Engine combo hp/tq ?

[Jazz]

What hp and tq can I expect from this combo?
sbc on alky, 1/4 mile slick track.
dart little m block
4 stage dry sump
45# 3.335 crank
6.2 rod
14.5-1 comp
4.145 bore
16* 270 cnc heads ( brodix )
053 bowtie 2-pc fully ported intake
1.75 int 1.6 ex rockers ( jesel )
.937 lifters
jesel belt drive
4-7 swap comp cam
intk dur @ .050 268
ex dur @ .050 269
int lift at valve 743
ex lift at valve 653
108 lobe sep
2.150 int valve
1.625 ex valve
custom 850cfm pro system carb
1 3/4 step 1 7/8 pipes

wanting a top end engine. Will this combo work? What can I change?

[soonersublime]

850 HP 740 ftlb

Can't get that much better.

[dynamic performance]

those numbers will never happen with that combo. also the cam is too big for starters

[soonersublime]

I'm guessing wrong on torque. It would be around 680 not 750

My guess is based on a build in the "how to build chvey small-block circle-track racing engines" book by Jeff Hueycutt.
The specs on the motor that I am guessing this on were
431ci
14:5 cr
forged crank
hbeam rods
dome pistons
sb2.2 aluminum head
2.18 in 1.6 ex
.760 in valve lift

Not too many differences and I am assuming similar flow.

[dynamic performance]

840to 850 and 680+ can be done with good sb2.2 stuff. will not happen with 16 degree stuff

[soonersublime]

missed the stroke some how. Thought it was 3.5 for some reason.

Yep way to much cam for that motor.

I've seen 16* stuff go over 800hp but not in a 358
Shoot I've seen 23* stuff get close.

IMO if the cam is backed down to around a .650 lift you could get er' to 620 HP and 500 ftlb

[go2fast]

We did a 360 ci with 15 deg heads. We used a cam a 263 @ 50 in and 269 @ 50 ex on a 106 cl put in at 100 deg had a .725 in lift and .710 ex lift. It made 745 hp and 578 tq

[Jazz]

In a rough ball park, what sort of cam specs should I be using with this combo to get a good even balance curve on both the tq and hp?

[go2fast]

I Would say about a 262 in @50 and 268 ex @50 grind on 106 center line have them to put the pin in at 102 and put the cam in at 100 deg with a 430 lobe with 1.6 ex and 1.7 in rockers should get about 730hp and 570 tq the hp max @ 7200 rpm and tq 5500 rpm max rpm about 8600 to 8800

[JETAM]

750 hp @7500 565 tq @ 6000 for current combo. I agree for this size motor you could shorten the intake duration 259-260 range and go to a 106 lobe angle and pick up your bottom end tq numbers quite a bit.

[dynamic performance]

go2fast is on the money. but i would use a hxl lobe from comp which is a .445 lobe lift

[1Blacksheep]

Those kind of numbers need to turn rubber wider than 8" to go anywhere.I love it when that happens.
Tire width x 100 - 20% = speed

[fast_crew]

Get the compression up to 15.5 As mentioned cam ground on a 106-108 installed at 102 but I would bring the dur. split together alittle. 260/264 or there abouts. Take advantage of the extra torque that can be made with the alky instead of letting it go out the exhaust with too much exh dur.

[fast_crew]

Backing the lift down to .650 has nothing to do with making hp or torque, or the curve for either. As long as the heads keep flowing and parts allow you want the lift. The dur. and lsa determine the power curve. A cam with .500 lift and 270* dur @.050 still won't make good power for a roundy round car.

[parrot69777]

Call someone like comp cams and get a custom ground cam.....then take it to someone who has a dyno and have them dial it in. If you listen to most on this site....you will just be chasing your tail.

Not bad mouthing anyone....but even if you build 2, 3, 10 engines identical....they will all have different readings.