Thread: Desktop Dyno?

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Hey, can someone here crunch some #'s for me on DD? I have my first show coming up this weekend and I'll feel kinda dumb saying, "I really have no idea."

- 1986 5.0L H.O. engine (stock '86 flat-top pistons)
- E6 heads -- thermactor bumps removed, port & polish, skirts ground down
- Custom cam: .491/.471, .219/.209 @ .050, 112 deg sep
- Weiand 289 tunnel ram intake (P/N 1988)
- sync'd dual Holley 390 cfm vac secondary carbs (P/N 8007)
- Pertronix ignition
- MSD Blaster II coil
- Full-length 1 5/8" headers, Turbo mufflers, 2.5" pipes, no cats

And if you could run it with GT-40 heads, too; I'd be interested in the difference -- I have an opportunity to pick up a set on the cheap.

I'm thinking about 250-275 hp.

Thanks in advance,

- Joey

sorry its tuesday i just seen youre post. but after i get home from work today ill dtd it for ya. i have a comp cams dtd wich is within 5% accurate

Thanks, man. Very cool of you.

I have a 86 Ho f.i..They were rated about 225 stock,with the bunk heads .You should be close to 300,with the tunnel ram and those heads.Those cars are light,soo you should be able to keep up with the new mustangs!! Just dont follow the new ones thru the corners

Can't help you with the numbers but was just wondering how those dual 390's work on your motor? Thinking of doing the same.

Originally Posted by shawnlee28

I have a 86 Ho f.i..They were rated about 225 stock,with the bunk heads .You should be close to 300,with the tunnel ram and those heads.Those cars are light,soo you should be able to keep up with the new mustangs!! Just dont follow the new ones thru the corners

There's a considerable sphincter factor when those secondaries open up. It morphs into an entire other motor past 4K.

Originally Posted by chevy 37

Can't help you with the numbers but was just wondering how those dual 390's work on your motor? Thinking of doing the same.

The 390's rock. Please check out my cardomain site, particularly page 2, where I go into length about the tunnel-ram part of the build.

I run them with stock jetting, and literally bolted them on and laid a 50' patch down my father-in-law's driveway ten minutes later. The roller-cam engine, with its quick throttle response, seems to be a good fit for the tunnel-ram -- this is an older 289 "street" tunnel ram -- and the 390's appear to be an ideal size for a small-block. It runs a little rich and idles a little quick to get a good scary lope out of the cam, but it runs nice.

EDIT: They are Holleys, though. If I could do it again, I'd buy Edelbrock 1403's and save myself a couple hundred dollars in Excedrin.

I've heard the 390's are hard to dial in. Also need to have power check valves/ I have two 600 polished cfm edelbrock carbs sitting on a offy intake but way to much carbs for my engine. I think even the 500 edelbrock would be to much although I've run a couple 3 duece set up which push me back into my seat when I open them all up. Love the looks of the dual 4 barrel's and the sound is to much

Hey, Denny. Long time. You know what a PITA these Holleys have been from time to time. . .

Chevy37, the power valve reliefs are a cinch to put in. My problem with the Holleys wasn't so much dialing them in, as it was keeping them running; mostly rookie mistakes, though. Not using Vaseline on the injector needles, for instance. And before that, I had a sticking vacuum advance that kept annihilating my power valves until I tracked the problem down.

Dual quads are high on my "Hot Rod Glory" list, too. Wow factor, sweet sound, and tons of power. I like mine. . . when they run. . ..

Glad to help can you give me the valve size, compression ratio and the intake and exaust open and close points on the cam. if i use youre lift and duration the computer will automatically determine them and they may be off a hair

Here is what I get with appromating some of the inputs. I got the compression ratio from:

http://www.mustanggt.org/86gt.htm

http://www.virtualengine2000.com

was 2 if you still want me to run it i need the specs from the cam card intake and exaust advertised duration,intake center line and valve timing

Glenn, I don't have that info handy. I'll PM you with it in a few days. Thanks!