Has anyone had clutch or gearbox failures

 

Hi Graham
I have just got a gearbox failure at 84000 miles
The problem is when I change up to 4th gear it jumps back out to neutral then to 3rd.
I can bypass 4th and 5th to 6th which is ok but if I change down to 5th it will bounce around untill it gets down to 3rd where it will stay.
I am hoping this is just selector fork and drum problems
Paddy

 

I can't take my Bird into "never-never land". So I'm no help. I'm not sure what you are trying to build there. Do you want it to be streetable and good for the drags as well. Regardless of how stout you build that engine, it must have a breaking point. I'll re-visit this thread when those who turboed their engines chime in. Good Luck

 

Building my BB to be completly road legal but taking it as far as I can with the buget and skills that I have. After seeing and hearing the valve failure on the test motor, My answer to the valve problem was to fit drop forged stainless steel valves with Ti retainers and up rated springs.

 

Hi Graham, I have had no problems with clutch or gearbox.However I did have a standard conrod break last year whist revving to about 10,000.The motor had previously had a hard life in an off road car(rally cross I think its called) and developed 167 rear wheel HP.The motor in the V&M develops 183HP and is fitted with Carillo rods.Thanks for your call re carbon bits.Ray

 

I've managed to destroy the shells in the big end of No 3 piston and have damaged the carrillo rod and crank in the process, don't want to hijack the thread but does anyone know where I can get a single carrillo rod for my bird. Or should I get away with standard rods previous dynos were at 183.4Rwhp with it being remapped to rev to 11800rpm?

oh and anybody know where I can get a new crank:idunno:

Just for info the damage was caused by oil starvation after the bike had consumed 2.5 litres of oil doing 150miles on a track day. being on a track day the bike had regularly been on the limiter and had consumed the oil due to worn valve stem seals and much high revving engine breaking:crying:

 

99.99999999 % of the 'Birds out here will never see that sort of stress and we don't want to push that hard ............. cause we love 'em :inlove:

 

The retainers are apparently known to not hold in high hp motors.If you hit 200hp I doubt the clutch will hold but it might be fine.This is the man who knows all about Blackbirds Welcome to EFR Enterprises, Inc. -- Specializing in Turbo-Charging and Cycle Upgrades It was Elton who told me about the retainers.Mine only has 150 hp so no worries about valves or clutch.
Al

 

I havent had mine anywhere near 9 or 10,000 revs and probably never will. They cost to much to fix when they blow up. Mine has been pampered all its life and will stay that way so I can get the maximum life out of her.

 

Thanks for the info . I'll check out the link. Have already fitted kevlar and stainless Clutch plates with up rated springs.
Ray can you tell me which rod let go please mate.
Cheers Graham

 

Number 1 rod let go. The conrod exited the case at the front ,dented the exhaust and disappeared into the bushes-never did find it.As the gudgeon pin was intact it was apparent the rod had sheared through the small end oil holes.I am pretty sure fatigue (and not oil starvation) caused it because the crank was unmarked.

 

Graham, my BB suffered engine failure. I don't think it was caused from pushing it to its limits but the exhaust cam cracked and as a result it cracked the camshaft cover. Since then I have replaced the motor.Just to be safe I don't redline her anymore.

 

Sounds like a flaw in the cam when it was made.

How many miles did you have on the bike when this happened? How often did you redline the bike? Was the engine warm?

I have 15,000 miles and redline one or more times every time out just to clean out the cob-webs.

 

Thanks guys from the info , If possible do you have an idea of the engine load at the time of failure.
Cheers G

 

My younger bro was driving it on the highway and I'm sure he was pushing it. The whole story is in the Engine/Airbox forum under engine transplant.

 

Hi Graham, I am looking at the dyno readout for the engine that threw a rod at abt 10,000rpm.It was developing 167.7RWHP at 9883rpm and 99ft.lbs at 7026rpm.

 

Thanks gran1943bikes for the detailed info, also thanks to docsevicz , had a good read of engine transplant. It' s all going into the data base I am building up. Cheers G

 

Mine crapped out due to detonation at around 1000 miles. Had her rebuilt with Falicon crank, Carrillo rods, JE pistons. That was 28000 miles, 270+ HP, and countless dyno runs ago. Did a comp test last year and was still within 5% between the cylinders.
Not sure what the HP limit/time is as I haven't found it yet.

 

Pictures of this unit?:huh:

 

Any one else got any info

 

Gearbox problems on my 97 bird. At about 68000ks was jumping out of sixth gear. Had to replace 5-6 cog and selector fork for same. Dogs were worn and forcing out of 6th gear and loaded up selector fork causing it to wear away. Only those 2 parts replaced and rest of box looked new no noticable wear on any other dogs or parts. On the upper gears there are only three dogs on the gear. on the lower and first there are 5 dogs to engage. So I reckomend for longevity of gearbox to avoid clutchless shifting. No other problems since then and now has done 97000ks. Oh and regularly pulls 11000 revs 1st and 2nd gears and no problems yet. Owned the bike since it had about 60000ks on it.

 

Well, I can add some data to this thread, unfortunately. :crap:

I have been pushing the XX motor for a few years now, somewhat out of curiosity as well we intent to just make a stupid amount of horsepower. I can tell you that I have heard (I think Elton told me) that the clutch basket and valve spring retainerss have shown as the 1st weaknesses in the motor and tend to give out before 200HP. The next is the valve springs at higher than 11,000 RPM. Next are the rods, which supposedly start to fail over 225 HP, next would be valves, which tend to fail once you have put heavier springs in there with heavier retainers. I know a couple of guys who say that they are playing with stock pistons while nearing 350 HP without issue. They are forged, after all, so they may just pretty bullet proof.

I did not push the stock rods at all, I replaced them with Carillo's from the very start knowing I would easily push past the early limits. Same thing with the pistons and clutch basket. I increased valve seat pressure (by increasing from stock to stock + max boost PSI and then adding a couple more PSI to ensure they didn't ever blow open.)

I can tell you I did drop a valve, it looked like the shaft literally sheered after several hundred dyno runs, they were stock. I would definitely replace the stock valves if you are going to push high RPM or power out of the motor.

I can also tell you that under high boost that the cylinders started to move around a little, and Kent said that it would occasionally balloon out the sides a bit in the squish area, which is solved by a bit of skilled machining and a reinforcement plate being inserted.

The transmission seems bullet proof as I have not had nor heard of one failing. In fact, they take the 'busa output shaft and replace it with a billet version that is the same dimensions of ours and then use XX sprockets, so you can trust the transmission from the factory.

My bike does have more 'busa parts than 'busas have XX parts, but it was nice to give a little something to the pool, if you know what I mean.

 

with heavy duty clutch spring and a billet basket i was using stock honda plates on a low boost tune on my motor...that was making nearly 350 hp. at that point i was actually running a completely stock trans as well and it held up just fine. if you plan on running higher rpms i would definatly suggest sending your crank off to someone like falicon and have them do their things to lighten and balance the crank, and also increase the size of the oiling holes. elixxer is your head studded? i somehow never saw any ballooning in the cylinders before this last rebuild but i did run into a few problems with the compression actually pulling the stud threads out of the cylinders. ive also heard some of the big motor guys say that the stock airbox is only efficiect till bout 180hp and a sealed and slightly modified stock box is only good till round 190-195 after that they went to a sheet metal intake.

 

I am using stock head studs and have pushed extreme boost through this motor. The main thing that would cause you to rip threads out would be that you either had too much timing in the motor or ran it too lean and had detonation issues. Up to 350 HP, you shouldn't have to worry about cylinder ballooning if you have a safe/good tune up in it. It was over 450 that it would start to happen, again, according to Kent Stotz. (I live less than 30m from Kent and about 45m from Elton, I have picked their brains a lot over the last 4 years or so.)

 

kent and elton both know this bike inside and out. in theory on full boost my bike will put out 500+. last tuning session i made 479hp on 23 pounds

 

So how much over stock bore and/or stroke are you? (Or are you using nitrous?) What's your CR?

I've been down every path with this motor, including methanol, and 23 pounds is less boost than this motor would normally take to produce that kind of power, should be close to 30 on stock bore, lowered compression at around 11,500 RPM, and even there it would be running dangerously lean or with a few degrees of risky timing.

The only way I safely made about that kind of power was when I had a full ice cooler (63 degree intake temps) or when I ran methanol on a stock bore.

Before you get defensive, remember that I have the man behind the highest horsepower 'busas in the world designing my system and the best tuner in the world (Job Spetter Jr.) doing the tuning.

So, how do you explain that you are making 70ish more HP than you should?

 

Thank guys this is just the sort of stuff I've been looking for. Cheers G

You know what they say. Speed is just a matter of how much money you want to spend.

 

the bike is built with the intention of drag racing and actually looks very similar to your bike cept in a very deep dark metallic red. the bike will actually safely rev to around about 13250, but my rev limiter is set at 13,000 and will be shifted between 12,500 and 12,750 depending on how quickly i can hit that button. over the past two years i have tested numerous combinations not only to find the best combinations for peak horsepower, but also to find the limits of the motor so i know what not to push for when actually racing. id much rather poof a motor in a dyno room then on the big end of a track @ 180+. finally my bike is together again going in for the final tuning session at the end of next week and well see wat kinda number i get on 31#. hoping for 515ish, then just gotta find a track that can hold it!!!

 

We have a lot in common -- if we joined our efforts we could probably save many $$!! ;-)

 

haha we should have formed an alliance 2 years ago and skipped a few headaches

 

Hey xx2wheelin,if your up for a drive,Grand Bend is hosting Canada's fastest streetbike shootout next Sunday.Which usually brings Phil Stoll,Ronnie Mitchell and some other heavy hitters up here.I heard Kent came up here for the original Aug 10 date which was a total downpour and can't make the SEPT 7 date,major disappointment for me.

The track is awesome,Stoll has run 7.47 in October here.It was in the low 50's that day,don't know how he got traction.

 

Not to jack this thread but I was wondering if Phil Stoll showed up to this?
He's my cousins son. His Dad used to be quite the racer himself.