Help me pick a cam
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Help me pick a cam
My truck is a 1984 F150 4x4 BUT, I have a 91 roller 302 in it. I would like to get a new roller cam but would like to just use the stock springs. How much lift can i go before the stock springs will bind? I had a cam that was 471 lift in my old motor with stock springs and never had a problem but I didn't know if the springs in the roller motor are differant. I want a nice lope and to have good low end
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From: Ottawa, Ontario
Originally Posted by mvvette97
I want a nice lope and to have good low end
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Originally Posted by Conanski
I quess you don't realize then that those 2 goals are mutually exclusive. A short duration cam with minimal overlap will build best low rpm torque, but to get a lope you need a long duration cam with lots of overlap. The stock springs will handle 0.500" lift, but valve clearance and float will become a problem with cams targeting high rpm HP.
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From: south louisiana
Nice lope, good bottom end and low lift ? That's an easy one---- Ford Racing B303. I'd improve the lift specs though with 1.7 rockers (.480 to .510) It will be fine with the stock roller springs. The rpms will be limited to 5500-6000 by the lifters anyway unless you upgrade these.
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Originally Posted by baddad457
Nice lope, good bottom end and low lift ? That's an easy one---- Ford Racing B303.
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well, maybe I should ask, does it have about the same or less bottom end as the stock cam? It doesn't bother me to be about the same as the stock cam on the bottom but I don't want it to have less, a 302 doesn't really have a ton of bottom end anyway
Originally Posted by Conanski
It's all relative I guess... but i don't call flat under 2500rpm "good bottom end".
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that's why I'm asking you guys. I have always cammed cars that are not as heavy as trucks. I have a 228/230 in my 2000 trans am and I love the power it makes but as you know the car is alot lighter. Lope sounds cool but honestly I pull alot with this truck so reving to 5K is not what I will be doing.
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From: south louisiana
I've run it in a 5.0 in my Ranger with a Ford A321 intake and 650 Holley DP with 1.7 rockers and it was fine on bottom. Run it with big heads and a single plane intake and it sucks below 3000.
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From: south louisiana
Originally Posted by mvvette97
well, maybe I should ask, does it have about the same or less bottom end as the stock cam? It doesn't bother me to be about the same as the stock cam on the bottom but I don't want it to have less, a 302 doesn't really have a ton of bottom end anyway
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Originally Posted by baddad457
The B cam won't have the same bottom as a stock cam. If you want an excellant bottom end cam that maximizes the torque, then the factory F4TE cam is hard to beat. Hard to find a good used one though. They were O.E. in all 94-up truck,Explorer/Mountaineer & van 5.0's . It will not be a lopey cam though. What gearing you have in the 4x4? If you REALLY want a puller, you need to move up to at least a 351W.
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From: south louisiana
Your 91 Merc 302 has the small "base" roller cam. Lift is less than .400" Duration is 244/256 (int/exh) The F4TE truck cam has .422/.445 lift (int/exh) and a 256/266 duration (advetised, not @.050) This cam has 10* less duration and .020 less lift on the intake than the Mustang HO roller. Adding 1.7 roller rockers to yours will help some, mainly in reducing friction. Now, you also need to avoid a head swap with this engine as the pistons do not have valve reliefs. The valve seats are 1/8" deeper in the heads than all other small block heads. That's the reason the pistons don't have reliefs. A cam swap with the stock heads is OK, just not with any other head, without changing pistons too. You've got the E6SE heads on this motor. Good for bottom end torque, just 25 hp shy of the E7TE heads on top.
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So are my pistons a flat top with no relief then? I see what you are sayin. Would this truck cam that you told me about cause any valve to piston problems? If I understand right, as long as I keep the stock heads i shouldn't have any clearance problems with a mild cam or going with 1.7 rockers but if I put differant heads on the valves will set too close to the pistons and cause VP problems, correct?