MER Performance

Just finished 2 604 CID N/A , RM Builder cams, Merlin blocks. I know there has been past talk about these lifters not working unless they were modified to having a larger internal clearance and the manufacturer made these changes with a different part # for the marine use and if using the RL932, they said to use 15w40. The original design was for 20w50. We did some testing concerning these issues and came up with no problems as stated from others. The results were sent back to the manufacturer. I know priming the system before start-up was on concern. I was able to prime all lifters to the rockers with oil with a cordless drill all 16 with Valvoline 20w50 racing oil. Here are some facts: A Merlin block comes in with a lifter clearance of .0022, Dart block is
.0012, stock 502 block .0022-.0025. The lifter has to be installed with a clearance of .001- .0015 to allow the oil to be maintained within system other wise the oil will flow around the lifter, either out the bottom or out the top, dropping the pressure and volume of oil down the line. This lifter was designed to have the tight internal clearance for it use and tested and proven with those specs. I myself or RM Builder, will not use the second design lifter for those reasons. The manufacturer has alittle sheet in the box with the clearance specs. The Dart block needs more clearance for marine use. The Merlin is to large, I lifter true the block and install bronze bushings and finish hone to size, also the Merlin block doesn't have the taller lifter bosses and on the top side they have a radius under-cut which is taken away by the bushing and extends the boss alittle. If your running $700.00 lifters they should be in bushings and not cast iron. After some hard testing the lifter bodies show no scratches as you would get from cast iron. The lifters maintain their needed oil supply as the oil heats-up. The stock GM block same thing, it's not going to prime-up and maintain the oil supply to the rockers, unless the clearance is kept to spec. Also when you install lifter bushings, before finish hone, you take a 18-24" drill bit and drill the oil passages out in the lifter oil galleys, that way you know they are clear of any defects from casting, you just have to make sure everything is CLEAN before assembly. If you are not measuring the complete build, maybe you shouldn't be building it! This lifter to bore clearance is also the same for the same manufacturers solid roller 8620 body with oil pressure to the wheel. you can run .0025 on a solid roller and maybe only have some wheel tracking across the lobe of the cam,but you will also start side loading the wheel to the lifter body and cause a failure of the wheel and needle bearings. Maybe RM BUILDER can give some input from his knowledge of cams and valve train installations.

articfriends

iTrader: (1)

Your post is somewhat confusing,first off are we talking about morel hyd roller lifters or one of the re-boxed house brands that are the same thing? Second off,are you stating these lifters CANNOT be used in a stock 502 block/will not work without re-bushing the lifter bores when using a stock block? There are alot of times there is a desire to install a new cam and lifters in a otherwise assembled long block hence and lifter bore work is not going to happen.
Third off,if this lifter needs .001-.0015 clearence and a dart block typically has .0012 wouldn't that be about perfect so what do you mean by the dart block needs more clearence in a marine application as that seems contradictory to the point you are trying to make.
As far as the merlin block,at least the merlin 2 block,I think I was the first person to run morel hyd roller lifters in one (at least the first one that had problems) and I had massive oil control issues at idle due to the short lifter bores and bevel/chamfer on top of lifter bore exposing the oil fill hole/center band on lifter body allowing oil pressure to bleed off at idle. This was with a .600 lift cam w/std base circle,I had the base circle reduced .060 and that cured my oil problems and those lifters were ran over 100 hours in 945 hp motor. Please clarify your statements though as it isn't completely clear what your trying to get acrossed,Smitty

articfriends

iTrader: (1)

After re-reading your post several times I am seeing you addressed the problem with the merlin block that I re-iterated that personally happened to myself except you "fixed" the chamfer problem they created by re-bushing the lifter bore instead of changing the base circle and you were able to kill 2 birds with one stone,you not only extended tghe lifter bore slightly eliminating the problem caused by the chamfer but you also were able to tighten the bore up at the same time to a more ideal clearence. Maybe after someone reads my post describing the merlin block problem I had and this post it will help clear up what you were trying to accomplish,Smitty

MER Performance

Your right Smitty, I guess the average guy, wouldn't understand my point. Since you know what I'am talking about and have run the 1st design Morrel lifter, with no problems except the base circle using 20w50 oil you know there is no reason for morrel to have the 2nd design it defeats the engineering that was taken from the begining. I have .680 lift even with that on a Merlin block you are bringing the lifters oil hole to about .170 to the radius at the top of the block. I was addressing some reasons why some might have priming problems before start-up and that are specific clearances to use for proper operation. Your right about the dart block being .0012, I would open it up alittle more. Back when they started with the solid roller lifter,it was my understanding from my sales rep. that some times lifters would stick from being to tight in some blocks. I forgot you were using the same lifter. What were your lifter clearances? I recall Bob, telling me about your cam now. As well know there has been some negative feed-back on these lifters, that caused a design change, my point is they work and blocks should be measured for lifter clearance as you would fit a wrist pin or your bearing clearance, I feel that maybe that part of the build has been over-looked and that the lifter is not always just a drop-in part and never checked for proper clearance. Thanks for your input on this. Glad to see another set of morrels running the way they were designed. Mark

MER Performance

Thanks to RM BUILDER, for the cams 1st set of HI REV LIFTERS and a cam with .680 lift and 225# seat pressure and 575# open spring pressure, turned them up to 6400rpms. Results , better than expected for what we had to work with.

PatriYacht

Hyd. roller or solid roller?

Nordicflame

iTrader: (4)

Well, I'll add to the data pile here
I installed two sets of the pre revision, high rev Morel lifters in a new twin 1000hp build (tall deck Bowties) for a Husltler.
It's running 20-50w VR-1 and it is performing flawlessly.
I also installed two sets of these same lifters in my personal 588s (tall deck Bowties) that I built at the same time and am running straight 40w VR-1 and they too are performing flawlessly.
Before I was able to fire these motors in the Spring I was reading a lot of disturbing chatter about these lifters being an issue.
A whole lot of unnecessary tossing and turning at night for an apparent non issue

Just very happy I didn't have any issues and all is well and good

Dave

MER Performance

Thats one reason we did the test, NEGATIVE CHATTER. Thanks for the positive input. Mark

articfriends

iTrader: (1)

Mark,my lifters were not the hi rev version as they were just not ready yet in the spring of 07 when I was finishing my motor. As far as my lifter clearence,I was using a new,never ran dart block that I had sent out to be prepped. I was waiting for the hi rev marine hd morel lifters right until we got a week from my Dyno date,the lifters just weren't ready. At the last minute RM builder found me a set of the std bbc lifters which I receieved 3 days before dyno time. I had already assembled the motor as far as I could and when I went to put the lifters in I found they were at .001-.0012 clearence which I considered to be just a little tighter then I'd like to see BUT tearing motor back down and honing lifter bores would have moved everything back to the point motor would have never made it into the boat that season as my schedule was very inflexible at the time so I ran them. This motor does have excessive oil pressure,it will see up to 100 psi cold, I never had that problem with the merlin block and it's sloppy clearences,Smitty

articfriends

iTrader: (1)

I'm running 185-190 seat and 480-490 open on the std lifters,revs hard to 6000,Smitty