Piston Rings 1275 Turbo Rebuild

Page:

Home > Help Needed / General Tech Chat > Piston Rings 1275 Turbo Rebuild

Brocky

User Avatar

807 Posts
Member #: 224
Post Whore

Katy TEXAS

4th Nov, 2012 at 04:05:38am

Alright Guys,

Just about to start my rebuild after stripping the teeth off the big end of the laygear, managed to pull over and switch off sharpish and get a tow home. Besides I couldn't get any gears, and with the quaife in there wasn't taking any chances....

Obviously 12psi was a bit much for the standard box, even with new bearings and good tolerances, although I suspect there may have been a little coolant in the oil which may have lead to the gear teeth over heating as it looks like the head gasket was just about to go (after 2 years or so of occassional weekend abuse) as there appeared to be oil on the face towards the back of the block.

Straight cut set on order,

On inspection input bearing is still tight and smooth as are the lay shaft bearings,

Anyway, as the usual precaution have done a full strip down and the oil pump and main/big end bearings look fine so no harden gear teeth fragments found their way up the pick up.

Pulled the pistons and all looks fine, no broken land or rings and bores are clean, just the slightest pitting on the side of the crowns between 3-4.

Note: Engine was not burning oil, and pistons still faily tight on gudgeons.

My question is can I clean up the pistons and re use the rings ??

I have 2 new sets of 1275 Original AE Turbo rings, but wonder that if I deglaze the bores to run the new ones in that the bores might be too slack verses putting the old rings in and not getting a good seal since I cannot garrentee they will be in the same place rotationally speaking. Or does this not matter ?? Guess I would have to measure the bore wear, but don't have the instruments to hand.

Last thing I want is an oil burner and would like to make the most of the spares/blocks I have avalible here in the states, since I also have another set of very low milage 1275 turbo pistons, in A1 condition which I plan to put in another 1275 sleeved block, so will be using one of the new sets of rings there, although I am told I could rough up the rings on those and put them in new sleeves.

As a side note I have a 1380 and a 1310 block, but don't want to shell out for pistons if I can use the 1275 options first.

Any advise on the rings will be appreciated.

Cheers

Brocky

Edited by Brocky on 4th Nov, 2012.

BTW - I took my buddy VTEC Pete out for a spin this weekend, and even though I am running her in, he gave it a name, the "Brocket"...cause I'm a brocket maaannn, nah nah nah nah nah nah nah nah nah nah nah....

Build thread - http://www.turbominis.co.uk/forums/index.php?p=vt&tid=7483

Katy Mini Owners Club Thread - http://www.turbominis.co.uk/forums/index.php?p=vt&tid=505552

Let's make sure you embarrass at least one VTEC MINI today !

https://www.facebook.com/groups/17557298589...096464253807802

BENROSS

User Avatar

9812 Posts
Member #: 332
Resident Cylinder Head Modifier

Mitsi Evo 7, 911, Cossie. & all the chavs ...... won no problem

4th Nov, 2012 at 05:32:44am

Hi they are NLA sorry to say, I would shell out and get +20 omega10CCS dish cast pistons and a rebore, job done buddy

Brocky

User Avatar

807 Posts
Member #: 224
Post Whore

Katy TEXAS

4th Nov, 2012 at 05:50:18am

Hey Mr Ross (Steve),

Hows it going, that head is still going great guns btw

Maybe you havn't had you coffee yet but I actually have 2 off, unused boxed sets of 1275 turbo piston rings, still in the paper pouches, possibly the last 2 from minispares.

So are you saying don't put the old ones back in ?

Maybe better if I give you a phone? Same number ?

Edited by Brocky on 4th Nov, 2012.

apbellamy

User Avatar

16540 Posts
Member #: 4241
King Gaycharger, butt plug dealer, Sheldon Cooper and a BAC but generally a niceish fella if you dont mind a northerner

Rotherham, South Yorkshire

4th Nov, 2012 at 09:51:57am

How worn are the bores? Take the block to a machine shop and get the measured. If they are tight enough, get it honed and use new rings. If they are worn, bang the old ones back in. As long as you don't damage them getting the pistons out and put them back in the same bore, they should be OK (maybe not as OK as before they came out, but should still seal).

On 11th Feb, 2015 robert said:
i tried putting soap on it , and heating it to brown , then slathered my new lube on it

minimole23

4309 Posts
Member #: 1321
Post Whore

Wiltshire

4th Nov, 2012 at 10:43:02am

Is there any lip in the top of the bores? If there is you will probably want a rebore, if not you should get away with a hone. I ran 5 thou piston to bore clearance on my last motor and compression was perfect, with no oil comsumption, ring gaps were at the limit of reccomended tolerance though.

On 7th Oct, 2010 5haneJ said:
yeah I gave it all a good prodding

Sprocket

User Avatar

11046 Posts
Member #: 965
Post Whore

Preston On The Brook

4th Nov, 2012 at 12:14:44pm

On 4th Nov, 2012 Brocky said:
Hey Mr Ross (Steve),

Hows it going, that head is still going great guns btw

Maybe you havn't had you coffee yet but I actually have 2 off, unused boxed sets of 1275 turbo piston rings, still in the paper pouches, possibly the last 2 from minispares.

So are you saying don't put the old ones back in ?

Maybe better if I give you a phone? Same number ?

First thing I would do is take the rings out of the packest and check that they actually fit the pistons. There have been people who have bought 'turbo' rings from Minispares and they did not fit the turbo piston.

Have a search *wink*

On 26th Oct, 2004 TurboDave16v said:
Is it A-Series only? I think it should be...
So when some joey comes on here about how his 16v turbo vauxhall is great compared to ours, he can be given the 'bird'...

On 26th Oct, 2004 Tom Fenton said:
Yep I agree with TD........

Brocky

User Avatar

807 Posts
Member #: 224
Post Whore

Katy TEXAS

4th Nov, 2012 at 02:25:58pm

Now you have me thinking...

Diameter and thickness look correct, as per dims on box,

I picked these up about 5 years ago before leaving the uk,

Only thing is that the oil ring is a different design ?? any ideas, or may be just an improvement over the years?

I'm taking the block into the machine shop to get some work done for fitting squirters, so can get them to measure up, I guess the other thing would be to use one of the rings positioned at different points down the bore and measure the ring gap? I can at least do this at the top and middle to see if there is lip / step

Edited by Brocky on 4th Nov, 2012.

Sprocket

User Avatar

11046 Posts
Member #: 965
Post Whore

Preston On The Brook

4th Nov, 2012 at 03:43:24pm

the oil ring is the problem. Apparently they are 'deeper' than the groove in the piston, therefore will not compress up enough to fit in the bore.

Like I said, fit them to the piston and confirm one way or the other.

On 26th Oct, 2004 Tom Fenton said:
Yep I agree with TD........

Brocky

User Avatar

807 Posts
Member #: 224
Post Whore

Katy TEXAS

4th Nov, 2012 at 04:48:15pm

Understood will have a look at it
Could be a show stopper
Might have to give the old rings a go if not

apbellamy

User Avatar

16540 Posts
Member #: 4241
King Gaycharger, butt plug dealer, Sheldon Cooper and a BAC but generally a niceish fella if you dont mind a northerner

Rotherham, South Yorkshire

4th Nov, 2012 at 05:02:47pm

or get total seal rings

On 11th Feb, 2015 robert said:
i tried putting soap on it , and heating it to brown , then slathered my new lube on it

Brocky

User Avatar

807 Posts
Member #: 224
Post Whore

Katy TEXAS

4th Nov, 2012 at 05:36:56pm

Not something I've heard of ?

Who sellers them ?

apbellamy

User Avatar

16540 Posts
Member #: 4241
King Gaycharger, butt plug dealer, Sheldon Cooper and a BAC but generally a niceish fella if you dont mind a northerner

Rotherham, South Yorkshire

4th Nov, 2012 at 06:17:40pm

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=355598

we ran them in the upside down skip, worked well and more importantly fitted. I would expect you will get them cheaper as they are made in the US.

On 11th Feb, 2015 robert said:
i tried putting soap on it , and heating it to brown , then slathered my new lube on it

Brocky

User Avatar

807 Posts
Member #: 224
Post Whore

Katy TEXAS

4th Nov, 2012 at 06:29:37pm

Perfect,

Thanks AP,

apbellamy

User Avatar

16540 Posts
Member #: 4241
King Gaycharger, butt plug dealer, Sheldon Cooper and a BAC but generally a niceish fella if you dont mind a northerner

Rotherham, South Yorkshire

4th Nov, 2012 at 07:23:34pm

No prob's

On 11th Feb, 2015 robert said:
i tried putting soap on it , and heating it to brown , then slathered my new lube on it

Brocky

User Avatar

807 Posts
Member #: 224
Post Whore

Katy TEXAS

5th Nov, 2012 at 03:36:52pm

Ok Sprocket,

Cleaned up the piston and took off the rings,

Average depth of oil ring groove looks to be 3.35mm - 3.50mm

Average width of new oil ring section looks to be 3.6mm - 3.7mm

I guess this is what you where talking about, must had missed that thread originally and just assumed that replacement rings would be exactly that....bit pissed that I didn't pick up on it sooner, but will be giving Total seal a call today, so not a total loss.

The more I think about it the more I am thinking deglaze bores and new rings, since they are avalible here, but will get the bores measured up for sure.

Good job you said really as I wouldnt have though to check, and would have popped on the ring clamp and tapped away....

Edited by Brocky on 5th Nov, 2012.

Brocky

User Avatar

807 Posts
Member #: 224
Post Whore

Katy TEXAS

5th Nov, 2012 at 09:59:48pm

On 4th Nov, 2012 minimole23 said:
Is there any lip in the top of the bores? If there is you will probably want a rebore, if not you should get away with a hone. I ran 5 thou piston to bore clearance on my last motor and compression was perfect, with no oil comsumption, ring gaps were at the limit of reccomended tolerance though.

Hey Minimole,

I just did the Haynes check using the piston 3/4 inch down the bore, it recommends that anymore than 10 thou should be rebored.

There is a slight lip on the thrust side of the bore but I can only just get the 0.01mm (3.93Thou) feeler down the side of the piston, so sounds like slightly less piston to bore clearance than yours, but did you measure the clearance after you deglazed the bores for new rings ?

Actually based on the recommended Skirt clearance - Top figures 0.1mm is below the top tolerance of 0.114 *smiley*

Cheers

Brocky

Edited by Brocky on 5th Nov, 2012.

minimole23

4309 Posts
Member #: 1321
Post Whore

Wiltshire

5th Nov, 2012 at 10:16:28pm

That engines still under the bed as a spare. I'll stuff a feeler gauge down the side tomorrow and see what I can find.

My machinist measured it. That said though, I did select a low milage block that had no step in the bore.

I swear I remember fastcarl saying a few years ago he ran some silly piston to bore clearance in one of his engines, so with total seal rings you should be ok if you do hone it out a little more.

On 7th Oct, 2010 5haneJ said:
yeah I gave it all a good prodding

Brocky

User Avatar

807 Posts
Member #: 224
Post Whore

Katy TEXAS

5th Nov, 2012 at 10:39:12pm

Just spoke to total seal and as you say the ring gap issue goes away with thier no gap ring,

They recomend a hone with 280 grit (US could be different to UK Scale),

2 - 3 rotations should only remove 2 10 thousanths on an inch.

140 bucks delivered, which at todays exchange rate is 87.50 quid, which is pretty close to your price apbellemy !! Looks like the uk wins this one since they are manufactured here !?

Ironically I can buy Scotch Wiskey cheaper here than in Scotland...go figure ??

Cheers

Brocky

Edited by Brocky on 5th Nov, 2012.

fastcarl

User Avatar

6965 Posts
Member #: 507
Fastest A Series Mini in the World

leeds/wakefield.

6th Nov, 2012 at 08:07:24am

Now then gents, i will throw a curve ball into the mix here,

last year i can across a set of rings marked up as above and had the correct thickness rings, but the oil rings, [seperate thin ones] would not got into the groove using the supplied spring spacer, i fitted the old spring and they went in, these were for old standard turbo pistons,

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

Brocky

User Avatar

807 Posts
Member #: 224
Post Whore

Katy TEXAS

6th Nov, 2012 at 03:47:24pm

Thanks Carl,

The trouble is with the new rings I have is that the 3rd ring design is completely different so I'm not sure the spring is interchangable in my case.

Since I measured up the bore I'm still half temped to bang the old rings back in, since I hear people have found that they tend to rotate anyway ?

So as long as you put the same ones back the same bore the right way up etc, they should seal, assuming they were springing out at the same rate around the bore, i.e. making a uniform circle,

Trouble is if it doesnt work, I 'm out of pocket for at least a full gasket set and hours of labour to go back in and replace them.

My blocks going in to the shop to get the Bimmer squirter work done, some tapping and plugging and a 3 thou scim to bring the static cr upto 8.2 so I'm think just get it honed anyway? and bang in a set of total seal rings.

Edited by Brocky on 6th Nov, 2012.

apbellamy

User Avatar

16540 Posts
Member #: 4241
King Gaycharger, butt plug dealer, Sheldon Cooper and a BAC but generally a niceish fella if you dont mind a northerner

Rotherham, South Yorkshire

6th Nov, 2012 at 04:12:25pm

I would fit the TS rings anyway, the old ones are probably 25+ years old and are bound to be worn. We successfully put 25psi+ through the van with them and it always ran very well.

On 11th Feb, 2015 robert said:
i tried putting soap on it , and heating it to brown , then slathered my new lube on it

Brocky

User Avatar

807 Posts
Member #: 224
Post Whore

Katy TEXAS

6th Nov, 2012 at 04:15:15pm

Just did the ring gap, came in a 0.5mm on the top comp ring 3/4 inch down the bore, this is 0.2mm over the recommend end gap,

I think I'd better get the TS ones like you say :)

Edited by Brocky on 6th Nov, 2012.

John

10023 Posts
Member #: 1456
Mongo

Barnsley, South Flatcapshire

6th Nov, 2012 at 04:20:58pm

Surprised me how strong the original MT pistons actually are.
The pistons were clean as a whistle when they came out of the van too, no additional hints of det compared to when they went in.

I'd be more than happy to run them again if the pistons are in good condition and the bore clearances are within tolerance.

As Andy says we lobbed 25psi+ down the neck of the van with the TS rings on a re-honed std block.

Edited by John on 6th Nov, 2012.

If something is worth doing, it's worth doing half of.

Brocky

User Avatar

807 Posts
Member #: 224
Post Whore

Katy TEXAS

6th Nov, 2012 at 04:45:10pm

Pistons have cleaned up remarkably well,

They rotate very freely on the pin but there is no rock from up and down or side to side, and there is zero sign of any det, well at least on no. 1, no.3 still has 0.5mm of carbon on it lol, but suspect will be good under neath,

Note the mark on the edge of the crown is a stain which will sand off easily

The max I ran on these was 10-12 psi with my cossy intercooler, but the motor had only been ran standard before that

I do have another set of original pistons that are in even better shape, but also have another 1275 block that has been sleeved previously, and there is no step in the bore at all, but needs new cam bearing, that can be the next build/spare motor.

Thanks for all the help by the way guys, :)

Edited by Brocky on 6th Nov, 2012.

Sprocket

User Avatar

11046 Posts
Member #: 965
Post Whore

Preston On The Brook

6th Nov, 2012 at 05:50:40pm

What CC in the head do you have that has brought thr CR down below 8.2?

There is not much to come off the block before the pistons are flush with the top, the turbo pistons are already near the top.

On 26th Oct, 2004 Tom Fenton said:
Yep I agree with TD........

Home > Help Needed / General Tech Chat > Piston Rings 1275 Turbo Rebuild

Users viewing this thread: none. (+ 1 Guests)

Next ->

To post messages you must be logged in!
Username: Password:

Page:

Piston Rings 1275 Turbo Rebuild
Turbo Mini Forums

Welcome to the TM Forums
Feel free to join our community for help, advice and banter!

Piston Rings 1275 Turbo RebuildTurbo Mini Forums

Welcome to the TM ForumsFeel free to join our community for help, advice and banter!

Piston Rings 1275 Turbo Rebuild
Turbo Mini Forums

Welcome to the TM Forums
Feel free to join our community for help, advice and banter!