Dyno Results?

[AndyBrown]

Andy,

One explanation for these very high HP readings on small motors could be the method used to measure the small amounts of torque being developed. I do not know what type of device is being used, load cell, spring scale, or torque wrench, but measurement is difficult at best. Big motors with big torques are easy to measure.

Jim

I'm betting it's the dartboard method! Or better yet, the spanner on the prop nut method -"whoa -it flew X feet, must have X torque"

SAW boats need the torque and the HP to peak at the same RPM, which is also the rpm that will give the boat it's top speed. There is no such thing as going through the HP peak with higher revs for a SAW boat, unless the pond is very short and accelleration is part of the equation.

By that I assume you mean - under-propping for accelleration rather than peak speed - Obtaining the fastest possible speed for the pond available....kind of like reducing pinion gear diameter to suit a car track?

Yes!

 

[EatMyShortsRacing]

If you want to see a good looking torque/HP curve check out the VZ-b Spec OS 21. Peek HP and torque are almost at the same RPM range.

http://rcnitro.com/RN/articles/dyno_vzbvspec4.asp

Very good example to look at. The O.S. 21 VZ-B's peak BHP is 2.93 @ 28,050 rpm & its peak torque is 104.6 oz. in. @ 26,500 rpm. The Collari .21 GT's peak BHP is 3.02 @ 34,500 rpm & its peak torque is 94.8 oz. in. @ 27,700 rpm. The Collari's torque curve is very flat over a wide rpm range allowing the motor to develop high HP at high rpms. Also notice the large differences in the construction of the liners of these two motors.

Hmmmm Collari.... is that the real Collari or the Collari company which prevents Mr Collari from even using his own name as a web domain????

http://www.lcollari-innotech.com/

From that page....

THE FIRST IS ORDINANCE DATED 3 MAGGIO 2005 WHICH , AT THE REQUEST OF Ms PATRIZIA ARMAGNI AND A.S. srl CALLS FOR

-the injunction against the use by Mr lamberto Collari of the company name "LAMBERTO COLLARI MOTORSPORT" di Lamberto Collari , as well as the use of the brand "LAMBERTO COLLARI MOTORSPORT"

-the seizure of the products bearing the "LAMBERTO COLLARI MOTORSPORT" OR " LAMBERTO COLLARI MOTORSPORT " BRAND

-the Injunction against the publication of INTERNET of the notice which appeared on the WEB SITE of Mr Lamberto Collari relating to use of the word Collari

THIS DECISION WAS CONFIRMED ON 21-07-2005 BY THE LAW COURT OF BOLOGNA WHICH BY DECISION OF THE ASSEMBLY OF JUDGES ON THE ONE HAND REJECTED THE APPEAL MADE AGAINST IT BY Mr Lamberto Collari,AND ,ON THE OTHER, INTEGRATED THIS BY FORBIDDING Mr Lamberto Collari FROM USING THE DOMANIN NAME www.lambertocollari.com

Another intersting point.... dont those 5+2 engines look just like Rossi engines????? LOL

 

[AndyBrown]

Thay ARE Rossi engines.....with an LC plate on the side.

 

[EatMyShortsRacing]

Thay ARE Rossi engines.....with an LC plate on the side.

Hmmmm so thats why I ordered Collari piston/liner sets for my Rossi engines

Since Rossi doesnt seem to have a great presence here in Australia....

Got my Rossi 45 RiverKing (outboard) thru Eurpoe at about AUS$380 landed including header...

 

[eekern]

the collari afore mentioned was also the winning engine in the last ifmar 1/8th scale onroad worlds and the v-zb has converted more than a few novarossi owners in the 1/8th scale buggy ranks

 

[EatMyShortsRacing]

the collari afore mentioned was also the winning engine in the last ifmar 1/8th scale onroad worlds and the v-zb has converted more than a few novarossi owners in the 1/8th scale buggy ranks

It is good to see that competition is coming back into engines.... That can only mean better gear for us!!!



But does anyone know the story why Collari (the man) seems to be at war with Collari (the company)???

 

[Jim Allen]

Thay ARE Rossi engines.....with an LC plate on the side.

What Andy says about the Collari .21 GT is true. I wonder if this is also the case with the Sirio .23, which looks very much the same as the Collari except in brass. Big difference in price here with the Collari costing about $650.00 & the Sirio costing $350.00.

 

[Jim Allen]

Quote from website

New In the Box Rossi 45 Marine Outboard River King Model 132R45 engine and Rossi Tune Pipe Kit with instructions, accessories and a glow plug. This is a new engine with three year factory warranty.

The retail price of this engine is $507.

The specs for this engine are:

2.40 HP

27000 RPM

BORE: 22.41 mm

STROKE: 19.00 mm

PORTS: 5

Glow Plug: Standard

Rossi engines are hand made in Italy, built to the most precise tolerances, with the finest Swiss CNC machine equipment, using the best quality materials to give you the highest performance and longest life.

Not sure if i read this right but thats less hp than an os .21 buggy engine??

i find that hard to belive either rossi are being conservative or os is over quoting

there hp figures

Quote osengines.com

SPECIFICATIONS

Stock Number: OSMG2068

Displacement: .21 cu in (3.5 cc)

Bore: 0.653 in (16.6 mm)

Stroke: 0.629 in (16.0 mm)

Practical RPM: 3,000-40,000

Output: 2.5 hp @ 33,000 rpm

Weight (w/o muffler): 12.7 oz (360 g)

Includes: TP-3 glow plug, 8 mm and 9 mm carb restrictors, exhaust seal and dust cap set

Requires: Glow fuel, tuned pipe and manifold.

13890 .21 VZ-B V-Spec-T Parts Listing

Anyway regardless of what kb has to say

i will still be buying mac's when they become avalible

Maybe Andy has it correct when he says the biggest advertizer has the most HP! Could this be possible in this highly competitive market?

 

[AndyBrown]

I don't know the reasons or details, but Collari has been through a few manufactures. Picco, Rossi, and now Sirio.

It is the Sirio based engine that won the 2005 1/8 On-road World Champs (Collari's son was the driver). Not the Rossi based engine that ESR is talking about.

Pulstech, Better be careful what you say here...you'll get labled as a Cronie.

 

[John Finch]

I have only one thing to say about all this dyno and rpm hype........ The fastest boat turning the fastest rpm is not usually the one making the fastest lap. How fast you get thru the corners and how quick the model gets to top speed is more important than top speed itself.

 

[Don Ferrette]

I have only one thing to say about all this dyno and rpm hype........ The fastest boat turning the fastest rpm is not usually the one making the fastest lap. How fast you get thru the corners and how quick the model gets to top speed is more important than top speed itself.

Absofrikkinlutely!!! There is simply no substitute for how a boat performs ON THE WATER!! The baddest motor on the planet won't be squat in a sub par hull just like a great hull can make an average engine look better than it is. What matters is the complete package, period. All the "projected hp" numbers don't mean jack squat, it is the total package that wins races. B)

Don't get me wrong, a dyno can be a great tool in engine development, but we live & learn at the pond.

And 3hp on 30%? Yeah right. Maybe with a 45. <_<

 

[Bart Drieghe]

Jim , ( or others )

Got a question ,

Instead of using a (airplane)prop as a load for the engine , could i use an oilpump ( of a car engine ) with some kind of regulator on it to give more or less load on the engine ?

I don't want to make a dyno bench , only a testbench for the engines .

Thanks in advance ,

B

 

[Terry Keeley]

Terry,

Usually, if you can pipe the engine up "rapidly", from half throttle to full throttle, you will be able to pipe the engine up at the lake.

A flat wide torque curve is what is best with high engine rpms, because HP is a function of both torque & rpm. I would want an engine like this for SAW. You should not go faster when running past the peak HP rpm because both torque & rpm are decreasing.

I guess that's the limiting factor for our two strokes, whether you can get it to the rpm where the pipe comes in and quickly enough. If it won't come on the pipe with any decent load it won't go very fast anyway...

 

[lohring]

Our experience with the Quickdraw engine is somewhat different because of its power curve. The current engine's power peaks at a little less than 18,000 rpm then only drops off a little until over 20,000 rpm. It definitely pays to turn 23,000 rpm in a straight line rigger since there is a limit on the pitch of available propellers. Draggier hulls go fastest when propped for just past the power peak. For heat racing the fastest laps on a rigger result when the engine is at the power peak when exiting the turn. This gives maximum acceleration and the ability to over rev with little loss of power results in high speeds entering the next turn. Again, draggier hulls like monos don't benefit as much from this and don't pick up as much speed.

Because this is the only engine we have both dyno and data logger data on, I don't know how to use dyno data to set up nitro boats. Knowing the dyno results and the on the water speed and rpm has been a big help getting the most out of the Quickdraw where there was no reliable experience to go by.

Lohring Miller

 

[Jim Allen]

Jim , ( or others )

Got a question ,

Instead of using a (airplane)prop as a load for the engine , could i use an oilpump ( of a car engine ) with some kind of regulator on it to give more or less load on the engine ?

I don't want to make a dyno bench , only a testbench for the engines .

Thanks in advance ,

B

Bart,

Absorbtion type brakes must use water because oils won't be able to absorb very much power without boiling. Been there & tried to do that.

Jim

 

[Terry Keeley]

Our experience with the Quickdraw engine is somewhat different because of its power curve. The current engine's power peaks at a little less than 18,000 rpm then only drops off a little until over 20,000 rpm. It definitely pays to turn 23,000 rpm in a straight line rigger since there is a limit on the pitch of available propellers. Draggier hulls go fastest when propped for just past the power peak. For heat racing the fastest laps on a rigger result when the engine is at the power peak when exiting the turn. This gives maximum acceleration and the ability to over rev with little loss of power results in high speeds entering the next turn. Again, draggier hulls like monos don't benefit as much from this and don't pick up as much speed.

Because this is the only engine we have both dyno and data logger data on, I don't know how to use dyno data to set up nitro boats. Knowing the dyno results and the on the water speed and rpm has been a big help getting the most out of the Quickdraw where there was no reliable experience to go by.

Lohring Miller

So for SAW you ended up going faster by reving past the power peak, do you think you could go as fast by turning more pitch at a slower RPM, nearer the power peak? Would the boat get there faster?

 

[Racerdude]

Where does one purchase the dynos in question?

I asked around a lot a few months ago, and no one I spoke with was able to really tell me where to get one.

I am planning to build one if I can't buy one.

Thanks

Jay

 

[legendscar24]

Jim,

You info is very well founded, we have the same sitiuation in the Legends Cars series, guys are turining their engines 10500 rpm at the end of the straight, Yamaha shows the tested power curves and torque and Hp starts a decine at about 9700, some times guys would ask why I ran lower geared rear end and my answer would be close to what you are trying to explain, your going past the best useable torque and HP, what you say makes good sense.

Mike

 

[AndyBrown]

Our experience with the Quickdraw engine is somewhat different because of its power curve. The current engine's power peaks at a little less than 18,000 rpm then only drops off a little until over 20,000 rpm. It definitely pays to turn 23,000 rpm in a straight line rigger since there is a limit on the pitch of available propellers. Draggier hulls go fastest when propped for just past the power peak. For heat racing the fastest laps on a rigger result when the engine is at the power peak when exiting the turn. This gives maximum acceleration and the ability to over rev with little loss of power results in high speeds entering the next turn. Again, draggier hulls like monos don't benefit as much from this and don't pick up as much speed.

Because this is the only engine we have both dyno and data logger data on, I don't know how to use dyno data to set up nitro boats. Knowing the dyno results and the on the water speed and rpm has been a big help getting the most out of the Quickdraw where there was no reliable experience to go by.

Lohring Miller

So for SAW you ended up going faster by reving past the power peak, do you think you could go as fast by turning more pitch at a slower RPM, nearer the power peak? Would the boat get there faster?

Terry,

I think you mis understood, for racing or oval times you want to rev past peak a little. You want the engine near peak power and torque when pulling out of the turns.

For SAW you want your top speed and peak HP to happen at the same rpm unless the pond is short and

acceleration is part of the equation.

Lohring is talking about going past peak with the gas engine for the best SAW speed because they don't have a prop big enough, so they go past peak and get some extra speed. If they had the right prop the big speed would come when the engine was turning at about 18,000.

 

[EatMyShortsRacing]

I don't know the reasons or details, but Collari has been through a few manufactures. Picco, Rossi, and now Sirio.

It is the Sirio based engine that won the 2005 1/8 On-road World Champs (Collari's son was the driver). Not the Rossi based engine that ESR is talking about.

Pulstech, Better be careful what you say here...you'll get labled as a Cronie.

I guess what I am trying to work out is why Lamberto Collari is obviously not associated with and probably at war with l collari-innotech (the company with his name that is stopping him from even having a website www.lambertocollari.com)....

Quote from website

New In the Box Rossi 45 Marine Outboard River King Model 132R45 engine and Rossi Tune Pipe Kit with instructions, accessories and a glow plug. This is a new engine with three year factory warranty.

The retail price of this engine is $507.

The specs for this engine are:

2.40 HP

27000 RPM

BORE: 22.41 mm

STROKE: 19.00 mm

PORTS: 5

Glow Plug: Standard

Yeah the HP rating there does not make sense.... My last Rossi 45 inboard was an absolute powerhouse!!!! I cant see it being out performed by a K&B... Even the base model K&B 45 outboard is rated at 2.5 HP

Maybe coz the 40/45 engine has been around so long that they measured the HP years ago (and maybe with a different method) and never really thought about re-testing???? Or maybe thats on standard fuel???

Tell ya what.... I will get my 7.5 boat going and compare engines...