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dl1970 Samba Member
Joined: September 25, 2024 Posts: 9 Location: New Zealand
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Posted: Sat Aug 09, 2025 2:28 am Post subject: Cylinder scratching Grants rings |
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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.
Last edited by dl1970 on Sat Aug 09, 2025 10:46 am; edited 1 time in total |
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RWK Samba Member
Joined: June 24, 2009 Posts: 1626 Location: S.W. MI
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Posted: Sat Aug 09, 2025 5:49 am Post subject: Re: Cylinder scratching Grnts rings |
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Did you de-burr and clean rings before install? Possible sharp edge or F.O. on new rings from mfg. _________________ 73 Type 181
63 Type 113
63 Type 261- 428 071
62 Type 241-378 025 178 530 |
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Alstrup Samba Member
Joined: July 12, 2007 Posts: 7867 Location: Videbaek Denmark
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Posted: Sat Aug 09, 2025 7:46 am Post subject: Re: Cylinder scratching Grnts rings |
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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. _________________ https://www.thesamba.com/vw/forum/viewtopic.php?t=435993 |
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dl1970 Samba Member
Joined: September 25, 2024 Posts: 9 Location: New Zealand
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Posted: Sat Aug 09, 2025 10:49 am Post subject: Re: Cylinder scratching Grants rings |
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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? |
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modok Samba Member

Joined: October 30, 2009 Posts: 27707 Location: Colorado Springs
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Posted: Sat Aug 09, 2025 2:34 pm Post subject: Re: Cylinder scratching Grants rings |
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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. |
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oprn Samba Member

Joined: November 13, 2016 Posts: 14885 Location: Western Canada
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Posted: Sat Aug 09, 2025 3:11 pm Post subject: Re: Cylinder scratching Grants rings |
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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! _________________ Our cars get old, we get old but driving an old VW never gets old! |
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dl1970 Samba Member
Joined: September 25, 2024 Posts: 9 Location: New Zealand
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Posted: Sat Aug 09, 2025 3:18 pm Post subject: Re: Cylinder scratching Grants rings |
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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? |
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dl1970 Samba Member
Joined: September 25, 2024 Posts: 9 Location: New Zealand
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Posted: Sat Aug 09, 2025 3:20 pm Post subject: Re: Cylinder scratching Grants rings |
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There was plenty of oil on the cylinders i had wiped it out for the photo. |
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dl1970 Samba Member
Joined: September 25, 2024 Posts: 9 Location: New Zealand
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Posted: Sat Aug 09, 2025 3:59 pm Post subject: Re: Cylinder scratching Grants rings |
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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..... |
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modok Samba Member

Joined: October 30, 2009 Posts: 27707 Location: Colorado Springs
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Posted: Sat Aug 09, 2025 4:05 pm Post subject: Re: Cylinder scratching Grants rings |
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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 |
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