With all the other hemi threads we've been talking about lately, I wanted to start this one. I changed directions with the 291 DeSoto hemi build a little bit, going with the 330/341 heads now. They're getting really nice port work, a nice 5 angle valve job and the compression is right about at 10.5:1 with the cc volume of the new heads. Now the cam I have currently is a stock reground 291 cam. I sent it off to Isky and had turned to .465 lift, 270/270 duration, using hydraulic flat tappets from Hot Heads, the good old "white box" lifters... yea not too fond of them either. I really don't want to use a cam where I lose the stock base circle, although I am running a set of NOS Isky adjustable pushrods. I called up Contrera's Camshafts Thursday and talked to Donnie Johansen about the build. We talked about just grinding a new cam, although it'd have to be another regrind, they don't have new flat tappet cam blanks, but I did manage to find one which he said he'd be interested in checking out. He brought up the roller cams they make, and gave me the idea to run a solid roller in the 291. He said they have a spring that works really with them as well, not too terribly much seat pressure. I've seen 345 DeSoto use the hydraulic roller in his 291, and opening up the lifter deck to fit the roller lifters in, not a big deal to me. For me, the sound of a solid lifter hemi is about the greatest sound in the world. I do plan on driving this car A LOT, so is there any real disadvantage of a solid roller in a street car? I know an old issue was seat pressure, but it seems that this has pretty much been resolved. Any input is appreciated, I'm here to learn anyways. Thanks in advance guys!
My opinion ONLY, but unless you're going to run at the track and need to trick around with different clearences, I don't see the need for a solid cam. On the Street, it's basiclly set them, and forget them. Adjustable pushrods are a PITA, especially when you can slap a set of hydraulics in and forget it...although you'd still need to adjust them with a reground cam. I guess it's 6 of one, and a half a dozen of the other. Watch the lift with Stock valves. There isn't a whole lot of clearence there. The profile of a Roller cam is a great help...which is why I'm glad to have mine...
hi there.. don't let a solid roller scare ya, i run them in all my junk, on the street,and in our racecars.. (o.k., our "shop truck has a hydraulic flat tappet) we take 500+ mile trips several times a year,adjust them once every year, (or two) no worries,, my one hot rod has an insane camshaft (for a street rod) and haven't had a problem....they get driven ALOT
Valve clearance won't be an issue here. The pistons can be fly cut for clearance if need be. We measured for the pistons last week, but still need to call Ross to get them here. I absolutely LOVE the sound of a solid cam though. Donnie said that preferred the solid to hydraulic. Just looking for some real world experiences. Thanks for the input guys!
Sounds like it, we talked for quite a while, not in any hurry to rush me off the phone at all. I can't wait to get this thing together and hear it on the dyno, I'll have videos when that happens!
I am not an engine builder. When I was building my "Pro-Street" the only thing I did not do myself was build the motor. I left that task to a very good local enging builder. When it came time for the cam he wanted to use a solid roller as the engine was going to be a serious performer. I balked a bit knowing that the severe valve spring pressures you have to run with a solid roller don't tolerate street driving very well. He talked me into the solid roller and I figured I should listen to the expert. GUESS WHAT, during the first season I broke a pushrod and the motor scattered. He did the motor over using a flat tappet cam and I have not had a problem for years. Just my two cents.
The specs on my hydraulic roller are pretty mild...the lift/duration isn't excessive, and the springs were chosen to do the job with out putting undue strain on the rockers/guides/valves. That, together with the fact that I'm NOT going to beat on it, should due fine. That's not saying that I'm not going to put my foot in it. I'm just not going to over rev it or pound on it. Even with all the prep, attention to machine work/assembly, etc., it's STILL a Street engine...a fifty year old one at that. I learned 45 years ago, in a Southeast Asian Counrty, not to beat on the horse that might have to get you out of Indian Country...
A good reground cam is hard to beat,,,I went solid with mine. I love the sound of solids. Adjustable pushrods work fine. Tommy
The high spring pressure shit has been resolved now, it's not nearly as bad as it used to be. Either way, I want to use a solid roller or a solid flat tappet.
Reground cams have been around since the first day that Ed Iskenderian realized he could improve the profile. When properly done they will last the life of the engine. We have sold hundreds of reground cams and have never had a complaint or return of 'failed' cam. The amount of base circle that is lost is a function of the lift. If you value the sound more than the ultimate performance then tailor the grind to that goal and go easy on lift. An added benefit is less wear on the valve train. .
I had Cget Herbert hisself grind a few cams for my circle track cars and his cams always performed better than the Engle's they replaced (I had an Engle dealer for a ssponsor). I guess I missed the high spring pressure controversy as I never ran stiff springs but I never revved past 6,500 either.
I had Chet Herbert hisself grind a few cams for my circle track cars and his cams always performed better than the Engle's they replaced (I had an Engle dealer for a ssponsor). I guess I missed the high spring pressure controversy as I never ran stiff springs but I never revved past 6,500 either.
Solid roller or regrind? I realize regrinds have always been around, but with new technology, especially roller technology, it frees up some pretty decent horsepower. The lift isn't anything crazy either from the way he was talking.
Just for grins, here's a picture of my roller. It's a crummy picture, but you can just make out the difference in the lobe design, over a flat tappet...
A couple of things to consider for you. One, keep in mind that a hydraulic roller cam is a completely different animal than a solid roller cam. I'm a little vague about which one you are considering- you mentioned that 345 has a hydraulic roller, and so did he. Later in your post, you mentioned a solid roller. If you are also contemplating a hydraulic roller, then you have, basically, two things to look at: cost and overall valvetrain geometry. The cost is what it is and it appears that you are trying to build it correctly, not cheaply, so I imagine it's not an issue. So far as the geometry is concerned, I can't really answer that in reference to the various Hemis- Gary & others would know. I can say that there are certain engine designs, such as the 385 Series Ford, that don't accept hydraulic rollers easily because of the height of the lifter body....they can be made to work but it's distinctly not a bolt-in because the pushrod angles are a problem. (On the other hand, solid rollers work just fine in the BBF with no real issues.) I would assume it's not an issue because you would have heard by now, but nothing surprises me anymore. There are two main killers of solid rollers on the street: excessive idle time, and valve float (because of too much rpm or insufficient valve spring pressure at either seat, open, or both). Careful choice of springs and a right foot with some sense will deal with valve float, and possibly a rev limiter if necessary. When you experience valve float with a solid roller, the wheel itself gets a microscopic flat spot on it, which produces some interesting valvetrain harmonics, and worse. Too little spring pressure is more dangerous than too much when considering the roller cam....and remember that adequate seat pressure does NOT necessarily equate to adequate open pressure, and vice versa. Solid roller idle time is a different story. There's no one "right" answer here- it depends on your driving habits. If you figure on a lot of idle time, I would consider using either a break-in oil, such as the Brad Penn or Joe Gibbs oils, or one of the "break-in" additives, all the time. I realize that this seems contrary to what you may hear- "roller cams don't need to break in!" but you aren't doing it for the lobe/lifter interface, you are doing it for the roller axle and bearing which often are insufficiently oiled at idle. I keep a rough idea of how many hours I have on the engine and how much idle time, and pull it apart to inspect everything when I reach a certain point. Some lifter bodies can be rebuilt, and some cannot, so ask before you buy. Rebuilding the lifters is usually around $200, which may or may not be a good deal depending on the original cost. Keep in mind, also, that there are other factors...a set of lifters that didn't survive with one lobe profile might well have worked with a more conservative one. A solid roller designed for street use is going to have less ramp acceleration, less overall lift and duration, and is going to be much easier on the lifters from that point of view. Whatever you decide, I would suggest picking one source for the valvetrain and getting the cam, lifters, springs, retainers, and locks from them. Be precise in telling them what you are doing, what you have to work with, and what you expect from it. If you do your homework and choose a reliable source, and have reasonable expectations, a solid roller cam can work fine.
I understand everything you've mentioned, the kind of post I wanted to see here. I'm talking about getting a solid roller, I just mentioned 345 got his from the same place, Contrera's Cams, Donnie Johansen works there, from the Howard Cams legacy. He puts everything together, cams, lifters, springs. The way he was talking, it was only like a .380 lift or something pretty mild, but said it's a great cam, especially for the street.
Yea, a lot less lift than a flat tappet. What is the difference power wise of a low lift roller say, .375, compared to a flat tappet at say .465 lift? Is the roller aspect going to make up the power difference?
A lot of this depends on the head flow characteristics. Without knowing anything about the cams in question, I would expect the roller to have a considerable amount more of .050 duration than the .465 solid cam. The roller design in and of itself offers fewer frictional losses (although often you have higher rotating resistance due to higher spring pressures so it's a wash). You have to consider lash as well....older cam lobe profiles often call for .028 lash or maybe even more while some modern solid profiles can even be as low as .012. And of course the hyd. roller has no lash at all, the lift is what it is. It sounds to me as if the Johansen roller may be conservative to ensure long and reliable street life....nothing at all wrong with that. He's done it for a while and has a good rep. I doubt that you're leaving much on the table with the loss of lift, and probably getting it back in other cam design areas. Some head designs really like a lot of lift (comparative to other designs), but blowers tend to cover up a lot of holes anyway.
I'm not a cam expert, but I do know that with roller lifters the opening/closing of the valves can be a lot more aggresive than a flat tappet. The valve is literally wide open within a relatively few degrees of .050...and closing is just as quick. The longer/faster the valves are held open the more mixture goes in/out. You'd have to get Donny to give you the details. I know that when I switched to a roller in some of my other engines, I could use a much more aggresive cam than I could with a flat tappet grind...and the engine didn't even sound like it was cammed, but when you opened it up, the differance was apparent. A Hemi has superior breathing charactristics, and a well designed roller compliments them. I guess that's why Chet Herbert started cutting them for the Hemis in the mid 50's...
Absolutely nothing wrong with using a solid rollar cam on the street, particularly if you're going to have the cam ground specificly for your engine combination and 'street use' application The problems a lot of guys had in the 'old days' with running solid lifter rollers on the street was due to the fact that most of the 'off-the-shelf' - either new 'speed shop sourced', or used, 'swap meet sourced' roller cams that were commonly used, on the street, were usually all-out, 'race only' grinds with long durations, super-high lift and/or near vertical ramps on the lobes that required huge valve spring pressure and exotic high-dollar valve gear in order to work. With a roller cam ground for your applicattion, particularly by a guy with the knowlege and reputation of Donnie Johanson, it should work great for you. And there ain't nothin' quite as nasty on a 'street engine' as the sound, throttle response and power of a solid roller! That cam gonna' make yo' 'Deee-Sota' sing!!! Mart3406 ============================
Yea, way I'm looking at it, I'm sure Donnie knows what he's talking about, especially with all the years under his belt. Sounds like he has just the right setup.
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