964 piston

A place for Impact Bumpers, 964 and 993 content

Moderators: hot66, impmad2000, Barry, Viv_Surby, Derek, Mike Usiskin

Post Reply
Bob
DDK Seasoned Poster
Posts: 34
Joined: Wed Aug 29, 2018 7:04 pm

964 piston

Post by Bob »

Are these 100mm pistons standard 964 if so does any one know what compression ratio I should have .heads are 3.2 so is case with solex cams and pmo cards.
MBEngineering
I luv DDK!
Posts: 779
Joined: Fri Mar 31, 2006 10:54 am
Location: Kendal CUMBRIA
Contact:

Re: 964 piston

Post by MBEngineering »

HI Bob

I take it you are trying to fit 964 pistons and cylinder to a 3.2, with the 3.2 heads, the 964 runs 11to1 CR with knock sensors, the CC of the 3.2 head is larger, I would have to check the CC of both heads to see the drop in CR

if you are using the 964 cylinders, I take it you know the stud spacing is smaller on the 3.2 and you will have to mod the cylinder in a mill to make them fit the 3.2 studs

the job is do-able with some work, you will have to check the hight of the piston pin, un-less you are fitting the 964 crank in the 3.2 cases

regards mike
Bob
DDK Seasoned Poster
Posts: 34
Joined: Wed Aug 29, 2018 7:04 pm

Re: 964 piston

Post by Bob »

Sorry I'm try to upload some pictures engine has been converted but awhile ago and I'm rebuilding it and want to check what's been done etc
Attachments
piston.jpeg
piston.jpeg (19.03 KiB) Viewed 911 times
Bob
DDK Seasoned Poster
Posts: 34
Joined: Wed Aug 29, 2018 7:04 pm

Re: 964 piston

Post by Bob »

MBEngineering wrote:HI Bob

I take it you are trying to fit 964 pistons and cylinder to a 3.2, with the 3.2 heads, the 964 runs 11to1 CR with knock sensors, the CC of the 3.2 head is larger, I would have to check the CC of both heads to see the drop in CR

if you are using the 964 cylinders, I take it you know the stud spacing is smaller on the 3.2 and you will have to mod the cylinder in a mill to make them fit the 3.2 studs

the job is do-able with some work, you will have to check the hight of the piston pin, un-less you are fitting the 964 crank in the 3.2 cases

regards mike
Bob
DDK Seasoned Poster
Posts: 34
Joined: Wed Aug 29, 2018 7:04 pm

Re: 964 piston

Post by Bob »

Managed to get picture on are these standard pistons?
MBEngineering
I luv DDK!
Posts: 779
Joined: Fri Mar 31, 2006 10:54 am
Location: Kendal CUMBRIA
Contact:

Re: 964 piston

Post by MBEngineering »

HI Bob

looks like a Std 964 piston,

I would clean the top off and check to see if there is some machining for valve pockets on the piston, to get the C.R. up,

did you check the valve timing before you striped it?

regards mike
Bob
DDK Seasoned Poster
Posts: 34
Joined: Wed Aug 29, 2018 7:04 pm

Re: 964 piston

Post by Bob »

Not checked it yet 1 side is stripped. There was a electric fire over 1 side carbs were sent back to pmo to be rebuilt. So some was stripped by others but I want to go right though it
Bob
DDK Seasoned Poster
Posts: 34
Joined: Wed Aug 29, 2018 7:04 pm

Re: 964 piston

Post by Bob »

Cam timing is coming out at 4.2 and solex cams are 4.2 to.4 .6 do engine builders always stick to porsche set over laps ?
Bob
DDK Seasoned Poster
Posts: 34
Joined: Wed Aug 29, 2018 7:04 pm

Re: 964 piston

Post by Bob »

ive cleaned up pistons and barrels on the top of the piston is E on bottom 100p 36 + w6 +
on the cylinder there is a 1 then a 2 then a 5 in a triangle could any one tell me what the wear limits are on these
Post Reply