motor was dynoed

[fast shelby]

I am disappointed in the numbers it made. I am thinking of switching to a turbo set up. This motor is going into my 67 Shelby replica for use on the street and track. I was going to put it into my 92 but there is no way it would pass emmisions.

Run down on engine:
SVO W351 block
Bored and stroked to 427
SRP forged pistons
4340 rods and crank
Edelbrock Victor Glidden heads
Edelbrock Super Victor intake (ported by Chapman Racing)
750 Holley carb
dual stage plate set up by Speedtech
Spraying 200 and 100 shot on 100 octane.
740 lift custom roller cam with T&D rockers

 

[Mattys5Oh]

800hp!?!?

 

[87'GTstang]

So if 838.56 hp / 798.64 ft/lbs torque dissappoint you, what numbers are/were you looking for?

Ever had the setup tuned?
I'm not a big carb man, but would anyone think that a 750 could possibly be a little undersized for a 427? Also, what kind of setup does the carb have one it? 2 or 4 barrel carb? Are the secondaries tuned to open up at the right throttle pressure? How big are the jets on it for the fuel delivery.

Also, what size are the valves on the cylinder heads?

 

[fast shelby]

Sounds bad that 835 hp is not enough but I was looking for around 1000 hp.I am looking at changing the carb to a 850

 

[fast shelby]

the valve sizes are 2.15 intake and 1.56 exhaust. They flow 365 on the intake.

 

[Mattys5Oh]

the valve sizes are 2.15 intake and 1.56 exhaust. They flow 365 on the intake.

HOLY CRAP!!!!!!!! I was expecting 500hp max. Shows what I know about 351 based strokers! lol

 

[I_AM_CANADIAN]

Ok someone explain me something, I thought all dyno graphs were supposed to have the torque and hp cross at at 5252? Why doesn't this one?

 

[fast shelby]

Ok someone explain me something, I thought all dyno graphs were supposed to have the torque and hp cross at at 5252? Why doesn't this one?

I never noticed that. It may because we turned on both stages at 4600 rpm??? Iwill have to ask my engine builder.

 

[Scorcher2005]

HOLY CRAP!!!!!!!! I was expecting 500hp max. Shows what I know about 351 based strokers! lol

maybe all ~500-600 hp all motor...but that 838hp was w/ 200 shot of nitrous

 

[pricha]

Yeah those numbers seem a little low for the combo. My friends car makes around 1000hp at the wheels with 400 CI, Victors, Super Victor(ported), Dominator and 300hp shot of spray. Car runs 8.2 at 165 mph at 2950lbs. The only real difference I see is the carb. Maybe a restriction? What size exhaust on that motor?

Pat.

 

[whitehorseupnorth]

Ok someone explain me something, I thought all dyno graphs were supposed to have the torque and hp cross at at 5252? Why doesn't this one?

Your right.. They have to. Thats how the formula works. Something must be wrong with the dyno or the software. HP & TQ willalways meet at 5252..

Torque * RPM
-------------- = HP
5252

 

[Scorcher2005]

Your right.. They have to. Thats how the formula works. Something must be wrong with the dyno or the software. HP & TQ willalways meet at 5252..

Torque * RPM
-------------- = HP
5252

and maybe thats why your numbers are low?

 

[fast shelby]

the primarys were 2" to a 4" collector. I am definatly going to a bigger carb. once it goes into the car. I hope it will smooth the hit of nitrous a little

 

[87'GTstang]

the valve sizes are 2.15 intake and 1.56 exhaust. They flow 365 on the intake.

1.56 on the exhaust - how the hell does that flow well?
2.15 sounds like a pretty good valve size but come on, why only 1.56?

This whole thing really sounds like an intake problem - undersized carb and smallish exhaust valves (forget getting a better exhaust, you have to flow something first ). An 850 sounds like a pretty good size, just make sure you pick some good-sized jets to feed all that power.

Any idea as to what your air/fuel ratio is or if your exhaust is more rich or lean (especially at WOT)?

 

[shootme5150]

and maybe thats why your numbers are low?

if the software is dividing by 5400, that's going to give you a big knockdown, yes.

 

[fast shelby]

1.56 on the exhaust - how the hell does that flow well?
2.15 sounds like a pretty good valve size but come on, why only 1.56?

This whole thing really sounds like an intake problem - undersized carb and smallish exhaust valves (forget getting a better exhaust, you have to flow something first ). An 850 sounds like a pretty good size, just make sure you pick some good-sized jets to feed all that power.

Any idea as to what your air/fuel ratio is or if your exhaust is more rich or lean (especially at WOT)?

the heads have a 1.56 exhaust due to the fact the raised the exhaust port .630 for a straight out exhaust flow. As for the fuel ratio I did not get that paperwork but they have it.