351 W Dyno Results

[UtahBullitt]

Hey motor heads
What gives?? I Just got my dyno results on my 351 W. It is installed in a 69 Bronco so forgive me for that. Here's the run down:
351 bored .030 over, stock stroke, new Hpyer piston, moly rings, Trick flow T/W heads with 2.02/1.6 valves, not ported or anything, cam .530 lift 112 cen. 215 dur. @ 50, Trick flow 5.8 intake with 1" spacer, 70MM throttle body, 73 MM C&L mass air, 24# FMS injectors, FMS harness, A9L computer, long tube headers, 2-1/4inch crush bent dual exhaust with Dyno Max mufflers. I guess that's all you need to know. It maxed out at 175 HP at 4500 RPM and around 250 ft/lbs of torque, the torque peaked around 2k and held steady all the way through which is good. It is running pretty lean probably because of the C&L, I've heard they are famous for that. The tuner suggested going to larger exhaust and maybe a smaller throttle body, and a different mass air, but is this going to make up the 100 HP I seem to be missing? Or is the Bronco drivetrain just sucking up all my power? I have an NP 435 4 speed truck tranny going into a stock Dana 20 Transfer case, into a Ford 9" with Detroit locker and 31 spline axles, turning 33" tires. I though I would have twice this much power? What is up?
Thanks

 

[larrendeuce]

I'd say your missing more than 100, is the engine running ok? those are like stock numbers.

 

[408stroker5.0]

The Bronco drivetrain dosn't help. But I don't think that's your biggest problem. Something else is definetly wrong. You should be making WAY more power than that.

 

[UtahBullitt]

Yes, The motor is running good. It isn't broken in yet, only has about an hour of time on it. The numbers seems way strange to me to. Although the guys at the dyno shop didn't really act like it was any big deal, of course they didn't spend 6K to get where I am at with the motor. I am wondering if the dyno numbers are right.

 

[larrendeuce]

I'd say the crush bent 2 1/4 inch exhaust is killing it. What compression are you running?

 

[SmockDoiley]

Well your super low duration is killing the topend power for sure and its really mismatched for the combo. The exhuast is hurting too and your drivetrain is soaking up probably 100 horses. The 9 inch alone requires like 60 horses; then the 4 speed and transfer case. Plus its a fresh engine that may not have seated yet or the comp hasnt learned yet. All these factors plus a lean condition could give you crappy numbers. IF you doubt the power loss, pull the engine and run on an engine dyno. Hope this helps.

 

[UtahBullitt]

The compression is 9.5 to 1. Thanks for the info guys. What size of exhaust would you recomend and I am assuming have it done by a shop that does mandrel bends. How much duration would you recomend while still keeping it able to be handled by the stock computer? I really don't need a ton of high end HP, but wouldn't mind it as long as it doesn't kill my low end HP.

 

[larrendeuce]

If you ran an Xtreme Energy 282hr Cam you would be making around 350hp to the wheels. 112 LSA, 282 intake 289 exhaust, .565, intake .574 exhaust lift. The exhaust should be at least 2.5 inch on duals.

 

[eric88gt]

Here's my opinion.
1. Deal with the lean condition first of all.
2. Change the exhaust. A good mandrel bent 2-1/2 inch exhaust will definately help, but don't expect a dramatic increase in HP or torque from just this.
3. The TB is just fine for your setup, I would take it somewhere else to have it tuned if your "tuner" thinks an aluminum headed 351 needs a TB smaller than 70mm.
4. That cam may not be optimal, but it isn't the reason for the extremely low numbers. While it may not be the greatest high-rpm grind, it should have easily put down more than 250 ft-lbs.

And also, what was your timing at and how lean was it running?

 

[CobraWannabe]

I'm thinking timing too. And it may need some break in milage. Don't beat it too hard before it's broken in.

 

[UtahBullitt]

If you ran an Xtreme Energy 282hr Cam you would be making around 350hp to the wheels. 112 LSA, 282 intake 289 exhaust, .565, intake .574 exhaust lift. The exhaust should be at least 2.5 inch on duals.

My current cam has .530 lift do you think this much lift would mess with my piston clearance? Thanks

 

[UtahBullitt]

Here's my opinion.
1. Deal with the lean condition first of all.
2. Change the exhaust. A good mandrel bent 2-1/2 inch exhaust will definately help, but don't expect a dramatic increase in HP or torque from just this.
3. The TB is just fine for your setup, I would take it somewhere else to have it tuned if your "tuner" thinks an aluminum headed 351 needs a TB smaller than 70mm.
4. That cam may not be optimal, but it isn't the reason for the extremely low numbers. While it may not be the greatest high-rpm grind, it should have easily put down more than 250 ft-lbs.

And also, what was your timing at and how lean was it running?

We set timing at 14 and tried running it up to 18 but at 18 HP started dropping off so we went back down to 14. I agree with you on the tuner situation, but here in Salt Lake City they are the only shop that has a chasis dyno. If I was in So Cal I could probably take it to one of 100 different shops.
Thanks

 

[Bone Racing]

1...get 30 lb injectors minimum
2...open the heads up a lil
3...tranny and exhaust hurtin it a touch
4...def wrong cam

 

[SmockDoiley]

From a guy that has a 4X4 jeep and has built cars before; the drivetrain will take a lot of power. Its not really the lift that needs fixed, its the duration. Get something with like 220-224 duration, and your lowend will still be fine. A 351 with heads can stand a good amount of duration since its such a large engine.

 

[hllon4whls]

I'm thinking timing too.

This is what I am thinking. What is the timing reading at 3200 rpm? What is your base? Any detonation?

33 inch tires, big 4 speed and transfer case= loss of hp through drivetrain.

 

[blown5.0]

the biggest question, is your cam an old school hyd flat tappet? I hope its at least a hyd roller cam.

 

[UtahBullitt]

the biggest question, is your cam an old school hyd flat tappet? I hope its at least a hyd roller cam.

It is a roller cam.

 

[eric88gt]

I agree that eventually he needs to change the cam, but it won't solve the problem that he's having right now. First he needs to get it tuned correctly before throwing parts/money at it when the cam isn't the main problem.

 

[SmockDoiley]

He said his timing is 14 which is pretty fair, now as long as his total timing is in the low 30's then I dont see any problem with his timing. If all cylinders are holding pressure, everyone is firing, he fixes his lean problem and his timing is working then I dont see what else it would be besides drivetrain soak. He's got a weak ass cam and hes pushing through an old 4 speed, dana transfer case, and a built 9 inch with big tires. This isnt a mustang so stop thinking with your mustang heads. I say change the cam, break in the engine, drop the timing to 10* making sure the distributor is correctly advancing, and make sure your A/F is around 13/1.

 

[QDRHRSE]

Who built the engine? I'm not thinking that there is anything wrong with the assembly but sounds to me like the cam is advanced- thats bad for an injected 5.0. Lots of engine builders recommend advancing cams 4 degrees. A engine builder that doesn't have a lot of injection or Ford experience might do something like that. Just an idea....