Minispares +40 piston rings
Turbo Mini Forums

Hi all,

This is a bit of an ongoing saga regarding piston rings i'm having with minispares.

How many of you are running the turbo pistons or have the Mega rings in say a set of omega etc ?

Next question is did you check the ring gap (ring not fitted to piston) before you built up your engine???

If anyone has some of these rings and a +40 bored block, i'd like you to try the rings in the block and measure the gap between the ends of the ring and tell me what you you find.

If my memory serves me right i think the gap should be around 6-7 thou, but one of mine measured in at 32 thou i think, massive anyhow. This undersize ring was marked as +40 !!!!!!! same as the rest. Very strange indeed.

Anyone else come across this or has the pistons or rings on the shelf they can try ????

I've a spare piston with rings and + 40 freshly bored block, but this is the rings coming with the pistons, not a ring pack, does it is in interest?

Yes, could be one thats affected. How long have you had the piston ? Take the top ring off and try it in your +40 block. The undersize one i had came on a piston. 1 of the 4 was undersize.

Edited by Mirage on 1st Dec, 2006.

I'm just about to order some +40 Mega flattops. But this is worrying...

Surely a machine shop bores the block to the size of the pistons, then if the rings do not fit send them back.

Annoying i know.

JF.

Your right john, but its a bit worrying when 3 are right 1 is wrong and they are all marked on the rings as +40. I sent my affected ring back about 18 months ago!!!!!! My worry is that an undersize batch have been marked as +40 when they aint. I'm trying to sus out if current stock is undersize or not. These rings need to be checked in the bores before fitting back on the piston.

It's certainly not unknown to remove a little of the ring to pen up the gap if its a little undersize, depends on what your building the engine for. I ordered a spare pack of rings with my pistons and all these were fine, but this was in 2001. When i first ordered the pistons i found the ring lands had been machined wrong (sized for standard rover rings) way to big for the rings they came with, so i had to tell minispares there pistons were duff, they quickly got this sorted out with a new batch of pistons.

Well glad they are being helpful.

I do run plus 40 megapistons and found them to be good, rings the lot.

Pretty sure Omega rings are the same and still fairly easy to get hold of.

JF.

The rings are the same. I believe minispares made there rings the same as the omegas, as i believe there was a question mark over the availabuility of the omegas at the time.

Did you check your rings before you installed them ??????

i have +40 's and they seem to fit spot on

i have a spare set of pistons here if you want me to pop a ring in the post

whats going on with this site today? axel is talking abou the size of his bum hole, wil and ben are talking about substitutes for toilet paper, and rich is talking about his dodgy ring!! heavens above


(does this mean that your doing some work on the car??)

It's getting mighty itchy to i may add!!!!!.

Wolfie, when you say they seemed to fit fine did you fit the rings into the bores and check the gap? When did you buy them ? If you wouldn't mind sending them to me i'd be well interested in checking them out, its just the top compression rings. I'll check the 4 if you want. PM me and i'll let you have my address.

The dodgy ring looks ok on the piston, its only in the bore that you will see it. The gap i had was about 1.25mm!!!!

Spoke to Minispares earlier today and they are keen to check this out. Wish theyy would just send me another of theirs for me to check to see if its right or not.

Nic. been doing a little of late, should be off to paint just after christmas. Was gonna take a few weeks of before christmas to do some on it but more work in so thats cancelled :(.

Update.

I think minispares have sent my dodgy ring to an engine builder to take a look at it. Just had an email back from them, it was i suspected a +20 ring that has been stamped up +40 by the manufacturer!!!!!!!!!!!!!!!!!!!

Check your rings carefully!!!! lol

Ring gap is not an issue with new rings as long as its above the minimum and not stupidly large you could get a bus through it.


Als long as the gap is bigger than minimum you'll be fine



*edit* But if its a +20 labled as +40, then the ring tention will be all wrong and no good

Edited by Sprocket on 14th Dec, 2006.

forgotten to reply :o
didn't check gap , but did have a good look, ordered their is 2 years.

on this line, why on earth do minispares deliver the mega pistons with the rings on???!

Mini sprocket what do you class as driving a bus through ? The ring gap should be within tolerance for the engine / ring etc. If its to large you are gonna get increased blow past and increased temperatures below the ring.

I'd say ring gap becomes an issue when the manufacturer puts the wrong size on them. lol

Oops i forgot to update you all.

Had an email from minispares this week, The ring in question WAS indeed a +20 ring that was stamped up as a +40 !!!!!!!!!!!

There is no way of knowing if this was a single mixed up ring or a batch of them. I got these over 4 years ago, so i wouldn't worry about buying a set of pistons. Just check your rings of the pistons in the bores before you build. I'm gonna check the new set i get as soon as it arrives.

I suspect a lot of people, some engine builders included dont bother to check as modern parts are so good for size it not needed. This relies on the manufacturer never making a balls up, it always pays to check everything.

Edited by Mirage on 17th Dec, 2006.

Good point ..... well made.

Every day is a school day ...........

How fast and how expensive ...... the same question...