Langadorf

I'm currently running a Comp Cams 306 hydraulic roller. It has 230/244 duration and a 112 LSA and .51/.54 lift. From my understanding, this cam is intended for fuel injected whereas I am running a Holley 750 DP carb. After talking with different people and cam tech support (mostly idiots?), I've been recommended the three following hydraulic roller cams:

CC432 (230/236 duration, 110 LSA, .51/.52 lift)
CC433 (236/242 duration, 110 LSA, .52/.54 lift)
CC443 (242/248 duration, 110 LSA, .54/.562 lift)

Any opinions on which would be best for my setup (look below)? Would I even notice a difference from my current cam? How much does a 2 deg difference in LSA make? Also, I don't need the gear for the optispark (I'm HEI) so that's why I don't need an LT1 specific cam - any hydraulic roller will work.

The reason I'm considering this is that I have the heads pulled off for some port work and want to do all that I can while I have it apart.

My goal is to be as quick as possible but still be "driveable" on the street. This is my second/fun car, so I'm not concerned w/ emissions, gas mileage, or anything like that.

Here are my new engine/car specs:

'79 Vette - Race Weight 3500lbs (looking to shed some more); Daily Driven Weight up to 3700lbs
383 LT1 (originally from a '94 Camaro)
Compression Ratio: Somewhere around 12:1 to 12.5:1 depending on gasket choice
Aluminum LT1 Heads: Currently getting ported. Expect flow numbers around 260i/170?e
Edelbrock Victor Jr. Single Plane Intake
Holley 750 Double Pumper Carb
Hooker 1-3/4" LT Headers, Dual Flowmaster Exhaust
3.55 rear end, 2500 stall, TH-350 trans
K&N air filter, 160 deg thermostat, MSD 6AL

Thanks,


[Modified by Langadorf, 8:02 PM 7/25/2002]

MasterDave

Anything over 230 intake dur. is gonna make your car a bear to drive on the street. A 110 LSA is gonna make it an intense idle. I have the CC XE274H. Of those choices your setup seems to me to call for the CC432 but it would be nice to see if you could get a 112 LSA in it. BTW, nice combo. Maybe Curtis will chime in here for ya, but I know he doesn't like 'shaker' engines and will probably set ya up differently.

Langadorf

I'm open to choices besides these if there is something better. What sort of difference is there between 110 and 112 LSA? I was told 110 would give me better throttle response where a 112 would give me a slightly wider torque band. Is there more?

Fevre

Damn that's alotta comp. What type of gas are your running now? I am going to build a 383 with a crane hyd roller but keeping it mild at 10/1 and little smaller cam then you.

Langadorf

Currently, I'm able to run this 11.7:1 compression on street gas. My timing might be a bit retarded, but it works. This is in part due to the reverse flow coolant design - the heads are cooled first, resulting in lower combustion temps.

The LT1 guys I know with EFI (93 and up) often run up to 12.5:1 on street gas. I know having the computer, etc., helps so I don't know what the absolute limit would be w/ a carbed setup.

BTW, I'm only looking to rev to around 6200 RPM. I heard past that I'd run into valve float w/out a rev kit.

Smokehouse69

Chevyhigh Performance used the CC432 (230/236 duration, 110 LSA, .51/.52 lift) AKA 282 grind, in a 383HT with Vortec heads and made super torque numbers. The write up was in this months issue. They used it as a replacement for the Chevy Hot cam and it made a big difference. I think they were running 1.6 roller tip rockers also. They also used a Holley 750 for their testing.
Of course their compression ratio was around 10-1, instead of the 12-1 you'll be running.

Langadorf

In regards to that article, do you know what kind of specific numbers they were getting with that setup? How did those heads flow?

Also, what exactly is the benefit/downside to going w/ a lower LSA such as a 108/110? Better throttle response, carb signal, etc? I've always heard mixed stories on this. Does a smaller LSA increase or decrease effective compression, etc?

Fevre

The HT 383 is the engine I should have bought to start with: 383ci, forged crank and roller cam. What a basis for an insane build up! Some guy on the forum built one with a blow and some other aftermarket parts and said it was cazy powerful and some idiot buy it from him for $9,000, he did spend $7,000 on it. I am going to exp with dif rocker arm ratios to see what I like before buying a set of full rollers. I have the oem stamp steel and 1.6 rollertip so that should give me an indication of what will work better in full roller form. I want an engine that is good for cruising around without it coughing and spitting all the time.

I think that the lower the lobe sep that greater the bleed off so lower comp and smoother idle but don't qoute me on that.

Langadorf

I had always heard you get a worse idle w/ less LSA. What I'm not sure on is the effect on performance.

Fevre

I am not sure but when you look at cams they tend to getter wider in their lobe seperation as they get longer in duration. And it always seems that the narrower ones are listed first when there is more than one to choice from and that is usual the order in which they are listed from least to most powerful. I am just to trying to apply some logic to it but like I said I could be wrong.

goinbroke

Sorry to go off subject here, but just curious. Noticed you were from college station. Are you an Aggie?

Rip

Langadorf

Yep.

Aaron-74

I've got the article right in my hands...

compcams XE282 HR 230/236 110LCA
Intake (1.52) .510
Exh (1.52) .520
Intake (1.60) .544
Exh (1.60) .555
CompCams 977-16 springs
TFS 215cc R-series heads
64cc
2.08 intake
1.60 exhaust

Peak power
491HP@5700
500Ft-Lbs@4300
Red line @ 6,200 making 471HP and 431 ft-lbs.
Used Hedman 1 5/8 headers.
1,345.00$ on the heads
240.00$ on the cam
132.00$ on the springs


This is the sweetest street motor I've seen in a while..I'm planning something along these lines. :reddevil
Hardly broke 6,000.00$

Smokehouse69

Aaron, I thought they used the stock Vortec heads on the engine. Or was that some of the earlier tests?

Aaron-74

On the earlier tests the used the Vortecs. On the final they used the TFS.


[Modified by Aaron-74, 11:02 AM 7/26/2002]

Langadorf

That sounds similar to my goals. Do you know what the flow numbers were on those heads?

Also, how different is that cam from the one I have now? Are we talking a definitive, noticeable seat-of-the-pants difference - or just a MPH or so in the quarter?