Carrera Specs

[armandodiaz]

Can someone tell me what the piston specs on a stock 3.2 Carrera. I might purchase a set of 10.2:1 pistons and I want to make sure they are for a Carrera not an SC.

So far the only info I have is that they are 95mm. I'm waiting for the demensions of the wrist pin. Anything else I should ask for?

This will be for a track engine where I would get heavily penilized for increasing ci, so I'm trying to keep stock size. With that type of compression I assuming twin plugs are a must?

[Jeff Alton]

The easiest way, as you seem to know, is by wrist pin diameter. They must be aftermarket, I can't think of an stock piston with that CR. If you know who manufactured them, maybe they can tell you if they marked them with a number of some sort of system to identify them.


Jeff

[armandodiaz]

They are J&E pistons. Do you know the pin diameter should be for Carreras? How much do you think they are worth?

[ChrisBennet]

Carrera wrist pins are 23mm, SC's are 22mm if I remember correctly.
-Chris

[armandodiaz]

Thanks for the info Chris. Any idea on $$$$?

[KobaltBlau]

since new JEs are $840 on pelican, I would say 350-500ish if they have been used in an engine but measure out perfectly. If they have never been used, maybe 500-650?

[ChrisBennet]

Pelican sell's 10.5:1 JE's for $840 w/out rings.
I don't know much about these things but I'd look them over really closely before I bought them. The factory cylinders came in a something like 4 different diameters ("tolerance groups" or something like that) so I'd also want to measure and confirm that they had the correct fit with my cylinders. JE's don't come in different sizes so perhaps I'm being overly cautious. I've just learned to "Trust No One, Measure Everything Yourself" when it comes to motor parts.
Hopefully somebody who does know about these things will weigh in and we'll both know then.
-Chris

[Jeff Alton]

Charles, you out there?? Chris is right about the wristpins.

Jeff

[KobaltBlau]

BTW my values are wild ballpark guesses based on other parts purchases. don't put too much stock in them!

[ricochet]

I don't know much about these things but I'd look them over really closely before I bought them. The factory cylinders came in a something like 4 different diameters ("tolerance groups" or something like that) so I'd also want to measure and confirm that they had the correct fit with my cylinders.

You guys are much better learned than me and I sit back and learn. You may well be right, but I thought the classes were by weight (5 or so). If wrong, I apologize. But my thoughts were weight classes, all diameters should be better matched. If I "blueprinted" an engine, I'd go for swing weight (AND diameter). But I'd also first ask for you guys to offer info. Is a learning experience everyday, till I die. Thanks guys.

[ChrisBennet]

Originally posted by ricochet
I don't know much about these things but I'd look them over really closely before I bought them. The factory cylinders came in a something like 4 different diameters ("tolerance groups" or something like that) so I'd also want to measure and confirm that they had the correct fit with my cylinders.

You guys are much better learned than me and I sit back and learn. You may well be right, but I thought the classes were by weight (5 or so). If wrong, I apologize. But my thoughts were weight classes, all diameters should be better matched. If I "blueprinted" an engine, I'd go for swing weight (AND diameter). But I'd also first ask for you guys to offer info. Is a learning experience everyday, till I die. Thanks guys.

I tend to forget stuff almost as fast as I learn it. I didn't want to mislead anyone with wrong info so I pulled out the spec book this morning and checked. 3.2 cylinders come in two height tolerance groups/"Height Groups" (5 & 6) and four diameters/sizes:


Sorry about the slanted scans but if you're a couple degrees off plumb like me, they look just fine.
-Chris

[ricochet]

Thanks Chris,
I am in an uphill learning curve. I thought I'd read about A-E piston weight grades and thought that was it. I live and learn, great info. It was slanted, huh? Thought that was just me. Thanks

[anh911]

If you are planning on using JEs in a 3.2 you need to also determine what cylinders you have. JEs aren't meant to be used with the alusil cylinders only the nikasils.

[KobaltBlau]

Nice post, chris.

What book are those from?

[ChrisBennet]

That's a scan of the Spec Book (Techinical Specification Carrera '84-8?). It's a little pocket size book.
-Chris