Dyno Stuff

[Speeddog]

140 at 5000 rpm

It must have been one of the super rare S8R.

[Truckedup]

Is that a conical rear hub I spy?

    Ya, the frame is a 1975 oil frame the engine is more or less a 1970.I built the bike from a pile of parts.....It currently holds the 650 push rod modified production record in the one mile standing start..125.00 mph

  Can a 900 Ducati two valve make 110  HP with enough reliability for land speed racing? It wouldn't stand a chance against the best OHC Japanese 1000's but might catch them off guard...

[MonsterHPD]

    Ya, the frame is a 1975 oil frame the engine is more or less a 1970.I built the bike from a pile of parts.....It currently holds the 650 push rod modified production record in the one mile standing start..125.00 mph

  Can a 900 Ducati two valve make 110  HP with enough reliability for land speed racing? It wouldn't stand a chance against the best OHC Japanese 1000's but might catch them off guard...

I'd guess 110 honest rear-wheel horses from a 900 is a tough proposition regardless of reliabilty ... perhaps with the right dyno ....

[koko64]

Great effort out of the little Trumpy! I've owned two '73 T140's that were passionate love affairs.

Your question is worthy of it's own thread. Speeddog, Eric, DuckStew and Dirty Duck may have some input for you. 110 is more likely with an 1100 motor but maximum effort 900 motors reportedly can go to 100hp if worked to 944/964 and major head modifications.

[koko64]

I'd guess 110 honest rear-wheel horses from a 900 is a tough proposition regardless of reliabilty ... perhaps with the right dyno ....

There must be a SOHC 2 Valve class.

[Dirty Duc]

There must be a SOHC 2 Valve class.

Don't say that to the scta people... [Roll]

You guys run event gas? At Bonneville you can run ERC110k in the gas class.

Naturally aspirated on pump gas, I suspect the limits are fairly well explored.

The blower bike started as a 1000ds. Dual spark being one of the mods to make a 900 fast, and the class breaks normally being at 1000 make it seem like a better starting point.

[koko64]

It must have been one of the super rare S8R.

The rare V8 32 valver.

[koko64]

Don't say that to the scta people... [Roll]

You guys run event gas? At Bonneville you can run ERC110k in the gas class.

Naturally aspirated on pump gas, I suspect the limits are fairly well explored.

The blower bike started as a 1000ds. Dual spark being one of the mods to make a 900 fast, and the class breaks normally being at 1000 make it seem like a better starting point.

Did I stumble into racing politics?

Maybe a carbed 1000 with headwork and hotter cams? Is that allowed?

[Truckedup]

  1000 cc push rod 2 valve Guzzi can crack 100 hp with a lot of money...

[clubhousemotorsports]

I don't bother with air/fuel measurements for wot, simply jet for best power

Keep in mind unless you are towing the Dyno on a flat bead trailer at speed when doing this you are leaner when you are actually riding the bike and your jetting will be leaner causing the power you think you have to be lower. You can guess with adding high speed fans in front of the dyno but you really should be finding peak HP on the dyno and then going a tad richer on the mains so you are not too lean when adding 100mph wind.

peak power often is around 13.5-1 but unless you are dealing with a fuel injected bike that will use airbox pressure you almost always want to be closer to 12.5-1.



As to the 110hp 900 I see no reason it would not be possible on somebody's dyno (probably not mine) I have seen 900's in the 90's with 50% builds so an all out build might just get there. I do have a couple 985 motors that are pretty close to full built. The best case would have been one that used to have tipped up port heads and all the lightened internals (rods,crank etc)and as a race bike running too high for street compression it might have been there when fresh. The problem is that is a lot of $$$ to spend on a motor to get it there.

I am going to be building a 1100 evo motor this winter/spring that is going  to be a pretty full build. So far 107 on my dyno is the highest hp 2-valve.  IIRC a st3 which is not aircooled is about 100hp stock and I am putting some hi comps in one this winter as well so lets see how the 3 valver works with a little compression.

[Truckedup]

Keep in mind unless you are towing the Dyno on a flat bead trailer at speed when doing this you are leaner when you are actually riding the bike and your jetting will be leaner causing the power you think you have to be lower. You can guess with adding high speed fans in front of the dyno but you really should be finding peak HP on the dyno and then going a tad richer on the mains so you are not too lean when adding 100mph wind.

peak power often is around 13.5-1 but unless you are dealing with a fuel injected bike that will use airbox pressure you almost always want to be closer to 12.5-1.



As to the 110hp 900 I see no reason it would not be possible on somebody's dyno (probably not mine) I have seen 900's in the 90's with 50% builds so an all out build might just get there. I do have a couple 985 motors that are pretty close to full built. The best case would have been one that used to have tipped up port heads and all the lightened internals (rods,crank etc)and as a race bike running too high for street compression it might have been there when fresh. The problem is that is a lot of $$$ to spend on a motor to get it there.

I am going to be building a 1100 evo motor this winter/spring that is going  to be a pretty full build. So far 107 on my dyno is the highest hp 2-valve.  IIRC a st3 which is not aircooled is about 100hp stock and I am putting some hi comps in one this winter as well so lets see how the 3 valver works with a little compression.

  Yes, the dyno can be lean compared to the race track...Off the trailer with no jetting changes the bike ran 128.2 mph at the 1-1/2 mile track at Maine setting a new track record at that time...I went richer on the Mikuni 34 MM flatslides and the speed picked up 1/10 mph..Too close to make a call....I run leaner that the competition and go faster...of course the detonation risk is evil on the 1930's technology Triumphs...

I mentioned 110 HP just for an example. and not as a dyno queen...I have no real idea on the durability of 2 valve engines and if real power means special cranks ,rods and so on that gets real expensive...  Thanks for your info...

[clubhousemotorsports]

I am going to assume you are talking of the old air force base in Maine for top speed runs or are you at the oxford drag strip?

Different bikes will take different jets it is just ballpark figures when you are getting jet sizes from someone else. There are too many variables between bikes for what you are doing. your Dyno will be the best judge of what works on your bike. Yes Lean can bring in detonation and that can get expensive so fat is safer within reason.

A safe mild build on a 900 motor is 80's at the rear wheel up about 10hp and +10 on torque the motor would be stock reliable. porting does not hurt reliability either. When you start getting into exotic materials like Ti rods, crazy cams  or pushing limits with squish this is when you start to see a drop in practical reliability and need to treat the additional costs as maintenance. At 110 or 100hp I would also expect a shorter life before the cases cracked.

[Truckedup]

 Loring AF base...We also raced at the one mile track in Ohio but that closed this fall...i use aftermarket rods on the Triumph so the stock crank becomes the limiting factor at about 70 HP and or above 7500 rpm..
I have seen 900 Ducati engines for reasonable prices. I was thinking of pulling the stock engine building another one and 80 hp at the rear wheel should do the job.. But at my age you might think the stock engine is enough to scare me...

[clubhousemotorsports]

No problem with a stock or mildly built 900 motor. They are very good motors with easy to use power.

Big bore gets you more torque than just hi comp and cleans up the cylinder at the same time. 944 or 950 and there is lettle added risk of losing cylinder seal.
lighten the flywheel and mount a bank of keihin FCR's and you have a great setup. IMHO one of the great engine combinations.

[ducpainter]

I like my 900.