solid vs roller cam question

[infotraker]

I,m currently rebuilding my 468 BBC in the Sanger pickle ski hydro.
Engine has 10.5 to 1 comp, 2 750 hollies on tunnel, msd ign, 990 heads. going to either comp solid or solid roller cam setup. Boat rpm range 2k - 6500k (used for skiing and occassional full throttle runs).
Question is : Will it be worthwhile to go for the roller setup, what are the pluses and minus ? I was told that the roller will add about 30 extra horses and all components will last longer, faster rev etc. Looks like the roller cost is about 300 - 400 more than solid. Any ideas will be appreciated.

[coolchange]

You can have a roller and a solid with the same specs. ( lift duration) but the roller "can" make much more power because the ramp speed on a roller can be much higher. i.e. the speed at which the valve opens. You can see the difference just by looking at them. Solid will have an egg shaped profile and a roller will usually be oval shaped.

[Fiat48]

Yeah, what he said. With a roller, you don't have to worry about the cam going flat. I wouldn't use anything else.

[schiada96]

If you idle around alot I wouldn't go with the roller solid cam. You will have lifter problems. A nice cheep solid cam will work to 7k.
my .02

[Morg]

schiada96 is correct, but- Their are lifters available now which are designed to oil the cam at low rpm. Have not heard how well they work. In theary you are not relying on the crank windage for oiling.
Essentialy here's my thoughts. With the rpm range you mentioned you should be fine with solid. But, if it were my deal I would not even consider solid.
-Your cam will last longer
-no break in
-Eventualy you will step up the motor, then you will need the rollers
Morg.

[smalls]

Go Roller, Jim

[DansBlown73Nordic]

Im in the same boat. Trying to decide on roller or flat tappett. I got a really great deal on a used roller cam and lifters so Im going to try one out. ( Thanks John) :wink: The difference in price is more the $400 if you consider stud girdles and valves.

[bonesfab]

comp cams has the lifter you need. endurex solid roller tappet. has oiling groove on the side to help oil bearings in the roller itself. part # 866-16 not cheep but right. don't go cheep on springs either.. my 2 cents worth

[Moneypitt]

The primary reason for roller lifters is the allowable valve spring pressure!!!! You can't run high tension springs with any flat tappet set up. The valve springs are the primary governing factor in the higher rpm ranges. Weaker springs, valves float, stronger springs, excessive loads on the flat tappet lifter/cam lobe. Roller lifters, less load.. The oval shape if the lobe has to do with the fact that the lifter contact is round, and the actual contact point of the lifter/lobe is shifted considerably. Try degreeing a roller cam using a flat tappet lifter, the contact is on the edge of the lifter, so everything is way off, and the same goes for using a roller on a flat tappet cam, won't work, and its not the rate of opening, that will stay pretty much the same, its how those stiff springs get the valves closed. Remember, at 6000 RPMs, each valve is operating 100 times a second!!!!!!!! Moneypit

[schiada96]

Originally posted by bonesfab
comp cams has the lifter you need. endurex solid roller tappet. has oiling groove on the side to help oil bearings in the roller itself. part # 866-16 not cheep but right. don't go cheep on springs either.. my 2 cents worth
Thats about all your opinion is worth
ha ha
how is the better half ??

[BrendellaJet]

Moneypitt is right about the shape of the lifter vs the shape of the cam lobes, however the roller will allow steeper ramps as well. If you dont already have a girdle, guide plates and rockers, go with the jesel sportsman shaft rockers, pretty affordable when you add all those other components up...