roller rockers?
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just another Rockwell looser
Joined: Feb 2003
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From: Cocoa, FL
lift is what ever lobe lift cam you have times the rocker ratio..As for clevlite i thought to mainly stayed in the bearing world. Yeah advertised duration is pointless to me. hell even on some websites i have seen hyd roller v.s solid roller v.s solid flat v.s. hyd flat with the same duration at .050 and have significantly different advertised. oddly enough they always advertised the hyd higher. I would think that the solid would be higher if not the same because of possibly the ramp rate allowed with solid cams...but maybe they factor in the slop in the hydraulics...I dunno. the company in question is Competition cams if that helps.
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just another Rockwell looser
Joined: Feb 2003
Posts: 4,042
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From: Cocoa, FL
you can look at the cam specs. The lower the lift and duration to more it will more it will tend to flatten and move the torque curve left (lower rpm range). the more lift and duration usually equals more power but also equals hgher rpm peak, less drivabliltiy, more frequent repairs, and other mods required to motor utilize such cam.
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Your right quadzjr, advertised duration means little as the maufacturer can list it as whatever it wishes.
Bigbrown84truck, if your interested in the most low end torque, I'd say the stocker is your best bet. If your looking to blow some cash, I'd say the small crane cam would give you a little more low end torque...just not so sure, IMO, it would be worth the investment. If your truck is in fact an 84, you should consider the chevy 250 inline six rockers, just double check that you have studs and not pedastel mount rockers, before you buy them, you should be able to pick these up for around $30+/- and bolt right in.
Bigbrown84truck, if your interested in the most low end torque, I'd say the stocker is your best bet. If your looking to blow some cash, I'd say the small crane cam would give you a little more low end torque...just not so sure, IMO, it would be worth the investment. If your truck is in fact an 84, you should consider the chevy 250 inline six rockers, just double check that you have studs and not pedastel mount rockers, before you buy them, you should be able to pick these up for around $30+/- and bolt right in.
Last edited by Motorhead351; Dec 12, 2005 at 01:06 PM.
Postmaster
Joined: May 2002
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From: Broken Arrow, OK
Duration is the only thing that's really going to cost you low end torque. As a general rule you want as much duration at 0.050 as you can get for a given advertised duration. Another thing to consider is that the stock cam has no overlap. The cam grinder could move the exhaust closing point and intake opening point closer together and maybe even give it a few degrees of overlap and you should get a nice gain from idle up to a few hundred rpm beyond what you have stock.
Fleet Owner
Joined: Sep 2005
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From: Lake Tahoe, Nevada
Take a look at Cliffords "torque monster" cam. He claims 70% torque off of idle. Minimal overlap, high lift. Spendy at $199 but probably the best high performance low rpm grind out there.
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Originally Posted by Bdox
.... Cliffords "torque monster" cam. He claims 70% torque off of idle.
Judging by silver streaks dyno run, I would say the stock cam would come pretty close to offering the same results.
https://www.ford-trucks.com/forums/s...5+dyno+results
Last edited by Motorhead351; Dec 12, 2005 at 11:08 PM.
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just another Rockwell looser
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From: Cocoa, FL
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Postmaster
Joined: May 2002
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From: Broken Arrow, OK
The difference between any of the cams with comparable rpm ranges is probably pretty small. Two of the most important things to consider are the intake closing point and the exhaust opening point because these two determine how long cylinder is sealed. You should be able to do about anything you want with the cam and it will make excellent low end torque as long as you don't stray too far from stock on these two things.
Fleet Owner
Joined: Sep 2005
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From: Lake Tahoe, Nevada
Originally Posted by Silver Streak
The difference between any of the cams with comparable rpm ranges is probably pretty small. Two of the most important things to consider are the intake closing point and the exhaust opening point because these two determine how long cylinder is sealed. You should be able to do about anything you want with the cam and it will make excellent low end torque as long as you don't stray too far from stock on these two things.
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just another Rockwell looser
Joined: Feb 2003
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From: Cocoa, FL
thats why the head will get ported while it is in the shop to put the chevy valves in. Yeah it wouldn't make much sense to put bigger valves in and not touch the ports.
What size valves are stock? what is the normal to increase to? 2.02 / 1.6 like the small block?
What size valves are stock? what is the normal to increase to? 2.02 / 1.6 like the small block?
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Shrouding implies the chamber wall is too close to the valve, inhibits flow.
To unshroud, you need to remove material from the combustion chamber wall.
On the efi head, you mess with the efi combustion chamber shape, you potentially change its design, its designed as a swirl/fast burn, I suppose you could call it, head, which implies it needs less total timing to achieve a complete burn efficiently. Obviously, the stock eec is not gonna know this change was made or make the appropriate changes, to gain full benefit from your efforts, you'd need to add timing...tuning/chip. Something of a trade off huh?
Stock valve sizes are 1.78 intake, 1.56 exhaust.
The normal upgrade is 1.94/1.6 but as you can see, the exhaust isn't that bad, so maybe focusing on replacing the intake valve would be the best move.
Don't be suprised if you find out your head is cracked, seems to be a good possiblility with the efi head.
Good luck
To unshroud, you need to remove material from the combustion chamber wall.
On the efi head, you mess with the efi combustion chamber shape, you potentially change its design, its designed as a swirl/fast burn, I suppose you could call it, head, which implies it needs less total timing to achieve a complete burn efficiently. Obviously, the stock eec is not gonna know this change was made or make the appropriate changes, to gain full benefit from your efforts, you'd need to add timing...tuning/chip. Something of a trade off huh?
Stock valve sizes are 1.78 intake, 1.56 exhaust.
The normal upgrade is 1.94/1.6 but as you can see, the exhaust isn't that bad, so maybe focusing on replacing the intake valve would be the best move.
Don't be suprised if you find out your head is cracked, seems to be a good possiblility with the efi head.
Good luck
Last edited by Motorhead351; Dec 16, 2005 at 11:39 AM.