SwarBar wrote:

I don't think he would do it, or he would've just handled it. How would you accomplish lightening the pins without compromising their structural integrity?, hone out the core?


Sterling wrote:
Exactly. I'm not paying my machinest to fix this, ROSS is going to have to deal with it.

 

On factory pistons there seems to be two different types of pins, at least. S3 pistons have 2mm larger hole than 968 and all '87+ 928 pistons based on limited sample I have seen. In Adam's case its better to have Ross make things good but I would not hesitate to have 968 pins machined to make them even.

What was the reason why factory added material in to pins anyway? Have there been problems in S3 engines? Would S3 pins be safe to use in 968 pistons? This would be very tempting especially if crank balancing is going to give problems. Haven't measured it yet but there is signifficant weight difference in pins. Material is most likely same meaning its possible to calculate saving if someone has number for later pins.

 

If the pins were all the same dimensions, and all made of the same material, they'd all weigh the same. If the same material, those two heavier ones would have to either have a smaller core diameter, or be longer.

 

I would make ROSS send two overnight. There is no reason the pins should be out of weight tolerance by that amount. Sounds like their QC has some real issues.

 

I agree with everyone regarding Ross should make things right, if one has the continued time and patience.

My previous-post perspective comes from trying to cut your losses with Ross and get on with the build (..and your life! ), since removing 6 grams from a wrist pin is not a big deal.

Believe me, I feel for ya and what you're going through!

 

I would check the scale, or Ross shipped two different pins.

Porsche has many different weight pins that all fit the same pistons. Some are lighter than others by up to 20 grams.

They seem to have gone heavier as the engines hp increased. FYI 944T pins are VERY heavy.

Marc

 

Hey Adam,

Any updates? I am still contemplating a second opinion on my stuff and hoping you will get there first

 

Me: Hey, my machinest says that two of the pins are out of spec.
Ross: Doesn't sound right, have your machinest call.
Machinest: Hey, two of the pins are out of spec.
Ross: Doesn't sound right, send the two pins, plus one that's in spec.
Week later.
Ross:Hey two of the pins are out of spec.
Machinest: You don't say.
Machinest (to Adam): I TOLD you to go with JE.

My machinest said he would call me as soon as he got the pins back and got the bobweight calc'd. It is Seafair around here though, and one of his specialties is building the motors for the open class piston hydros, so two weeks before and a week after he's usually pretty tied up with that stuff.

I can put in a call though.

 

Thanks for the update. Don't push on my part, I was just curious

 

Hey!!! What happened to the playboy bunnies in the chocolate nighties??
Hmmm???

 

The chocolate bunnies have turned into a serious case of indigestion.

I will be very happy when all the parts are done and I can actually start building this beast.

 

so any sujjustions on were to get pistons like these are they strait from ross ?

 

You can order pistons "like" these here.

This particular set was ordered with the assistance of Motorsport SLC, who insisted on straightening this mess out, but whom I've told to get back to building motors, restoring 928's, and other important business, and that I'd handle this one. They've made it absolutely clear that they are willing to jump in at any time, but as far as I'm concerned its not their issue.

Pistons can be ordered directly from ROSS.

 

what do you mean "here"?
here on rennlist??

 

Actually, it was kind of a joke.

If you click on the word "here", it's a link to JE pistons.
If you want ROSS, click on this.

Note that my ROSS pistons, although coated, cannot be run in the alusil bore. I will be nikasil coating the cylinder bores before using the ROSS pistons.