interpret torque trace from dyno run

[IaTR6]

never mind, I can't attach the pdf
Dennis

[donkelly23]

Copy to a jpg

[IaTR6]

I think I can.....So, is it possible this shows the shifting of the gears? I thought the trace was only started when
the vehicle was in the gear for the test. What do you think?
Hey Carl-Thanks for your kind offer! I'm so incompetent, I'm sure there will be something else.
Dennis
You cannot view this attachment.

[minorv8]

No gear changes, continuous pull on high gear.

[88v8]

OK, so silly question I never thought of, what if it's an auto? How does that work?

Ivor

[IaTR6]

I believe this is a continuous pull in a direct drive gear, although I have seen it done in a lower gear. The question,
is why the roller coaster trace in the
lower rpm? I question things like accelerator pump, power valve, and transition
to the secondaries of the four barrel.
As to automatics, I haven't thought about that. I do know that the dyno operator I watched earlier this year
would pull traction control fuses on the newer cars to keep it from activating.
Anyway, I'm just curious-of course, that supposedly killed the cat, so I should be careful!
Dennis

[roverman]

I would look at BSFC/ air-fuel data log, throughout the pull, also timing ? Electronic inj. ? Exhaust temps ?

[88v8]

Yes, perhaps this is what one gets with an 'out of the box' setup that hasn't had dyno time to tune the carb/ign  properly.

Over here in the UK, I often see Rover V8s with the Edelbrock 500, if I ask the owners how much dyno time they needed to set it up properly they just look at me.

And the same with sidedraught Webers. People want the bling, but won't pay to make it work properly.

Ivor

[IaTR6]

I'm going to try for more information on the engine. All I know right now is that it would
be considered old-school hotrod ding. 351 Ford, bored and stroked to 408. Single four barrel
(Holley I think) of unknown cfm, alum heads, uprated cam. Apparently the owner sent the original
engine to a builder, and offered up the intended use, and the builder went from there.
No dyno time prior to this run, so tweaking of timing, jets etc has not been done.My original
curious question was regarding the up and down curve, not having seen anything like that before.
I'll tget more info and get back-it's just a mind exercise!
Dennis

[roverman]

We certainly have people here, skilled in Holley set-ups ?  I wonder about power valve function and vacum secondaries ?
                                                                           Not Holley skilled, Art.

[MGBV8]

Over here in the UK, I often see Rover V8s with the Edelbrock 500, if I ask the owners how much dyno time they needed to set it up properly they just look at me.

I used an Innovate O2 tailpipe sniffer with 12-14 inch extension to get it farther into the exhaust pipe.

[IaTR6]

Well, I am now sorry I started this thread, as I cannot get enough information on the engine.
All I can find out is it is supposed to be a Ford 351 bored and stroked to 408.
It has Flotech heads (which ones?), A Holley "Brawler" carb (how many cfm?). Beyond that - nothing!
A fine example of someone going to an "engine builder", and saying: I want a hot rod engine. What
you get is a mystery after that. You might get a runner, or a dog, and only chance determines the outcome.
Could some dyno time researching the ignition and fuel system to unlock the actual potential? I would
think so, but I'm guessing that may not happen. There was no A/F recorded, the dyno operator asked if
the owner wanted that, but apparently the owner didn't recognize the value. I asked about the carb secondaries,
and he was too afraid of the engine exploding to be that close! I'm frustrated to say the least. The owner should be in possession of
a list of all the components in the engine. If not, I become very suspicious!
I originally thought this would develop into a conversation on technical aspects of tuning, and it fell off a cliff - Sorry!
Dennis

[MGBV8]

It takes more that just slapping parts together.  It's not just chance. They need to work well together & match the application.

IMO, it should be making more like 400 RWHP.  May not can do it with tuning since you don't really know anything about the internals of the engine. If you aren't happy with the power, tear it down & see what you have inside. Then, you can compare some magazine builds to see what combination of parts will deliver what you want

[DiDueColpi]

I'm going to go with wheel spin on the dyno.
Torque was 350ish @ 1600 rpm and maxed @ 372 @ 3500 rpm.
Doesn't compute to me.
Could have been a lot of other reasons but that run should go in the dumpster.
Cheers
Fred

[IaTR6]

Oh criminy!! I now realize that the obvious bit of information that I left out was that this isn't mine!
Dang. It belongs to a cousin of mine who I thought was more savvy than to just ask for an engine build without knowing
what to ask for. This is HIS dyno run, and i am not competent enough to interpret what went on, and
thought I would ask all of you. What transpired was that he doesn't know what he has, and without that information, it's just a waste.
And because of that, I wasted your time, and I'm sorry for that. I know all of you like a good challenge, and that
shows in your interest in my question.
I hope that the next time I ask something it will include all the pertinent details.
Thanks again,
Dennis

[roverman]

I don't consider a waste of my time, keeps my gray matter out of cobwebs/lol. Did anyone mention potential of "wheelspin", on chassis dyno ?
                                                                       Art.

[MGBV8]

Yep.  Fred Key did a few days ago.