Why one and three groove valve keepers?

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dibbons

dibbons

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Just curious why 340 intake and exhaust valves are manufactured with different groove designs. The intakes only have one groove and the exhaust have three. My best guess is that it had something to do with valve rotation, but maybe an engineer on the forum can answer my question best. Thank you.

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Looks like you have 2 groove intakes and three groove exhausts.

The multi groove locks actually butt together and allow the valve to rotate and it reciprocates. This, is supposed to make the valve spin and keep carbon from building up on the seat. I almost never use multi groove valves/locks unless it's a bone stock deal with hydraulic lifters. If it has a solid lifter, or even a fairly fast hydraulic lobe, it will beat the snot out of the locks pretty quickly.

The single groove locks do not butt together and grab the valve very tight. The valves don't rotate. When they do, from float, bounce, surge or what ever they usually fail. You can see valve float fairly easily on the tip of the valve.
 
mopowers said:
Those are 2-groove intake, 4-groove exhaust. I always wondered why they did that as well.
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it is quite simple

they designed that so you can eliminate engine builders or machine shops that dont know mopars
you bring the heads in, have them look em over and when they act surprised to see two different types of retainers you pack up your stuff and move on down to the next shop
 
Hahaha
diymirage said:
it is quite simple

they designed that so you can eliminate engine builders or machine shops that dont know mopars
you bring the heads in, have them look em over and when they act surprised to see two different types of retainers you pack up your stuff and move on down to the next shop
Click to expand...
 
yellow rose said:
Looks like you have 2 groove intakes and three groove exhausts.

The multi groove locks actually butt together and allow the valve to rotate and it reciprocates. This, is supposed to make the valve spin and keep carbon from building up on the seat. I almost never use multi groove valves/locks unless it's a bone stock deal with hydraulic lifters. If it has a solid lifter, or even a fairly fast hydraulic lobe, it will beat the snot out of the locks pretty quickly.

The single groove locks do not butt together and grab the valve very tight. The valves don't rotate. When they do, from float, bounce, surge or what ever they usually fail. You can see valve float fairly easily on the tip of the valve.
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I agree, but have never really had a problem with Chrysler locks. It is interesting that HP 360 and 340 engines had the multi groove, 4 groove, locks on the intakes as well.
 
66fs said:
I agree, but have never really had a problem with Chrysler locks. It is interesting that HP 360 and 340 engines had the multi groove, 4 groove, locks on the intakes as well.
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That is true, but a SFT cam will beat the valves up fairly quickly because the lock will turn on the valve. You see this when you look at the valve and the material between the grooves is gone and they are razor sharp. That means the lock was beating the hell out of the valve.
 
I recall grinding the edges on the multi-groove locks so they didnt butt together, but gripped the valve. Simple mod, a little fiddly, read about doing that from some articles or bulletin I believe back in the early 80's when there wasn't a plethora of valve choice, just worked with what you had, Worked fine.
 
So is this the consensus, to grind the locks so they do nut butt when using the multi groove keepers? I assume some caution has to be taken when doing this, like not over heating them and radiusing the edges a little.
 
mopowers said:
Those are 2-groove intake, 4-groove exhaust. I always wondered why they did that as well.
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Right. I wasn't gonna say it. Math. It's simple. LOL The groove count is in the VALVES, not the keepers. Those install into FOUR groove exhaust valves and TWO groove intakes. I believe the method behind that madness was they were thinking the extra heat in the exhaust valves needed more holding power. At least, that's all I can think of.
 
12many said:
I recall grinding the edges on the multi-groove locks so they didnt butt together, but gripped the valve. Simple mod, a little fiddly, read about doing that from some articles or bulletin I believe back in the early 80's when there wasn't a plethora of valve choice, just worked with what you had, Worked fine.
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Really? I've never seen valve locks that butted together completely on both ends. There's always a gap. In fact, I JUST assembled a slant 6 head WITH two and four groove valves and they don't butt completely together. I've assembled a crapload or heads through the years too and so far not seen the need for that mod.
 
RustyRatRod said:
Really? I've never seen valve locks that butted together completely on both ends. There's always a gap. In fact, I JUST assembled a slant 6 head WITH two and four groove valves and they don't butt completely together. I've assembled a crapload or heads through the years too and so far not seen the need for that mod.
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Old post but my experience of this initially was in 1983 when I had a 1970 Dodge Charger R/T w/440 Magnum and IIRC the factory intakes were single groove and exhausts were 3 groove that butted. I read in the old Mopar Performance book about grinding the ends of the locks “if” they butted together. Only enough so that they didn’t butt. The theory was that they grab the valve tighter. I recall using the Isky single locks on the intakes, and doing as the book mentioned on the oem exhaust locks. Was it necessary? Not likely but it was a shoestring budget mod and I was using that book as my guide on building a so called performance engine. Great book by the way, was the Bible for me in my early days of messing with engines. Also, “Moper” replied “x2 very old trick” ....yes, 38 years ago =old!:eek:

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12many said:
Old post but my experience of this initially was in 1983 when I had a 1970 Dodge Charger R/T w/440 Magnum and IIRC the factory intakes were single groove and exhausts were 3 groove that butted. I read in the old Mopar Performance book about grinding the ends of the locks “if” they butted together. Only enough so that they didn’t butt. The theory was that they grab the valve tighter. I recall using the Isky single locks on the intakes, and doing as the book mentioned on the oem exhaust locks. Was it necessary? Not likely but it was a shoestring budget mod and I was using that book as my guide on building a so called performance engine. Great book by the way, was the Bible for me in my early days of messing with engines. Also, “Moper” replied “x2 very old trick” ....yes, 38 years ago =old!:eek:

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I could certainly see doing that IF you had that situation. I've never seen it though.....not that that means a damn thing. lol
 
Not hair splitting. Back in the day there weren’t a gazillion choices for retainers and locks etc. If you wanted to use the stock components in a performance application there were simple mods you did. Now there’s no reason to bother. Locks are cheap and plentiful. And they don’t butt.
 
yellow rose said:
That is true, but a SFT cam will beat the valves up fairly quickly because the lock will turn on the valve. You see this when you look at the valve and the material between the grooves is gone and they are razor sharp. That means the lock was beating the hell out of the valve.
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Never had a Hydraulic flat tappet cam but one. Maybe not as radical as yours. Hundreds of thousand miles on a couple engines, stuff looks like new.
 
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