What are your opinions of solid rollers in Lt-1's? As well as the specs of this cam

TPIS solid Roller


700-702
Intake Exhaust
Advertised duration 286 286
Duration at .050 248 248
Gross lift .607 .607
Lobe separation 110

 

You will have to adjust your valves more often with a solid roller. Some people say they can do it once a year, I've heard people say every week, which I think is a little excessive.

As for the cam specs itself, it would likely make good power but when you combine the 248 duration with the 110 lobe seperation it's gonna have an idle very similar to a top fuel dragster. You might consider a 112 or even a 114 for a little better low end performance. It'll make your power curve a little less "peaky"

 

I fail to see why anyone would choose a solid roller lifter over a hydraulic roller unit, particularly in a street car. The hydraulic units have come a long way in the last 40 years....

Larry
code5coupe

 

The ability to run very high spring loads without damaging the lifter. Stronger springs means higher RPM potential. If you want to turn over 7000 RPM's reliably you'll want a solid roller.

I agree they are a little more trouble but they aren't THAT much more trouble if you don't mind tinkering.

 

Is this car going to be street driven, or just for track use?

 

Street driven car, the reason I ask is because before the thing would scream all the way to 6500 with the ZZ-X hyd. cam and I want a little more power. I probably only drive 10k miles a year anyway.

 

ok what size motor is it ? trans and converter? rear gears?

 

383 ci, 6 spd, 3.97 rear

 

ohh yeah go for it , thats a bad azz cam. i run a soild roller in my car and it drives fine, i check the valves every month and they always check fine . you can go a year with out checking it

 

Hydraulics can easily go beyond 6500 with the right spring rates and lifters. I don't recommend running heavy spring rates with a Comp "ostempered" core hydraulic roller cam. These cores cannot handle heavy spring rates. However if you use a billet steel core such as a Crane with a cast gear, even Comp offers them now, but you have to ask for them specifically to get the cast gears. Running a billet core will allow much heavier spring rates, as these cores are the same metallurgy as what a solid roller is made from.

If you run a billet steel cam core with a steel gear you would have to use either a steel gear or a Comp polymer gear. Either gear will have to be modified to fit the LTx oil drive shaft as it is not a standard shaft size that the various cam grinders will be willing to build distributor gears for. The LTx drive shaft is .427" OD as compared to a .500" MSD distributor shaft or a .491" GM shaft size. You would have to machine a sleeve to fit the shaft and then pin it together.

As for lifters you can run a modified OE hydraulic roller ie; a cheater lifter that the stock eliminator guys use. These lifters are basically a hydraulic lifter with its guts modified rendering it basically as a solid. It does have about .020" of hydraulic movement so that the NHRA inspectors can still qualify it as a hydraulic lifter. Schubeck Racing offers these as well:

http://www.schubeckracing.com/rollerhydraulic.html

I use lifters modified by Allen Sherman. Once installed you basically zero lash them cold. Then on a warm engine, double check the lash. Allen recommends adjusting them one flat of the poly lock after zero for street use. Using these lifters you can run spring rates the same as a solid roller cam without fear of damaging cams or lifters. So there you have, solid roller cam performance without the hassle of solid roller cam maintenance

 

A mech roller camshaft that is 248 @.050 is a waste of money. The biggest benifit of a "real roller" is the fast opening and closing rates of the ramps. As for the valve adjustment it would be about every 5-6 months on it if the car were driven as a part time car (every 10-12,00 miles). The only real advantage I see to this cam over a Hyd Roller of the same Dur @ .050 is the lift (.607) and the potentional for about 7000 rpm, the 110 LSA is wide enough to mask it till then but you won't be making much power after that. Yes the idle will be no joke. Rember that the old Z-28 "off road" mech camshaft GM desgined back in the day was 268 @.050 on 114 LSA and it was desgined to pull to 7800rpm in a 327 inch motor. Now I know roller grinds are much better at making power at high rpm due to alot of things (mainly the fact that the lobe won't run off the edge of the lobe b/c of the big wheel on the end of the lifter) so they can be more aggressive the more the lobe opens the valve, but it still took a cam that was 268 @.050 to make 7800 in 327 inches. In 383 inches, even with a "modern" roller camshaft, it is going to take a bigger cam (than 248 @.050)to make power beyond 7000rpm.
The smallest roller I would use is a Reed R292/302ULX
258/267 @.050
608/626 lift (1.5)
106/115 (110 LSA)
Heres my .2 on roller cams in a street car, If youre gonna run a real roller and deal with adjusting valves, replacing valve springs every year and the fact that everyone just laughs when you tell them you still have the "hotcam" make the most out of it.
Will

 

a cam with a duration like that on the street never. someone with the same engine a cam 220/230 at stop lights would eat you up. all that top end power were you going. sorry but true.