Advice on these pistons appreciated.
Turbo Mini Forums

Guys.

These are the pics of what remains of my old Omega cast 1293 pistons after they've been through the ultrasonic bath.

In your opinion, could these three pistons be re-used ?

Read on ......

As you may recall, I detonated No 4 in April at the RR and this lead to a couple of broken ring lands. My fault for running too high a static CR and too much boost.

The other three have cleaned up real well and show absolutely no signs of det with only minmal wear after only about 1800 miles of use. The route I chose when I did the rebuild was to fit 4 new pistons machined to 15 cc so I don't need these three pistons anymore.

The three here are offset bowl 6cc pistons modified to 8cc.

I'm thinking of offering these for sale as I think they're pretty good, even if they were re-used for a Normally Aspirated motor rather than turbo'd.

I have all new rings for all three and a spare set of rings for a fourth piston but this is missing a 2nd compression ring (long story but in a previous life I had to buy a full set of rings from MED just to get hold of one bloody ring which I broke doing a dry build one day).

When the machine shop removed the pistons from the rods, the press just snicked a few of the faces either side of the gudgeon pin bosses and I've cleaned these up with emery and they appear fine in my opinion. The marks are all well below the oil control ring and have polished out nicely.

This was no fault of the engineer who pressed them out as I had previously mentioned that I wasn't going to be re-using the pistons so he rightly assumed they were for the melting pot.

But I'm loathed to scrap em when they appear bloody good and could be re-used. They have not seen much use comparitively speaking and are well within limits for roundness/ovality. All the ring lands and ring grooves are excellent, as are all the crowns and squish areas above the 1st compression ring. As I said, they're 8cc cast and will come with new rings.

If the advice is positive, then I'll put them up for sale in another thread to see if anyone wants em.

I'd value your opinions please - 7 shots below.

Cheers guys.

Richard.

Edited by turbominivanman on 28th Dec, 2010.

Minivanless, but reluctantly happy living with the decision. There'll be another one day.
http://www.youtube.com/profile?user=minimadmotorman#p/u

Pics added now.

Richard.

Edited by turbominivanman on 28th Dec, 2010.

Minivanless, but reluctantly happy living with the decision. There'll be another one day.
http://www.youtube.com/profile?user=minimadmotorman#p/u

I,d be happy to re-use these.

I'd also use them, BUT, (and I'm sure you know this) without a matching 4th they are nothing but nice ornaments.

i would get new pistons.

if you want it to last again & i assume you don't want to pull it out a again.

it sucks but i would bite the bullet & buy new ones. :(

look like very good pistons actually.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Thanks for the replies.

Tom. I'm assuming here that you mean without a similar 'part used' 4th piston it makes it difficult for a machine shop to bore a block but could you explain please. Thanks.

Bearing in mind these pistons are effectively off the shelf +0.020 Omega OP120's, they'd probably suit someone who could find a fourth piston for a budget rebuild or only wants to use one of the pistons to fix a problem of their own, I was thinking they had alot of potential to be re-used. It's not as if you'd get anything different from these if you bought new ones, apart from the extra 2cc in the bowl.

NickG - please forgive me but I'm not re-using these pistons. I have already used new pistons on the vans fresh motor. However, please could you explain why you think these pistons should not be used as that would be helpful.

Thanks again.

Richard.

Minivanless, but reluctantly happy living with the decision. There'll be another one day.
http://www.youtube.com/profile?user=minimadmotorman#p/u

Hey Richard.

By all means use them.

I Have just been there before with tiger parts and for the extra money and piece of mind I would get new ones.

Even if it means waiting a few extra weeks it's worth it.

Nothin technical about my explation at all Richard.

Just keep it in mind. Good luck ps love that bloody van

Edited by NickG on 28th Dec, 2010.

if you can get a 4th piston use them, but use a new ring pack if possible

Edited by BENROSS on 28th Dec, 2010.

Yes Steve.

That's what I was thinking. And a new ring pack is a must, hence thats why I showed it in the photos.

I suppose the best thing I can do is to source a fourth piston myself and the missing ring to make up the set. Then either build a short motor or stick em up for sale as a set.

Will put up a wanted post for a single cast +.020 Omega.

Cheers for the help guys. Much appreciated.

Hope to get to a few early meetings now that the van is up and running again.

Cheers.

Richard.

Minivanless, but reluctantly happy living with the decision. There'll be another one day.
http://www.youtube.com/profile?user=minimadmotorman#p/u

You going to Bingley this year Rich?

iam sure! that you will get one, make sure the lands are perfect!

Minivanless, but reluctantly happy living with the decision. There'll be another one day.
http://www.youtube.com/profile?user=minimadmotorman#p/u

Smashing, I'll be there all being well.

im hoping to go to,

you entering it again richard?

Minivanless, but reluctantly happy living with the decision. There'll be another one day.
http://www.youtube.com/profile?user=minimadmotorman#p/u

yes please, thatd be great! i'll book the day of work.