TheSamba.com :: View topic

Sat Aug 09, 2025 2:28 am

I Have just installed Grants rings on 90.5 aa pistons/cylinders. On checking deck height i have noticed these scratches. They are in both number 1 and 3 cylinder. Is this normal? I suspect its the oil spacer as it seemed large on installation compared to the aa oil spacer ring. The red/green tabs on the oil spacer were definitely in the correct position prior to install.

Sat Aug 09, 2025 5:49 am

Did you de-burr and clean rings before install? Possible sharp edge or F.O. on new rings from mfg.

Sat Aug 09, 2025 7:46 am

Probably correct.
I always run a piece of Scothbrite over them and then give them a couple of tours in the ultrasound before installation. Works well.

Sat Aug 09, 2025 10:49 am

Everything was cleaned and de burred. There is a lot of scratching to honing more obvious in bottom left of photo. Doesn't really catch a finger nail yet but does not seem right. If this was run would they get worse?

Sat Aug 09, 2025 2:34 pm

I agree it's probably the oil ring rails, but not a tension issue.

Sometimes the chrome surface on the oil ring rails is rough on cheap rings.

It will probably wear in and work ok, but I don't consider it a good sign.

Sat Aug 09, 2025 3:11 pm

I know I will get flamed for this but... those are bone dry! Put a but of light engine oil on them man! It will pick up the odd but of dust etc. that gets missed or drops in after the fact, capture it, hold it and not score the cylinder walls!

Sat Aug 09, 2025 3:18 pm

Thanks for that madok i was hoping you would reply!. Something is not right the other cylinder has worse scoring and they are evenly spaced like the peaks on the control ring. what are my options to fix? Will a hone effect the ring gap? I have the original AA oil control rings can they be used with the grant top 1 and 2 ring if a hone works?

Sat Aug 09, 2025 3:20 pm

There was plenty of oil on the cylinders i had wiped it out for the photo.

Sat Aug 09, 2025 3:59 pm

I believe i have found the issue. The rings were ordered online as standard replacement rings for 90.5mm pistons. (The online part number was P1484.) I have just checked the box supplied and googled the part number. The rings supplied were P1484.020. The .020 is for 20 thou oversized pistons apparently.... Definitely ordered as standard replacement not oversized. If anyone else is ordering Grant rings online check the part number when they turn up and avoid this.....

Sat Aug 09, 2025 4:05 pm

no, the ring is for .020 over 90mm
which is 90.5mm

It's just roughness in the chrome of the oil rails.
Probably grant isn't as good as they were 10 years ago.
And good chance that grant company is buying their oil control rails from another company, that's often how it works.

May have to get another set of rings and mix and match if you want perfection.

I've always thought grant has very good quality IRON rings

But deves and hastings and npr have very good oil rings