camshaft help

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n8ball

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I am looking to change the camshaft in my 67 4spd valiant, the car has a 451 big block with about 10.2:1 compression, iron heads ported by muscle motors, mopar single plane intake with a 850 speed demon carb. It is now setup to go with a solid roller cam, so that is what I intend to do.(not impressed with the hydraulic roller that is in it now) The cam I am looking to get is a comp cams XR292R specs are duration @ .050 I/E - 254/260 with lift of .582/.588 on a 110 LSA. I would guess with this cam, the iron heads would be holding me back and I will address that later. As a baseline the car ran 116.5 mph(my disappointment) in the quarter on a small hydraulic roller, duration @ .050 I/E - 230/236 lift - .528/.539 on a 112 LSA. My goals for the car with the cam swap on the ported iron heads would be to run 121 mph trap speeds or better. Does this seem like a reasonable goal for the cam swap? Does anyone else have other comparable cam suggestions? Experience with this cam? Aluminum heads will come later, Indy EZ or bulldogs ... not sure yet, then I will expect some serious pump gas power :thumrigh: Any input is greatly appreciated

-Nate
 
Some more information about your car would be useful. You should see a gain with the cam but gaining more than 5 mph with a cam swap may be asking alot. 116 to 121+ is a huge gain.
 
Thanks for the reply, not sure what other info would be helpful regarding horsepower production. Yeah, I wasn't sure if the 5mph gain at the wheels was reasonable on ported 452 heads(I don't have the flow bench #'s)... most of my camshaft knowledge comes from ls1 vehicles... and there an approx 40-50 rwhp gain is not uncommon at all on camshaft swaps with stock heads. I am just trying to get an idea of what to reasonably be able to expect from the swap. I was kind of dissapointed with the performance of the current camshaft, so I wanted to have some realistic goals for this project. Other camshaft suggestions that people think could achieve this goal are very welcome, I am in no way married to the camshaft I listed the specs on previously.

-Nate
 
I agree thats alot to look for on that cam swap. I think what Moparracer means is gears , convertor , tires and so on as that has alot ot do with power band on how the car will perform. Also what are you shifting and trapping at now. It sounds like it will pick up with that cam if its degreed right and if the rest of the combo is setup for it. Good luck , Ron
 
Ahh.. well the car has 3.91 gears and runs a 27 inch tall tire. The car is a 4spd so no converter. Right now I shift the car at about 6K the motor is running out of breath above that, and it traps at 116.5 mph. With the new cam I hope to be able to stretch that to about 6500 - 6600 rpm. The car could use some steeper gears as 6600rpm in 4th gear would be about 135 mph but the car is mostly a street car so I like the additional cruising ability provided by the gears.
 
Has the car been to a chassis dyno? It would eliminate any shifting issues from the power question. Off the top of my head, I cant figure out why a stock 452 headed 451 couldnt pull well over 6K with a hydraulic roller. It sounds to me like it has another issue. You said the heads were ported by muscle motors..What stage did they go to? Both your cams are reasonable in size, so I'd think either one could get you faster, assuming the shifting was good. (I cant drag race a stick very well..so it's not meant as a bash..)
 
Those aren't bad numbers for a small hydraulic roller. These cams are made more for torque than high rpm horsepower. The cam you are looking at looks like a decent grind and should give you a sizeable gain but if it is quicker or not depends on you ability to hook this animal up. Don't forget the valvesprings also.
3.91's and a 27 inch tire are a little inadequate on a motor of this caliber. LS1's respond so well to cam changes because their heads flow massive amounts of air in stock form, more than our ported factory iron heads. They also keep flowing to higher lifts than our iron heads. We don't need to be talking about GM junk here.
In order to get the speeds you are looking at, the car will need to be running in the high 10 sec. zone. Traction and a little more gear will be needed.
My hats off to you for doing this with a stick car. Sounds fun. :burnout:
 
The car hasn't been to the dyno unfortunately. I suspected the original crane hydraulic roller lifters were to blame for the performance problems, as they never seemed to hold adjustment and the performance would suffer greatly... up to 6mph in trap speed. I have replaced them with comp mechanical rollers and now the motor is coming apart again for some other repairs so I wanted to try a new camshaft while the motor was out. I don't remember what stage the head port was.. its been a couple years but it was probably a stage one street port. With the new cam I intend to go to the dyno to get some quantified shift point numbers. Thanks for the input
 
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