slightly magnetic with the MAHLE (Nikasil)
cylinders. However, to my knowledge, the MAHLE cylinders have the "MAHLE" on the side of the cylinders similar to this:



If the cylinders are magnetic, but don't have the MAHLE markings.......I THINK they are MAHLE's?????

Hopefully, someone can clear this question up.

Regards,

P.S. My MAHLE's have the same markings as the one's in your photo.

[efhughes3]

My 3.2's say Mahle as in the second post.

Where in Dallas do you live? I'm doing my build in Highland Village.

[TxSquash]

Ed,.. we have met. I've been to a couple of Saturday coffee meets. I've got a 78sc that I have been redoing on and off for a year and half. Originally I just needed a new paint job, so I stripped it to bare metal. Then I thought I'd drop the engine and cleaner' up while she was at the painter. So out came the 3.0, pretty easy too. Put er' on an engine stand, popped the valve covers,... and guess what. Eight broken head studs,... 5 exhaust on one side 3 on the other. So today while watching the "boys" dent the "rams" I pulled the P/Cs. Hopefully sometime this week I'll try my hand at the broken studs. I've got the right kind of heat (oxy) and enough stud to grab on to,... so I'm hopefully.
But I could use your advise on a machine shop to clean up my heads. I'm not planning to split the case. With 100k and no evidence of any metal in the sump, filter, chain housings, I think she is clean enough to button back up.
I have been following your rebuild on the board. Meticulous,... almost a work of art. When I finish mine.. I plan on writing a post titled "the bargain-basement rebuild".
Keep up the great posts,... this board is the best!
Doug

[Henry Schmidt]

The Nikasil cylinders will only be magnetic on the inside (bore) of the cylinder.
The high nickel plating is what will show attraction to the magnet.
The aluminum casting will not be magnet on Nikasil, Alusil or Silimal.
If the bore shows any sign of magnetic attraction it is Nikasil.
As for mixing up Alusil cylinders it really doesn't matter if you're throwing them in the trash.

[efhughes3]

Hi Doug: Just sent you an e-mail.