How many get away with reusing P's & C's on 130K mile 3.2??

[efhughes3]

I'm going to start my teardown from my track mishap where I did an over-rev due to a mis-shift. I'm hoping that I didn't bugger up any of the heavy metal in the engine. Am I nuts to try and re-use pistons, or is this pretty regular? I'll of course inspect them for ring groove wear, etc.

I would also like to keep the cylinders, and of course they'll be inspected. Is reseating rings as much of a crapshoot as some relate?

I'd like to keep the $ down. That's not to say I'm going to be cheap as I'll do stuff like ARP rod bolts, EBS valve springs, etc to make it a better engine, but P's & C's add up real quick, as you all know.

Also, one last question, do I change out head studs, or just get new fastening hardware? I'm not planning on ARP studs, I'd just go steel for replacement, but I'm wondering what the rule of thumb here is.

[JeremyD]

You will "probably" be OK - but I would definitely recomend that you either send to EBS to get them measured of find a machine shop locally to have them measured. My opinion is that if you don't do this all the time, or have the equipment to properly do this - it's very easy to get wrong.

As far as the head studs - they are a biotch to remove (remember lots of heat to break the loctite) and if I was in your shoes I would start shopping now for at the minimum - 12 steel replacement studs for the dilivar. I would definitely change out the hardware = but again, you'll get a better idea when you start taking everything apart. (I would invest in one of those bigger ultrasonic cleaners from harbor freight)

The other option would be to just look for a set of the euro p & c's - you have decent gas in texas - right?

[efhughes3]

Thanks Jeremy. Yep, I plan on doing a lot of shipping to EBS. I do have 93 octane in TX, but we'll be back in Cali at some point, so I need to consider that. I may go ahead and at least machine heads for twin plug.

[1972_911T]

I shipped my 140k miles 3.2 cylinders to EBS last month they were perfectly in spec and reusable, had them re honed at the same time to ensure correct new ring seating. Very resonable price for the service.

Steve

[efhughes3]

Originally posted by 1972_911T
I shipped my 140k miles 3.2 cylinders to EBS last month they were perfectly in spec and reusable, had them re honed at the same time to ensure correct new ring seating. Very resonable price for the service.

Steve

That's good news...

[JeremyD]

talk to Jon at EBS - great guy to deal with -

[Eagledriver]

They are not that hard to measure. The pistons will show their wear by how much they are scuffed and how much machining grooves are still visible. Usually they have minimal wear. The same goes for the cylinders. The thing to measure is the piston ring groove clearance. You do that with a feeler guage and so it's easy. You also can remove a couple of the top rings and check the end gap with them in the cylinders. The specs are in all the books. I bet your old rings are still good. the big thing is the side clearance in the grooves. The spec is .004 inches but I'd allow a little more if you keep the old rings. I'd say .006 with old rings will get you another 100k miles of normal use.

-Andy

[efhughes3]

Originally posted by Eagledriver
They are not that hard to measure. The pistons will show their wear by how much they are scuffed and how much machining grooves are still visible. Usually they have minimal wear. The same goes for the cylinders. The thing to measure is the piston ring groove clearance. You do that with a feeler guage and so it's easy. You also can remove a couple of the top rings and check the end gap with them in the cylinders. The specs are in all the books. I bet your old rings are still good. the big thing is the side clearance in the grooves. The spec is .004 inches but I'd allow a little more if you keep the old rings. I'd say .006 with old rings will get you another 100k miles of normal use.

-Andy

Thanks Andy. I'd figured on the ring groove thing as being critical, along with roundness. That, and no huge gouges from valve guides bouncing around in there.

While I want to get out of this as economically as possible, I'm going to go ahead and re-ring as part of the project.

I got my pricing back from EBS, it's only $85 for THEM to inspect the Ps and Cs, so for that money, I'm following Jeremy's advice and relying on their expertise. I was within $100 (their quote was less) on the total of what I'd figured, so that was good too.

[JeremyD]

ring end gap and piston side clearance (at least at the top of the cylinder) are easy to measure - it's the ovality and the taper that are a biotch.

[Jeff Alton]

If you want to practice your technique measuring, take them to a trusted shop and watch them do it. Then head home and with your bore gauge try to replicate the measurements.

Ed, if you want to play with a bore gauge, I can send it with the cam tool.
(which I will send tomorrow or thursday)

Cheers

[Eagledriver]

Before you send them take the time to measure the end gap of a couple of rings. I found that a brand new set of Goetz rings had a wider gap than my old original rings. Measure the new rings when you get the set back to make sure you got an improvement instead of an unimprovement.

-Andy

[efhughes3]

Thanks Andy, will do.

[efhughes3]

Ran compression check on two cylinders today...what a beyotch getting the hose threaded into the sparkplug holes! At any rate, one was 90 PSI, one was 190 PSI. So it's refreshing to know that things may not be too bad inside. Also, when cranking over with the plugs out, it was turning smoothly with no BAD NOISES.

[gulf911]

my .02

Ed,
Had my motor (3.2) apart to add Ti retainers and AASCO springs, PO checked P&C's all ok so re-used. That was in 2001! motor is still very strong. If its done right it should last quite some time..

[efhughes3]

Thanks Gulf. I've played around measuring one of the pistons, and it looked like it may be in spec. I got the P's out yesterday, and hope to get a little more serious about measuring next week. Headed to the Houston ALMS race this weekend...