We are currently running on the new domain and server: www.Speed-Talk.com

IMPORTANT: Update your bookmarks to https://www.speed-talk.com/forum/
(Right-click the URL and select "Bookmark this link")

Free - hi-tech 5-75 hp dyno

General engine tech -- Drag Racing to Circle Track

Moderator: Team

David Vizard
Guru
Guru
Posts: 1664
Joined: Thu Jan 15, 2015 12:19 pm
Location:

Free - hi-tech 5-75 hp dyno

Post by David Vizard » Mon Dec 02, 2019 8:20 pm

I asked myself if this post should be in the 'wanted' or 'for sale' department. I figured I cannot possibly be profiting from this because I am, after all, giving it away so that is why you are seeing it here. That said, I am sure some naysayers will conclude that I have some personal agenda here and that giving this dyno away will net me some unforeseen profit.

Anyway, here is the grife on this dyno.


I built this dyno back in the late 1990’s to test pistons and valves that would, if successful, be used in Cosworth’s F1 engines.


Because of the nature of the test parts involved the amount of extra power/torque was expected to be quite small and so the dyno had to be a) ultra-repeatable and b) accurate. Having had past experience designing and building ultra-precision dyno’s I knew going in that a conventional absorption brake was not going to cut it. For accuracy and repeatability, I chose to go with an inertial dyno. I used what, at the time, was a novel concept that allowed the dyno to not only show whatever output at any given acceleration rate i.e. 200 rpm or 500 rpm or even an oddball 334 rpm per second but also steady state output. The software that I used, done for me by my trusted friend Bill Anderson, could get all or any accelerated output rates from just one pull.


The dedicated test engine (comes with the dyno) was basically a Briggs & Stratton side valve junior dragster unit although I have to say that not much, if any, original B&S parts were used. Essentially this test unit, with a 12,000 rpm red-line, was used as the valve train was capable of a valve motion that was close enough to that of the Cosworth F1 engines to prove (or otherwise) the newly designed parts. Also it was much more convenient to work with than a single cylinder from the F1 engine.


The dyno itself is capable of repeating within less than 0.01 of a lbs/ft. The big problem was making the test engine repeatable. To this end I made an oil cooled cylinder head so a copious quantity of oil was pumped through the head and into the engine sump. From here it was drawn out and passed though a large, thermostatically controlled, radiator with a big cooling fan. This move allowed the control of pan and head temps to within 2 degrees F of the target temp. With this cooling plus a selected oil and a gas brew we came up with accuracy and repeatability that was nothing short of outstanding.


As it stands the dyno will need a cosmetic rebuild to bring it to its original visual condition.
Also, the software that Bill wrote is nowhere to be found but Keven Gertgen at Performance Trends has a program that will work with this dyno.


BTW the dyno is sensitive enough to deliver in-cylinder pressure results without any in-cylinder pressure transducers.


So I am willing to let both the test engine and the dyno go to a good cause. Who ever gets it will need to organize shipping from APT in Riverside CA.
I would like to see this go to a school where it can get the maximum of use for the maximum of people.


If you are interested in giving a good home for this dyno just post here with why you would like it and we will see who has/can make the best claim.


The photo below is as the dyno was a few weeks back.
You do not have the required permissions to view the files attached to this post.
David Vizard Small Group Performance Seminars - held about every 2 months. My shop or yours. Contact for seminar deails - davidvizardseminar@gmail.com for details.

GARY C
HotPass
HotPass
Posts: 5784
Joined: Tue May 14, 2013 10:58 pm
Location:

Re: Free - hi-tech 5-75 hp dyno

Post by GARY C » Mon Dec 02, 2019 8:36 pm

If you know anyone with SEMA, their High School program may be a good home for it.
https://www.sema.org/sema-enews/2019/47 ... kkqQ9WUnFg
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!

David Vizard
Guru
Guru
Posts: 1664
Joined: Thu Jan 15, 2015 12:19 pm
Location:

Re: Free - hi-tech 5-75 hp dyno

Post by David Vizard » Tue Dec 03, 2019 9:08 am

I forgot to say that with an increase in flywheel size the dyno could be modified to record up to about 250 HP.
I also omitted to mention that it needs no cooling tower or water tank. You can run this in the middle of a car park with no connections - or in your driveway - neighbors permitting!

Right now it is perfect for junior dragster motor testing.
DV
David Vizard Small Group Performance Seminars - held about every 2 months. My shop or yours. Contact for seminar deails - davidvizardseminar@gmail.com for details.

David Vizard
Guru
Guru
Posts: 1664
Joined: Thu Jan 15, 2015 12:19 pm
Location:

Re: Free - hi-tech 5-75 hp dyno

Post by David Vizard » Tue Dec 03, 2019 8:05 pm

Another thought occurs to me. This dyno is a good prototype for a college or school dyno as it is cheap and easy to build even by a relatively small shop and needs no dyno cell. A working one could go out the door for as little as $5500 ready to run!
DV
David Vizard Small Group Performance Seminars - held about every 2 months. My shop or yours. Contact for seminar deails - davidvizardseminar@gmail.com for details.

Racer71
Member
Member
Posts: 55
Joined: Mon Jun 24, 2019 12:36 pm
Location:

Re: Free - hi-tech 5-75 hp dyno

Post by Racer71 » Tue Dec 03, 2019 8:26 pm

How would it do with 600cc bike motor? I build some for dirt track racing, would be nice to compare cyl head work and coatings etc.

David Vizard
Guru
Guru
Posts: 1664
Joined: Thu Jan 15, 2015 12:19 pm
Location:

Re: Free - hi-tech 5-75 hp dyno

Post by David Vizard » Tue Dec 03, 2019 8:32 pm

Racer71 wrote:
Tue Dec 03, 2019 8:26 pm
How would it do with 600cc bike motor? I build some for dirt track racing, would be nice to compare cyl head work and coatings etc.
Flywheel enlargement would be required but nothing too difficult to do.
DV
David Vizard Small Group Performance Seminars - held about every 2 months. My shop or yours. Contact for seminar deails - davidvizardseminar@gmail.com for details.

mekilljoydammit
Member
Member
Posts: 178
Joined: Mon Feb 09, 2015 6:40 pm
Location:

Re: Free - hi-tech 5-75 hp dyno

Post by mekilljoydammit » Wed Dec 04, 2019 8:32 am

OK, so what is this novel concept that allows steady state or constant ramp speed on an inertial dyno? That's an interesting detail.

David Vizard
Guru
Guru
Posts: 1664
Joined: Thu Jan 15, 2015 12:19 pm
Location:

Re: Free - hi-tech 5-75 hp dyno

Post by David Vizard » Wed Dec 04, 2019 12:00 pm

mekilljoydammit wrote:
Wed Dec 04, 2019 8:32 am
OK, so what is this novel concept that allows steady state or constant ramp speed on an inertial dyno? That's an interesting detail.
And I thought no-one was going to ask.

Oh and BTW it was stated by a high up in a well known dyno company that super accurate steady state figures from an inertial dyno were impossible. If I had only heard that before I did it! Professor Blair also thought at one time it was impossible until I explained to him how to do it.

Before I spill the beans I want to see if any one else can come up with a solution.
David Vizard Small Group Performance Seminars - held about every 2 months. My shop or yours. Contact for seminar deails - davidvizardseminar@gmail.com for details.

williamsmotowerx
Expert
Expert
Posts: 739
Joined: Sat Feb 10, 2007 1:24 pm
Location:
Contact:

Re: Free - hi-tech 5-75 hp dyno

Post by williamsmotowerx » Wed Dec 04, 2019 3:26 pm

Tried sending you an email. This is perfect for my size engines.

Tuner
Guru
Guru
Posts: 2347
Joined: Sun Apr 01, 2007 5:26 am
Location:

Re: Free - hi-tech 5-75 hp dyno

Post by Tuner » Wed Dec 04, 2019 7:30 pm

David Vizard wrote:
Wed Dec 04, 2019 12:00 pm
mekilljoydammit wrote:
Wed Dec 04, 2019 8:32 am
OK, so what is this novel concept that allows steady state or constant ramp speed on an inertial dyno? That's an interesting detail.
And I thought no-one was going to ask.

Oh and BTW it was stated by a high up in a well known dyno company that super accurate steady state figures from an inertial dyno were impossible. If I had only heard that before I did it! Professor Blair also thought at one time it was impossible until I explained to him how to do it.

Before I spill the beans I want to see if any one else can come up with a solution.
Eddy current brake with the starter/generator on the left.
Image

mekilljoydammit
Member
Member
Posts: 178
Joined: Mon Feb 09, 2015 6:40 pm
Location:

Re: Free - hi-tech 5-75 hp dyno

Post by mekilljoydammit » Wed Dec 04, 2019 8:07 pm

I'm really curious because all the methods I can readily think of are cheating... some sort of non-inertial load.

I definitely don't want to deprive someone who could use this exact thing by throwing my hat in the ring, but given the capabilities of the data acquisition I have at my disposal, I think I could get some interesting work done with something like this.

BLSTIC
New Member
New Member
Posts: 37
Joined: Wed Dec 05, 2018 7:14 pm
Location:

Re: Free - hi-tech 5-75 hp dyno

Post by BLSTIC » Wed Dec 04, 2019 10:08 pm

You wouldn't have some kind of CVT between the engine and flywheel would you? It wouldn't work continuously, but you could get a few seconds of steady state in.

Or as has been mentioned, a retarder of some kind on the flywheel

Is there torque measurement on the shaft between the flywheel and engine? I'm wildly guessing at this point but if you had data at that point you could calculate quite a lot...

Kevin Johnson
HotPass
HotPass
Posts: 8254
Joined: Tue Nov 22, 2005 5:41 am
Location:

Re: Free - hi-tech 5-75 hp dyno

Post by Kevin Johnson » Thu Dec 05, 2019 2:57 am

The integral calculus. Progression to infinitesimals can be a defined step function and each step is a steady state of finite but defined duration. Think about the riser and tread in a staircase.

mekilljoydammit
Member
Member
Posts: 178
Joined: Mon Feb 09, 2015 6:40 pm
Location:

Re: Free - hi-tech 5-75 hp dyno

Post by mekilljoydammit » Thu Dec 05, 2019 8:24 am

Kevin Johnson wrote:
Thu Dec 05, 2019 2:57 am
The integral calculus. Progression to infinitesimals can be a defined step function and each step is a steady state of finite but defined duration. Think about the riser and tread in a staircase.
Right, but if you go that path, you're going to have to deal with that the engine isn't truly steady state but has power pulses and the like. Also he did talk about holding specific ramp rates, which to my mind argues against a math based solution

Kevin Johnson
HotPass
HotPass
Posts: 8254
Joined: Tue Nov 22, 2005 5:41 am
Location:

Re: Free - hi-tech 5-75 hp dyno

Post by Kevin Johnson » Thu Dec 05, 2019 9:27 am

mekilljoydammit wrote:
Thu Dec 05, 2019 8:24 am
Kevin Johnson wrote:
Thu Dec 05, 2019 2:57 am
The integral calculus. Progression to infinitesimals can be a defined step function and each step is a steady state of finite but defined duration. Think about the riser and tread in a staircase.
Right, but if you go that path, you're going to have to deal with that the engine isn't truly steady state but has power pulses and the like. Also he did talk about holding specific ramp rates, which to my mind argues against a math based solution
The power pulses are part of the claims (in-cylinder pressures).

Ramp rates. LOL. Welcome to Zeno's paradoxes. You would need a sample of the signal produced by the machine self-regulating at the target sweep rate. This might already exist in a large table or be calculated. This can then be extracted/removed/masked from the testing pull.

Really, I think the signal processing capabilities have long existed ala submarine warfare but were probably considered munitions.

Anyways, I have work to do -- perhaps David will explain along a completely different vein.

Post Reply