450 triple race bikes

[sharp2183]

I’m tentatively thinking of trying to pick up a 450 triple race bike for next season. Do these come up for sale very often?

And for anyone who has built them, what the cost to do a quality job (with a good tune)?

[WALRUS]

I'm curious as to why you would do this to a machine instead of just keeping it as a 600? Genuinely, I don't get it.. Care to enlighten? :)

[Grumph]

I'm curious as to why you would do this to a machine instead of just keeping it as a 600? Genuinely, I don't get it.. Care to enlighten? :)

An obsolete 600 - meaning more than 3 years old - can be a competitive F3 bike. No fabrication to mount odd motors in odd frames - and if you keep the bits it can go back to being a 600.

[jellywrestler]

I'm curious as to why you would do this to a machine instead of just keeping it as a 600? Genuinely, I don't get it.. Care to enlighten? :)

cost of tyres for one, the 600 supersport ain't cheap whereas there's a lot of differnt styles of bikes in superlite/formula three so you can still play with someone somewhere through the filed, 450's are cheaper to register too.

[ellipsis]

I'm curious as to why you would do this to a machine instead of just keeping it as a 600? Genuinely, I don't get it.. Care to enlighten? :)

...liddler bikes is good...

[sharp2183]

I'm curious as to why you would do this to a machine instead of just keeping it as a 600? Genuinely, I don't get it.. Care to enlighten? :)

As above, cheaper race class, lots of competition in the field, use fewer tyres, etc etc. plus I’ve done 600s and thinking of something new.

[Mental Trousers]

I’m tentatively thinking of trying to pick up a 450 triple race bike for next season. Do these come up for sale very often?

And for anyone who has built them, what the cost to do a quality job (with a good tune)?

Mine cost very little to convert as I disable the fuel injection on 1 cylinder when I want it to be a 450cc triple and reenable it when I need a 600cc. If you go to JayCar and get some switches, relays etc you can set it up to swap backwards and forwards at the flick of a switch so you can run F2 and F3 in the same day. Of course gearing is a compromise. Best to put the switch somewhere you can't reach it when riding though to avoid allegations of cheating.


I'm curious as to why you would do this to a machine instead of just keeping it as a 600? Genuinely, I don't get it.. Care to enlighten? :)


my 12 year old bike (bought as a runner for $4000) is competitive in F3/Superlite vs finishing last all day every day in F2/600's
4 days for a set of tyres vs 1 day (600cc)
my engine was built 6 years ago and is still going strong because it's so understressed as a 3 cylinder it's ridiculous
the choice of aftermarket parts available is enormous compared to other F3 bikes
handling/suspension/tyres of a modern 600 vs quicky/hard to get stuff for other F3 bikes


That's a start.

[sharp2183]

Awesome info MT. I don’t suppose you have it tuned specifically for the 450?

What bike are you running?

[Mental Trousers]

Awesome info MT. I don’t suppose you have it tuned specifically for the 450?

What bike are you running?

It's tuned for 4 cylinders. Tuning for 3 only seems to be worth an extra 1hp if you're lucky. One thing the 450's do respond to is some ignition advance. It gives marginally more power (less than 1hp) but on the dyno the torque and power curves are much smoother and the engine just feels better.

2005 CBR600RR

[AllanB]

Hmm - it's a IL4 that you just stop injecting fuel into one pot to make it a 450 triple?

Presumably you still thrash it within a inch of the rev limiter in either format?

[jellywrestler]

Hmm - it's a IL4 that you just stop injecting fuel into one pot to make it a 450 triple?

Presumably you still thrash it within a inch of the rev limiter in either format?

that's a basic way of doing it, some remove the piston and put a balance weight on the crank and other things too

[Mental Trousers]

Hmm - it's a IL4 that you just stop injecting fuel into one pot to make it a 450 triple?

Yep.


Presumably you still thrash it within a inch of the rev limiter in either format?

Mines set to 15,500rpm and it's happy bouncing off the limiter all day long. Although that's not very useful as power falls off a cliff at 14,800rpm



Hmm - it's a IL4 that you just stop injecting fuel into one pot to make it a 450 triple?

Presumably you still thrash it within a inch of the rev limiter in either format?

that's a basic way of doing it, some remove the piston and put a balance weight on the crank and other things too

There's a bunch of ways people have done them


The original way was to plug the exhaust near the collector, remove the exhaust valves and plug the guides
Be lazy and do what I did, unplug the injectors on 1 cylinder from the loom then fool the ECU with a resistor
The Americans have often used a 5th set of injectors with a loop of tubing that connects to the inlet and outlet of the injector and filled with water to keep the injector from catching fire (none ever have but still)
The Americans have also been known to buy a second set of cams and grind the lobes off the appropriate cylinder, then disable fuel injection on that cylinder
Drill holes in the piston then add weight back in around the gudgeon pin
Because we can do anything we like to the engine in Superlite the most popular method here is to remove the piston + conrod and put a bob weight on the crank

[Dave-]

Some ECU's will throw an error code when they can't detect a coil/injector.

[Mental Trousers]

Some ECU's will throw an error code when they can't detect a coil/injector.

All of them do. Mostly we fool them. On the Honda's you can use a simple 360R resistor across the plugs on the loom side. GSXRs you can use an inductor (but it absolutely needs cooling) instead. With other machines it's easiest to use a 5th set of injectors. Or you can do the Woollich Racing thing and flash the ECU.

[Dave-]

GSXRs you can use an inductor (but it absolutely needs cooling) instead. With other machines it's easiest to use a 5th set of injectors. Or you can do the Woollich Racing thing and flash the ECU.

Totally curious now, how do you go about cooling them? rig them into the coolant?

5th set of injectors? huh? as far as I know the most "sets" you can get a 2 in bikes with staged injection?

What about the spark plugs?

Do you remove the 2nd stage injector too?

[HenryDorsetCase]

In terms of power do you get a straight up 75% of the 4 cylinder output (say 90hp??) or are there other losses?

[Mental Trousers]

Totally curious now, how do you go about cooling them? rig them into the coolant?

Using an inductor is rare. But the 1 person I know of who did this routed the wires to the front of the radiator and bolted the inductor on there so it was sitting in the air stream.


5th set of injectors? huh? as far as I know the most "sets" you can get a 2 in bikes with staged injection?

What about the spark plugs?

Do you remove the 2nd stage injector too?

Spark plugs stay in most cases. Still gets spark just there's nothing to light up. The spark plug hole is so restrictive it's a complete waste of time to remove it and take care of the air and oil pumping in and out. It was away from anything that could catch fire and the air was enough cooling.

So, as you know, a 600 has 4 sets of injectors. With the 5th set you unplug the injectors on 1 cylinder and plug in the 5th set, which aren't attached to fuel at all. They're simply there to make the ECU think there's still 4 working cylinders. Usually people cool them with a C shaped piece of tubing that attaches to both ends of the 5th injectors and fill them with water.

You have to do both injectors on a cylinder, otherwise it's not a triple.


In terms of power do you get a straight up 75% of the 4 cylinder output (say 90hp??) or are there other losses?

It's less than 75%, depending on how you disable a cylinder. The best 450 triples have the piston + conrod removed (no pumping or friction losses) and they get somewhere around 72%. They do vibrate a little, but nothing serious. Still way more reliable and cheaper than a suped up twin though.

[HenryDorsetCase]

It's less than 75%, depending on how you disable a cylinder. The best 450 triples have the piston + conrod removed (no pumping or friction losses) and they get somewhere around 72%. They do vibrate a little, but nothing serious. Still way more reliable and cheaper than a suped up twin though.

Or a 25 year old ex-streetbike that has had the tits thrashed off it....

[wayne]

would removing the camshaft lope and crank on missing cyclinder help with balancing ?

[Grumph]

would removing the camshaft lope and crank on missing cyclinder help with balancing ?

No. If you go the full crank plus a bolted on bobweight you can achieve quite good balance.
If you take an end cylinder off including removing that crank throw, you're left with a 3 cylinder crank which is out of balance due to:
1/ the phasing - 2 up, 1 down at 180 degrees. Big rocking couple as the 2 up are adjacent.
2/ all the bobweights are all the same weight. To work, the one odd one must be the same weight as the total of the other two.
Laverda made this work on the 180deg triples - the center cylinder is the odd one and it's bobweights match the total of those on the outer two.
It's in balance...

I was told of a 450 triple built by reputable people iin ChCh. The valves had been removed but the piston was still in place. Inlet and exhaust ports blanked off. The guides had not been blocked however so oil went into the cylinder and it had a habit of hydraulicing till someone realised....

[HenryDorsetCase]

Here's a stupid question: which cylinder do you disable? Like take a sawzall to one of the end ones* or something else?



*I know that is unrealistic. No one has that much RTV and spare bits of MDF to block up the holes.

[Grumph]

Here's a stupid question: which cylinder do you disable? Like take a sawzall to one of the end ones* or something else?



*I know that is unrealistic. No one has that much RTV and spare bits of MDF to block up the holes.

In theory, the one inboard of the primary drive is the best choice. The main bearing feeding that bigend carries a high load from the primary so if no oil is being bled off to the bigend, it should run cooler/better lubrication.

[Mental Trousers]

I was told of a 450 triple built by reputable people iin ChCh. The valves had been removed but the piston was still in place. Inlet and exhaust ports blanked off. The guides had not been blocked however so oil went into the cylinder and it had a habit of hydraulicing till someone realised....

Did that one end up with holes being drilled in the piston and tungsten being inserted into the wrist pin to balance it?



Here's a stupid question: which cylinder do you disable? Like take a sawzall to one of the end ones* or something else?



*I know that is unrealistic. No one has that much RTV and spare bits of MDF to block up the holes.

In theory, the one inboard of the primary drive is the best choice. The main bearing feeding that bigend carries a high load from the primary so if no oil is being bled off to the bigend, it should run cooler/better lubrication.

Most people have disabled #2 or #3. I had the opportunity to dyno my bike before the engine was rebuilt and we tested disabled different cylinders to see which would be the best. #1 was terrible (by comparison to the others) and it ran like shit, #4 was better but not as good as disabling #2 or #3. Probably different for other engines though.

[Roguenut]

It's tuned for 4 cylinders. Tuning for 3 only seems to be worth an extra 1hp if you're lucky. One thing the 450's do respond to is some ignition advance. It gives marginally more power (less than 1hp) but on the dyno the torque and power curves are much smoother and the engine just feels better.

2005 CBR600RR

Over in South Australia I'm thinking of doing the triple thing with my 2006 CBR600RR. Have you experienced any problems so far with that setup?

[Roguenut]

Over in South Australia I'm thinking of doing the triple thing with my 2006 CBR600RR. Have you experienced any problems so far with that setup?

BTW It seems like the original information on 450cc triples is no longer available at www.450triples.com but the Wayback Machine still has older copies.

Here is the method I plan on using (https://web.archive.org/web/20150328002322/http://www.450triple.com/build-method--3.html).

[Mental Trousers]

BTW It seems like the original information on 450cc triples is no longer available at www.450triples.com but the Wayback Machine still has older copies.

Here is the method I plan on using (https://web.archive.org/web/20150328002322/http://www.450triple.com/build-method--3.html).

Yep, that's me :niceone:

One thing that this engine seems to like is running 1+ tooth on the front sprocket and 3+ teeth on the rear sprocket.