Dyno testing

[interalian]

A local shop has an outboard dyno that's basically just a water pump load cell with a pressure gauge. Apparently there's a table of pressures for outboards to give equivalent to HP ratings. Anybody know what the correct numbers would be for a '79-82 crossflow 140?

BTW, the guy running this shop is a d!ck and after being treated like a schmuck there yesterday whilst inquiring about dyno work, I'll never darken his door again. But I digress...

 

[Faztbullet]

These dyno's are ok for testing engines if lake to far to drag em to(sold mine). The do not measure torque which is what is required to calculate HP. What they measure is pump pressure in a closed hydraulic system and ok for comparing a stock engine against a known standard(new motor).These pressures will change due to oil gets thinner during run and require a lot of water to keep em half way cool. I only used mine to test for WOT ignition problems. You could never use this unit to compare if a modification help or hurt a motor, this is where you need a powerhead dynamometer.The only way to measure your HP is to test it on a torque vs RPM dyno.​

 

[interalian]

That makes sense. I've had cars run on DynoJet before (my M5 made 285whp and surprised the heck out of the operator who wouldn't believe the scale should be set to 300 as he was used to small block Chebbys and didn't belive a straight 6 could make power).

I really just wanted to have a shop make sure my WOT timing was right since I married two engines and suspect I'm a bit on the retarded side for timing. Tried daylight tesing but the sunlight washed out the strobe. Maybe I'll pick an early morning on a cloudy day and try again on the lake.

Sparkies look good after about 50 hours: