I am getting my stock motor rebuilt to a 383. The parts are as follows.

Heavy Duty Blower JE pistons -31cc
Eagle Rods 5.7" H-beam
Eagle Crankshaft 383 4340 forged
Piston rings speedpro plasma moly
Comp Cams Pro Magnum Roller Rockers 1.6 ratio
Comp push rods
4 Bolt Mains

My builder after talking to Comp Cams decided on 230/236 114 LSA cam. Comp Cams apparently did a test with a 350 SBC w/ a P600B and with the above cam, they said it worked very well (not sure what that means).

I was originally thinking of 224/236 116LSA. I want the car to be very streetable that’s why I went the SC route. Is anybody running a 230/236 114LSA cam on their 383 SC setup? How is the low end, idle, and vacuum? What are your opinions on the choice they made?

I am going to be keeping my P600B w/2-core intercooler and 8lbs pulleys to start with then try to pulley up to 12 or 15lbs pulleys to shoot for approx. 500rwhp.

Kris

 

If your goal is 500rwhp, and your looking for optimal streetability, than both of the cams you mentioned are more than you need IMHO.

With my supercharged setup, I used a 214/222 114lsa cam, and it made over 600rwhp, and had great driveability. I mean that as in nearly undetectable lope at idle, and smooth cruising at 1300 rpms in overdrive.

Just to clarify, the cams you mentioned aren't really 'bad', but definitely not necessary for the power level you are looking for.

 

Ideal cam for you: CC XE lobes #3190/3192 on a 114LSA. 214/224 @ 0.050" with .565/.605" lift with your 1.6 rockers.

Rich Krause

 

The 230/236 cam is probably too big. I sure wouldn't go down that road.

Not sure just exactly what the altitude is in Grande Prairie, but in Calgary with an altitude of 3,400 feet, the 224/236 lsa of 114 is coming up a bit short on vaccum. I get 9" at an idle of 825 rpm and while driving I sometimes see 14", this leads, on occasion, to the condition know as "hard pedal", which if you're not expecting it can be quite ... exhilarating . I'll be playing with low speed timing and closed throttle timing later on when the weather gets warmer, if that doesn't do it, then I'll be putting in an auxillary vaccum pump to help the brakes.

The 224/236on a 116 lsa may be a bit better for vaccum.

The 224/236 cam makes gobs of power and peaks out some where north of 6,300 rpm. I like the higher revving cams myself, but like what INTMD8 and Rich Krause say, you don't need such a large cam if your goal is 500hp and good streetability.

Hope this helps

LWM

 

Thanks for the replies

INTMD8 you brought up another point seeing how it’s a M6 in your opinion would the 230/236 cam have a problem cruising at 1500-1300 rpm.

rskrause I was thinking that the 224/236 would work for my current setup and would give me room to grow when I get AFR heads. I should mention that my stock heads are just going to be cleaned up a bit. The elevation here is 2500ft be the air quality sucks usually converts to 4000ft. So would I need to go bigger than 214/224 to compensate or do I just turn up boost.

LWM I did a search and seen the problems you were having with vacuum which made me even more concerned. How does load effect vacuum? I would think that less load = more vacuum. So would a M6 make more vac than an auto?

Kris

 

Just got off the phone with my builder and the motor that Comp Cams tried the 230/236 cam on was an LT1. It was in a car (Camaro or firebird not sure) and they assured my builder it was very streetable. Descent idle, good vacuum, and smooth cruise. I guess they are P&P the heads and cleaning up the intake manifold if it’s needed.

The customer service seems to be excellent hope that dosen’t change after the final check is cashed.

Kris

 

I would want to know the LSA and what the lift numbers are. The LSA needs to be 114 or higher and there needs to be more exhaust lift than intake lift. And since the exhaust duration is not that much greater that the intake duration if you do chose this cam make sure you spend more money on the exhaust port of the head instead of the intake. Look for an I/E ratio of 75-80%. I think even with a blower cam the I/E ratio needs to be atleast 70%. Good luck in your build up.

 

Those guys at Comp Cams do all their work at sea level. You will not see any where near the vaccum they see.

Seeing as how your air in GP checks out at 4,000 feet, I wouldn't recommend going any larger than the 224/236 cam. Calgary air is also a bit thin, usually checks out at an equivalent to 4,500 feet. I should also add that a lot depends on how well the rings seat in. If you get excessive blow by, then the vaccum will also be low. My engine has only 1,000 km on it and the rings may seat in a bit better later on. Don't get me wrong, I do have vaccum enough to operate the brakes, but they are not nearly as good as when the engine was internally stock.

And on the other hand lots of guys have run the 224/236 cam and larger with no issues about not enough vaccum. As they say, your vehicle may vary.

Hope this helps

LWM

 

Just for comparison I'm running a 228/236 511/533 113 LSA cam with 1.5 RR's on my blown 383, It has a lopey idle but very streetable, Tons of Torque and high end. I see 14 inches of vacuum at idle and about 20 when cruising.

 

I'm not going to be too fussy about head flow until I get my AFRs. I guess the 230/236 114LSA 544/555 cam is going in.

I was told a manual and auto will have a different amount of vacuum at the same idle speed. How much I don't know.

In a few months I will let you all know hows in turns out.

Thanks for all of the replies.

Kris