Modified 100mm Porsche 964 Nikasils - Progress

Wally · Post by **Wally** » Thu Jan 15, 2004 1:37 pm

Hi,
As promised I will try to post some pics that I could save on our dutch website and redirect here.
A few more pics will be posted as my pic hosting skills and the capacity of the host site will allow...
Description of the work done can be found in the thread "Hey Wally", one page or so back on this forum.

These are the redrilled cylinders.

These are an unmodified and not cleaned set of used piston and cylinder and a modified set.

Greetings,
Walter

Wally · Post by **Wally** » Thu Jan 15, 2004 2:13 pm

This is a 914 2,0 ltr head, cut mirror wise for the pistons with a 1,5 mm clearence. Deck height will be set at appr. 1,0 mm.
With that deck heigth I will need spacers of around 7mm. The spacers will be very 'wide' since the area around the studs will also sit on the machined case (cylinder area machined down).
Note that we have not machined the top fin off one bit. Also the ridge on which the cylinder will rest is not turned down, all to maintain maximum strenght and as much cc's in the head as possible.
The head has not been been ported or flowed yet and probably will not also. The area besides the valves will have to be 'unshroud' as it is called I believe. That procedure will also be used to cc the heads for the final CR. Not sure what it will become, but hope somewhere around 1:10,5

I hope its all clear at bit

Greetings,
Walter

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Thu Jan 15, 2004 2:23 pm

SWEET!

Wally · Post by **Wally** » Thu Jan 15, 2004 2:30 pm

Thanks Jake,
That does mean s/th to me.
Take care,
Walter

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Thu Jan 15, 2004 2:31 pm

Wesayso · Post by **Wesayso** » Thu Jan 15, 2004 2:39 pm

Hmmmm, interesting....

Now if I could copy that and....

Great stuff Wally!

Bobtail · Post by **Bobtail** » Thu Jan 15, 2004 4:52 pm

Nice crown ,Shame you aint usin the head to go with it

How many km's do those have on them?Do you know?

Compared to the supervee pistons I used to have You should be in the right ballpark compression-wise.

Post by **Piledriver** » Thu Jan 15, 2004 5:24 pm

Bobtail---Perhaps you could set him up?

Wally · Post by **Wally** » Fri Jan 16, 2004 12:05 am

Bobtail wrote: How many km's do those have on them?Do you know?

That set had about 90.000 km (60K miles?) on them.

Really, there is not a mark on the piston wall to be seen. I mean, all the original porsche machining marks in horizontal direction are unmarked on the piston! One would assume, since the piston travels up and down, that vertical marks would be there, but nothing. Its truly amazing. Also because the piston and cylinder have a much tighter fit than I'am used to.

The barrel, once cleaned, is also super smooth at both TDC and BDC. All honing cross threads are still there. Just because of the quality of these parts, its a feast to work with them.

Also, after seeing these alu, Nikasil cylinders you are spoiled! I assure you.

Walter

Richie · Post by **Richie** » Fri Jan 16, 2004 1:35 am

Hello,

Darn Wally, you got me all giddy again

! It looks awesome and more doable than I imagined, think should have measured my set a bit better. My compliments to Roberto as I assume he has done the machining. Offcourse you get my compliments as well.
Now, mine's a turboset, soooo.......

Cheers,
Richard

roberto · Post by **roberto** » Fri Jan 16, 2004 10:24 am

Looks Great!!!!
Very good idea

greetings Roberto

njv · Post by **njv** » Fri Jan 16, 2004 5:31 pm

hello wally

that looks very interesting indeed very doable ive a wilco tame machinist just in the next vilage from me!!! any chance you could post a picture of what you mean at the case opening with the spacer and stuff?

good luck with it.

roo · Post by **roo** » Tue Jan 20, 2004 12:47 pm

wally got your email, came over for a peak, and great stuff. my only question: does the raised section of the piston have a dish to it or is it just machined flat. i can't imagine it being dished but i can't quite tell in the one pic if it is or istn't.

roo · Post by **roo** » Tue Jan 20, 2004 12:56 pm

i guess in the other pic that i missed

it looks pretty darn flat. but is that a hole in the middle that needs to be weleded up?

Wally · Post by **Wally** » Tue Jan 20, 2004 1:27 pm

Haha, no thats not a hole ! Please!

The original piston has a slight dent in the middle, but because I haven't cleaned or polished anything in the pics, that dent is still black from carbon residue, so are the two dimples left and rigth.
Those two are original valve pockets for the porsche inlet and exhaust valve.
I may have to machine valve pockets for the type 4 valves later on. I have not measured that yet.

Take care,
Walter