socal85tam

iTrader: (4)

I'm planning on changing my intake to a HSR, and I don't want to make the same mistake that I did, on choosing a too small cam. I would like to use something with 230sh degrees of duration at .050" and with lift no more than .520" so that I can keep the same springs that I have now, the lobe separation angle would have to be somewhat computer fiendlly.

What cam do you guys think that I can use close to this specs, and still be able to use the stock ECU with a custom chip?



10.7:1 383 1 piece rear main seal (roller)
TFS 195
HSR 58mm TB
Vigilante 2800
3.73 gear ratio
hooker shorty headers

Thanks

Dyno Don

iTrader: (7)

Gabe:
The problem you will find is, the cams in that duration will be more than .540 lift. You can adjust the distant on your springs in various ways to gain more room. (offset keepers, or retainers)

socal85tam

iTrader: (4)

Thanks for the info Don. What do you guys think about comp cams 290HR-12. Will this be to radical to use on the street once in a while? Anyone using it in a 383?
The specs are in the picture.

VincentZ28

iTrader: (2)

Lots of people is using that cam with the same set up and running in the 11's.

BrandenCali

Wow then I can't wait to install my cam remember for a 383ci there is no need to over cam.. Im using the zz4 and made plenty Power..

TraviZ

iTrader: (2)

that exhaust lift is rated at 540, would that be too much for your barrier? i run a variation of that 276 cam and i love it.

socal85tam

iTrader: (4)

What are the specs in your cam? Like dur @.050" and lobe sep*. I'm debating between the 290HR-12, and the XR276HR-12 . If I have to change the springs to use this cam, mabe I will. But like Branden said, I don't want to over cam either. I would rally like to use something in the middle, like the XR282HR, but I don't know if my ECU is going to like the 110* lobe sep*.
All opinions are welcome.

Dyno Don

iTrader: (7)

You must stay away from 110* and when going bigger it is advisable to go to 113* to keep fom losing vacuum.

TraviZ

iTrader: (2)

my cam is 503/510 lift 224/230 duration @ 112 duration

xr276hr-12

cali92RS

I have the same cam in my 350 w/super ram.
Still trying to get the tune smoothed out (likes to stall).
But my brakes didnt really seem to be affected, as some people are concerned with because of its vacuum.
I run 3.89 gears and a t-56, had 3.73's. I wouldnt go smaller than that with this cam.

socal85tam

iTrader: (4)

I think I've decided. I'm going to use the 276 cam you guys recomended to keep the car streetable. I talked to a guy from comp cams yesterday, and he told me that if I wanted to use that cam, that I needed to order the small base circle version, because of my stroked motor. The cam that I'm running now is a regular base circle cam, so the internals of the engine were clearanced. My question is: Do I still need to use a small base circle cam even though my engine was clearanced to accept the cam I have now?
The duration and lift of my cam are:
214 220 dur @ .050" lift
.482 and .495" lift with 1.6 rockers
112 lobe*

The duration and lift of the one I want to use are:
224 and 230 duration @ .050"lift
.503 and .510" lift with stock ratio rocker arms

socal85tam

iTrader: (4)

Nobody knows the answer? Don?

RWB____s

I don't think that you would if everything has been clearanced already. To be sure , call Comp Cams and ask them.

Dyno Don

iTrader: (7)

Honestly...that is something that can only be answered when the engine is assembled. Anything else is just a guess.

BrandenCali

So probably be on the safe side no matter what is to check clearances again.. Don said the same thing with my 383 even clear for a zz4 cam.. A larger cam like I have is going to be a smaller base circle.. But duration is much diffrent.. So to be on the safe side and considering your going this depth.. Id do it..

socal85tam

iTrader: (4)

I called comp cams today, and talked to a different service tech. I explained everything and he said that I will be OK with a regular base circle cam. I think that it is like Don said, a guess, because I got two different opinions from them.
I'm going to go to have a talk with the guy that clearanced my block at the shop that built my short block, and ask his opinion. If I don't have a choice, I'll order a small base circle cam and a new set of pushrods.

Thanks to all for your help.

89 TA

I'm no expert, but I did put together my own 383. On my engine, the block didnt get clearanced for the cam the top of some connecting rods did. The block was clearanced for the bottom of all the conn. rods. My understanding is you pretty much use small base circle cams on 396's and up. unless you went with the 3.80 crank instead of 3.75. but not sure. What ever the outcome please let us know. I'm just waiting to have some home time, so I can install James ported super ram and cam. Just to see how many more 10-bolt rear ends I can brake.

socal85tam

iTrader: (4)

I just talked to the people that built my short block, and they told me that I will be ok with a regular base circle cam, so, I changed my mind and I'm going to go with the XR-282HR custom ground at 112*.

89 TA

So did you change your cam?

socal85tam

iTrader: (4)

I got the cam a few months ago, and the rest of the parts also, but, last month, a member of the family was driving my camaro, and busted my camaro's oilpan. I'm waiting to have some time to take the engine out, and fix the oil pan problem and at the same time, do the cam and intake swap.
I'll post the results as soon as I do the swap. Thanks for posting .

VincentZ28

iTrader: (2)

What intake are you taking off?

Dyno Don

iTrader: (7)

--------------------------------------------------------------------------------

[I'm planning on changing my intake to a HSR,]

socal85tam

iTrader: (4)

An edelbrock base, with slp runners, and ported plenum. Its a killer intake for the street with the cam I currently have and the 383.

socal85tam

iTrader: (4)

I just started the engine after the cam and intake swap. Everything seems to be working fine, I might need to tune the computer soon.
The cam idles very nice, not too radical for me, wich I like. The installation of the HSR was easier than what I expected.