Marc Rozman: roller cams and solid oil
Once Ed got done with the [355 Pro Stock] race motor, Chrysler got out of doing race testing in-house, as they felt it was more important for us to do production testing. Special Vehicle Engineering (SVI) in Troy, took over all those tasks after that. We never saw racing again, per se.
I went from doing that testing to doing valvetrain testing. They were looking to do a new roller package on the small block (318 and 360), going from a flat tappet cam to a roller cam. I did it in cell 6A for about a year, on a higher rpm dyno, so we could run different RPM. The other cells were converted over to doing camshaft scuffing tests, and it ended up being mostly durability testing, because we were in the test cell with the console.
Andy Mueller was the engineer, a sharp guy, and he did a lot of testing. That progressed well, it was a good program — the block redesigned for the roller package, getting the rollers and the spiders to hold the rollers in place, the whole package worked out pretty well. I can’t remember any problems at all, production-wise, on the roller package on the V8.
That cut down quite a bit on the friction. That’s what you want to do, get the friction down, get the horsepower back up, because the emissions brought it down, so that was a good project. That was a lot of fun. I learned a lot about valve train, about lost motion, keeping valves under control, spring rates, different spring designs. That was a fun program. [According to other sources, it also increased the precision of valve timing.]
We’d run the engines on power steering oil to do our durability, instead of motor oil. We’d run an engine for 24 hours or less on power steering oil, and it would be equivalent to running an engine for a hundred thousand miles. We would run the test, throw the oil in there, and when it was done, tear it down. We were looking for camshaft wear and scuffing. It worked.
The cams ran and the ball bearings were happy, there are some lubrication properties in steering fluid, but not as much as the motor oil.
By that time, the 2.2s were coming in on board for development, and those were flat tappets; initially, we had problems there. Later on, we converted the flat tappet 2.2s over to the roller package, to minimize friction, and for lower wear and tear, and I think we used the power steering oil for those, for durability and to accelerate the wear on them. That was a very worthwhile and fun project.
I spent about a year and a half, probably, doing the V8 and the 2.2s back to back. I learned a lot there. We used to run the different sensors on the valvetrain for the 2.2s, and look at different motion in the valves, and try to figure out what spring ratio to have, what spring designs. Do you need a single spring, dual spring? All kinds of different things to look at, so it was pretty fun stuff.
Cold oil and premature failure
We did some cold testing. You have to run the engine in the cold room. We had some carts set up where you can actually build a cart up with an engine, and put all your components on there, and ship it off to a cold room, 40 below. Do a cold start on them, and check for valvetrain operation, with cold oil.
You’d be surprised how things happen when it’s cold. We found out back then some of these oils that were out there, weren’t the best oils. We use a certain brand of oil for testing [and didn’t find any problems], but we had problems in the production engine, where certain parts of the country were having problems with the oil, not flowing properly. A lot of oil is high in paraffin content, and that oil would not flow in cold weather.
We were breaking rocker arms in half. It takes a lot of load to do that. We discovered that we had the oil pumped up, under cold conditions. If you have the valves open during combustion, while the combustion forces the valve back into the seat, and then you’ve got your pumped up adjuster inside, the next thing you know, you got all this pressure pushing the rocker arm in the cam, well that’s going to snap.
We had to identify the problem and resolve either a band aid or a permanent fix for it. So, we went through the series of tests there, with different oils, and different parts and pieces, and came up with some band aid parts first, and that worked out pretty good. And then the roller cams came out later for 2.2s that were a lot better.
They’re more costly, but long term, roller cams are much better for friction and for durability and they rev a little faster too, a little quicker, so, they added to the performance of the vehicle, which we needed back then with the 2.2, and that was fun. Learned a lot there also.
Is paraffin still an issue?
Well, oils today are a lot different, and better refined, but the biggest problem then was that certain oils, like the Sears oil, the Spectrum Oil, was awful. I mean, it… the first thing you asked customers who had a problem was, “Do you buy Sears oil?” Sears oil was nasty stuff.
Quaker State was made from Pennsylvania crude, and that’s fairly high in paraffin. Look at some oils where they come from, and there’s different grades of oil. Based on that, the refinery process is different. Some oils have this higher paraffin, and there’s a cost involved in filtering it out. So, if you want to be cheap about it, you leave it in there.
Paraffin is a wax, so it’s slippery. It does lubricate, to a point, but we used to take those cans of oil and put them in the cold room along with the engine, just to look at them when they are cold. You see a visual of the oil in the can, and you can take the can and hold it over your head, and look at it. And like, “Yep, it’s there, but it’s not moving, at all.”
It was that thick that it just wouldn’t move, period. That was kind of scary.
You know, we do some testing on the flat tappet cams, and you have a 2.2 in the cold room, 40 below, do a cold start in the morning, not a lot of fun. You’ve got a big winter coat on, and even so, you can’t survive in there for very long.
You do a cold start on a 2.2, the valve cover off, get your stop watch, and it would probably be a good six minutes before you saw any oil to the cam. Then, it’d start oozing out, a little bit, and then, then ooze a little bit more as the engine got hotter and hotter and the you start to get the oil thinned out.
It could be as long as six minutes without any oil lubricating the cam. Then you wonder why you had a scuffing problem. People get their cars in the cold climate area, and they get their cars fired up, and they’re in a fast idle, and maybe it wasn’t running properly, because the oil wasn’t flowing well. So, what do you do when it runs poorly? You give it more gas, right? Rev it up, put it in gear, and blast off.
So, we had a high degree of warranty issues with the cam shaft scuffing, and if you look at the warranty report, all of your warranty was all in the cold climates, Chicago and Detroit, and New York, … a lot of claims on camshafts. Down South, you can see there’s nothing at all for claims.
We knew we had an issue there with the oil, and what could you fix the fastest, and the cheapest? Maybe recommending a different oil might be good. Try different squirter holes for the oil squitter to make it bigger, so it falls better, but the bottom line was that we just had to get rid of that flat tappet. You know, it just wasn’t working.
But with the roller package, even if you had minimal oil, it was still rolling and functioning and not scuffing the cam, so that was the better way to go.
That’s when the synthetics were getting popular, too, and synthetics always flowed. That’s when Mobil 1 came aboard. Mobil 1, you could be 40° below, and it’d still pour out of the can. That’s when I switched to Mobile 1 in my car for the winter time, even though it costs more. I knew for sure that I could start up my car in the morning, and it would always flow.
You can run a lower viscosity, and it would lubricate properly, and it had good additives. Flowing oil is a good thing to have in the motor, when it’s cold. So people were developing pressurized, add on, oil type units where you can, under pressure, shoot oil into the engine first, to get things pumped up. But, even then, it was depending on what oil you had in there.
We had problems too, when you the engine fired up cold, and you turn the engine over, and the oil pump it as draws more oil in, you suck it in... and because it was cold, with the higher viscosity, it spiked the oil pressure. We would monitor the oil pressure, it would be recorded. You should see some pressure, of course, hopefully.
Sometimes it would spike to 110 PSI plus, blow the filter off altogether, or pressurize the valvetrain so much that the adjuster would get pumped up with high pressure, and the cold fluid couldn’t bleed down. The next thing, you’re running with the lifters pumped up. That means the valves could be open; it depends on design, the adjuster and the follower. There was a potential for the valve to be off its seat during combustion.
So you may get some popping, some poor running… but if it’s running poorly, and you give it more gas, you rev it up and… it made the condition even worse. There again, once the oil got warmer, then the adjuster could bleed down properly, and function properly. But that took time. It depends on your drive cycle in the morning. Some people work only fifteen minutes away, and by the time you got to work, it’s barely where it needed to be. So, you do that day after day after day, and something’s going to break.
The Marc Rozman interview by section
- Joining Chrysler, EPA testing, and running the dyno
- At the road test garage; working the water brake
- The famous Cell 13 and Hemi testing; working with legends
- Last 440, Pro Stock 355, and 3.5 V6
- Roller cams, cold oil, and snapping rocker arms
- Turbo 3.3, exploding engines, and troubleshooting
- The shaker table
- Working with engineers: learning and troubleshooting
- Marc’s 1969 Dodge Charger