1293 ring gaps.
Turbo Mini Forums

What ring gaps would you advise for a 1293 turbo motor?

Ive done a bit of reading and 15thou seems to crop up.

On the second ring around 11-12 thou?

If they are too tight, which i think they might well be, how do you go about filing them to fit correctly? Ive not done this before so am looking for some tips from who has!!

Thanks!

15 on the top one is MAX. I use approx 12 on the top one, and 10 on the rest.

Cheers ill try it!

Ok bit confused, I took the rings off and put them in to each bore, seating them flush by pushing them down with the piston.

Turns out the majority of them where too large a gap, so i took them out the bores and bent the ends over bit to get the correct gaps.

But when i fit the rings back onto the pistons, they obviously get bent open again so what am i supposed to do?

Cheers

Stop bending the rings you may break them!!

You dont bend piston rings, the gaps are determined by the bore size. When they are inserted in the bore their "springyness" holds them open and therefore against the bore walls. The gap is determined by the size of the bore and the size of the ring. Usually they are OK but sometimes you may have to file the ends of the rings to make the gap bigger, you cannot do anything about the gap being too large.

When you say the gaps are too large how large are they?? It could be that the bore is worn, wrong size or the rings could be the wrong size or faulty.

Terry

Edited by Turbo Tel on 3rd Aug, 2008.

website:- http://www.terryhunt.co.uk

No worries i barely bent them enough to snap them.

The bores are a fresh 1293 rebore. And the rings are for the omega 1293 piston.

Top ring was 15 and the second about 12.

The oil scrappers however are both 15 thou

What did you have theblock bored to? W
What is the finished size?

As turbo Tel says...file ends to correct gap. Never bend them!

no longer a series, but still 1.3 turbo.

Actual bore size is 71.1mm

How can I go about checking the rod caps are with the right rod?

Minispeed gave them back to me rattleing around in a box, seperate to the rods - with no markings!!

Is there a way to find out which caps are for the right rods?

Schrödinger's cat - so which one am I ???

well not an ideal situation to be in.

but buy process on elimattion.

take one rod and in turn fit each cap to it. and find one which is nice on smooth were the join is. then go to the next rod.

but a internal micro would realy be needed to sort this little mess out.

always looking for them bigger bunches of bannanas

Yeah Minispeed are a bit of a joke to be honest!!

I've been building my block up today, have spent the last 3 hours using the "process of elimination", some of the caps where obvious that they didnt suit the rods, running a fingernail over the joins showed relatively big steps where the cap wasnt suited to the rod.

I put all the pistons/rods in and have now found the smoothest combination, im quite happy with it, the cam's just about to go in now so hopefully i'll have it all timed in tonight.

There are 24 different possible combinations of cap/rod (4 factorial) - even if you have found a combination that feel OK side to side by fingernail (a very good test in most cases) have you checked the top/bottom diameter with an internal micrometer for your "best fit" ???

Schrödinger's cat - so which one am I ???

No I havnt, unfortunately I dont have many tools, im also building this engine on my conservatory floor.

Have come across another problem now anyway, the timing end of the camshaft wont fit through the bearing, god knows whats wrong with that. Can you even get different thickness cam bearings?

EDIT:

Got some wet and dry around the inside of the bearing, it fits now and is fairly tight but turns smoothly.

Edited by richminiturbo. on 4th Aug, 2008.

Yep its .10!

So from what you said its pretty accurate! Minispeed managed to get that right thank god..

Then there's something wrong with the rings, ie. they are too small.

Which make pistons are they?

They are cast Omega 10cc dish 1293 ones.

Hmm. I don't have much experience with Omegas. Maybe others can help.

EDIT: Meant honed not bored

You don't hone a bearing. The cambearing is the softest metal known to mankind.