Run in stand/dyno build.

[Terry Keeley]

I tried the FSR coupling with the needle bearing and it slipped the same.

I got my Consigliere to have a look at one of the sprag type bearings and the rpm graphs and he came up with a great idea. What if you put in stronger springs so the sprags stayed hooked up better? He also had the idea to use a bit of rubber o ring to test it. His consulting fee just went up a bunch (again).

It did slip on a few earlier runs but it was better after I leaned the needle a little and the motor smoothed out, night and day tho from other runs with the stock springs. I'm going to order some proper springs and hopefully they'll hold.

Here's an rpm plot of run D with a little slippage:

Closeup at 15K:

Here's a smooth run (F):

Anyway I'm going in the right direction I think. When they said these types of dynos were consistent they weren't kidding. I got three runs within 0.08 HP of each other with virtually the same torque.

All three together, EGT & CHT are identical:

 

[Wasted wages]

That's pretty cool Terry.... Data that is repeatable shows you are getting closer to cranking out realistic numbers... or at least comparitive data that can be measured between modifications..

Surprising thing to me is that the torque numbers are not higher... heck, there are servos that produce more torque!!

 

[Terry Keeley]

No wonder the springs in the cheap bearing I'm using are crap, they sell for 90 Indian Rupies = US$1.22!

https://www.indiamart.com/proddetail/one-way-clutch-bearing-8449145733.html
Shows a pic of the bearing with the cover removed showing the spring pockets, I'm trying to find a better bearing with this arrangement.

edit: Got one of these coming: CSKP Sprag Type Combined Bearing Freewheels | Stieber Clutch

 

[Ricky Neal]

Getting there Terry.

Do you have any of the dyno designs in CAD? I would be happy to pay some money if you have as it will save me some time. I don't really have time to machine all the components manually so would subcontract them to a job shop to speed up the process

 

[Terry Keeley]

Getting there Terry.

Do you have any of the dyno designs in CAD? I would be happy to pay some money if you have as it will save me some time. I don't really have time to machine all the components manually so would subcontract them to a job shop to speed up the process

I wish I did, I'd put them out there free for anyone who wanted to build one.

I'm still using graph paper, pencil and eraser, lol.

I could send you a good photo of the plans, the grid is inch with 1/8" divisions. If you draw it up and send it to me I'll go through it and make corrections as needed. Then we could offer it to anyone (with a disclaimer of course!).

Making it a dyno only (forget the fan part for running in motors) and not adding the eddy brake (don't seem to be using it much) would simplify things a bunch.

 

[Ricky Neal]

I wish I did, I'd put them out there free for anyone who wanted to build one.

I'm still using graph paper, pencil and eraser, lol.

I could send you a good photo of the plans, the grid is inch with 1/8" divisions. If you draw it up and send it to me I'll go through it and make corrections as needed. Then we could offer it to anyone (with a disclaimer of course!).

Making it a dyno only (forget the fan part for running in motors) and not adding the eddy brake (don't seem to be using it much) would simplify things a bunch.

Actually, that sounds like a great idea, I would be happy to put it into CAD for the community if you are happy too?

Would you have any objections to me doing a version in metric?

I cannot promise how quick I can do it but as its a reasonably straightforward design It shouldn't take long once I get started

Ricky

 

[Terry Keeley]

Actually, that sounds like a great idea, I would be happy to put it into CAD for the community if you are happy too?

Would you have any objections to me doing a version in metric?

I cannot promise how quick I can do it but as its a reasonably straightforward design It shouldn't take long once I get started

Ricky

No objections at all whatsoever, I'd just be happy there are plans for others who want to go down the rabbit hole.

I've done quite a bit of R&D on this (with my Consigliere) that will surely save you and others some valuable time and money.

The only thing I'm not 100% positive of yet is the one-way bearing but that Stieber unit is coming tomorrow and will give it a shot, it may need the springs replaced as well. You may want to try the BMX freewheel instead.

Shoot me a pm with your email and I'll send some photos.

 

[charles siler]

Terry the one thing that I’ve been pondering is making the turn pipe adjustable while you are running the motor just to get the Ultimate pipe adjustment without saying 9.5” or 9.25” extra it would cost super cool to see ya incorporate it to hit ultimate peeks . Super cool Charlie

 

[Terry Keeley]

Terry the one thing that I’ve been pondering is making the turn pipe adjustable while you are running the motor just to get the Ultimate pipe adjustment without saying 9.5” or 9.25” extra it would cost super cool to see ya incorporate it to hit ultimate peeks . Super cool Charlie

One of the first things I want to try is adjusting pipe length, I have spacers for my SAW boat that goes from 9.5" to 12". I always figured the shorter the faster, right? Now that I see the way the power drops off suddenly at about 21K (with this stock set up) I'm not so sure. I remember Lohring and Bontoff had a slider type rear cone they played with, maybe they'll chime in.

There's so many variables to test with just a (mostly) stock motor.

Pipes are obviously a big one, does Tommy tape really do anything? Bearings? What about the needle setting? Plugs? Fuels? Water cooling amounts? Carb size? Head volumes and squish clearance?

I have some definite ideas about how these things effect power but seeing is believing as they say.

Once I've optimized all the "stock" variables I have some ideas about liner taper and piston materials I want to try, that's probably next winter's project.

I'm about to get very busy.

 

[Brad Christy]

Terry,

How did you ever find time to work?

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC

 

[Ricky Neal]

No objections at all whatsoever, I'd just be happy there are plans for others who want to go down the rabbit hole.

I've done quite a bit of R&D on this (with my Consigliere) that will surely save you and others some valuable time and money.

The only thing I'm not 100% positive of yet is the one-way bearing but that Stieber unit is coming tomorrow and will give it a shot, it may need the springs replaced as well. You may want to try the BMX freewheel instead.

Shoot me a pm with your email and I'll send some photos.

PM sent

 

[Terry Keeley]

Terry,

How did you ever find time to work?

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC

No idea! Been retarded three years now and am busier than ever!

 

[TJ Hammons]

Hiya Terry,

I've been lurking around here for a little while and that's an awesome design! I've been wanting to ask you a few questions since you're up and using it. When you're making a pull, what temps are you seeing on the engine/plug? One of the things I've always wondered is if my dad and I have run our motors too cool. Recently took an old 40 rigger out and restricted the water flow and saw an improvement. I realize that each engine will have it's own sweet spot for temp range, but I'm wondering if you could give some potential insight in regard to optimal run temps. We currently run 40 riggers and will eventually work into a 60 this year sometime.

Would also love to know what plug are you running, what's your nitro content, bowl volume, squish clearance, that is if you're willing to divulge

Thanks!
-TJ

 

[Terry Keeley]

Hiya Terry,

I've been lurking around here for a little while and that's an awesome design! I've been wanting to ask you a few questions since you're up and using it. When you're making a pull, what temps are you seeing on the engine/plug? One of the things I've always wondered is if my dad and I have run our motors too cool. Recently took an old 40 rigger out and restricted the water flow and saw an improvement. I realize that each engine will have it's own sweet spot for temp range, but I'm wondering if you could give some potential insight in regard to optimal run temps. We currently run 40 riggers and will eventually work into a 60 this year sometime.

Would also love to know what plug are you running, what's your nitro content, bowl volume, squish clearance, that is if you're willing to divulge

Thanks!
-TJ

Here's some temps from run F above:

That's typical of what I've seen from the few full runs I've been able to do so far. Interestingly the thermistor (resistance based) sensor and the IR gun both showed much lower CHT, there's a reason all full scale racing use only thermocouples. These might go higher as I cut back the water, lean on the needle, run hotter plugs etc. So many variables.

I posted on the Fireball plugs thread what I thought about restricting the water:

"From what I've seen most guys don't burn their expensive nitro very well. They run full water, a super cold plug like an OD289 then they havta lean the crap outta the needle to make it "go".

Cut back on the water, run a hotter plug and richen the needle a bunch, you'll go faster, mill better and will be a whole lot easier on plugs and motors.

Andy Brown put me on to this way back and it works!"

For heat racing I ran K&B HP's for years but started to burn the insulator, I've switched to ODO287's and will never go back. I tried 288's and 289's and found no difference between the two but they were both way too cold, had to lean the needle down a bunch. I run 60% nitro for heat racing for everything from 21's to my VAC91's. I also run ODO77's at times and am gonna try some old super hot K&B 1L's. New O'Donnell V2 plugs?

You can get a lot more power by increasing the C/R but if you lean on the needle too much you'll hurt stuff pretty quick. I've been running 15:1 on my 21, here's an old thread about it: https://www.intlwaters.com/threads/on-line-head-volume-calculator.74796/d

My old VAC45 came close to 14:1 and that's what I run on the VAC91. I don't run as close as some guys and like 0.012" on my 21's to 67's and 0.014" on my 91's. Much less and I start to see the imprint of the squish band on the piston as things heat up and expand.

What 45's are you guys running?

 

[TJ Hammons]

Thanks for the info Terry! Love the graph and data. I think I'm going to try a warmer plug provided I can get my hands on some.
We've got a few MAC 45's and I picked up a V5 from Stu at the Cinci TT event in October. I need to go back in my notes and see what he recommended for starting squish on the V5. It's a stock motor currently.

 

[LohringMiller]

What I know about pipes applies to gas engines with higher exhaust temperatures. A properly set up simulation program let's you "test" a lot of designs without touching metal. I use EngMod2T. It can simulate glow ignition but is just guess work without real world dyno measurements.

The sliding cone pipe was one of my early ideas. You could change the diffuser position along the header while holding the tuned length constant by moving the cone. We found that the position of the simple, 2-stage diffuser wasn't critical. That's why moving the pipe along the header to change the tuned length is an acceptible solution. However, when you look for a few percent gain with fancy, multi-stage diffusers, everything matters.

My favorite empirical pipe design program is below.

Lohring Miller

 

[Terry Keeley]

What I know about pipes applies to gas engines with higher exhaust temperatures. A properly set up simulation program let's you "test" a lot of designs without touching metal. I use EngMod2T. It can simulate glow ignition but is just guess work without real world dyno measurements.

The sliding cone pipe was one of my early ideas. You could change the diffuser position along the header while holding the tuned length constant by moving the cone. We found that the position of the simple, 2-stage diffuser wasn't critical. That's why moving the pipe along the header to change the tuned length is an acceptible solution. However, when you look for a few percent gain with fancy, multi-stage diffusers, everything matters.

My favorite empirical pipe design program is below.

Lohring Miller

Very interesting software, it's going to take several days to digest!

 

[LohringMiller]

The exit from the port to the pipe inlet is the latest area where tuners found more power. Our wide ports are similar to the triple port designs for ringed pistons. The program shows this, but I'm attaching the drawing below to make it clearer. Otherwise don't go too crazy with diffuser design. I get best power with a two stage diffuser, a 1.2 horn coefficient and around a diameter coefficient of around 3. The spreadsheet incorporates these factors from your engine and expected power inputs. The big factor will be guessing the speed of sound from the average pipe temperature. I would expect that nitro engines would have a lower temp. The spreadsheet below gives a quick idea of this.

Lohring Miller

 

[Terry Keeley]

Very happy and quite surprised the new clutch bearing is working right outta the box. I tried four other sprag type bearings and a needle bearing before I found this one, wish I tried it first, wudda saved me a lot of time (and a few pesos).

Gonna start by testing glow plugs, will go cold to hot with OD289, 287, 277 and K&B 1L. First tho I havta find the optimum needle setting for each plug, it makes a huge difference on the output.

Here's an OD 289 that "surged" at top end, I think what's happening is it's too rich with too cold a plug to keep the fire lit.





Here's a complete run with the needle leaned from 7 to 6 3/4 on my old school flowmeter:





Unfortunately I clicked the start/finish recording according to the manual and got weird data, then the pipe coupler slid heating up the flywheel and throwing the magnet. Will be back at it soon.

 

[Steve White]

Terry, do you monitor the head temperature on all dyno pulls? Wondering what it was when it was surging.