valve keepers
Race Director
Joined: Dec 2002
Posts: 13,348
Likes: 233
From: SCMR Rat Pack'r Charter Member..Great Bend KS
Impossible to tell from a photo. One appears to be used, the other not. Would have to do a hardness test to determine heat treatment.
What makes you believe one is NOT heat treated??
What makes you believe one is NOT heat treated??
Safety Car
Joined: Apr 2016
Posts: 4,648
Likes: 1,059
From: N.E. Ohio OH
Finalist 2020 C4 of the Year - Modified
On the edge where the radius is, hit them with a fine file. You can tell right away if one is harder than the other. You are not trying to remove a big chunk of metal, just gauging the hardness.
Thread Starter
Burning Brakes
Joined: Apr 2014
Posts: 829
Likes: 192
After further inspection, I dont think the black ones even fit properly. I think someone was in this engine not too long before I bought it and changed the exhaust valve keepers but used mis-matched keepers.
The engine had a rod knock when I bought it. I think the previous owner had gone in looking to fiddle with valve train to solve the knock and changed the keepers.
Look at these two pics. One shows the black keepers and how they have no gap (wrong) between the keepers when seated inside of the retainer. This retainer wobbles slightly.
The silver colored ones have the gap (correct) and the retainer is snug with no movement.
Would you concur that no gap is incorrect?
Drifting
Joined: Feb 2017
Posts: 1,274
Likes: 399
From: Tacoma WA
2024 C4 of the Year Finalist - Unmodified
Agree fully with C409. I lost an engine once when a keeper fatigued to point of failure, drop a valve and resulted in pushing the piston out the side of the block. 427 at 6800 rpm and it was an ugly and expensive lesson. Now I replace components like this whenever an engine gets examined.
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
Never heard on intake and exhaust keepers on engines with the same size valve stems. Back in the 70s SBC had some 3/8" exhaust valve stem heads. The guy before you probably lost a few. As with the others new retainers and keepers are cheap piece of mind.
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Burning Brakes
Joined: Apr 2014
Posts: 829
Likes: 192
Can I get a moderator to move this to "other cars"? I'm sorry but I should have posted it there in the first place. It's actually a Mazda 2.2 I'm working on here.
BTW, I've learned that Mazda made the exhaust valve keepers without gaps. The purpose was to create slight clearance between the valve stem and inner part of the keepers. It was done on exhaust valves only and is designed to allow them to rotate.
Some high performance Mazda engine builders don't like this because they say the potential for wear in this design can drop valves at high rpm. Those guys will typically install intake keepers on both the exhaust and intake.
So thats why those two keepers I posted picture of are different. The black one is an exhaust keeper and the silver one an intake.
BTW, I've learned that Mazda made the exhaust valve keepers without gaps. The purpose was to create slight clearance between the valve stem and inner part of the keepers. It was done on exhaust valves only and is designed to allow them to rotate.
Some high performance Mazda engine builders don't like this because they say the potential for wear in this design can drop valves at high rpm. Those guys will typically install intake keepers on both the exhaust and intake.
So thats why those two keepers I posted picture of are different. The black one is an exhaust keeper and the silver one an intake.
Last edited by JD1964; Jul 20, 2020 at 05:27 PM.
Safety Car
Joined: Sep 2004
Posts: 3,953
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From: Mission Viejo CA
Thread Starter
Burning Brakes
Joined: Apr 2014
Posts: 829
Likes: 192
Yeah, I dont like it either. I ordered a set of intake keepers and I'll be putting them on the exhaust side too and omitting the rotation.