Very cool! it was a 477 BBC. around a 270 cam. It only made 752HP at 6800RPM's :D . It was interesting looking at fuel curves, VE, and the like. I hope to dyno my 496 in a month.

It is pretty cool huh. Wait till it's yours. The adrenaline flows and the nerves get shot. But as far as I'm concerned, it's worth every penny. If nothing else, the engine is broken in and ready to romp on once it's in the car.
I'll be on the dyno with my 498 about the same time you are. It seems to be taking forever to get there.......
Ron

Hate to be a drag, and it may just be from my conservative (or asinine behavior according to Mr. Ed), but be careful of how your engine (or chassis even) dyno runs are performed. The rpm/sec of the pull, timing, jets, dyno headers, velocity stack, cool input air from outside, lack of an air filter, no accessories or exhaust, so on, (in my limited experience, correct size k&n vs no filter = no difference, I saw the k&n thread earlier, I only use it because I like the way it looks), and if they pull the engine down from high rpm or brake it up from low RPM (wat & oil temp usually tell this method) can make a huge diff on a dyno run. A few buttons on the dyno computer added a *ton* of power to my "dyno runs" to make power that didn't exist, they really weren't there, but showed with just a few keystrokes.
please don't think I'm being a negative pain naysayer, to use friendly terms, (people have called me worse) but dyno methods can really vary. The 477 may have well made 752 totally legit hp, but dyno headers, cool air, a velocity stack and a very fast rpm/sec will inflate #'s quite a bit.
Just for an *anecdotal* (spelling?) example, I've had 3 cams in my motor, all the same cept for .6 more CR from test 1 to test 2 & 3, and the engine made almost the exact same hp/tq, but ran with almost 25-30hp more on the last, very conservative dyno (same dyno #'s, 25-30hp more track hp).
it is sure fun to watch the engine go on the dyno, (the control room is usually separate for a reason! watch your ears) esp when you watch that water heat up as the water brake goes nuts, but, keep in mind if you are being made happy or getting whats there. I was "made happy" my fist dyno session--- The car performed very well for a somewhat mild combo (10:1 454 w/hydro roller), but not what the dyno predicted. Use it to tune, I guess..
Out of 3 engine dyno sessions, I've had 1 truly honest, 1 pretty honest (good rpm/sec, but velocity stack, dyno headers & dyno carb) dyno sessions, and one all out "max it out" method.
They are great tuning aids, esp if you have a nice air/fuel hooked up, but IMHO take them as relative #'s and not absolute #'s unless you know the dyno operator is showing you what you have vs what you want.
The thing I wish I could truly figure out, and I know onakind (if I spelled wrong, sorry), is torque converters and dynojets. there is a dynepack load dyno a state away from me, but, still, I don't know if its worth it.
If you can't see the AF ratio, esp on a chassis dyno, its not worth the cash unless its just for un, BSFC I have yet to totally figure out, but Harold's UDHR4 had good #'s in that dept, my solid roller doesn't.
Sorry for the ramble, I just finished a big project and have some free time. One quote I love, which has nothing to do with the post, was when I was getting my engine dyno'd post cam change at SD concepts in RI, and Scott (the head person) was on the phone and said "listen, you can't run a solid roller with lobes shaped like squares on the street." Made me feel better about my cam.
But point noted, there was a 15-25hp difference b/w a regular dyno w/ velocity stack, my carb, dyno headers, and a dyno with my headers, my carb, and my mufflers.

Sorry this was so long..

Had a night out for celebration..

Matt

My guy's dyno is an inertia dyno. So it's really more like the dragstrip with your car in high gear.
My last engine made 560hp on it, and by all of my calculations and simulation programs, the car ran within a tenth of what it should have. So I consider the results to be quite accurate.
And like I said, if nothing else, the engine is tuned and ready to go in the car.
Ron

Out of curiosity, was it a dynepack or mustang? I've heard both can estimate 1/4's very well..
How did your auto (I assume) deal with the dyno? Or did it act just like it would on the street?

Matt

of course the engine builder said this was a conservative dyno. He also said there are ways to "cheat" and get inflated results. He said they have dynoed engines on this dyno and then carried them strait to some "big name" engine builders (to remain unnamed) with no changes made and their dyno showed over 100HP more... graemlins/sad.gif anyway, he has alot of integrity and I trust him. I'm looking forward to him breaking in the engine and putting the initial tune on it, as a side benefit I get to see what kind of "flywheel" power my engine is capable of. graemlins/beers.gif

There are many ways to cheat numbers out of a dyno. But it is a really cool site to see. The shop I used to work at I got to see 1800hp Blown BBC's dynoed all of the time. Nothing beats that sound. graemlins/thumbsup.gif

I think you guys are mixing up both chassis and engine dyno's, and noone is making the distinction as to which one you're talking about smile.gif

IMO an engine dyno isn't nearly as useful as a chassis dyno unless you're trying to squeeze every drop of power out of a full on race motor. Either is definitely cool to watch though!

Matt,
His inertia dyno is not a chassis dyno. It's an engine dyno and measures flywheel HP.
Ron

I was talking primarily about engine water brake type dynos...
I was just trying to say some dyno operators are less, well, forthcoming in how much real torque the engine is making.
I was just using a point the fact that 3 engine dyno's have said I have the same hp each time, yet they all run different track mph...
Some operators will add 90hp with a few changes, and some will try to get an honest picture. I was just trying to say watch out for the guys who aren't trying to give an honest picture...
I didn't mean anything personal to anyone if I came across as pain in the rear..
BTW it is fun to watch and I have a video or two of my engine up on an engine dyno getting run.. I kinda wish the run lasted longer, because that sound is "full load" like nothing else.
I haven't personally had luck with chassis dyno's because I run into issues with torque converters, so I only use the #'s as relative #s to eachother..


Matt

I didn't take any of this as personal, nor are you being a pain!
I didn't know that a dyno operator could skew the results.
My guy's dyno is a simple setup. It's a 700 lb + flywheel and the computer measures how fast the engine can spin it up.
And trust me, that 700lbs grunts the engine pretty hard.
He picks a start and stop RPM, then hits the go button. It's just the engine against the wheel.
of course we make sure temps etc are as close to the same from run to run.
His dyno is home made btw.
Ron

You're in Portland, I am in Hillsboro. Kinda close. I'd like to see what he's built. Can you give me the phone number? Sorry for interrupting your thread.

Pony, you have mail.
Ron