Club 80-90 Forums

ajsimmo wrote: ↑06 Aug 2020, 20:18 Or not. Follow the Grant instructions,

Fair point

Any idea why Grant give that guidance. I have used TotalSeal rings on other engines and unless I'm suffering from brain fade they were at 120 spacing

ajsimmo wrote: ↑06 Aug 2020, 20:18 Or not. Follow the Grant instructions, abutted ends of the springy expander ring above either gudgeon pin hole, then top and bottom thin rail with gaps 1-2" left and right of the expander join.
A bit like this.

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Did a wet run using this configuration. Checked 1 and 2 comp ring gaps. Both fine.
Also checked the oil rings gap. In spec.
However when the oil spring is fitted with both oil rings either side it wont compress to fit in sleeve. The oil rings should sit above and below the spring? Or against the raise tabs on oil spring?

Perhaps l need to clean out the piston grooves more?

Regards
Stuart

Oil rings should sit on the spring ring tabs i think stu 

it should say in the destructions

Your instructions say something about being for pistons with deep oil ring groove

cant read it all as only part shown in your piccy

Cobra88 wrote: ↑06 Aug 2020, 22:04 Your instructions say something about being for pistons with deep oil ring groove

cant read it all as only part shown in your piccy

Cheers Rick,

Instruction sheet reads for original factory groove spec. All my pistons are marked VW Mahle

Surely the oil rings must fit above top and below bottom of spring and not on raised tabs? Otherwise they cannot compress.
Perhaps l need to check oil groove height gap. Not the depth. And clean out a bit more carbon.

I would trial fit the rails individually without the expander.

That will give the confidence that they are the right size, then you can repeat the exercise with the expander in place.

Grooves need to be cleaned of carbon first though

Thanks.
Ive checked oil ring gap in sleeve. All good and within spec. And all piston grooves cleaned of carbon.
Question is do the oil rings sit above and below spring rail or against spring rail on raised tabs? If latter one cannot compress rings to slide in to sleeve. If former the piston groove is too tight.
Will clean grooves further again and give another go

Hmm, well you made me do some reading and I couldn't find an answer.

Three threads for you to read though

https://www.thesamba.com/vw/forum/viewtopic.php?t=639159

https://www.audizine.com/forum/showthread.php/859262-Grant-Piston-Rings

https://www.mgexp.com/forum/mgb-and-gt-forum.1/new-and-improved-grant-piston-rings.3999455/

You are not the only one with issues installing these rings, but as Andrew was able to post a photo for you showing the correct alignment it seems he uses them........ or he had a trial set and he doesn't use them.

In the absence of instructions I would expect that the rails sit on the expander, any other method would leave the outer part of the ring unsupported and liable to movement and breakage.

Ok, I'll bite! You knew I would
Here's a pic of a used DG piston, with the oil control ring fitted as per Grant instructions. It (they) went on easily and move freely but snugly in the groove. Pretty near perfect fit, I'd say.

No problem compressing it, either.

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Just had a look at the links. This made me smile: "A quick search of "piston ring orientation" shows that you are fine so long as you don't do what anyone else recommends. "

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Aha! Top man.
Here are many answers' to help me. I thank you very much.

The oil rings actually sit above/below spring ring tabs and not butted up against.

So l need to clean out that groove more.

Kind regards
Stuart

ajsimmo wrote: ↑07 Aug 2020, 12:31 Just had a look at the links. This made me smile: "A quick search of "piston ring orientation" shows that you are fine so long as you don't do what anyone else recommends. "

That made me smile too, thanks for the great pictures, much better than the manufacturers instructions



You've also shown Stu what a used piston should look like, more cleaning required

937carrera wrote: ↑07 Aug 2020, 12:55

ajsimmo wrote: ↑07 Aug 2020, 12:31 Just had a look at the links. This made me smile: "A quick search of "piston ring orientation" shows that you are fine so long as you don't do what anyone else recommends. "

That made me smile too, thanks for the great pictures, much better than the manufacturers instructions



You've also shown Stu what a used piston should look like, more cleaning required

I have been following this youtube guide throughout

http://www.bing.com/videos/search?q=you ... RV&PC=SMSM

Still cleaning ??

937carrera wrote: ↑15 Aug 2020, 17:49 Still cleaning ??

Hi David,

. Got bigger fish to fry! Whatever that means

See ...

viewtopic.php?f=39&t=172189&p=8273238#p8273238


Back on it next week.