trying to make a decision on what cam to purchase.....here are the cam specs:

Comp extreme 284 hydraulic 240/246 duration @.050 .507/.510 lift 110 LS

Lunati Special Purpose Mechanical 240/249 duration @.050 .507/.519 lift 106/102 LS

All things being the same.....which cam would make more power being that they are so similar?

Note.....YES I know these are big cams The motor will need it and the car is setup for it.

They're not really the same. What's the suggested valve lash for the mechanical cam. Lets say .018". That would make the mechanical cam's lift .018" less. That very tight LSA on the mechanical cam would make a very poor street cam. It would probably idle at 1500 rpm. Sounds like a stocker cam but the lift is too high.

Solid cams are good for very high reving engines. 6000+ rpm I use an Xtreme Energy hydraulic cam with anti-pumpup lifters and have no problems at high rpm. A hydraulic cam is very low maintanence. I don't have to worry about adjusting valves.

I wouldn't say those are big cams. Well ok, maybe for a 283. I had a .550 lift cam in a 383 that was driven on the street. 114 LSA let it idle at 700 rpm.

The one that would more power would be the solid cam but as I just mentioned, it wouldn't work on the street. It also depends on the rest of the engine and the car setup.

Just adding to what he just said. If you are going to be doing more street, but also some strip action, try not to go over about 6,000 rpm when your at the dragstrip. You might "float" the lifters. If you do go with the hydrolic one.

:lala:

Well actually the reason I choose that cam for comparison was because my buddy just put his motor together and got his car driving...a similar car to mine....we both have 3.73 rear gears and a manual tranny, he has better heads (ported aluminum heads) and i have race ported vortecs with the appropriate screw in studs, springs, ect......well anyways, he has that same exact Lunati solid cam but one size up from that one (with 249/259 duration at .050) and his car idles just fine at about 1,000 rpms, well I mean it idles ROUGH but IMHO that is only a plus And as far as being streetable.....man his car is torquey as hell with that cam! Pulls like a freight train from 2,000 rpms on up. With 3.73 gears and a 5 speed do you really need a super torquey cam?? His rockers do clack a little buts its really negligable with the hood closed. What are anti pump up lifters and how much do they cost? And I wouldn't mind having to adjust the rockers every once in a while if that is the only catch......I usually have the valve covers off for one reason or another every few weeks anyways! Thanx for the input guys.....I've got bout a week to sit on it till the money comes

Chris,

You'll have to list the rest of your setup for a proper response.

I used to run a Solid lifter Crane290A with 240 dur & .545" lift if i can remember correctly.

It all depends on how much compression, how good your heads/intake flow & what you got upstairs for a carb. Also what type of tranny with what stall (if applicable) are you using with what rear-end gears?

I yanked the Crane290 because it was very big for a street-car. Same setup still exists in my profile only replaced by a CompXE284.

If it matters, i prefer the Crane over the current COMP power-wise, but the Comp for driveability.

Also most cams dont require setting lash as often anymore as long as you use some good polylocks on those rockers.

Ok heres the detailed list.

Car weighs approx. 3,200 pounds

1988 roller 355 block (no roller cam or lifters in it now though)
SB flat top cast pistons, approx. 9.5 CR with 64CC heads
Vortec heads extensively ported, flow aprox. 272/220cfm .500 lift
1.460 valve springs, cut down guides
Serpentine belt system
Proform 1.5 full roller rockers
Edlebrock Super Victor vortec intake
Holley 650 double pumper carb, milled choke tower
HEI with disabled vacuum advance (was pinging) moroso advance kit,
Dynamax 1/58inch shorty headers, full 3inch single hooker exhaust, no cat
WC T-5 5 speed from 92 Z28, gear ratios are....?? I think 2.76 first
Richmond 3.73 gears, Posi
lowering bars........eibach springs....ect..ect.....
I can't think of anything else at the moment.

With the same setup as now except with stock vortec heads, the 268 cam, stock rockers and an RPM intake it ran a corrected 12.9 @107 (@2,900ft)

Chris......if you really want that motor to cream & dont mind checking over your valve lash once a month(to be on the safe side) go with a SOLID!


The L/S is a little tight but it should be OK on pump gas.

But if it was me, the extra lift with less duration on a solid cam is very appealing & i would be considering it.

Damnit, now i gotta go solid again!