subboz

Havent been around much on the board due to truck and sled. I am going to go with a solid roller cam this spring and was curious what yall are running in the roller market and what might be too big. I know all about the converter and header issues. I am looking around 520-550 lift but dont wanna go to big. Already went too small on current cam. Trick Flow g1 heads withy 1.6 roller rockers.

bence13_33

That's a pretty stout cam for a small block. I'm running a 294S cam in my 468 big block and it has lift of .595"/.595".

First and foremost you need to consider your compression ratio. If you are running an 8.9:1 compression ratio, a huge solid roller cam with .550" lift isn't going to work out for you. Another thing you need to consider is your rear end gears. If you have 3.08 gears and upgrade your convertor and go with a huge cam your convertor is going to have to work a lot harder and the convertor most likely won't last that long.

I would say you have the heads to justify a bigger cam (I'm not up to date on small block heads but assume that they have 2.02/1.60 valves). The other issue is headers. Your manifolds are going to severly hold back the performance of your motor. In fact, I would imagine just by switching to headers with your current setup you would see an increase in performance.

My main concern would be your compression ratio. Your current cam is small, I put a cam similar to that in my 8.5:1 compression stock 1976 L48 350 motor that was in my 'Vette. Definitely not a performance piece.

Do you really need a solid roller camshaft? If so look at shelling out around $1200 to correctly switch to a roller cam. You could change to a solid flat tappet and have comparible performance, with a lot less cost and less valve train wear. FYI you should look at roller lifters as disposible items and be extremely **** about your valve lash (that will be the first sign something is going south with your lifters). Valve springs also fatigue quickly, I've heard from a few sources that you can expect around 3 years on a set of valve springs (especially if you go with a hairy camshaft).

Monty

Duration and overlap is what makes a cam "big", not lift. Larger durations and overlaps also require higher static compression ratios to achieve effective dynamic compression ratios, lift has very little effect on this.

Generally, you match the lift to the flow characteristics of the heads and intake, and match the duration to the operating range, engine displacement, gearing, etc. You can run .600" lift at the valve with 220@.050" and it would run almost identically to .500" valve lift and 220@.050", everything else equal, except the larger lift cam might make help make more power if the cylinder heads have a flow advantage at the higher valve lifts. Obviously the more lift you have per degree of duration, the more intense the cam, and there are mechanical limits to this based upon the lifter type used, but with a solid roller you can run very intense cams. I've run as much as .700" on the street with less than 250 @ .050", but you need very good springs, of the appropraite rate, and be prepared to check lash often and change springs every year or two depending on usage. Additionally, at those rates, shaft rockers, lightweight titanium valves, retainers, locks, and even pushrods become a necessity. It gets expensive. These days, .600" with a roller cam and 1.6+ ratio rockers is pretty commonplace on the street.


[Modified by Monty, 12:50 PM 3/21/2003]

subboz

Sounds like you guys need a little more info. I am looking for specific cam recommendations within a defined parameter ground.
1. 10.5 compression
2. 2.02 valves
3. 3.73 grears
4. Headers
5. Performer RPM
6. Solid Roller with appropriate recommended springs
7. Weekend Runner with monthly trips to strip
8. Generate vacuum for power braks
9 2500 stall converter
I am aware of valve lash checks but I only logg aroun 5k a year on the car. I am in the ballpark for all items needed to make a bigger cam run but didnt know what yall were or if you were running for solid cammed motors. I want streetability but more performance from 2000-6000. The currrent cam is a sissy. Turning 13.7 with the exhaust manifolds 3.38 gears and the wippy cam.
As always bigger better faster is always needed. I have noticed that these heads need to breath and want more fuel and cam but just gotta get it there without going to big and losing some drivability.

BeaterShark

I'd recommend taking a look at either the CompCams Xtreme Energy street solid roller ( http://www.compcams.com/catalog/060_061.html ) or Crane's street rollers ( http://www.cranecams.com/master/apps/chevy27.htm ).

For the 350, I'd suggest the smallest from the pages above.

I went with the CompCams 274 and have had it on my 383 for about 17k miles. I get about 14" of vacuum at 750 RPM, although I don't have PB so I couldn't comment there. I just pulled the intake and all of the lifters were in great condition. I had no pitting and all roller wheels were tight. I'll probably go another 15k before I check again.

I think that when most people think of solid roller cams, they are thinking about the race type. Both of the lines from Comp and Crane would do fine in a street car. What kills a valvetrain and lifters are the exteme spring pressures needed for those race rollers. I believe you should be able to get 75k miles out of 400lb open pressure springs.

There is no way that a solid flat tappet cam has less valvetrain wear than an similarly speced solid roller.

Again, keep the lift/duration/spring pressures in check and you'll be able to run a more aggressive lobe profile with a solid roller than with either a solid flat or hyd roller and keep the reliability in the same ballpark.



[Modified by BeaterShark, 9:17 AM 3/24/2003]

Monty

I've been running custom solid roller cams based off of Comp's Xtreme Energy Street Roller lobes on my last 3 engines and like them very much. Thye seem to make very good power and don't beat up the valvetrain as mentioned above. On my 650hp NA SBC427, I had a cam with the Xtreme Energy lobes as well as one with Comp's Hi-torque .406" lobes which Comp describes as very aggressive and the power differnence was around 2%, which isn't a bad sacrifice for increased streetability and durability improvement for the vlvetrain. even peak power wasn't negatively effected too much, 635hp vs 650hp.

I'm using those lobes in my current TT setup as well, I think Gkull also went with them as well recently.

gkull

Crane has to nice sollid rollers an their web sight. The 232/240 would be a nice cam in a 355 ci with mid to high 10 compression. With 1.5 rockers and 155# dual springs The lifters should last 50K miles.

I had a Crane custom and now I'm going with a Comp Cams custom billet solid roller. I preferr larger lifts though.