piston ring question
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Tuned
Joined: Sep 2024
Posts: 274
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piston ring question
Hi guys
I am buying standard size piston rings for this 360 we're rebuilding. We've used a bore gauge within the cyl at several points (my son is a machinist and we've confirmed specs) and the standard size rings will be fine. Having not ever replaced rings, is it going to be necessary to file these rings to meet spec of the ring in the cylinder? I've looked at many online sources plus the OEM Ford manual and it talks about if/when cylinders are bored out and how rings need to be adjusted etc..
My completely dumb question - how similar are rings to getting sparkplugs that come pre-gapped?
What's the best suggestion if they need to be reduced? I see these hand-powered grinders that seem effective.
Please school me.
I am buying standard size piston rings for this 360 we're rebuilding. We've used a bore gauge within the cyl at several points (my son is a machinist and we've confirmed specs) and the standard size rings will be fine. Having not ever replaced rings, is it going to be necessary to file these rings to meet spec of the ring in the cylinder? I've looked at many online sources plus the OEM Ford manual and it talks about if/when cylinders are bored out and how rings need to be adjusted etc..
My completely dumb question - how similar are rings to getting sparkplugs that come pre-gapped?
What's the best suggestion if they need to be reduced? I see these hand-powered grinders that seem effective.
Please school me.
Lead Driver
Joined: Oct 2018
Posts: 7,879
Likes: 2,367
there's a 99% chance the gap if anything will be wider than it should be in a worn bore. but always check.
If they do need filed, I just lightly hold them in a vice using a rag in the jaws to protect the ring and file them. it doesn't take very long.
Be sure to hone the bore and use cast rings.
If they do need filed, I just lightly hold them in a vice using a rag in the jaws to protect the ring and file them. it doesn't take very long.
Be sure to hone the bore and use cast rings.
Thread Starter
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Tuned
Joined: Sep 2024
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thanks Sixpack .. the ones I've been recommended are these Hastings 574 good? bad?
Bore has been hone with new hone and has nice crosshatch now .
Bore has been hone with new hone and has nice crosshatch now .
Hotshot
Joined: Feb 2004
Posts: 10,809
Likes: 2,605
From: The Shenandoah Valley
If using new standard size rings in a used engine that has wear, highly unlikely you'll be needing to file any ring gaps, but you might want to insert rings in each bore with no piston, square it with the bore, make sure gap is enough, using feeler gauge. If you want to file gaps, you'll need larger rings. They do need some gap as they can get hot in use.
I know you know it, but space gaps around the piston like 120 degrees apart ..... not lined up.
I know you know it, but space gaps around the piston like 120 degrees apart ..... not lined up.
Logistics Pro
Joined: Jun 2004
Posts: 4,767
Likes: 3,379
From: South Central Utah
The engine I bought for my truck was rebuilt a long time ago and never started.
The person who rebuilt it bought it out of a 6 year old low mileage Mercury and had the pistons knurled to try and compensate for some cylinder wear.
I have been told the knurling the pistons was quite common back in the '70s and earlier and could make up for about 0.002" cylinder wear.
The pistons were the factory standard pistons.
I found a new standard piston on eBay.
I also found these rings on eBay too.
The production date, 1978. That was 2 years after my engine was rebuilt.
I bought cast rings because as far as i could tell that's what he used.
I lucked out and did not have to adjust the ring end gap.
If I had I would have done it exactly like 440 sixpack suggested.
It all went back together quite well and runs great.
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Tuned
Joined: Sep 2024
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it was a comment in this thread piston ring discussion
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Cargo Master
Joined: Oct 2020
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In Hastings' numbering scheme, just a number means a set with a plain cast iron top ring. A 2C prefix means that it comes with a chrome plated top ring and a 2M means that it comes with a moly filled top ring. Don't get the cast, get the 2M574 set. There is no advantage to running a plain top ring except for the initial price.
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Laughing Gas
Joined: Feb 2011
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With a stock bore thats still in spec usually new rings will not need gapped or if they do its very little...or if one is **** about being right at nominal of the tolerance. Assumptions can't be made. Every ring needs checked for the cylinder its going into. Insure that when the cyclinder bore dimensions were checked, it was done at 3 locations. Top of ring travel, 1/2 way down and then near the bottom of ring travel. For this type of rebuild I'd use cast iron rings.
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Tuned
Joined: Sep 2024
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In Hastings' numbering scheme, just a number means a set with a plain cast iron top ring. A 2C prefix means that it comes with a chrome plated top ring and a 2M means that it comes with a moly filled top ring. Don't get the cast, get the 2M574 set. There is no advantage to running a plain top ring except for the initial price.
Hotshot
Joined: Jul 2020
Posts: 10,478
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From: Near Salt Lake City
I would use the old cast iron rings
That old motor was designed around cast iron rings
If going racing or not worried about the rings seating quick, go chrome moly
Some chrome moly rings don't seat for 10k miles and burn oil forever
Knurling pistons is a band aid
That old motor was designed around cast iron rings
If going racing or not worried about the rings seating quick, go chrome moly
Some chrome moly rings don't seat for 10k miles and burn oil forever
Knurling pistons is a band aid
Cargo Master
Joined: Oct 2020
Posts: 2,676
Likes: 785
I would use the old cast iron rings
That old motor was designed around cast iron rings
If going racing or not worried about the rings seating quick, go chrome moly
Some chrome moly rings don't seat for 10k miles and burn oil forever
Knurling pistons is a band aid
That old motor was designed around cast iron rings
If going racing or not worried about the rings seating quick, go chrome moly
Some chrome moly rings don't seat for 10k miles and burn oil forever
Knurling pistons is a band aid
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