cam question
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From: MNT.Washington, KY
Car: 87 Iroc
Engine: L98
Transmission: T-5 3.42's
cam question
I just picked up a Goodwrench 350 crate motor...it has 250 horses, and i wanna crank it up a bit...actually, a lot. I want to run a CompCams 268 Xtreme Energy cam in it. The cam itself has 224/230 degrees at .050 lift and .477/.480 valve lift with 110 degree lobe separation. I know i have to switch over to 1.6 rockers and throw in a 2,500-3,000 stall converter, but what else will i have to modify to run this cam with stock heads?
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87,
Without a doubt, valve springs. That will probably mean machining the heads to accept the larger diameter springs, which won't be so bad since the heads will likely have to be machined for valve guide height and push rod clearance at those valve lifts. As long as the heads are off, you might as well install screwed rocker studs now rather than wait until they "pull-out" studs do just that. And of course, you'll want to use hardened push rods, and if the rockers are not self-aligning, you'll have to machine for screwed studs anyway, since something will need to hold down the guide plates.
The stock valve sizes will be acceptable with the stock ports, but it would be very tempting to dress up the ports while the heads are off. That's your call, but as long as the heads are under the mill...
And all the extra work being done by the camshaft may require a heavier timing drive, and since the cam should be degreed, you'll possibly need to drill the cam sprocket for a new dowel position anyway. Other than that, just slide in the new cam and you're on your way!
Without a doubt, valve springs. That will probably mean machining the heads to accept the larger diameter springs, which won't be so bad since the heads will likely have to be machined for valve guide height and push rod clearance at those valve lifts. As long as the heads are off, you might as well install screwed rocker studs now rather than wait until they "pull-out" studs do just that. And of course, you'll want to use hardened push rods, and if the rockers are not self-aligning, you'll have to machine for screwed studs anyway, since something will need to hold down the guide plates.
The stock valve sizes will be acceptable with the stock ports, but it would be very tempting to dress up the ports while the heads are off. That's your call, but as long as the heads are under the mill...
And all the extra work being done by the camshaft may require a heavier timing drive, and since the cam should be degreed, you'll possibly need to drill the cam sprocket for a new dowel position anyway. Other than that, just slide in the new cam and you're on your way!
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Engine: 350, Vortecs, 650DP
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Originally posted by Vader
87,
Without a doubt, valve springs. That will probably mean machining the heads to accept the larger diameter springs, which won't be so bad since the heads will likely have to be machined for valve guide height and push rod clearance at those valve lifts. As long as the heads are off, you might as well install screwed rocker studs now rather than wait until they "pull-out" studs do just that. And of course, you'll want to use hardened push rods, and if the rockers are not self-aligning, you'll have to machine for screwed studs anyway, since something will need to hold down the guide plates.
The stock valve sizes will be acceptable with the stock ports, but it would be very tempting to dress up the ports while the heads are off. That's your call, but as long as the heads are under the mill...
And all the extra work being done by the camshaft may require a heavier timing drive, and since the cam should be degreed, you'll possibly need to drill the cam sprocket for a new dowel position anyway. Other than that, just slide in the new cam and you're on your way!
87,
Without a doubt, valve springs. That will probably mean machining the heads to accept the larger diameter springs, which won't be so bad since the heads will likely have to be machined for valve guide height and push rod clearance at those valve lifts. As long as the heads are off, you might as well install screwed rocker studs now rather than wait until they "pull-out" studs do just that. And of course, you'll want to use hardened push rods, and if the rockers are not self-aligning, you'll have to machine for screwed studs anyway, since something will need to hold down the guide plates.
The stock valve sizes will be acceptable with the stock ports, but it would be very tempting to dress up the ports while the heads are off. That's your call, but as long as the heads are under the mill...
And all the extra work being done by the camshaft may require a heavier timing drive, and since the cam should be degreed, you'll possibly need to drill the cam sprocket for a new dowel position anyway. Other than that, just slide in the new cam and you're on your way!
IMO, if you're gonna do all that crap to stock heads, you're still gonna end up with stock heads. By the time you spend all that money, you might as well go with a set of aftermarket heads.
That's all if the heads aren't the Vortec heads. Which on the regular crate 350, they aren't, are they?
AJ
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