Anybody have desktop dyno?

[Jims86tpisub]

Hey Guys!
I was wondering If someone with desktop could run this cam for me?
Its a comp cams 12-388-4
Specs:
RPM range: 1,000 to 5,000 rpm.
Duration at .050" lift: 206/212 (int/exh)
Valve lift with 1.5 rockers: .425"/.440" (int/exh)

350 C.I.

Compression should be 9.0:1 or 9.5:1 with the 193 Swirl port heads.
Running Tuned Port Injection, all stock components, Speed density.
Thanks!
Jim
PS- I did use the search function already.

[eventhorizon66]

This will give you something to play with and it's FREE!  For your heads, unless you know the flow numbers (which you can input), I'd just select GM 882 casting since its the closest thing to your heads (select the "Port Flow" button in the cylinder heads section, then select the "Open" button at the bottom of the popup box, run through the files until you find "GM882").  Oh, and don't bother registering.  You can just exit out of those first pop-up boxes everytime.

My guesstimate is 250hp and 350-375 lb-ft...for what it's worth (nothing ).

[Jims86tpisub]

Thanks! i`ll give it a whirle!

[Jims86tpisub]

well, I ran the combo on camquest, and with the info I know, and fudging on the heads the best I can, assuming 300 cfm(lowballing) i got 237 hp @ 4000rpm, and 403 Ft. Lbs @ 2000 rpm. Not bad, considering , the stock engine(per Sales Brochure) was 165 hp @3800, and 275 ft lbs @1600

[Captkaos]

For 193 heads you are definitely fudging it....   on the high side.  Stock 193 heads Peak flow numbers are more like 170 cfm intake and 150 cfm exhaust

[eventhorizon66]

300 cfm

Maybe if you replaced the heads with these.

[Jims86tpisub]

Actually, i meant the tpi system, i was lowballing the tpi at 300 cfm., sorry bout that!

[eventhorizon66]

I would think about 600 cfm from the stock 48mm throttle body sounds reasonable.

[Jims86tpisub]

at 600 cfm i have 250 hp@ 4000, and 410 ft lbs @2500. For the head flow numbers, it wants the flow at specific valve openings, and i havnt been able to find any info on the stock flow results of the 193`s

[eventhorizon66]

Here are the numbers @ 28 in/h20 pressure drop through a stock untouched 1995 Tahoe 193 head w/ 1.94" & 1.50" valves.


------------Intake-------Exhaust
Valve Lift----Flow---------Flow
0.050--------38.7---------27.6
0.100--------70.4---------55.7
0.200--------100.2--------115.6
0.300--------145.7--------125.8
0.400--------164.7--------138.9
0.500--------178.9--------146.8

*These flow numbers were posted here by FSC member "Fast305"

[Jims86tpisub]

Thanks...trying that now

[Jims86tpisub]

OK, input those flow numbers, and i got 245hp@4000, and 403 ft. lbs.@2000................Nice!

[HAULIN IT]

Jim, Sounds like a nice street engine! There are a few things to concider here, though. Comparing the "dyno" numbers to the stock 165hp & 275lbs is somewhat misleading. The manufactures rate the engine at Net power (all of the pulley driven accessories on that model, the complete exhaust, complete emission system & air cleaner) & the "dyno" numbers are Gross numbers (say, an electric water pump, correctly sized headers & BIG pipes, a VERY large supply of air-what ever the engine needs). Have Fun, Lorne

[Jims86tpisub]

Jim, Sounds like a nice street engine! There are a few things to concider here, though. Comparing the "dyno" numbers to the stock 165hp & 275lbs is somewhat misleading. The manufactures rate the engine at Net power (all of the pulley driven accessories on that model, the complete exhaust, complete emission system & air cleaner) & the "dyno" numbers are Gross numbers (say, an electric water pump, correctly sized headers & BIG pipes, a VERY large supply of air-what ever the engine needs). Have Fun, Lorne

I feel ya Lorne.......Just looking for a step above what I have. Im basically going to end up with an 87 to 95 engine with the crane cam and tpi. if it feels good to the butt dyno, then so be it...and if not, save more pennies, and grab some S/R torquers!

[eventhorizon66]

The butt dyno is by far the most important measurement tool for a street engine.  Good luck.  I hope it all works out for ya.