ESE's works engine tuner

[wobbly]

The only thing to add is you can make the Boyesens bigger and lower by cutting back the gasket area that does nothing.
Depending on how far back you go you may need to fill the cavity in the case with epoxy, this also gives better gasket support anyway.

[190mech]

Smitty,Have you seen the Rossi thread on PitLane?
http://www.pit-lane.biz/t1666-techni...es-boat-engine

[peewee]

i checked where the ring gap ends up, i plan to bring the B ports alittle further around back which will leave hardly no sealing surface afterwards, so ill be filling in the cavity at the back of the crankcase. might as well make the boyesens bigger while im at it

[dtenney]

Seattle Smitty….I think you may find that the pictures of the FOS cylinder that Yow pointed you to is not the work of Giusseppe. Those pics are the result of the work of a well known outboard race engine builder in Texas…..experimentation, for some, is alive and well in pro outboard racing.

[wobbly]

Of interest to those in watercraft racing involved with trying to add power at the bottom of the powerband is that the complication of sliding pipes is way to hard to implement on a multi motorcycle.
One of the World Champ winning twin cylinder open Jetski motors I built had a powervalve that was originally a Rotax type pneumatic system.
Completely dumb and mostly ineffective except out of the gate - as in the turns as soon as the injection was moved from WOT the pipe pressure would drop, and the valves followed suit.
When getting back on the gas, it took way too long for the pressure to rise again to open the PVs at the correct rate and rpm.
The boat had a small tank on board that held 100 psi, this was used to activate small flaps on the rear of the hull, to drop the nose when entering the turns.
So to get control over the PV electronically I simple connected the tank to the bottom of the PV diaphram via a small regulator and with 5psi drove the valves up and down with PWM
control from the injection computer against a return spring.
No extra power required and a linear opening rate was easy to program against rpm and a TPS to give a 3D map.
Then we took the next step, and used my experience from the BSL500 and added an ATAC volume on top of each header tube, controlled by a flat blade that simple slid back
to connect the header to the ATAC volume via a short tube 1/2 the header diameter.
This was like the flat plate sliding throttles as used in F1 car injection systems.
The ATAC was only required to be opened instantly at a set rpm, so was also activated by the 5psi pressure under another diaphram.
The air driven ATAC added another 32% of extra power at the very bottom of the powerband, needed no extra power, easily lasted all day and was simply controlled by the ECU with an rpm switch in software.
Seems like the perfect system to be used in a 125/175/250/500/700 hydro boat.
A diaphram can easily be made to have sufficient stroke to do both jobs, without having to push a pipe 130mm or so with lots of power needed for a servo controlled system on a multi cylinder.

[seattle smitty]

190mech, I had not yet encountered that thread (having been absorbed with Frits' thread in the same location); will check it out, much appreciated.

Well, well, here's another boat racer, a boat racer NOW, not decades ago, and a good one. And his appearance here is timely.

For any of the rest of you who might have any interest in my outboard racing references here, David Tenney is the son (right, David?) of Bill Tenney, one of the very big names in the history of our sport. Bill Tenney was, I believe, a participant in the intercollegiate outboard racing circuit of the "golden age" of American sport in the Thirties. After the war, Tenney, an inventor, designed and manufactured a small pulse-jet engine for the sport of control-line model airplane racing. He was still racing boats, and won several national class championships and set some competition and straightaway records. A little later he became the North American importer of British Anzani outboard motors (see my posts over several previous pages), and developed alcohol-burning versions of the 250 and 322cc twins which became popular with racers particularly in the Midwest and South. David, you really should be the one telling your dad's story; if you have done a good biography, I'd like to see it.

Anyhow, at some point in the Fifties, Jim Hallum, mechanical engineer, outboard mechanic, tuner of his dad's racemotors, and a model airplane racer using a Tenney Red-Head pulse-jet, went back to the Midwest to run his 150mph little control-line airplane at a nationals meet. There he met Bill Tenney. A couple of years later, Hallum was further developing Tenney's Anzanis for driver Gerry Walin. The most famous (though not ultimate) version was the 65hp, 100mph Class B engine as shown in the photo a few pages back.

David, I met your dad in 1968 during the NOA Nationals, when I drove back there from Seattle with Ron Anderson and Chuck Walters. For the rest, Ron Anderson is a mechanical engineer and racer who became a close friend of Jim Hallum, and a co-developer of Anzani engines (Ron and Jim used to get their stuff together and have friendly "dyno-races"). Ron and Jim co-developed the twin-powerhead-on-a-gearbox 700cc class Anzani, which I described a few pages back and which we took back to that race and attempted unsuccessfully to run. On Friday evening of the race weekend, David, your mom and dad invited us Seattle boys (plus Ron's wife) to dinner at your house. Nice folks, a good time.

Now that David Tenney has appeared here, I should leave any further descriptions of our part of the 2-stroke sporting world to him, since he knows a lot more than I.

(Sending you a PM, David)

[husaberg]

Of interest to those in watercraft racing involved with trying to add power at the bottom of the powerband is that the complication of sliding pipes is way to hard to implement on a multi motorcycle.
One of the World Champ winning twin cylinder open Jetski motors I built had a powervalve that was originally a Rotax type pneumatic system.
Completely dumb and mostly ineffective except out of the gate - as in the turns as soon as the injection was moved from WOT the pipe pressure would drop, and the valves followed suit.
When getting back on the gas, it took way too long for the pressure to rise again to open the PVs at the correct rate and rpm.
The boat had a small tank on board that held 100 psi, this was used to activate small flaps on the rear of the hull, to drop the nose when entering the turns.
So to get control over the PV electronically I simple connected the tank to the bottom of the PV diaphram via a small regulator and with 5psi drove the valves up and down with PWM
control from the injection computer against a return spring.
No extra power required and a linear opening rate was easy to program against rpm and a TPS to give a 3D map.
Then we took the next step, and used my experience from the BSL500 and added an ATAC volume on top of each header tube, controlled by a flat blade that simple slid back
to connect the header to the ATAC volume via a short tube 1/2 the header diameter.
This was like the flat plate sliding throttles as used in F1 car injection systems.
The ATAC was only required to be opened instantly at a set rpm, so was also activated by the 5psi pressure under another diaphram.
The air driven ATAC added another 32% of extra power at the very bottom of the powerband, needed no extra power, easily lasted all day and was simply controlled by the ECU with an rpm switch in software.
Seems like the perfect system to be used in a 125/175/250/500/700 hydro boat.
A diaphram can easily be made to have sufficient stroke to do both jobs, without having to push a pipe 130mm or so with lots of power needed for a servo controlled system on a multi cylinder.

Do you have any pics of the BSL set up Wayne I don't think I have ever seen it.........

[fatbastd]

Pardon the ignorance Wobbly, but what culled is that? Reed valves and meat in the wrong places makes it looks NOT like a 350F/G..

[wobbly]

I may have a pic somewhere - will search it out.
The BSL had a tube volume above the headers on the top cylinder pairs.
We found that this made less power when under one cylinder displacement ( 166cc ) and made no more when above 1.5x.
The short connector tube was 1/2 the header diameter with a rotating valve like a carb throttle plate.
The ECU snapped it shut with a solenoid at around 10200 in an engine that peaked at 12200 and reved to 12800
This added 32% as I said over the extra power made by the normal powervalved setup, and it would take full throttle from well under the pipe at 6000 and above.
Without the powervalve it was virtually unrideable, with both the PV and the Boost bottles in place it was easy to produce wheel spinning controlled power sides
from down at 8000 rpm.

[Haufen]

Can you show us some dyno graphs or tell us power numbers of the BSL?

With todays information and technology available, how much (crank)hp could be achieved with a 500cc triple? What would you say?

[wobbly]

We got 56Hp at the sprocket at 12200 on the single dyno test engine - near on 160 at the sprocket on the bike that weighed 13Kg less than the 180Hp
4 cylinder bikes at the time.
The 500. twin Honda factory bike made 140, so the package was dead on where it should be in relation to cylinder size.
This was a 59.6 square setup and I believe today I could with little effort achieve 60, that is 13.9 Bar BMEP at 12200 giving 63 crank Hp on FIM unleaded..
The single test engine had only a 3:1 primary drive, so I deduct about 5% from crank to sprocket.

[F5 Dave]

Interesting. so 3 x 56 is 168. I would have thought less loss with multi, but you will tell me next the single test had no gearbox.

so you are getting 8hp loss through that gearbox, so 4% which sounds reasonable. yes no otherwise?

[wobbly]

Yea, the single mule engine had a 1:3 primary drive to the dyno shaft.
So 56 sprocket power = 59 Crank = less 5%.
Translate the single dyno power to the tripple = 168 less another 5% for the gearbox and you have around 160 at the bike sprocket.
On a Dynojet it made 155 at the wheel, so that translates close to the very usual 12.5% reduction from crank to Dynojet power for a racebike = 177crank.

As I said I can now say with confidence, I would easily get say 63 crank, that would be 189 less 12.5% =165 RWHp, and at the time that would have been super quick.
Issue was we didnt have Jan and 100 R&D festerers looking for things to do - just me and 3 others with no time to sleep.

[F5 Dave]

Cool, interesting figures to know real world outcome.

[Frits Overmars]

Issue was we didnt have Jan and 100 R&D festerers looking for things to do.

... never needed anybody looking for things to do, Wob; there were always more things to do than time, equipment and the Great Leader permitted.