Grant piston rings

[dave66]

New piston rings Grant.
just going to rebuild the engine and get the first issue with new parts: the oil rings can‘t be compressed when the steel rails are installed as described in the instructions.
only when positioning the rings in the two colours area at the junction of the Expander Spacer the rings can be compressed and would fit in the cylinder. I can’t really understand if the size of the rings is wrong (should be the standard one) or the instructions are not correct.
The older expander spacers fit pefectly, but have a different pattern compared to the one of the new Grant rings, which could be the problem.
Any experience with these rings ?
Thanks for helping!
Dave

[trunt]

Did you check your other rings in the bore? They should fit but may need a little adjustment, that should inform on size.

I did mine a year or two ago with grant rings, a bit fiddly but they were ok in the end.

What kind of ring compressor are you using??

Terry

[flying farmer]

I have used them in the past, IIRC the coloured bits at the join of the expander have to be well away from the ring gap or they hang up on the rings and stop them compressing properly

[Jeff]

You’re not the only one to have problems with these rings - take a look here: https://www.socforum.com/forum/forum...ale-of-3-rings

[dave66]

Bloody hell ! Thanks Jeff, I just replied to Mark on the other post. Which alternative rings would be available otherwise and from which supplier ? County from Rimmers ?

[jbuckl]

More worrying bad parts news.
If only we could still get hepolite pistons & rings.
Perhaps some quality piston suppliers need to be approached ?

http://pistonrings.co.uk/

or omega pistons?
even if they work out much more money it would be worthwhile.
usually best to get a bulk order placed & few people are prepared to take that on .

[new to this]

More worrying bad parts news.
If only we could still get hepolite pistons & rings.
Perhaps some quality piston suppliers need to be approached ?

http://pistonrings.co.uk/

or omega pistons?
even if they work out much more money it would be worthwhile.
usually best to get a bulk order placed & few people are prepared to take that on .

We could still get hepolite pistons , but its down to cost they would be dearer than county pistons

[jbuckl]

We could still get hepolite pistons , but its down to cost they would be dearer than county pistons

Hepolite aren’t offering to make stag pistons afaiaa.
If I’m wrong, please give details.... they were bought by federal mogul, may now be with Mahle?
in my opinion the price could be well worth it compared to incorrect mass, form & rings & the trouble that causes.
my car has hepolites I managed to source years ago ...fitted last winter replacing the last set, which was supplied by the hepolite rep when I dealt with them in the 1990’s....£50 each as a favour....apparently the last +20 set from their stores. The next set came from Andrew puddifer.
omega might be a viable option though.

[dasadrew]

Interesting. As far as I recall, my Grant rings fitted according to the instructions without a problem. I do seem, however, to remember it being a pretty fiddly job. They seem to be the same ones. I fitted mine to original Mk2 domed pistons.

GRANT Piston Rings Stag 1.jpgGRANT Piston Rings Stag 2.jpgGRANT Piston Rings Stag 3.jpg

[Mark Serj]

Hi guys,

I have posted below the answer I gave Dave, with a bit more as well.

Sorry to hear you are having the same problems. In simple terms the plastic blocks on the ends of the rings have very poor quality control applied to them. I can say with pretty much 100% confidence that the problems you are experiencing is because the plastic on the inside dia side of the expander rings is too proud and holds the ends of the expanders away from the piston. This makes the installation not only difficult, but if continued with will force the pistons over in the bore, evidenced when you look at them after installation - they will clearly be hard over to the side opposite where you have put the expander ring joint. If left like this, bore scoring is highly likely, as is running over of the ends of the rings. I faffed about with this situation for many hours!

The solution is simple, just carefully dress the excess plastic away on the inside die of th eexpander ring until they sit properly.

The design of these expander rings is very poor. They can ride over each other with no persuasion at all when fitting and installing them. Its important that the oil ring ends are not coincident with the expander end, and you are 100% confident that the ends haven't run over each other before fitting. I always applied my ring compressor in a way that I held it against the expander joint position to keep pressure on it during tightening.

Once installed, if the piston is central in the bore then all is well. If not, then take it out and keep doing it until it is.

BTW I put my findings to Grant in the States and liaised with a helpful technician who passed all my findings on to their Head of Engineering. Despite me chasing them up for a formal reply at least half a dozen times, they have refused to reply, no doubt frightened s&*tless by threats of litigation due to wrecked bores, caused by their poor quality control.

Just for fun I had another poke at them again this morning, but with a bit more bite!!!



Regards

Mark

[MandM]

Hi Drew do we need to put a summery of this problem in the technical section (Engine) for future ref, what do you think?

Martin

[jbuckl]

Best solution is to source elsewhere so poor offerings become known & avoided. Not quite so easy to arrange though.

[dasadrew]

Hi Drew do we need to put a summery of this problem in the technical section (Engine) for future ref, what do you think?

Martin

Hi Martin,

I haven't really seen a "Tip or Trick" here for the technical section. Sounds a bit more like a warning about poor parts from a supplier and, for my own sanity, I'm not going down that route. Last time I wrote such a thing and documented it with photos and evidence I was reported!

Drew

[MandM]

Ok Drew , thanks anyway

[jbuckl]

Hi Martin,

I haven't really seen a "Tip or Trick" here for the technical section. Sounds a bit more like a warning about poor parts from a supplier and, for my own sanity, I'm not going down that route. Last time I wrote such a thing and documented it with photos and evidence I was reported!

Drew

We should be able to say what we find, factually, good or bad. Even if rhyming slang is required.