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Maurizio · Post by **Maurizio** » Sun Apr 23, 2006 11:36 pm

kterkkila,

My bottom end is a long frustating story of in the mail lost con rods (when send to the shot peener) no time to work on of the machine shop, etc. Still not finished, bought a standard engine so I have my car up and running again. Will in a few weeks make some time again to fight with the machine shop

So I have no reall live data of what the compression rate turned in assembled form. Goal was 1:11.5 from the pistons with 75 ts con rods and my head (have to check my notes for combustion chamber head side volume).
But the piston design was not simply shaving of the piston. The valve reliefs would be made deeper and the top of the piston is milled in a lathe to a nice spherical form.
I can send you a drawing of my design if you like. But it is not proven technology

Saluti,
Maurizio

kterkkila · Post by **kterkkila** » Mon Apr 24, 2006 8:34 am

Maurizio wrote:But the piston design was not simply shaving of the piston. The valve reliefs would be made deeper and the top of the piston is milled in a lathe to a nice spherical form.
I can send you a drawing of my design if you like. But it is not proven technology

That would be really nice

I'll need to do this piston change somehow, so all ideas are more than welcome.

kterkkila · Post by **kterkkila** » Tue Apr 25, 2006 3:56 am

Mats wrote:Weight (complete) compared to 75 piston?

75 piston with rings = 450g, 155 piston with rings 406g. I don't have pins of 155 pistons yet, but the 75 pin weights 128g. 155 pin is ca. 57mm tall, as the 75 pin is 71mm, which makes 155 pin to about 103 grams, if it's with similar thickness. Although I guess they are somewhat thinner..

kterkkila · Post by **kterkkila** » Tue Apr 25, 2006 4:07 am

kterkkila wrote: Although I guess they are somewhat thinner..

Quick correction.. ..155 pins are even more thicker.. ..they weight 112g.

Maurizio · Post by **Maurizio** » Tue Apr 25, 2006 4:43 am

Kimmo,

pm or mail me your e-mail adress and I'll send you the drawing and more info tonight.

Edit: mail send this morning

Saluti,
Maurizio

KingDom · Post by **KingDom** » Sun Apr 30, 2006 9:36 pm

Maurizio,

I have come in to this discussion a little late. However I am currently building a performance TS engine engine. The head is from a 75 and are matching it to a alfetta nord block. A lot of work!
I think the 75 and 155 TS have a 90 mm stroke crank which is why the rods are 1 mm shorter. So fitting nord rods in the TS engine will give you an extra compression point, but you will need to machine the piston top for clearance.
You can get lightweight piston pins from JE pistons.
Gozzoli has 11:1 forged pistons. Do not use the spruell pistons, I have these and the shape of the dome is incorrect. I have had to do a lot of machinig to correct it.
If you are wanting a stronger bottom end I think its better to go for aftermarket performance rods as the standard items are heavy and are limited to revs.

Ciao,
Dom

Maurizio · Post by **Maurizio** » Mon May 01, 2006 6:54 am

Dom,

stroke of a 75 TS is 88.5 mm.
We will see what the 155 piston route brings......

Saluti,
Maurizio

Mats · Post by **Mats** » Mon May 01, 2006 8:43 am

KingDom wrote: Do not use the spruell pistons, I have these and the shape of the dome is incorrect. I have had to do a lot of machinig to correct it.

Care to elaborate?

Maurizio · Post by **Maurizio** » Thu Feb 08, 2007 12:56 pm

An update: machine shop is exit. They screwed up a set 155 pistons and balanced my crank assembly before I was asked, so couldn't round of the knifeedged crank

And still after a full year nothing really finished

So what do I now have got now:

Balanced lightened crank.
Shot peened con rods with 0.5mm (shorter) offset bore.
Bottom end, line bore, new liners and main bearing 2 and 4 directly fed by oil channel.

Status: engine project is in the fridge due other house, a huge spare time consumption of current project @work and frustration.

TS_turbo · Post by **TS_turbo** » Thu Feb 08, 2007 1:21 pm

hmm nice how much is crank lightened

Maurizio · Post by **Maurizio** » Thu Feb 08, 2007 11:18 pm

Good question, no answer, never put it on a scale

kterkkila · Post by **kterkkila** » Fri Feb 09, 2007 3:57 am

Maurizio wrote:They screwed up a set 155 pistons

Really? What went wrong?

Kimmo

Maurizio · Post by **Maurizio** » Fri Feb 09, 2007 4:06 am

They made exhaust and intake side (valve reliefs) the same, not according my drawing.
When trying to fix it they didn't align the piston good enough and milled a hole in a piston

And that started a debate (short one, from my side) about who was going to pay for a new set of pistons

kterkkila · Post by **kterkkila** » Fri Feb 09, 2007 4:20 am

Maurizio wrote:They made exhaust and intake side (valve reliefs) the same, not according my drawing.
When trying to fix it they didn't align the piston good enough and milled a hole in a piston
And that started a debate (short one, from my side) about who was going to pay for a new set of pistons

Great.. Doesn't sound like too professional shop.. I'll hope they'll manage with the second set.

I have one new set of 155 pistons with rings, which I could sell if your wholesale runs out of those pistons

Maurizio · Post by **Maurizio** » Fri Feb 09, 2007 4:42 am

I'm not giving them a second, third, etc chance......
After the crank balancing story and the very long waiting time, I had it with the shop and took my parts home

My current standard engine in the TS is doing fine.
Priority list has changed:
- gearbox change (3th is getting almost impossible).
- my own design cage.
- allot more seat time to improve my driving skills.

Will get on with this engine when there is again some more spare time.