Hey, I resemble that remark. I do have half a brain. Only problem it is out looking for the other half

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 225 nitrous
64 Valiant Signet
64 Valiant 4dr 170

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Official Cookie and Mater Tormentor.

I probably would never do it myself, but I really enjoy seeing someone else do something out of the ordinary. Don't worry about the nay sayers. They will all be building modern Hemis before long anyway.

Keep us posted and take pictures!

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Its not that there are folks not willing to share info, its just that so few have done it with a Slant or any other engine to share the info with. There are reason roller cams, even hydraulic rollers use a billet and not a cast core. It has nothing to do with wear patterns, it has to do with the extreme spring pressure breaking the cam in half. Cast iron cam cores don't bend and flex well and will snap like glass very soon. As Ceej said, it has been done, but the 50 passes is hardly a test sample size of experimenting to claim success. Street driving on a solid roller is extremely harsh on the lifters at idle or low RPM's due to high side loading. So unless you intend to drive around in city driving environments at or above 2000 RPM, you can have issues. There is no such thing a low spring pressure on a roller. Even low lobe lifts that have only .500" lift requires almost double the open spring pressure as a flat tappet solid cam of the same lift. Roller cam profiles have so much faster ramps and opening and closing events, the much higher spring pressure is required to keep the lifters on the lobes, and not having the lifter bounce and causing lifter and/or lobe damage. The same thing will happen if you try to use hydraulic flat tappet spring pressures on a solid flat tappet cam.

I applaud anyone who is seeking to run a roller cam, but just know going into it, there are no free lunches, and not many places you can cut corners and skimp on components. I will be the first to tell anyone that there is absolutely no benefit in running a roller in a slant unless you are pushing the extreme with compression, RPM and head porting to be able to realize any benefit from one. But I do have a lot of experience personally with my own cars and engines in both street/strip applications and race only with roller cams, and there are always compromises you have to be willing to accept. You said that you didn't want to run a bronze gear, but with a roller you have no choice, end of story! You more than likely will not be able to run the stock rocker arms, they will fold in half due to the much increased spring pressure, and roller rockers are the only alternative. You will also need hardened aftermarket pushrods that also wont fold in half due to the extreme spring pressure along with better retainers and locks on top of the valve springs. So it quickly becomes a debate as to whether the much elevated costs to install and run a roller cam is justified for the little to no benefit it will provide you, unless of course you are pushing those extremes.

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There's no such thing as too much cam....only not enough engine!

Not choosing to differ but the issue with roller lifters needing billet steel cam blanks is because the contact patch of a roller on the cam lobe is tiny compared to the contact patch of a solid lifter on a cam lobe. That tiny patch concentrates the forces and causes the underlying metal to fatigue, break down and eventually come apart, typically spalling or fracturing away.
Billet steel is much more resistant to compressive fatigue than hardened cast material because it is denser.

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Doo Ron Ron and the Duke of Earl are friends of mine.....
https://www.youtube.com/watch?v=uX8Nj8ABEI8

And what would be your differing opinion be from, personal experience or internet hearsay...?

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There's no such thing as too much cam....only not enough engine!

Basically 40+ years of engineering experience in casting and manufacturing engine components including valve train components.
Specific to the topic under discussion, I have hands on experience setting the requirements and production parameters for the induction hardening of valve seats and cam lobes as well as setting the control plan for on going inspection to verify compliance.
And also just plain common sense. Look at the contact patch on a roller, compared to the contact patch on a solid lifter. Regardless of valve spring pressures, the roller concentrates the load in a much smaller area.

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Doo Ron Ron and the Duke of Earl are friends of mine.....
https://www.youtube.com/watch?v=uX8Nj8ABEI8

Those are fair and valid points, and a roller lifter does have a narrower contact footprint on the lobes. But the choice of selecting a cast iron core vs. a billet in the automotive realm is a liability and durability issue because their parameters and needs are much different than diesel, industrial and agricultural engines that are intended to last hundreds of thousands of hours or miles.

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There's no such thing as too much cam....only not enough engine!

CNC's points are all valid. But it's not fair to say there is 'absolutely' no benefit in a roller on a street Slant. There has to be. And the issue of roller life at low speeds? Well....that has been proven to not be an issue if you do it right, or even close to right. Look at the millions of 318's that were built with rollers....they idled just fine, for a long time.

A roller does require stiffer springs, especially seat pressure, but like anything...that is an engineering consideration and can be handled. Again....look at the 1990 318 engine. It had a roller, fairly mild springs, and lasted.

It helps the situation knowing your Slant is not gonna be a 7000RPM engine - that reduces the need for spring pressure a great deal. As for pushrods...anyone who goes through the expense of installing a roller cam then cheaps out on the pushrods deserves a failure. You can buy a killer set of Smith Bros pushrods for not a lot of money.

I'm not going to say zero or no benefit at all, it's just for the price point to step up to a roller might not give a proportional return for the money spent.

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There's no such thing as too much cam....only not enough engine!

I agree. It's a lot of money for a benefit that will be hard to justify for most engines. But then....that's hot rodding!

Old thread, but I want to throw out some more info to discuss. So, I have the new short block sans camshaft assembled. I got the single idler gear drive figured out and it will work, so I am wanting to revisit the solid roller camshaft idea. A friend and I have been discussing having a stock cast core ground with a small street hydraulic roller lobe and running solid roller lifters tight lashed. Plenty of people have done it with V8s successfully. Since hydraulic lobes are more gentle on the valve train, he thinks it may have a chance.

But here's the curve ball I want to throw out. Every SINGLE 5.2 and 5.9 Magnum roller cam is ground on a factory CAST core. Chrysler did not use billet cores. I realize they are hydraulic and I am talking about using a solid roller, but it;s just an idea to kick around and discuss.

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Rob

It is enough that Jesus died and that he died for me.

A hydraulic roller in a Slant has been discussed in other threads here as well. What block are you planning on using...? Many of the same requirements would still be necessary but mainly which hydraulic roller lifter to use. There isn't really a clear answer as to what will work correctly simply because it's never been done. So in a sense, you'd be a pioneer with having no guidance to direct you.....but it can be done.

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There's no such thing as too much cam....only not enough engine!

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

IIRC, Dave reported that the stock cams he had surface hardened for his roller spec cams, and most of them failed rather quickly. The material under the hardening gave way, and they started coming apart. He was running one of those cams at the time we spoke, which was the exception that had over 50 runs on it. I don't know if that one failed. Most made somewhere in the 20-25 pass range before converting to shrapnel in the pan. He could speak better to it than I, as we were sitting around the campfire in the pits drinking beer. (One of our favorite pastimes.) My memory may have some holes in it. Dave has buckets of broken slant bits for share and tell.
I have one of the billet cams in the rail engine. (Not fired yet.) There is a bunch of machine work to deal with roller lifters. Think about the clearance for the lifter link bars. It gets mighty tight in there. When you put roller lifters in there, yes, you shorten up the push-rods. Then you get to correct the geometry as the angle has changed. Lots of interesting choices to make with any particular paradigm.

For the street, not running gobs of lift, or demanding stupid ramp rates, I don't use roller parts in the slant six valve train. It isn't if, it's when is it going to break. More parts, weaker in some important ways. Except for racing applications, a roller isn't going to give you any particular power advantage. Incremental at best, on the side of the road awaiting triple A at worst.

It can be a fun exercise to be sure, but it's not going to net something noticeable at the speeds these engines turn, as a general rule. That, and nobody can see those pretty rockers when the valve cover is buttoned up!

CJ

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Part of Tyrde-Browne Racing