Hot Rod Forum banner

1 - 17 of 17 Posts

·
Learning from your mistakes
Joined
·
79 Posts
Discussion Starter #1
ok, i've tried to avoid asking this on here, but I can't bring myself to pay $50 for software i'm only gonna use once in the next 3 or 4 years. here is an engine combo I'm setting up and I think the camshaft might be too much.

1950 chevy PU
3.73 gears
2004r transmission
'80 L48 block from corvette (leaving bottom end stock)
scoggin-dickey vortec head kit (says good to .525 lift)
performer intake
q-jet
smithy mufflers (2.5" pipe to muffler, 2" out back)
1.6 roller rockers (self aligning)
Crane powermax cam (CRN-113942)
@50 218 intake 230 exhaust
lift .459 / .486
LSA 112

its says power from 2000-5000 rpm. The truck is gonna be a daily street driver, little to no towing but occasional heavy loads hauled in the bed.
Is this cam too much? I like the specs, but my logical mind keeps telling me i'm gonna lose a lot of low end power with it. Would I be better off with maybe CRN-113932. part numbers come from summit website.
 

·
http://teamrfc.gospelcom.net
Joined
·
1,742 Posts
That cam should work just fine. I had a XE268H in a 355 with vortec heads (224 230 @ .050 .477 .480 lift) and it worked really well. It had really good low end power. If I had it to do again, I would actually go with a little bigger cam (XE274H). I had a nova, so it was pretty light compared to a truck. Anyway, I think that cam should work well in your setup.

Adam
 

·
Registered
Joined
·
2,384 Posts
what cam?

Sounds like a good cam combo to me.

The intake duration is right on the money, if anything the 230 duration exhaust is at the upper limit of what you want for a street engine, thats stock or even slightly modified, unless you are going to run a high stall converter.
Have you looked at the Comp Cams units?
Comp Cams # XE262H, I think would be a better choice, due to the 2 degree narrower lobe separation and 6 degrees less duration on the exhaust side.
 

·
Registered
Joined
·
177 Posts
I agree that 230 may be stretching the exhaust duration a bit. The cam GM uses in the 330 hp 380ft lb engine would probably be the best of both worlds. Specs are 212 in 222ex .435 in .460 ex lobe centerline 112.5. Should be a fairly smooth idle and lots of low end torque.
 

·
wind & fire = guides to power
Joined
·
1,529 Posts


You don't want to see what the rear wheel HP is , but this is nice!:thumbup:
 

·
Learning from your mistakes
Joined
·
79 Posts
Discussion Starter #6
thanks for the input guys, I'm taking a look around at different selections and managed to find a demo version of desktop dyno, I can't modify the engine, but it lets me change cylinder heads and camshaft specs, so I'm looking at what changes these other camshafts you mentioned do.
USA1, where would I get the cam you mention? would gmpartsdirect have it?
and NXS, am I losing a lot of power getting to the rear wheels? I know the 2004r isn't the most efficient but I didn't think it was that bad, espcially compared to a 700r4.
 

·
Registered
Joined
·
2,538 Posts
i have to disagree with the single pattern. dual pattern is far better. the XE268 is probably as much as id go in a small block. i have been told the XE262 will make similar power with good idle characteristics(more vacuum)
 

·
Registered
Joined
·
2,384 Posts
too much camshaft?

From the looks of that graph, I would say that would be about 250-260 at the rear wheels.

The big advantage of a dual pattern cam is that it will give you a bit more top end power without sacreficing your lower end. Also if you have smog heads with soda straw ports ( read that as in stock Winsor Ford heads), a dual pattern really comes in handy, as it give longer time for exhaust to purge out the small ports.
And yes I am a Ford man.

Go find a Jegs or Summit catalogue, you will find most everything your heart could desire there.
BTW, Last year, While passing through Tallmadge, Ohio, I got a chance to see Summits new store. It is awesome. Not only do they have about every part on the floor that they sell, but its a museum of the fast and furious of all kinds of race cars. Dragsters hanging from the ceiling, old dirt track sprints hanging on the walls. When I walked in, on one side of the front door was a tricked out mustang and on the other side, a willys gasser pickup.
Its like Toyz'R'Us for men.

If you ever get out that way, ya gotta check it out. Its right on I-76, on the West bound side.
 

·
wind & fire = guides to power
Joined
·
1,529 Posts
It does really depend on the situation.

Trucks(4x4 & towing)

Fuel economy

Small exhaust

all benifit from the better breathing on the exhaust due to the larger lobe. I am partial to the equal duration myself.
 

·
Registered
Joined
·
2,384 Posts
camshafts

There are some basic considerations about cam profiles. Usage of the engine is of course the most important. In this day and age, with all the newer technology coming from the factories, exhaust systems are flowing a lot better than they did, 25 yrs ago, even 10 yrs ago, however, when warming up a stock engine, as a rule, dual pattern cams are still the way to go. Take note that most engines coming off the assemly line today are running them.
The advantage of running a single profile cam, is when you have a purpose built engine and need all your power in a narrower power band. The best you can hope for with a single pattern cam is a power band of 3000 rpm. Yes the engine will run below and above that power band but its all a matter of where you want the power, and how consentrated. With dual pattern cams, the rpm range has been opened up considerably to 3500- 4000 rpm operating range, and as a rule, your power dropoffs on both ends of your power band are less noticeable.

Regardless of brand or type of engine, be it a flathead, OHV, or OHC.
 

·
Registered
Joined
·
177 Posts
[
USA1, where would I get the cam you mention? would gmpartsdirect have it?
Most any GM parts dept can order the cam for you , or scoggin-dickey on the web. The part # is 24502476
 

·
Registered
Joined
·
319 Posts
Personally, I'd go with a split-duration design in the neighborhood of 216-222 duration at .050. With the 1.6 rockers you mentioned using, that cam you thought about will be even bigger and you might be disappointed in the combination. With a heavy vehicle on the street, design the motor for torque and you will be pleased. Good luck
 

·
Learning from your mistakes
Joined
·
79 Posts
Discussion Starter #15
wow, this is great. Thanks for all the help. I'm leaning strongly towards the comp cams EX-262H. I gotta keep reminding myself that its a truck and torque is gonna be more important than HP. I'm also probably gonna run stock rockers for a while, my truck needs a lot more important parts than fancy rockers right now(only reason for new heads is my current heads need new guides and they suck, not in the good way either) Plus I got another block I'm gonna make a 383 out of that I can go crazy with, but that's not gonna be for another 3 years or so.

Max, I'm hoping to get a job around the Cleveland area, I'm sure I can find my way by the summit store every once in a while if that happens.
 

·
Registered
Joined
·
2,384 Posts
Summits shop

You sure wont regret a visit to Summit, other than wishing you had more $$$$$$$$ to spend there. Its just over on the east side of Akron.
 

·
Glad the Jeep is on the road
Joined
·
809 Posts
Re: too much camshaft?

Max Keith said:

BTW, Last year, While passing through Tallmadge, Ohio, I got a chance to see Summits new store. It is awesome. Not only do they have about every part on the floor that they sell, but its a museum of the fast and furious of all kinds of race cars. Dragsters hanging from the ceiling, old dirt track sprints hanging on the walls. When I walked in, on one side of the front door was a tricked out mustang and on the other side, a willys gasser pickup.
Its like Toyz'R'Us for men.

If you ever get out that way, ya gotta check it out. Its right on I-76, on the West bound side.
Every couple months I find a reason to drive the 90 minutes over there.... and my sons always have to drag me out....
 
1 - 17 of 17 Posts
Top