how much HP

-
D

daves 72 dart

Well-Known Member
Joined
Jul 16, 2005
Messages
155
Reaction score
0
Location
Waterloo,Iowa
how much HP will it take to get a 72 dart swinger into the high 11's? IM going to build a 408 smallblock its going to be a street/strip car.If you guys can give a recipe for the 408 that would be great.thanks
 
A set of Eddy heads and a small roller cam. Compression a 10.5..........
 
please define specs for small roller cam? and are those out of the box eddys or P&P . - Inquiring minds would like to know!!
 
Out of the box Eddy's flow approx. 250 CFM at 28. I'd check the runout on the valve seats. A 'small roller' would be no more than .550-575 lift and dur. at, what, 240 at .050". I'd ask a 'cam' expert, which I'm not.
 
Well, it takes about 470 crank horsepower to get to 113 or so. That should be high 11s, depending on gearing and tires. I'll assume 3400lbs, say 28" street tires and a mild set of 3.91s. I would go 360 mains Eagle cast crank, Eagle H beam rods, Diamond dished pistons set to .010 positive deck, Edelbrock RPMs with the corrected bits done and a quick smoothing of any CNC leftovers. I'd run an Air Gap, a solid flat tappet in the .580 lift and 255-260 duration@ .050 range, on a 110 centerline and a Holley Street Avenger 770. You will be able to runs high 11s, mid 11s, and very possibly low 11s with the right gearing and convertor. You could go lower witht eh cam, but you would need to lose the quench (or some of it) to lower the static ratio to work with a smaller cam. Not a big deal really, but I hate giving up power if you dont need to. The milder version is the same setup, pistons at .010 down in the hole, and either a solid or hydraulic FT. Hydraulic in the [email protected] range, or a solid in the 240°@.050 range. You loose about .3 of static but you keep the dynamic reasonable with that cam. So it will be an 89 octane engine too.
 
i have a set of 4.88 in the car now i need to get some 4.10 and a 904 and 727 both with a fresh rebuild and a 3500 stall.i found a 408 for sale with 465 dyno proven hp at the crank.im thinking about putting the dart on a diet glass fenders and hood. how much weight will that shave? thanks
 
Lose he fenders, hood, some of the brackets for the bumper. The crash bar in the bumper if it has one. You could prob shave an easy 120lbs or more (i'm not sure of the weights..) off the nose.
 
Dave, That build up is very close to my stock stroke 340 and it made 480 on Dwanyes dyno. Will the 4" crank make much more hp or will it mainly gain torque and lower the power band ?

For what its worth my motor went 116 in the 1/4 before it had ore work done to the heads and another .5 in compression added which added up to about 25 extra hp.

I'll be real happy to get 11.80s out of it with 4.10s and a 26" tire and my converter which is probably a bit tight for the motor.
 
Adam, my feeling is, if you have to build the lower end anyway, go the biggest you can for the same money. In my builds, they all get align honed with new bolts/studs. They all get internal balanced. So money wise, it's a toss up between spending to have a factory crank cut down ($250-300 depending) and the cost of buying a new one outright ($280-330). I havent seen the same QC issues witht he small block cranks. Not sure why, but they always seen to be pretty good, even the cheapies. So I use them when possible. In this case, I like lower stalls, and my customers cruise a lot in the cars. So it's about milder gearing and stalls under 3K. So yes, the 4" arm is to lower the power peaks' rpm, and to flatten out the torque peak during the crutial 3000-5000 range. Those are mid sized 4" engine cams, but the heads work well with them. I'd expect just over 500tq, and the tq peak being close to flat from 2800 to 5000.
 
When i built my 410 stroker ,first time to the track with very little tuning it ran a 12.4 at 114/116 so with good tires high to mid 11's should be a breaze,Combo is as follows,4" crank,unworked eddy heads,RPM AirGap,750 eddy performer carb, compression is around 10 to 10.5 and a comp cams solid 244/[email protected] .520/.540 lift,i had the block line honed and used main studds and this was with 3.55 geared posi rear.
 
You must log in or register to reply here.
-

Back
Top