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Discussion Starter · #1 ·
I switched to Morel lifters after a second bad Crower Severe duty solid roller lifter. While discussing this with a builder, he ask how close I was to coil bind. I said oh not too close, and he said you need to be within .060 to .080 or over .200. He said it had to do with oscillation of the spring and that getting near coil bind would help to better control the forces and reduce the punishment the lifter takes.

I called PAC about my springs, and they told me the true coil bind measurements, which was slightly more than that listed in the catalog. I was at about .120" from bind at 1.950" installed height. So I've ordered a set of -.050 locks so that I can get down to 1.900". That should put them at .070" from coil bind, and hopefully I won't have to replace another lifter.

Anyway, thought you might find it interesting. It's not always the parts that are the problem. Crower makes good some stuff, and at over $500 a set they should last longer than they did. Now I know why, and perhaps these $600 Morels will last even longer.

http://www.racingsprings.com/mov10kvst.asp

http://speedtalk.com/forum/viewtopic.php?t=2474&highlight=
 

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I switched to Morel lifters after a second bad Crower Severe duty solid roller lifter. While discussing this with a builder, he ask how close I was to coil bind. I said oh not too close, and he said you need to be within .060 to .080 or over .200. He said it had to do with oscillation of the spring and that getting near coil bind would help to better control the forces and reduce the punishment the lifter takes.

I called PAC about my springs, and they told me the true coil bind measurements, which was slightly more than that listed in the catalog. I was at about .120" from bind at 1.950" installed height. So I've ordered a set of -.050 locks so that I can get down to 1.900". That should put them at .070" from coil bind, and hopefully I won't have to replace another lifter.

Anyway, thought you might find it interesting. It's not always the parts that are the problem. Crower makes good some stuff, and at over $500 a set they should last longer than they did. Now I know why, and perhaps these $600 Morels will last even longer.

http://www.racingsprings.com/mov10kvst.asp

http://speedtalk.com/forum/viewtopic.php?t=2474&highlight=
I Port and Polish heads.
Do not use different Locks other than the Locks that came with the Retainers.

Shim to .050 works well.
IMHO no less than .030 if you really need the Seat Pressure.

I like the Howard ElectroPolished Springs.
Serious Road Racers use them because they will not break.

Dan
 

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I switched to Morel lifters after a second bad Crower Severe duty solid roller lifter.........
Glen......what was the part # of those Crower lifters :eek: ?!?!?!?

Wow.....never heard about that 'coil bind' issue.

......I like the Howard ElectroPolished Springs......
Dan.....you have a part # or a link to those springs?

Thanks to both.......good info!!

KW
 

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It's not always the parts that are the problem.
I feel like that quote should be a mandatory read for all lol. Too many are quick to blame parts for the problem when the problem really lies in how they were used. I have heard so many parts get bad mouthed by amateurs/forum dwellers when none of the professional engine builders/machinists I know have anything bad to say about them.
 

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Discussion Starter · #5 ·
Glen......what was the part # of those Crower lifters :eek: ?!?!?!?
Kevin, these are BBC lifters. Part no. is 66291 http://www.summitracing.com/parts/CRO-66291-16/

BTW, when I called PAC, they confirmed what the builder said. Apparently the range between .200 and .080 produces a very bad harmonic and is to be avoided. I'm amazed by all the things I've learned in building this new engine. Fortunately I had good resources so that hopefully the price of knowledge isn't going to be too steep. I spent almost $5,000 on the rotating assembly alone on this build. I don't want to do that again if I can avoid it.
 

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Crower Severe Duty lifters are not recommended for street use at least for Chevy SBC's according to Crower. Comp Cams EndurX and Isky Redline are better choices, if that is the case.
 

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Well...WWGD?
 

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Discussion Starter · #11 ·

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If you are just going to race it then 300 plus seat is fine but if you plan on driving it you will find out that is a problem!!

Just for a setup to compare I run less than 200 seat on hydr. lifters to 7200 and no missing even with 20 pounds of boost pushing, trying to stop the valves from closing. Look at valve weight and total valve train weight to know the real answer as the spring pressure has to deal with the valve weight, lifter weight, pushrod and the cam grind/ramp will change this answer. You can just over kill it and set it at 300 plus but like I said, thats not a motor that will not have an issue if you street it.

You want as little spring pressure as you can because higher pressures eats HP, are harder to start by taking more starter/batt to turn them over and high pressure springs wear out faster. Bigger is not always better unless you really need it.

2 cents
 

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If you are just going to race it then 300 plus seat is fine but if you plan on driving it you will find out that is a problem!!

Just for a setup to compare I run less than 200 seat on hydr. lifters to 7200 and no missing even with 20 pounds of boost pushing, trying to stop the valves from closing. Look at valve weight and total valve train weight to know the real answer as the spring pressure has to deal with the valve weight, lifter weight, pushrod and the cam grind/ramp will change this answer. You can just over kill it and set it at 300 plus but like I said, thats not a motor that will not have an issue if you street it.

You want as little spring pressure as you can because higher pressures eats HP, are harder to start by taking more starter/batt to turn them over and high pressure springs wear out faster. Bigger is not always better unless you really need it.

2 cents
All that said, isn't the valvetrain on a BBC notoriously heavy? I think that would explain the use of higher pressure spings.
 

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All that said, isn't the valvetrain on a BBC notoriously heavy? I think that would explain the use of higher pressure spings.
Big Blocks are going to take more spring than small blocks but almost 350 closed most likely puts your open pressure around 700 to 800 hundered on a big block with the added lift they run. You better have some super duper pushrods, shaft rocks and the best lifters you can buy and it still may break that stuff. Those are pressures we use to run to turn a BB 8500 RPM's and it ate valvetrain parts doing it. You really flex stuff bad at those pressures.

Go with what the cam company says to run. They have done the testing to know how much is enough to keep everything working correctly. All my point was if you are breaking valvetrain parts now, adding spring pressure will only make that problem worse unless you have too little spring pressure and the lifter is floating off the cam at higher RPM to cause the lifter damage.
 

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The original question was how close to coil bind do we go. My best information to date is .040" because the spring actually opens a little past the lift of the cam (inertia) and at this clearance, stops the harmonics that would otherwise take place. 330 on the seat is the max load acceptable for stock diameter lifters. Any more and they tend to spread at the bottom, making them very difficult to get out of the bore. In NHRA Comp racing they are running the same spring pressures BB or SB: as much as they can get :) Generally 450 to 500 lbs on the seat.
 

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Discussion Starter · #20 ·
Big Blocks are going to take more spring than small blocks but almost 350 closed most likely puts your open pressure around 700 to 800 hundered on a big block with the added lift they run. You better have some super duper pushrods, shaft rocks and the best lifters you can buy and it still may break that stuff. Those are pressures we use to run to turn a BB 8500 RPM's and it ate valvetrain parts doing it. You really flex stuff bad at those pressures.

Go with what the cam company says to run. They have done the testing to know how much is enough to keep everything working correctly. All my point was if you are breaking valvetrain parts now, adding spring pressure will only make that problem worse unless you have too little spring pressure and the lifter is floating off the cam at higher RPM to cause the lifter damage.
These were good lifters, and the Morels have an even better reputation. I am running shaft rockers, and these are Terry Manton .120 wall tool steel push rods, primarily due to the plan to run N2O. The valves are 11/32 and Ti retainers to help reduce weight.

I've always heard that more spring pressure is better. I would agree that more pressure would take more power to turn, but not that much when considering the effects of all the springs helping out as well. With just a couple of rockers installed, it can be difficult to turn the crank against the springs, and the springs can actually spin the crank on the valve close. But when all of the rockers are on, it turns fairly easily as the closing valves help counter the force of the opening valves.

As for the how close to coil bind, all I know is to avoid the range of .080 to .200, and to not go less than .060 for a BBC. Perhaps the range is different for an SBC. Not sure.
 
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