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Greg I think your making more Crank HP than you think..your just running a freakin ton of goodies off the motor!!
Now remember Alt,A/C, water pump, Power steering..etc..
The #'s Matt show are probably with No equipment...at Dyno room conditions..Not real world weather from the back tires... Big Difference!
Russ
I meant in comparison to those flat-tappet cams. Shouldn't the increased lift and ramp rates of a roller produce a smoother torque curve and a better HP peak than a flat-tappet cam?
greg, your higher advertised duration is hurting your bottomend and your .050 duration is somewhat average and less than the comp cam so your peak hp is less, and so your accel rates are not that good, my program doesn't account for less friction so in reality you would have more power.
Yeesh, I miss all the fun! Go away for 1 day and look what happens.
Anyway, 45ACP, you've got the right idea, but I think it's lacking in some areas. First, stock Edelbrocks. These are not bad heads. However, the way they are, the ported stock FE heads flow just as good if not a bit better. According to DD2k, the standard going 390 build would make the same HP as your proposed motor with a bit less torque. You cant have that for the money you're spending.
Next, step up to the roller cam. The Crane 349511 would be a good one to use, as it gives about the same horsepower and a lot more torque than the 349521, but it wont be out until December 19th.
The way you proposed to build it, with the stock edelbrocks and the 343941, you'd be making 420hp @ 5000rpm, and 484ft-lbs @ 3500rpm. With the ported edelbrock heads and 349511 roller cam, you'd have 516hp @ 5500rpm, and 538ft-lbs @ 4500rpm. The torque at 2000rpm is still 490ft-lbs, so you're not lacking there either.
cam anyone get an average tq number off their dyno program? mine wont, i have to do it the old fashioned way.. :-( i was just curious which cam made the best overall torque...
Thanks for that great information; the transmission is the np435 4 speed. I like the torque of the 901 and 941 but am wondering what these cams do after 2500 to 4000 rpm. Is the torque curve pretty flat? I spoke to a guy named Dave Cope from my town last night that seems to know fe really well. He suggested I have a custom cam gound in the 224/230 range with 524/529 lift for this motor. Oregon cams makes them with part # 1425. He told me his 428 and buddies run very well with this grind. What are your thoughts?
the 941 kinda falls off after 4000, still has 460 ft/lbs at 5000 though.. average torque between 2000 and 5500 is 484 ft/lbs... LOTS! from 2-4500 it never makes less than 480 ft/lbs... it peaks at hp around 5300 or so, with that long of an arm in it you probably don't want to turn much more than that anyways..JMO I'll run that oregon cam and see what it does...
oregon cams doesn't list their specs online so i'm waiting back for their reply with the numbers.... with those kinda numbers for the 941 as well as the other cams, i don't think you'll see too big of a difference between all of them.. i liked the 941 for my 390, that big of a motor will take more cam and like it!! i'll see if i can get you average torque numbers on those other ones for the same rpm range, since i imagine you're interested in the flatest highest torque curve you can get...
Last edited by fordraceboy; Nov 16, 2005 at 05:40 PM.
as from previous discussions, extra stroke means more torque not horsepower. The hotrod build and dynosim are 2hp apart and that well could be in the slight comp difference.
as from previous discussions, extra stroke means more torque not horsepower
exactly the case, which means as soon as the torque drops off, the horsepower is usually soon to follow.. i'm just saying that for the long stroke i wouldn't wanna spin it too tight- thats alot of mass to be slinging around.. JMO, i guess it all depends on how and what you buiild the engine for..
Just from what I have noticed over the years....Rather your building a Squared motor,Big Stroker, or a High rever....your Peak Hp is generally 1000rpms over your peak Tq... Because you cant build a stump puller, and have it peak Hp at 6500rpm..JMO