Piston ringa

[jims56]

https://www.summitracing.com/parts/hsn-cm5531/recommendedparts

Comments on these rings. Would use them on some speed pro Hyper's. Or do ya have any yea or nea suggestions?
Thanks jim

[BamaNomad]

4" bore.. so that would be only for a 'std' 302, 327, or 350... more likely you'd need a 4.030 if you need to bore the block.

Personally I like to use moly rings, and I would have no problems with Hastings as a brand.

[markm]

Have used a lot of cast iron Hastings rings in my day with good results. Never been a big Moley ring fan as a result of mixed results.

[Rick_L]

Price is kind of high compared to equivalent ring sets at Summit. That may be because they are standard bore and not .030 or .060 over. For instance a Hastings set in .030 over is only $76 instead of $120. Sealed Power has .030 over rings of the same description for $35.

With hyper pistons, you need to watch your ring gaps as they are different from stock style cast pistons or forged pistons. You may want to consider the Keith Black rings, esp. if you have Keith Black pistons.

[BamaNomad]

Rick, Can you elaborate on how/why ring gaps are different with hypereutectic pistons (vs stock cast or forged pistons??)

[56ls408]

Price is kind of high compared to equivalent ring sets at Summit. That may be because they are standard bore and not .030 or .060 over. For instance a Hastings set in .030 over is only $76 instead of $120. Sealed Power has .030 over rings of the same description for $35.

With hyper pistons, you need to watch your ring gaps as they are different from stock style cast pistons or forged pistons. You may want to consider the Keith Black rings, esp. if you have Keith Black pistons.
I always heard that concerning Keith Black pistons isn't that due to the ring being closer to the top of the piston more heat so needs larger ring gap but hadnt heard that about hyperutectic like used in oem engines I never increased replacement rings end gaps when reusing oem pistons in the past supposedly Keith Black pistons will blow the top of the piston off if top ring isn't gapped to they're spec

[Rick_L]

There aren't any good "rule of thumb" rules to follow on ring gaps for hyper pistons. Just make sure you follow the recommendations of the piston supplier.
It's all about heat transfer. Hypereutectics require bigger ring gaps than the conventional wisdom for either stock cast pistons or for forged aftermarket pistons.

It's not about the ring groove being higher on the piston than others. We used to run a very high ring groove on pistons for drag race engines, also with thin rings. No difference for those compared to a more conventional setup - .001" gap per 1" of bore. Hypers are typically much more. Also their second ring gaps are as big or bigger than the top ring. Forged pistons typically get a smaller gap for the 2nd groove.

I can't really explain why, but I can explain that you should follow the recommdations.

[matt56]

Definitely follow the piston manufacturer recommendations re ring gap. Most of the speed pro hypers have fairly typical ring gaps; the KB's regommended gaps are typically wider. This is on the assumption of 5/64 ring width type pistons. Not sure about fancier ones.

My understanding (which seemed to make sense in the one only KB I looked at was the top ring is higher in the KB) and caused a requirement to allow for more thermal expansion of the ring. Not sure if that is fact but seems plausible.

[matt56]

And to the original question. For basic type engines I also have had success with plain cast Hastings rings (also sold under Summit brand; or at least were. They bed in easily and are value priced - $30ish for 4" or 4 1/8" bore sets.

Not marketed as a performance ring but my experience in hot street engines has been excellent.

[enigma57]

Jim, do you already have your new pistons? And are you building a 327?

[jims56]

Sorry guy's I totally forgot about this thread I posted back in July. It was a bad month, my brother in-law who had a black 55 passed away shortly after posting this question, my sister was a wreck.