Mechanical Roller Cam Breaking On The Street, Why ?

[mbrunson427]

Jay, you should get with our friend John Bamber on this one. He just designed a set of solid roller lifters for tractor pulling applications. I'm going to run them in my drag car motor. If they're good enough for 10,000 rpm in a 650 cube motor, they're good enough for the stuff that most of us do. I'm sure he earned some lessons designing these. Last time we talked to him he was modeling the instantaneous roller velocity to figure out how he needed to specify the materials and tolerances.

Reach out to me if you'd like to compare ideas with him.

[scott foxwell]

Morel "Black Mamba" Roller lifters.

http://morel-lifters.com

That's a great lifter. Gives the Chevy guys on a budget an .842 lifter that can handle just about anything you can throw at it without having to spend money on expensive machining to upgrade to a larger lifter. Designed for extreme racing. It's not a bushing lifter. It actually rides on an oil wedge just like the crank and rods. Upgrading to a larger dia. lifter with a larger wheel is a better option but not always feasible.

Scott, I'm anxious to learn anything you know about those lifters.  The reason is that I'm in the process of designing my own SOHC rocker arms, which of course have a roller lifter wheel on the side that rides on the cam.  I have settled on the same approach used by those Morel lifters, to provide full time pressure oiling to a bearing surface.  In fact, last week I just made up my first set of roller wheel axles on my lathe; pic below:



They need to be heat treated and finish ground, yet, but you get the idea.  The small hole on the side gets oil from the rocker body and the larger hole on top distributes it to the bearing surface.  The groove at the right side on top is for a pin, to hold the axle in place so that the hole in the axle stays lined up with the oil hole in the rocker body.  FYI, SOHCs have a 1" diameter roller wheel that rides on the cam.

Do you happen to know what material the pin in the Morel lifters is made from?  Looks to be some kind of a bronze alloy.  My axle is tool steel, and the roller wheel itself is bronze bushed, so that I can size the diameter for the proper clearance.  Any experience with the longevity of these lifters?  I've had it with the T&D rocker needle bearing failures I've experienced over the years in the SOHC, have wrecked a couple of dry sump pumps when needle bearing shards have gone through the pump...

The one thing that sets Morel apart form every other lifter company is there is no middle man, nothing out sourced. Material comes in one end of the building, and lifters leave the other. They do all their own centerless  grinding and most important, they do their own heat treat. I don't have a lot of input on details... a lot of what they do is proprietary but I can tell you that their tolerances on things like roundness and concentricity are the best in the business. I'm telling you this so you have an idea what makes their stuff so good and what to concentrate on. As far as materials, I really can't say. The material in their bushing lifters is something they developed with GM funding back in the 80's, and they bought a train car full of the stuff and have plenty left to last a long time. Crower and Isky are still experimenting with their materials and going from one supplier to another. Hard to be consistent like that. The axle on the Black Mamba I'm sure is proprietary as I'm sure are things like the clearances, finish, etc. are as well.
I like your idea. I don't know a lot about the SOHC other than there isn't much ratio to deal with so if someone wants any significant lift, the cam has to get pretty wild and that's probably hard on the rockers even with a 1" wheel. I don't know where T&D is getting their needle assemblies but I'm guessing it's not their "strong point" and I'm a huge T&D fan. There can be a world of difference between manufacturers just in roller needle quality. Heat treat and roundness/concentricity seems to be what separates the men from the toys in this venue (roller lifters). I don;t have any longevity feedback on the Black Mamba yet...they're pretty new, but I know Morel wouldn't release them without extensive R&D.

[scott foxwell]

How many RPM's does a "short travel" hydraulic add over a standard hydraulic? They seem like they would be a fairly good compromise between a standard hydraulic and a solid, on a regular street engine.

Short travel hyd. lifters really aren't hyd. lifters in the traditional sense. They move just enough to take up the lash ramp on a solid cam, then they become solid lifters. They're made to fool the inspector in hyd. lifter classes. They're very noisy.

[cdmbill2]

Jay, my latest stainless rockers from T&D are bushed, and as they are for the BBF, have pressurized oil to the trunion from the pushrod through the cup and then on out through the spring oiler ports. I realize the differnce with your SOHC motor valve train situation, but have you talked with re the bushing IF there was a way to get pressurized oil to them? Along those lines did you figure out how to get more ratio given you are going to make your own rockers?

To the OP, bush your block for .904 or .937 lifters, use the bushed style, I've had good success with Isky and bi-annual rebuilds at .900ish lift and just shy of 800lbs. over the nose using a 1.85:1 rocker. Can you run a bigger cam core in an FE? Tha't where I'm going with the 460 based motor I run to get more lift with less rocker ratio. The car sees a Drag Week, a few True Street events and a few thousand street miles a year.

[jayb]

I haven't talked with T&D on that Bill, my sense is that they are done messing around with the SOHC because the market is so small.  And I do have a design for a higher ratio SOHC rocker, but it requires a smaller diameter rocker shaft and some modifications to the heads.  At the moment I am maxed out on lift anyway with the standard rockers and the valve/piston/cam combination I am using, so I haven't pursued the higher ratio rockers.  The ones I'm working on now are the standard 1.3:1 ratio.

[67gt350]

Jay, glad to see you are still working on the rocker project. I have gained a ton of information from you and all the forum members about the FE and SOHC. I had an idea about the rocker shafts not being pressure fed. Could you drill into the cam bearing oil holes to get oil to the shafts and lube the rollers or possibly tap into them lower inside the head and run small fittings and tubing a lot like your solution to keeping the bearings on the idler gear lubricated?? After looking at some of your assembly pictures I see the rocker shafts are pinned at each end so grooves or holes for oiling would stay aligned. Are you still working toward a 1.5 rocker arm ratio?

[jayb]

Not sure I understand the question; the rocker shafts on the SOHC do get pressure fed oil.  What doesn't get oil are the needle bearings in the roller wheel end of the rocker; oil is squirted through the rocker body to the outside of the roller wheel, but there is no path from the rocker to the needle bearings themselves.  They rely on splash oiling, and as a result  they tend to fail.

I have a design for the 1.5 ratio rockers but as mentioned earlier it requires some modifications to the heads, to accept a smaller diameter rocker shaft. 

[67gt350]

Ok I didn't understand.. not owning one of these engines all I have to go on is pictures so trying to figure it all out without all the information gets confusing. As always Jay thanks for being patient with someone who doesn't know. Your plan is to create a path to the rear roller wheel through the rocker body so both ends will receive lubrication? In your other thread you talked about using a offset bushing for the smaller diameter rocker shaft, is that still the plan?

[jayb]

Yes, the oil path through my rocker arm is essentially the same as the path shown in the Morel lifter pictured earlier in the thread.  My rockers will be standard ratio right now, for one thing because I have enough cam to generate the max lift that my piston to valve clearance allows, and for another, if they work out I want to turn them into a product for SOHC engines.  If/when I go to the higher ratio rocker it will be with the smaller diameter shafts and offset bushings.

[67gt350]

That's awesome Jay! Another great product from FE Power.. I will certainly be following along.. thanks for the reply.

[preaction]

Jay are these the rockers you have ?

[jayb]

Yes, those are T&D rockers.

[427HISS]

Since the rockers religh on oil splash for the needels, why restricked oil to the heads like with the side oiler engine ?
It may not matter on drag car, but why on a street car that may see a drag strip a hand full of times per years ?
Like mentioned before, can the shafts be plumbed to accept a pressured tube to bath the rollers constantly ?

[cdmbill2]

Looking the size of the wheel that follows the cam on SOHC, i wonder if a much larger bearing/axle would help? That would require more material/weight on the cam end of the rocker but it would slow down the bearing speed significantly and maybe expose the bearings to more splash absent an internal pressurized oil supply?

[jayb]

They are actually much bigger than a roller lifter axle.  My design with the pressure oiling uses a 0.500" diameter axle.