Is there a better roller lifter than gm for .....?
 

Appx. 140# seat pressure / appx. 370 spring rate. The better Morels require 150# minimum on the seat IIRC. I'm wanting to keep a 509 build at no more than 500hp for several reasons; 1- I don't want ANY drive concerns and I know the drive will be hammered on. 2- I want to retain the silent choice. 3- Safety (a few family members will be allowed to use it), its a pretty speedy hull already; a somewhat light 24' vented cat hull. I was thinking of getting a single pattern cam cut with a symmetrical, somewhat low intensity lobe. Backing off on the duration for silent choice, I'm just afraid that the torque will just hit too fast and hard for the drive with a more modern, higher lift lobe that's on the short side duration wise.(I already have upgraded heads with higher compression and sub 300cc intakes) So are the GM lifters the best thing going for a mild cam?

There is a new lifter out that sounds very promising. Bob M. @ Marine Kinetics has all the specs on the new lifter. From what I'm told it stands up against other lifters very well.

And this will work good with lower spring pressures? Thanks for the reply. I probably can't reply back until Monday.

GM lifters are only good to so much lift. Not sure of the exact max lift, but I think its in the .550 range.

Lower spring psi's typically don't matter. It's a matter of how high of spring psi's (+lobe intensity/jerk/acceleration/and other lobe things I don't have a total handle on) the lifter can deal with.

The morels seemed to have a good reputation for a while . the machine shop I use has used Johnson lifters for some time now with good results as well.

What about the Johnsons did they do that left the morels "in the dust"? When did Johnson develop this new lifter ?

I've been running morels for a few years now because I was told they were the best here on oso. I did have one collapse on me, but was told it was more than likely a fluke.

I don't know about the Johnsons, but morels 5045 called for higher spring pressures than the 4603's. I am on the light side of spring pressure with a 4603 lifter, well, actually what john Callie's recommends for them , with 165/450ish . pulled to 6300 on the dyno, and been run around 5700-5900 in the boat , never any signs of valve float .

I'll have to check the part# then on the Morels I have. I know they have the .750 wheel and iirc they had a 150# minimum seat pressure spec. I really want to run silent choice, which is going to require me to shorten up the duration. Short duration, high lift and high compression = high cylinder pressure, correct? Even if detonation isn't an issue, and I don't think it will be, I think this set up will be a drive shredder. The cam that I have now is a 229/229 -.600 lift, 114 lsa . I have 17.5" of dry pipe to the wet elbow and diverter to the y pipe. I'm pretty sure this set up will be in the 550+ range with my heads. I've decided I would be happier in the sub 500hp range for what I want to do, which can be done with a pretty mild cam with my heads...this means I don't need a lobe that requires 150#+ seat pressure, which means I don't have an ideal lifter in the Morels I have. So, is the GM roller the best option for me? I re-read my post #1 and I must have been off my game that day.

the GM roller lifter with the dog bone retainer set up will be just fine for your application, it can and will handle 600 lift. and will run your pressures with no problem. In my humble opinion.

Something else to ponder. Changing wheel diameter on the lifter, can also affect the valve timing events. Minimal, but .............

LL
The force, or spring rate, that’s required for your valve train is a byproduct a very simple equation.
F= M*A

At sub 5200 RPM, on a lobe with a modest acceleration derivative that element is in check.
The mass of the BBC valves on both sides are some of the highest values found in engine design, particularly if you utilize an Inconel exhaust valve. The rate of your spring should ideally be ~ 420-440 to prevent premature spring fatigue and seat erosion at those mass levels.

If, for example, you utilize an Isky 8005 Plus, with a rate of 433#/in, set at
1.850” your seat force will come in at 151 LBS, with an open force of 411 Lbs. at .600” lift at the valve. That would allow you to utilize the assets your current Morels bring to the table while making for a very stable package.

Bob

Also if your lifters have a .750" wheel, they are not the cast bodied Street replacement design, which means they are a 4603 or higher. That would be another incentive to re purpose them into this build.

Bob

.578" is max safe zone on stock dogbone lifters....

Tim I understand and respect that, but I will disagree! I have been running more than .600 lift with them and 6000 RPM in the same engines for 15 years never had any issues. I never bought into that. Now I know many will doubt my experience with these lifters, but they work for me! I can run 5800 rpm for extended runs, and run north of 120mph ( as long as the drives stay together)

many may doubt,but not me.if you say you are doing it i 100% believe you.

They used those Gm lifters on the 525 EFI. That cam has around .610/.632 lift.

I rest my case! Now out to the jury.

Crane is who stated that .578" lift figure Full force mentioned.

If using the factory lifters, it is advisable to check in the motor when using a .600" + lift cam (1.7 rockers) just in case the cam grinder reduced the base circle at all/or enough where the lifter vs dog bone issue occurs. I wish Crane mentioned it this way, but they probably figured stating a lift figure would make it easier to understand for most....but who really knows why.

The 525 EFI came direct from Mercury Marine with Crane 16535-16, .300" long body, to accommodate the reduced base circle of the .372" lobe. The confusion stems from "factory" , GM or Mercury.The Merc "factory" lifter is not the same.The ability to run a short body lifter is all predicated on the base circle of the cam.

Bob

Thanks for reconfirming the base circle deal I mentioned, Bob. I gave that info on another site some years ago. They laughed, called me names, and i got banned shortly after. Ha !

When I said "GM" lifters, I should have been clearer, as I was referring to lifters that were sold by "GM Performance" label,

#17120061 is a taller lifter I believe.

#17120060 is the lifter used in say a 1997 454 Truck engine.

The 525 Lifter, was a crane piece. Not a GM piece. I was incorrect for associating GM lifters and crane/merc lifters. Sorry for the confusion there.

The 525 style lifters have an exposed lifter wheel, where the GM lifters, have the shrouded wheel. Possibly the GM lifters made by eaton or someone?

that information is well documented, but many guys aren't aware of it! when I had my cams ground I had some inside information from my cyl head machinist who was involved with GM for many years doing RD work for them! kind of like insider trading?

So the GMPP lifters are pretty legit?

Seem to work for me!

guess it's just what I was always told thats all... no biggie.. lol

Good. I have a set.

The way i understood is that the standard gm roller lifter if you went over .578 lift the oil hole in the lifter will come out of the lifter bore and the lifter will lose its prime and clatter..also some will experience oil pressure loss if you have a lower pressure oil pump..

i have a stock Gen 6 sitting on the stand at the moment with nothing in the block but crank and cam. i will pull the spider off lifters and do a little measuring this weekend...

Cole, they will work fine but as mentioned (and it is imperative) that you check the lifter height when it is down on the base circle!!! if it falls lower than the dog bone it will twist and the roller will not be squared to the lobe and all s?it will break loose. Also beware of your lobe accel rates. They are good lifters for mild cams. Do your do diligence! I run more than .600 lift But they are still mild cams in the big picture!

No wild lift here. Thanks!

isky red zones in my engines,seat pressure at 160lbs,cam and lifters look practically brand new after 8yrs of running.I'll snap a couple pics right before I install the intakes on my 088 heads.:D

and I use crane long body lifters in anything over .600" lift.

I think the idea of the torque being a drive shredder is completely dependent on the weight of the boat, the pitch of the prop, and the propensity of the driver to extend his throttle arm. ;)

What about simply increasing the LSA instead of greatly reducing the lobe's lift and duration? If you move the lobe centerlines further apart, wouldn't that decrease overlap, and therefore reversion? Then you might still be able to run your silent choice while still making some good power. Of course, you would expect a valvetrain with lower lift to last longer, but maybe not so much if proper components for a stable valvetrain are selected.

I am running the GM lifters at .625 lift and around 145/450 spring pressures and they work perfectly. Just make sure that they don't hit the dog bones at max lift and don't fall below them on the base circle and you will be fine. I personally and also a good friend have had bad experiences with the Morel lifters and I would personally not buy another set.