Topic: 1204cc - 120rwhp track bike by RPE in Oz

[chewbacca5000]

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[Retro Rocket]

Thanks Mick,
 Just can see how you can get that much out of a naturally aspirated carb bike? 

Thanks for posting.

Chewy, the gs1100's running round in historic racing here are pushing 175 HP, they wear carbs my friend...

[chewbacca5000]

Thanks Mick,
 Just can see how you can get that much out of a naturally aspirated carb bike? 

Thanks for posting.

Chewy, the gs1100's running round in historic racing here are pushing 175 HP, they wear carbs my friend...

For real?!  You got to be kidding me.  Man I think I am due for a trip to someplace warmer.  I read these post and think everything Australian gets a motorcycle at age 3 and is wrenching on it by age 5.  I wonder what the upper limit in HP for a street touring bike would be?

[Retro Rocket]

Thanks Mick,
 Just can see how you can get that much out of a naturally aspirated carb bike? 

Thanks for posting.

Chewy, the gs1100's running round in historic racing here are pushing 175 HP, they wear carbs my friend...

For real?!  You got to be kidding me.  Man I think I am due for a trip to someplace warmer.  I read these post and think everything Australian gets a motorcycle at age 3 and is wrenching on it by age 5.  I wonder what the upper limit in HP for a street touring bike would be?

That depends on your definition of a "street" touring bike, My brothers CBR1000RR weighs around 180 kgs and has 175 hp, he does lots of miles on it...

[chewbacca5000]

Thanks Mick,
 Just can see how you can get that much out of a naturally aspirated carb bike? 

Thanks for posting.

Chewy, the gs1100's running round in historic racing here are pushing 175 HP, they wear carbs my friend...

For real?!  You got to be kidding me.  Man I think I am due for a trip to someplace warmer.  I read these post and think everything Australian gets a motorcycle at age 3 and is wrenching on it by age 5.  I wonder what the upper limit in HP for a street touring bike would be?

That depends on your definition of a "street" touring bike, My brothers CBR1000RR weighs around 180 kgs and has 175 hp, he does lots of miles on it...

I mean for a SOHC4 cb750.

[Retro Rocket]

Thanks Mick,
 Just can see how you can get that much out of a naturally aspirated carb bike? 

Thanks for posting.

Chewy, the gs1100's running round in historic racing here are pushing 175 HP, they wear carbs my friend...

For real?!  You got to be kidding me.  Man I think I am due for a trip to someplace warmer.  I read these post and think everything Australian gets a motorcycle at age 3 and is wrenching on it by age 5.  I wonder what the upper limit in HP for a street touring bike would be?

That depends on your definition of a "street" touring bike, My brothers CBR1000RR weighs around 180 kgs and has 175 hp, he does lots of miles on it...

I mean for a SOHC4 cb750.

How much money have you got...   I imagine with all the quality parts available now, and one of Mike R's billet blocks, 90 to 100hp {at the crank} would be close..

[chewbacca5000]

Thanks Mick,
 Just can see how you can get that much out of a naturally aspirated carb bike? 

Thanks for posting.

Chewy, the gs1100's running round in historic racing here are pushing 175 HP, they wear carbs my friend...

For real?!  You got to be kidding me.  Man I think I am due for a trip to someplace warmer.  I read these post and think everything Australian gets a motorcycle at age 3 and is wrenching on it by age 5.  I wonder what the upper limit in HP for a street touring bike would be?

That depends on your definition of a "street" touring bike, My brothers CBR1000RR weighs around 180 kgs and has 175 hp, he does lots of miles on it...

I mean for a SOHC4 cb750.

How much money have you got...   I imagine with all the quality parts available now, and one of Mike R's billet blocks, 90 to 100hp {at the crank} would be close..

I better get out of the HiPro section and fast before I become I HiBroke! ha,ha,ha  So much engine candy, sooo much money.  My dream is to have an engine built with parts that are made just by members here, but I would probably be homeless at the end of the engine build. LOL

[Retro Rocket]

Thanks Mick,
 Just can see how you can get that much out of a naturally aspirated carb bike? 

Thanks for posting.

Chewy, the gs1100's running round in historic racing here are pushing 175 HP, they wear carbs my friend...

For real?!  You got to be kidding me.  Man I think I am due for a trip to someplace warmer.  I read these post and think everything Australian gets a motorcycle at age 3 and is wrenching on it by age 5.  I wonder what the upper limit in HP for a street touring bike would be?

That depends on your definition of a "street" touring bike, My brothers CBR1000RR weighs around 180 kgs and has 175 hp, he does lots of miles on it...

I mean for a SOHC4 cb750.

How much money have you got...   I imagine with all the quality parts available now, and one of Mike R's billet blocks, 90 to 100hp {at the crank} would be close..

I better get out of the HiPro section and fast before I become I HiBroke! ha,ha,ha  So much engine candy, sooo much money.  My dream is to have an engine built with parts that are made just by members here, but I would probably be homeless at the end of the engine build. LOL

Thats pretty much what i'm doing with the one i'm keeping, i'll be in it for , hold your breath, around 20 grand by the time its done....

[MRieck]

What about the spigots on the bottom if you nicasil ? Ot do you mean build the inserts with spigots on the bottom.
 How big is the bore and are they offset?

Right...Siamese them. If those inserts are just some melted pistons forget it......you would need some billet. 7075 I'd guess and a lot more machining. I don't think they are using CNC equipment.

[gschuld]

How much money have you got...   I imagine with all the quality parts available now, and one of Mike R's billet blocks, 90 to 100hp {at the crank} would be close..

As a reference, Benton's little ol' 915 motor with a JMR stage 4 ported k head managed 101hp at the rear wheel.
Take away a small amount for the extra zip he was getting with the oxygenated MR12 fuel he was using, and 95hp at the wheel with high test fuel is about right.  That number should rise with added displacement, but your asking more and more from the head.

That RPE 1202cc motor initially came in at 111RWHP.  They have since reported 120, and more recently 130 to the tire.

I'd be interested to see what was done to the cylinder head to support such power levels.

George

[Retro Rocket]

How much money have you got...   I imagine with all the quality parts available now, and one of Mike R's billet blocks, 90 to 100hp {at the crank} would be close..

As a reference, Benton's little ol' 915 motor with a JMR stage 4 ported k head managed 101hp at the rear wheel.
Take away a small amount for the extra zip he was getting with the oxygenated MR12 fuel he was using, and 95hp at the wheel with high test fuel is about right.  That number should rise with added displacement, but your asking more and more from the head.

That RPE 1202cc motor initially came in at 111RWHP.  They have since reported 120, and more recently 130 to the tire.

I'd be interested to see what was done to the cylinder head to support such power levels.

George

In some of their pics or videos I saw a head with modified inlet tracts, similar in looks to what CycleX did to their track bike that blitzed everything, I'll see if i can find the video...
At 52 seconds you can see the welded up intakes and again at 1:03, its visible a few times...

[gschuld]

That you tube link is for the 1050 motor they built for a street bike.  We're you thinking of a different video?

George

[Retro Rocket]

That you tube link is for the 1050 motor they built for a street bike.  We're you thinking of a different video?

George

No, I'm suggesting that if they are doing that for the street engine and getting good HP numbers at the rear wheel, they are probably doing the same thing for the bigger engines..  Your question was " I'd be interested to see what was done to the cylinder head to support such power levels", thats what CycleX did as well...

[kmb69]

Yep, that video shows welded up spigots at 0:52 and 1:03. They look cleaner than the Cycle-X head.

[chewbacca5000]

How much money have you got...   I imagine with all the quality parts available now, and one of Mike R's billet blocks, 90 to 100hp {at the crank} would be close..

As a reference, Benton's little ol' 915 motor with a JMR stage 4 ported k head managed 101hp at the rear wheel.
Take away a small amount for the extra zip he was getting with the oxygenated MR12 fuel he was using, and 95hp at the wheel with high test fuel is about right.  That number should rise with added displacement, but your asking more and more from the head.

That RPE 1202cc motor initially came in at 111RWHP.  They have since reported 120, and more recently 130 to the tire.

I'd be interested to see what was done to the cylinder head to support such power levels.

George

In some of their pics or videos I saw a head with modified inlet tracts, similar in looks to what CycleX did to their track bike that blitzed everything, I'll see if i can find the video...
At 52 seconds you can see the welded up intakes and again at 1:03, its visible a few times...

How much welding and machining do you think went into those intakes?  Did they bore the intakes out or something?

[gschuld]

Good point.

Here are the two photos at 52 sec and 1:03.

George

[kmb69]

After studying that video just a bit more, it looks like they did not do the "straight shot" like Cycle-X. Looks more like they just spaced them similar to a Z1. But they do say the head was ported. They just did not say how big.

[Retro Rocket]

Yes, they definitely look bigger than the stock intake spigots but you are correct, they don't have the downward angle of the cycleX intakes..

[kmb69]

Don't look nearly as big either. These are some intake ports!

[Retro Rocket]

Thats the drag bike head, looks a little different to the race bike head, different port angle...

[dragracer]

Kenny's head was set up to use Lectron carbs so the spacing really wasn't a factor as much as configuring a"straight port" design. Road race or street motors obviously need low, mid and top range power so racked carbs with slow jets and replaceable mains is a must. The lectrons Kenny set his bike up for only do two things, idle and full throttle. They aren't designed to effectively do anything else. Hence, the port angles and huge holes to match those 40mm lectrons.

[Retro Rocket]

Gday Frank, what i meant was, those ports in the pics are 90 degrees to the head, on the race bike, from memory, the ports were more in a down draft configuration...

Just went and had a look, on the CycleX race bike the ports were  angled 15 degrees higher...

[bear]

 "That RPE 1202cc motor initially came in at 111RWHP.  They have since reported 120, and more recently 130 to the tire."

[gschuld]

Is that yours Bear?  That's serious power for such modest rpms....

George

[bear]

That's why I can get a minimum of a hundred race hours out of them George.
Check out the torque curve.
HP's one thing but you've got to be able to race 'em.

Cheers,
Brian