Guys, I need your blunt and honest opinions as well as recommendations.
Here is my combo...
'70 Chevelle with basically stock F41 suspension.
I will be adding front disc brakes...power disc's will depend on the cam.
Car will be a true street/strip car...say 60/40 street over strip.
I already have this motor assembled and sitting in my garage...
461 cubic inches, 2 bolt block, truck rods, forged Speed Pro #2399 pistons, Edelbrock High Compression Roval Port heads(100cc chambers give 10.3:1 comp with these pistons) with no porting, Performer RPM intake, 800-830 cfm Holley, MSD Pro Billet distributor, Hedman Jet Coated 1 3/4" primary headers, etc.
The cam I have already installed is a Crane Hydraulic Roller 234/242 @.050 duration with .610/.632 lift, LCA is 112 and intake centerline is 107.
The advertised powerband is 2500-6500.
I would actually like to shift at or around 5800-6000. Would I be leaving anything on the table by shifting at this point? I've read and heard that hydraulic rollers don't perform past 5800-6000, true? Also, what kind of idle can I expect...rough, choppy, lopey?
I want to run into the 11's...will this setup do it or should I go solid roller and be done with it? Keep in mind, I still would like to shift at no more than 6000 rpm for parts longevity sake.

Give me your input now before I drop it in the car!

The LSA is wayyy too wide. Why not choose a solid flat tappet grind?

You should be ok with that cam.
I use an Ultradyne hyd roller 233@.050 .625 lift on a 109.
I shift around 5600 or so 1-2 and 6000 2-3.
I`ve been 6500 before but the set up responds better shifting lower.

Hyd rollers in a big block can run to 6500 or so, at least that`s been our experience.

the 112 is going to want more rpm, the wider the lobe seperation the flatter the power curve is going to be, more then likely you will end up shifting higher then 6000 rpms to get the full power range.......if you was to step down to say 108 lsa then your cam will peak out sooner and fall off faster in the upper rpm range.....and then you would see your motor giving up sooner say around 5500-6000 rpms....

the wider the lobe seperation the smoother the idle will be and the farther the rpm range will carry on up thru the power band and your idle vacuum will be more........

the shorter the lobe seperation the more radical the idle becomes and the power curve peaks out higher and falls of dramatically.and you have less vacuum at idle as well.....

like bigreds combo he has a shorter lsa and he knows his likes the lower shifting points that because it peaky.....if it was 112 lsa on his cam then more then likely that same combo would want to see 6500 shift points......

i run more solid roller cams then i do hyd. rollers and the same still applys.....

i would say run the cam and try different shift points and if you feel they are to high to get the e.t. you want then try another cam with the same specs with a shorter lsa.....

for the most part a shorter lsa will create more midrange torque , it will come on sooner ,peak higher and fall of fast.....compared to a wide lsa that will have less midrange peak torque but will carry it alot more longer and thats why they just look flatter and longer then a short lsa when you see dynos of them....

What gear and convertor do you plan on using?
Those heads/pistons worked out well with no mods?

If its a mild stall, 112 is just fine. If it's 3500+, then the tighter LSa will be a better performer, but idle quite rough.

Run it man.

That should be a real good cam for that combo. YOu could actually step up a bit larger as well. The LSA is a bit wide, but should give you a nice broad power band for street driving. Your not going to hurt that thing going to 6500. Give it a couple time shots at 6500 to see what it will really do. Probably won't be much different, but you could also advance the cam a couple or 4 degrees to bring the power band down a bit.

Did you have any fitment issues with those heads and your pistons? Any valve clearance problems? I have looked at those heads for my 396 engine, and would be interested to see how they perform for ya. Good Luck. graemlins/thumbsup.gif

Lots of good info guys!
The rear gear is going to be 3.73
The stall will probably be around 3600
Big Red, I know you're running a big car but, what kind of times are you seeing with your combo?
I like the looks of that cam you mentioned...especially the 109 with shorter duration.
The clearance's with my heads and pistons worked out great and plenty of room to spare. No notching the pistons require either.
I think these high compression heads(with alittle work) on a 502 shortblock with a cam change would be a killer combo! I'm guessing high 10's!

Big Red....Duh! I just saw your times in your signature. Are they still your best's?

I haven`t bothered to better the time because they told me to park the car due to no roll bar last time I ran.
I`m so very sure there`s quite a bit left in it it`s not funny! Just look at the 60 ft time alone smile.gif
But what`s also not funny is, cutting into a rare factory original. :(

My wife bought me a 71' chevelle for our anniversary last January. So the plan is to swap over the motor/trans into the chevelle and restore Big Red.

I'm running that same cam in my .030 over 454 in my Camaro. How is your piston to valve clearance? I had my block zero decked and I had pinston to valve issues. I am also using 781 heads that had been milled. I went with K/B 257 pistons and all was good. I run a 3000 stall converter. Don't believe any of the above about torqe/ rpm issues. Mine is over 500 ft/lbs torque from 3000-6000 rpm. I didn't check it below 3000. My engine does start to roll off at 6000 rpm, the hp starts to drop.I don't use stud girdles either, with them I might get a little more rpm but I'm happy where it is. My car is lighter than yours but I would say that you will be very happy with your combo. Mine idles well at 900 rpms with about 11 in. of vacuum, . I do have an H pipe on my exhaust, not too much lope.

Hmmm, I would have expected a might more vacuum.

Oh, it's a hydraulic. tongue.gif

:D You solid guys always raggin on us hyd. schlubs.Maybe I have a vacuum leak. I also run an ancient 850DP that is all reworked, replacing it might bring the vacuum up a little, but it runs too good. ;)

I would not hesitate to run that cam on a 112. Having run a number of hyd rollers, they are all fine up until about 6000rpm. I wouldn't (personally) count on 6500 at all, based on my limited experience and the explanation of the guy who did my last cam (from hyd roller to solid roller).
I was looking at hyd roller cams in the 242/248 @ .050 range in a 460, so I think you should be ok.
Hyd rollers work great, just don't expect SR revs or a quick rev feel to beyond 5500-- IMHO.
No matter what people say-- yes the engine may go to 6500.. or whatever .. I doubt it would make more power on a dyno up there.. after personally witnessing the destabilization of 2 different hyd rollers on an engine dyno at 5800rpms, with this fluctutation starting at 5200 but not mattering until atleast 5800, (all BB, heavy valve train, not saying 6500+ can't be done), then getting a solid roller-- you can feel the difference.. there is no chance I would have ever blown a hyd roller engine by over-revving it, my solid I can hit the rev limiter by accident every time I drive it..


Good luck.

matt

Phel69, I looked up your pistons and it appears you have about 10.5:1 compression with your zero decked block and shaved heads. My block was "squared" but, not decked. The heads were installed "as is" no alterations other than changing valve springs from the wimpy factory ones. My compression should be at bout 10.3:1 so, just about right for pump gas?
I may regret not having some headwork done but, I wanted to keep the velocity up in the intake ports. The stock flow numbers are decent and I really am intrigued by the way these small chambers may work.
My engine builder is a meticulous guy and even balanced the rotating assembly to within +/- 1 gram. So, I feel the motor is done right. Still, I kinda feel weird about not actually assembling it myself. Up to this point, I have always done everything myself. Never had a motor of mine die either. But, I wanted this one blueprinted and double checked so, I went with an expert. He has ALOT of experience in building extremely high dollar dirt track and asphalt motors. You should have seen some of the exotic stuff sitting beside my dinosaur in his shop.
If I can get into the 11.00's I will be tickled to death! Don't know if it can be done with this setup or not. But, I always have a 100 hp nitrous setup in standby if needed! :)

I am not surprised at reading an engine vacuum of 11" with the Crane Hyd Roller. That cam has seat dur. numbers of 296/304 on 112LSA. 76 degrees of overlap at the seat. Crane tends to build in much slower ramps in their cams and can tolerate a lot more compression. This cam would probably work up to about 11.5/1CR. Of course the other thing on the engine vacuum is where is the cam degreed and what is the carb jetting like?

For example, their SR236 idles at near 15" in a 468, and their NICE SR the SR246 does about 10". It's a 7000 rpm cam though, the small SR236 does 7 easy.

Hey Kentucky, don't fret about not assembling the engine. I didn't either mainly due to space at home and lack of a "clean-room" environment. I don;t feel like any less of a man.

They did phase the cam wrong though, had to pull off the timing cover and re-degree it.

SILVERSS454, you are correct about my compression being in that range. I think that it is a little closer to 10.3:1 becauseI had head work done, bigger valves and porting. At any rate it runs great on 93 octane. We used to have Sunoco 94 but 93 is the best local pump gas now. It is a good cam and I think that you will like it.