Max HP for all motor 1300?

[DarkFalcon]

Here is one that are made by Atom racing in Sweden a few years ago.  Stock bore and a home made exhaust....

http://www.kiruna.se/~mgrape/bighajja1300.htm

Yngve, I know from other correspondence that there are one or two guys in Sweden that really know their stuff. With respect to the Atom engine, does it have an epoxied head and will the home made exhaust fit within the stock plastic?

[DarkFalcon]

the origional post was what if money was no issue. so with that what could one make, not a street motor but a all out stock bore stock stroke motor? does any body know what a competetive 1298 4 valve pro stock motor made before people realized the advantage of a 1500 cc 2 valver?

I am not familiar with all of the thinking that went into restricting NHRA ProStock bikes to two valves per cylinder, but I tend to believe it has something to do with leveling the playing field, politics or restricting speeds than it does with any inherent advantage of a two valve design over a four valve design. I would argue that a four valve design is capable of making more power than a two valve design.

[Thomas Lindemann]

Hey Dark the point i was trying to get across is alot of people dont seem to think that a stock bore/stroke busa motor will make much more than 200 horse and many dont seem to think one will make that much. But for quite awhile NHRA prostockers were 1298cc 4 valve motors that made more than 200 horse. Difference is 66mm stroke vs 63 with the Busa having a much better head than a gs1100 or 1150. probably better than anything in that era period. So why do people have such a hard time with believing that giving the attention to detail and r&d of a prostock motor that a stock bore and stroke motor couldnt make 225-240 hp?

[DarkFalcon]

Thomas, I now understand what you are saying. One of the big guns would have to invest the talent, time and resources to make the Busa spin to 14,000 RPM and generate 104 ft#'s of torque to produce 275 HP which would be fairly proportional to the results obtained with a 1.5 liter producing 320 HP.

[Paul Flis]

While we're on the topic what would it take to get a Busa motor to spin to 14K and live.  I've got a piece of paper with my crank saying it was balanced to spin to 14k sustained, but what about everything hooked to it.  The valvetrain would be my guess for the weakest link(s).  Sure there are some great springs out there, but how many of them have been tested at those speeds and for how long.  I spoke to someone on the topic of valvesprings (for a ZX9) and heard some interesting things, which I haven't tried to prove yet.  Apparantly anything but springs sourced from a select few Japaneese suppliers are crap.  They fatigue and break under high rpms and ultimately destroy the engine.  Well that's only one part of it.  What about weight I would think the entire valvetrain would have to go on a diet.  Then with the entire assembly "balanced" including rods/pistons, maybe the motor will turn 14K and we already know that with the right setup these motors are already making power way past redline.

[DarkFalcon]

Absolute, I think valve train weight would need to be reduced along with the weight of all reciprocating components. The current bore/stroke ratio would need to be changed......bigger bore and less stroke... to reduce mean piston speed and provide room for larger valves.

[mike45]

I would cryo age most of the reciprocating components too.

[jorma]

Now if I could just get my hands on one of the hand full of short stroke billet cranks made in the UK for formula 1 sidecar racing!

[mike45]

Now if I could just get my hands on one of the hand full of short stroke billet cranks made in the UK for formula 1 sidecar racing!

It would be easier to get your hands on Pam Anderson's tits.

[jorma]

They're not what they used to be.....and I don't mean the cranks.

[DarkFalcon]

They're not what they used to be.....and I don't mean the cranks.

The Honda 600RR spins, I think, to 15,000 RPM. The material below features some of the technology featured in the engine.


Lightweight, New 'Slipper' Pistons

Minimising reciprocating weight and mass were also important goals in design of the new CBR600RR's engine in the quest for both higher rpms and higher power while maintaining top reliability. The engine's new skirtless forged 'slipper' pistons are significantly shorter and 15g lighter than the pistons currently used by the CBR600F and F/S. Each piston's set of advanced, lightweight and-at 0.8mm thickness for the top ring-ultra-thin rings boast superior resistance to power-robbing flutter at high velocities, and to blowby when high piston speeds meet high compression-characteristics augmented by the Honda-developed PMC (Powdered Metal Composite) aluminium/ceramic cylinder sleeves in which these pistons slide. For further minimised reciprocal weight, the pistons are mounted to the ends of their connecting rods by way of shorter, smaller diameter, and 8g lighter tool steel wrist pins.

'Nutless' Connecting Rods


Connecting rods also play a big part in helping to achieve peak power-producing engine speeds, and excessive weight or mass here slows response and acceleration while introducing vibration and stress that can adversely affect operation at higher rpms. The new CBR600RR's connecting rods feature a lighter 'Nutless' design first pioneered on the VTR1000F and VTR1000 SP-2, which use standard threaded bolts screwed directly into tapped holes in the body of the rod, instead of the conventional nut and bolt combination used in most rods to hold their endcaps in place. Requiring only one tool to assemble, the new design is 12g lighter than the conventional bolt and nut combination, for a total weight savings of approximately 35g per cylinder, or 140g overall. This significant reduction in reciprocating weight makes a major contribution to reducing the engine's mechanical load to help the new CBR600RR achieve a much more aggressively sharp feeling of responsive acceleration.

The RR's new connecting rods have also been carburised for an ultra-hard outer surface that ensures an optimal balance of strength and durability over the course of riding and racing extremes.

The end result of all these improvements is a quicker-revving engine that produces strong power throughout its wide rev range and almost instantaneous bursts of blistering acceleration.

[mike45]

'Nutless' Connecting Rods

quote] He He...You said nutless.

[gazza414]

maybe this should be in another Post , but here goes
DOES anyone have experience with the Busa motor reving past say 11,500rpm and under what conditions / applications.

I remember Motorhead mentioned sometime ago on this forum that he revved them harder 12K or maybe 13K even?

Its when you do the calcs for piston velocities and acceleration rates then translate these numbers to loads on pistons it becomes scary wrt what is acknowledged as "safe"

I also wonder if cryo work on cranks, pistons and rods is beneficial or more fashionable.??

[Yngve at work]

Now if I could just get my hands on one of the hand full of short stroke billet cranks made in the UK for formula 1 sidecar racing!

I know of one thats 58mm stroke. Newer been run because the rules changed...

If U really need one I can problaby get it cheep(ish).

[THE ICE MAN]

I also have 186 H.P. out of a stock bore bike using the factory stock bore oem piston's, i choose the stock pistons because they are lighter and better.
I port my own head's and had a 3 angle serdi valve job done with valve springs from japan, crank was lightned and balanced and I balanced my rod's and piston's, as for cams,I am running the yosh cam's bmc filter and my own modded  box, after market fuel pump and regulater.
This bike runs 201.5 + MPH in 9/10's, with the new cam #s i have it will run 203+ in the 9/10's
all of the Busas i have done with head work and the yosh cams with myself as pilot run 199MPh - 200 MPH in 9/10's.

[DangerMouse]

My friends 99 bike made 186 at the back wheel with this spec:

Yoshi cams.
Skimmed/ported head. (better off skimming the block not head!)
Stock pistons.
Yoshi Tri-oval system.
Full airbox mod.
All short stacks.
PCII with custom map.

It ran through a speed trap at 201 mph.

Could probably find another 4 to 5 brake by modding the ECU to extent the RPM ceiling 500 revs or so and re-dialling the cams to move the power up a bit.

[mike45]

Mine was still making power @ redline. An extended ECU plus a Sumo would have put me in the low 190's. My cam timimg was 105/106- .007 off the head.  After riding the bike for over a month now it works great as a daily rider. My goal was to get max HP without pulling the cylinder. Decking generally works better than head milling- that's a given. My motor never left the frame.

[DarkFalcon]

Mike, for a given deck height why would surfacing the cylinder deck yield any advantages? I would see it as a tool to achieve a target deck height while surfacing the head will yield a slightly higher CR.

[DangerMouse]

Mike, for a given deck height why would surfacing the cylinder deck yield any advantages? I would see it as a tool to achieve a target deck height while surfacing the head will yield a slightly higher CR.

Apparently on the Busa motor skimming the head shrouds the valves.

[DangerMouse]

Mine was still making power @ redline.

Yup the Yoshi cams do carry the power, I can't find the 186bhp graph but this is one of the runs where it made 184. As you say the power is being carried right up to the limiter.


[/img]

[mike45]

If you can shorten the deck to get the .040 or .039 I'd always go that route first. The CR will increase BUT the question is really good as the smaller chamber will burn better for sure and get the CR up faster. I'd like to ask does anyone round the chamber edges after milling (or decking) to help with the "squeeze" during compression cycle. I'll tell what I do after some feedback.

[mike45]

Mine was still making power @ redline.

Yup the Yoshi cams do carry the power, I can't find the 186bhp graph but this is one of the runs where it made 184. As you say the power is being carried right up to the limiter.


[/img]

I'd say that was flat @ 9,750.  You have that blip @7,500 though with the peak torque. What were the cam #'s.

[mike45]

Mike, for a given deck height why would surfacing the cylinder deck yield any advantages? I would see it as a tool to achieve a target deck height while surfacing the head will yield a slightly higher CR.

Apparently on the Busa motor skimming the head shrouds the valves.

I guess it depends on the porting and valve job. I really don't think .007 will shroud enough to hurt a stock bore especially in regard to helping compression. Once again I would like to hear what people do with the chamber edge.

[Wolf1397]

the origional post was what if money was no issue. so with that what could one make, not a street motor but a all out stock bore stock stroke motor? does any body know what a competetive 1298 4 valve pro stock motor made before people realized the advantage of a 1500 cc 2 valver?

Maybe I can shed some light on this issue that since I worked for two NHRA Pro Stock motorcycle teams from 1987 to 1989.  Most, if not all racers that used Suzuki 4-valve motors used either 1261 or 1321 cc displacement at the time.  There was a weight penalty for the larger displacement; so most engine builders/riders went quicker with the 1261 versus the 1321.  However, both engine sizes were on the dyno extensively.  The 1261 dynod in the low to mid 220s depending on builder and the 1321 were in the low 240s.  This is with 66 mm stroke and compression high enough to run diesel…

Wolf

[mike45]

I have always been a fan of motorcycle engine technology. When Honda began testing and applying 4 valve technology to GP bikes in the late 50's/early 60's the British laughed as they knew through extensive testing that 2 valve heads always flowed better. Thing was the British never explored the limits of flame front travel etc at really high RPM's. Honda discovered that one could sustain flame front beyond 20,000 and the only thing that could support that- not to that limit but with available technology- was a 4 valve head. Steep valve angles, air cooled egines , materials etc didn't allow such RPM's on larger bores. Nevertheless the 250-6 revved to something like 15,000 RPM's stillmaking power. The point is 2 valve heads will support tremendous HP through airflow just at a lower redline. Vortex heads-which rule 4 cylinder Pro Stock- support this fact. It is also easier to get a higher CR with a 2 valve head as the chamber can be smaller too. Can anybody add to this?