Compatability

[jmtaylor75]

I have a stock 1982 911 SC Targa. I want to do some engine upgrades. I would like to install 964 cams and change to carbs. I also have a set 100mm Mahle pistons and cylinders. Can these be installed as an upgrade without having to do any modifications?

[Walt Fricke]

Cams you can do. Carbs (with manifolds) you can do. I don't think you can go larger than 98mm with the Ps and Cs, but someone can correct me on that if I am wrong. What does Wayne's book have to say about this?

You don't have his book? Not read it cover to cover? Anderson? You should have one or the other, and preferably both if you are going to modify an aircooled 911.

[Steve@Rennsport]

You can install 100mm P/C's if you machine the case spigots and install twin-ignition.

[Walt Fricke]

Steve - is 100mm just too wide for the flame front from a single plug that is off to one side no matter what the dome shape?

With the aluminum case, might you still run into the head stud issues the mag cases had with spigot overbores?

[Steve@Rennsport]

Originally Posted by Walt Fricke

Steve - is 100mm just too wide for the flame front from a single plug that is off to one side no matter what the dome shape?

With the aluminum case, might you still run into the head stud issues the mag cases had with spigot overbores?

Yessir, thats correct. Those big-bore engines must have twin-ignition to run on any pump gas.

The 100mm cylinders are just fine in the aluminum cases as long as they are properly prepped. Head studs do not pull; one simply uses the right ones for the job. We've had good results with the 993TT ones and thats what I recommend.

[jmtaylor75]

Walt,
I do have Wayne's book but didn't see any reference to the 100mm Mahle stuff that I aquired in some horse trading. I appreciate the technical assistance as this is my first venture in to the air cooled world.
Thanks