283 Cam Help

Hi all: New to this forum so hello everyone. I have a 1966 Nova SS with a 283 stock engine, stock converter, 308 gears, 245/17 wheels, headers, Edelbrock torker manifold (I am changing to a performer EPS or RPM), Edelbrock 1400 carb and CPP power discs. I have been searching for a cam combination that will give me mild chop at idle, work with a stock converter and not have a major affect on the power booster. I have spoken to a well known cam manufacturer three times and each time given a different cam recommendation.

I would really appreciate any advice or experience any of you might have with this. Thanks in advance for your responses.

JT  

I would use about 250° of duration on a split pattern, with a 110 or 112° lobe separation angle. 4° of "ground-in" advance is VERY customary.

If the engine doesn't have headers use a 112° or even wider LSA. A more modern and "intense" hydraulic flat tappet should make about 205° of duration @.050 with the above mentioned kind of advertised duration. Don't be scared by a less intense exhaust profile. Look for 4-6° more duration on the exhaust side of the cam. Lift will probably come in around .425".

I estimate that a cam like this will pull 16-18 inches (of Hg) of vacuum with your motor - plenty for your brake booster.  

Thanks for the information, I can't believe how many different answers I get on this. I have been from a 218 218 @.50 112 LSA to a stock cam in recommendations. The latest one today was a 210 @.50 with a 110 LSA, they stated this would be the max they would go on a 283 because apparently most cams are rated for a 350 and the smaller displacement of the 283 makes the cam more aggressive than being installed in a 350 ci.engine. This really throws many tech help lines for a loop when I explain the combination to them.

JT  

It is true that a 350 can handle more overlap with the same or better street manners compared to a 283.

The main reason you need to cam small is because you have a small displacement engine with tall gears and very little modifications to make it "breathe" easier.

I don't think 210° @.050 on a 110° LSA is too far off. I believe that it's heavily dependent on how efficient your exhaust system is.  

can you run the .425" lift cam with stock valve springs and pushrods in the 283?  

It's never a good idea to run the stock springs and pushrods on basically any cam.

It's common for stock engines to break these components since they are likely 30 years old and were poorly manufactured (mass production 30 years ago!).  

wat all would i have to get to run about a .460" lift cam in my 283?  

JT,
Hi, I am new to this forum as well but will take a shot at it with my computer.
You left out what trans and exhaust you have, and the weight of the car - - especially whether the trans is a Powerglide or one that actually has a 1st gear, T350, 200-4r, 700r4, etc.

I assumed you had a p-glide and 2" duals, and hand shift the p-glide about 200rpm over peak power, and then calculated your engine power and timeslips. Yes these are all calculated and by far it is best to go to the dyno and the strip, make one change at a time, and re-test. That is not always practical!

So on the computer, here goes.
Your combo as described today, also guessing you have the "431" cam, at 0-advance:
2.73 60ft
11.31 at 66.8 1/8 mile
17.29 at 81.3

I think the Torker II is killing your low end. Does the car seem like  "dog" like this?
Changing to the Performer intake (I dont think you need the Perf RPM intake):
2.60
10.83 at 67.9
16.68 at 83.4
Wow, what a kick, mainly on the low end but all over.
To me, for a street car, the most important time is the 1/8 mile time and as you will see, the stock cam shows the best one here, due to that 3.08 gear and 1.82 "1st gear" in the powerglide.

Anyway I did compute some other cams.
The newer "929" cam, also Clevite 229-1273, computed to:
2.63
10.89 at 68.3
16.72 at 83.7
Well, nobody's computer is that good, not mine for sure, so I'd call it a tie between the "431" and the "929" cams.

Next try the Performer cam at 204-214 duration:
2.66
10.91 at 69.4
16.68 at 84.5
Slower at 60ft and 1/8 mile, not worth it.

Finally the Crane HMV-272, near copy of the "L79" cam:
2.70
10.99 at 69.9
16.70 at 85.2
Too big for your combo.

So I'd look for a Performer or similar intake, and leave the stock cam in it until you get a 3spd auto in there, then things might change.

But,  

I agree your intake is too much for the car, look for a performer or similar dual plane intake.  Cam wise look into a Comp XE256 12-234-2 or the 260H 12-206-2, for something a little lopier check out the 265 DEH 12-208-2, or N+300 12-670-4.  If your carb is 600 cfm that is probably also a bit much, getting down to 475-500cfm will help improve responsiveness.  

I'm building a small SBC to try to get mileage and have some fun.  It'll be going in my 1970 Long Bed PU.  So I've been all over this question for a few weeks looking for the best answer.  283's are pretty sensitive to camming.  Loss of vacuum and partial charge reversion is real easy to have happen.  It has to do with the relatively short stroke.  There is not a lot of time to close the intake at the precise best moment.

I will be starting the build in mine with a cam very similar to the old GM 929.  That is about 198*/204* @ 0.050 lift.  It might seem mild, but all the engine guys I have talked to say you need 10:1 in this motor to use any more cam.  And if you are not making at least 9:1, even this cam is too much.  I'll be making 9.25 or a bit more, so I'm OK, but you might not be?  Swapping on a pair of 305 HO heads (smaller chambers) will put you there.  305 Vortecs even better, but more costly with the dedicated manifold and all.  Once you leave the world of stock cams, you need to match cam and compression ratio in addition to your drive train.  

The 305HO heads do flow better and have accesory bolt holes in the end of the heads that will make bolting up alt and p/s easier. The 283 isnt anymore cam sensitive than any other Gen1 SBC. I done a similar build last year with a 283 and used a Crane Cam that had .454 lift[cant remember rest of specs] that had a slight but noticeable lope and had great street manners. If interested I can look up specs on the cam if your interested  

Hi there. let me try for a memory test.
    454"/454" should be 218/218 with 110*angle.
   I cancelled my order on this one and went for
   214/224*--112* Both were a Comp cams and would be
   O.K. for a 283/307/305. 100lbs springs are best
   but check for clearances on valve areas..Skyeking