10X

Jeff is putting Morel's in my motors. I don't plan to turn 6000 rpm but I'm glad to hear they are the way to go.

10x has a good point. I just got the heads off my engines this weekend. My heads also show signs of valve float. Crane advises using 150 on the seat and 400+ open. The guy that put my new heads together used 140 and I'm going to check them to see what they actually are. Last year, when I broke a lifter , I changed from solid rollers to hyd rollers, I asked the tech at Crane if I could use my existing cyl heads without changing springs. He said go ahead and it worked fine with 200 lbs of seat pressure. If the bearings in the lifter are the same size as solid rollers and the hydraulics can take it, why not?

As for the Morel lifters, I'm not happy adding to the weight of the valve train. I am considering using Comp's new beehive valvesprings to lighten it up some. How much difference is there?

Just a note form Morel. A company tested the solid lifter design to 8400 rpm for 5M cycles. Lifters were perfect. Decided to go for broke, repeated the test. Lifters were perfect again. That is a testiment to their quality.

Chris

It seems like the maximum spring pressure one would want, would be the minimum it takes to get the job done. If you can operate at 150lbs, why would you want to run 200? It takes away horsepower, and is much harder on the valve seats and the complete valve train.

The minimum spring pressure is that which controls the valvetrain with no float at your desired rpm. Valve float will damage parts and reduce horsepower. As far as running 200lbs, I was rushing the repair in order to salvage the rest of the season. I was not recommending it, just saying that it can be done and the hydraulics in the lifter can handle it. I do believe that Frank (10x) is right on the money and there is benefit to running a little more spring pressure.

There is a common misconception that the energy to compress the springs is lost.. not so.. the majority of it is returned on the back side of the camshaft. The energy that is lost is called hysterisis, which is internal friction in the spring itself. This is what causes the spring to heat up. If you were to graph the opening and closing rates on a linear graph.. then it becomes obvious that the valve is lifted off the seat, accelerated to full opening.. and then decelerated and slowly lowered onto the seat... The spring pressure isn't as big a factor on wear as you would think. But.. having the valve not follow the cam,,, the valve then "crashes" onto the seat.. This is much more damaging. Also it tends to hammer the keeper into the valve spring retainer. If you are using light weight retainers, they will begin to expand in the area of the keepers and quickly fail. Sometimes they will fail when not even running the engine hard. They have just give up and let the valve keepers slide through.

Not to change the subject. But has anyone experienced Rhoads hyd lifters? I have a bumpy cam and was wondering if they would calm it down a little. They make some interesting claims.

cstraub69, if the test was at 8400 then they must have had some fairly stout spring pressures. From what I hear in a boat application trying to idle for 5-10 minutes at a time at 800-1000 rpm the spring pressures create excess heat in the lifter due to lack of oil getting to the lifter/cam, then it is all down hill from there. Do you happen to know what Morel is recomending for pressures to run 6200-6500 with their solid roller? Is their design of the lifter any different than competitors that gives them an advantage or is it materialsn they use? Thanks, Bob

Hey there you go for a challenge.

5m cycles at idle.

I use Morel lifters (via Isky) in all of my engnies and never had a problem. The solid lifters are pressure fed pins. No idle problems that I have seen and 155ish on the seat for the hyd rollers. Spin them to just over 6K RPM

Morel makes lifters for Isky, however there are certain design differences in the Morel name lifters.
Bob