Low dyno numbers from a built 5.0...

[zimm17]

Where's my horsepower? (low dyno numbers on built 5.0)

I have a built up 5.0 in my Jeep CJ-7. Here's the rundown:

'86 lincoln MKVII motor, B&B, forged pistons, ARP hardware.
Edelbrock performer heads (small valve model)
Performer intake
BBK shorty headers going to dual 2 1/4" exhaust/flowmasters (No crossover pipe due to no room for it)
Complete Ford motorsport MAF/harness/ECU/19# injectors
Cobra 65mm TB
Stock distributor with MSD coil/8mm wires/NGK plugs
Stock valve train

Dyno chart attached.

Granted I'm turning 33" tires through a T-5 and transfer case, but shoulding I be making more power?

Does the cam suck? ECU need modification?

I attached the cam profile from the engine builder, but I can't tell much from reading it other than it's a very conservative cam. I wonder if the Lincoln 5.0HO cam is different from the mustang version?

 

[5.0lpowerhouse]

Those tires probably aren't helping you, what kind of gears do you have? what was your A/F on the pulls? Timing? give us some more info so we can try to help you out better

 

[SmockDoiley]

I cant read that junk on the cam specs. It would be nice to get real numbers like duration and lift. Is it a stock cam, because it says stock 5.0 cam on it. Your power looks pretty good for having a weak cam. And your most likely losing 100 horses through a T-5, transfer case and whatever rearend you have. Get a meaner cam because your engine doesn sound that built to me. Your intake is pretty conservative too.

 

[Mike86Stang]

I can't really imagine the MK cam has any real performance built into it seeing it's a LUXOBARGE cam lol. I'd try for a new cam... the rest looks ok we need air fuel ratio what compression are you running? What timing? You could pick up a few HP with some RR.

Don't be too hard on your #'s you have ALOT of parasitic loss. Your turning alot of extra mass with those BFT , you'd show more power by simply swapping to a smaller tire I bet

 

[HappyG]

I cant read that junk on the cam specs. It would be nice to get real numbers like duration and lift.
the "real" lift and duration numbers are all there, it pretty much is a stock replacement cam, the lobe centers are a little different , but there were a few different "stock" cams also, and the lobe centers varied quite a bit with those anyway. you numbers are fine, your just used to seeing numbers that people post on here, some real, many imagined. what you have is a strong stock rebuilt motor.
btw, the lincoln ho cam is the same as the mustang ho cams, which is the same as the cobra cam too!

 

[86Cobra]

the "real" lift and duration numbers are all there, it pretty much is a stock replacement cam, the lobe centers are a little different , but there were a few different "stock" cams also, and the lobe centers varied quite a bit with those anyway.

Yep, it's all there. Stock GT cam.

btw, the lincoln ho cam is the same as the mustang ho cams, which is the same as the cobra cam too!

The Cobra cam is slightly different. A little less duration (208-209) and a little more lift (.451 w/ 1.6s).

 

[10SecondHatch]

higher gear ratio like 2:73 or 3:08 will bring up the hp

 

[plastic_cow]

Gear ratio matters for HP? I've never heard that before (then again, I'm a newb... perminantly...)

 

[Ranchero5.0]

HP is affected by the gear ratio and how the motor accelerates. 3.73's will live with more initial timing vs 2.73's because the 3.73 combo isn't working as hard to accelerate the motor. Same for cam design and selection.

For this combo, I'd probally run a stock GT cam and 1.7 rockers if it's an auto and maybe a mild cam (less than a E cam) if it's a stick. We did the stock GT and 1.7's on a Autozone 302 longblock and it barked the tires (33's) on a full size '89 bronco with that mild combo.

Jamie

 

[HappyG]

funny, the cam in my cobra was the same as my other mustang? hmmm...?
oh well



The Cobra cam is slightly different. A little less duration (208-209) and a little more lift (.451 w/ 1.6s).[/QUOTE]

 

[86Cobra]

funny, the cam in my cobra was the same as my other mustang? hmmm...?
oh well

Look up the specs anywhere. You'll see they're different. The Cobra cam is the same cam the 5.0 T-Birds used.

 

[zimm17]

Update:

I didn't think about axle ratios... I was running the stock axle back then, probably 2.73 gears in it. I'm now running 4.56. Would that matter on a 3rd gear dyno pull?

I didn't get A/F or timing checked, he just strapped the jeep down and got HP/Torque.

Sounds like I need to find another dyno and try it out and get some real numbers. I'll be back...