100mm 964 cylinders on a 3.0 block

[Dpmulvan]

Originally Posted by Henry Schmidt

Slotting the cylinders to adjust head stud spacing, reducing the spigot diameter (thinner cylinder wall), boring the case (irreversible change), .120" base shim.(unstable cylinder platform). If you try to use late 964/993 cylinders you have to machine the heads flat. More irreversible changes.
All of it is ugly.

Back in the day when the 964 recall happened, the dealers had boxes of the early cylinders they were throwing away. One batch we got was 11 sets. That makes playing with these cylinders intriguing.
Now, not so much.

I have to come up with a plan for the two 3.0s I have. I could see where all these changes would invite issues down the road.

[Henry Schmidt]

Originally Posted by Dpmulvan

I have to come up with a plan for the two 3.0s I have. I could see where all these changes would invite issues down the road.

There is always this option....

Originally Posted by Henry Schmidt

Porsche 911SC-Leistungsgesteigert (Performance increased)
We're starting a simple 911 SC rebuild and resurrecting a little know option offered by Porsche by in 78-81.
Here's some information.



We're making sets using 95mm cylinders bored to 97mm and plated by Millennium. CP X-brace pistons are then custom fitted.
The pistons are designed to use 3.3 liter turbo rings so replacement is cheap and easy.
$ 3,185.00 plus shipping.

Engine type 930.03 or 930.09 * 3.1 *
Engine displacement: 3122 cc
Bore x Stroke: 97mm x 70.4mm
Power: 210 hp @ 5900 rpm Binary: 280 Nm @ 4300 rpm
0 at 100 km / h: 6.4 seconds Max speed: 230 km / h

We will include a reground set of Carrera cams. The new profile is 964.
When purchased at the same time as the piston and cylinder set, the price is $500.00 exchange. You can exchange 911SC or Carrera cams for the core.

[Aircooled4evr]

[QUOTE=[B]Henry Schmidt[/B];11126405]We can have the custom pistons made for you at a reasonable price.
Send me an email with contact info and we'll try to work something out.
Discount for quantity? of course, we've got piles of the stuff.




Wow! I obviously don't know who I am "talking" with in here!
Sorry for my late reply. But now I'm finally back in my beloved "porsche world" I think it will be easier if I just send you an email!

Cheers, Mads

[stephen1070]

Originally Posted by Henry Schmidt

You can modify them if you have a mill and a lathe.
I would seek a custom piston to maximize this modification.

70.4x100 is a cool high revving oversquare engine. They are commonly found in the likes of Formula 1 cars, two-stroke racing engines and anything else where you want to rev the engine up to produce power. They keep piston speed down which helps reliability by putting less force into things like your crankshaft and connecting rods. In general, these engines will produce more horsepower than torque and require gearing to take advantage of their top end pull.

We built a 66x100 engine a few years back that saw rpm close to 9000.

Henry, a little off topic but can you describe the characteristics and/or your experience with a 3.2 modified with a 80.4 mm stroke and 100mm bore. I'm also wondering if retaining the motronic efi would be adequate in a street car with say a 7,000 RPM limit. Thank you for your contributions to this forum.

[Dpmulvan]

Henry I’m still debating what to do, I’m thinking maybe I should sell both of my 3.0 and get something else, but people are asking stupid money for 3.2’s et. Maybe I should give you a call I don’t know any east coast places.

[Henry Schmidt]

Originally Posted by stephen1070

Henry, a little off topic but can you describe the characteristics and/or your experience with a 3.2 modified with a 80.4 mm stroke and 100mm bore. I'm also wondering if retaining the motronic efi would be adequate in a street car with say a 7,000 RPM limit. Thank you for your contributions to this forum.

80.4 stroke in an air-cooled engine will need pretty short rods or some crazy dimensioning. Long stroke generally means better torque but nasty rod angles.

The stock 3.2 injection will support very large engine with the right injectors and programing.

[Henry Schmidt]

Originally Posted by Dpmulvan

Henry I’m still debating what to do, I’m thinking maybe I should sell both of my 3.0 and get something else, but people are asking stupid money for 3.2’s et. Maybe I should give you a call I don’t know any east coast places.

A 3.0 core is a great platform if size is not your primary concern.
You can email me with question/thoughts and we'll tease something out or
you can call as well but right now my scheduling is unpredictable.

[Aircooled4evr]

Originally Posted by Henry Schmidt

I haven't looked in years but I may even have a set of slotted cylinders and base shims on the shelf ready to go.
If I can remember, I'll check tomorrow.

Send me an email.

Hi Henry Schmidt, I'm interested in buying a good 100mm set of you, and maybe a set of pistons as well. But I have several questions.
My email is: madsracing@gmail.com
(yeah yeah ... You may laugh now ... I was young when I made it!) ...
However, I will also try to write to you.

Sincerely, mads

[Aircooled4evr]

Hi folks. Do you know, if this is an active mail for Henry Schmidt: supertec1@earthlink.net ?

[Henry Schmidt]

Christmas vacation. We'll talk after the new year.
Cheers

[Aircooled4evr]

Yay ... Wish you, and everyone in here, a happy new year, MUCH better than 2020!

[Aircooled4evr]

Will there be a problem with driving with the original 964 pistons, with new piston rings? I'm thinking, my plan is to drive with high compression, dual ignition, knock sensor and everything else that the 964 has. So is this not a sensible way to go?

[colingreene]

Originally Posted by Aircooled4evr

Primarily because of the price!....
I can make the modifications myself, to use the 100mm.
And if the heads need to be modified, to achieve a better squeeze in collaboration with the 964 pistons, I can probably do this as well. (even though I just finished polishing them)
In addition, I'm curious what characteristics 70.4 X 100mm will give!

Mine hauls ass.
If you don't need to cut the case, don't.
Mine came to me this way I wish it was not. It makes it a real headache if i ever have the cyls that came in it damaged and need to replace them.
While its good to know I can potentially do something with 964 cyls it looks like something id rather avoid.
My case was opened up to take some Mahle Motorsport cyls and pistons that are 100mm

[Aircooled4evr]

Originally Posted by colingreene

Mine hauls ass.

I really had problems reading after this ...

[Aircooled4evr]

Originally Posted by colingreene

Mine hauls ass.
If you don't need to cut the case, don't.
Mine came to me this way I wish it was not. It makes it a real headache if i ever have the cyls that came in it damaged and need to replace them.
While its good to know I can potentially do something with 964 cyls it looks like something id rather avoid.
My case was opened up to take some Mahle Motorsport cyls and pistons that are 100mm

OK, I'm still on my way to the 964s 100mm... But ... anyone have a qualified bid where one could find a set of Mahle 98mm cyl for human money? (and what is "human money" for you guys)?

[colingreene]

Originally Posted by Aircooled4evr

I really had problems reading after this ...

well whatever?
I just dont think its a good idea.

[Aircooled4evr]

Originally Posted by colingreene

well whatever?
I just dont think its a good idea.

100% meant for fun!

[Henry Schmidt]

Still looking for cylinders? Send me an email and I'll give you the latest information from my parts store.
Cheers

[Aircooled4evr]

Originally Posted by Henry Schmidt

Still looking for cylinders? Send me an email and I'll give you the latest information from my parts store.
Cheers

You've got Mail.