My B4/B5 Project

[Bartjan]

my bandit 400 is gonna become a bandit 500 with 498cc instead 398cc.

how its gonna happen:
- 45,2mm GSX400F crankshaft instead of the original 40,4mm
- 59mm pistons

these earlier topics started it:
stroke enlarging?
here is the crank to stroke your bandit or gsxr!

plans for the future:
- RVF400 swingarm with Ducati 996 rear wheel (alreaddy have the swingarm, wheel, disc, brake caliper)
- VV head (alreaddy have a generation1 head and carbs (with throttle positioning sensor) and generation2 wiring loom with cdi   )

ill keep the 1st post (this one) updated with changes

Last Update: 4 sept. 2007
ps. most pictures are clickable to see larger

done so far:
ordered and received alot of stuff like:
- 3 crankshafts (2 are still in the UK, other one is here but took 2 months to arrive from japan)
- 4 pistons 59mm
- gasket set
- yoshimura exhaust
- gsxr400 cams (also still in the UK)

1st i cleaned the exhaust and mounted it.

2nd picture is during cleaning, the left 2 pipes were cleaned the other werent yet
i used harpic toilet cleaner, gloves and scotchbrite to clean them (be sure to dry good after cos the toilet cleaner will make it rust really fast)

for the people interested in difference from the standard exhaust; i dont have any dyno runs, but i can tell the next best hp-indicator....     top speed
top speed was about 165km/h, once it did 172km/h with wind from behind and slightly downhill
now i can reach that going slightly up with the wind coming from the front. when i had the wind from the side it went 180km/h no problem before i had to break for a car...
note: these km/h-numbers are actual km/h's taken from a digital km-counter, the standard B4 km-counter says im driving at about 125miles/200km an hour when i reached the 180km/h

some pictures of the gasket set


some pictures of the gsx 400f crankshaft

some fast measurements

compare with B4 crank (thanks Jay for the picture)


as seen there are some differences which have to be solved.
things that have to be done:
- i need to machine the left side of the crank to make it shorter
- i need to machine a piece to go to the right side of the crank to be able to use the flywheel (or run without if its for race use, like Jay does)
- i need to machine the conrods or get other/custom pistons or get other conrods, cos the gsx400f have 14mm small-ends instead of 16mm

today i thought about how to solve the problem of the conrods.

the gsx400f conrods have the following measurements:
small-end: 14mm
big-end: 35mm
heart to heart length: 97,1mm
standard Bandit 400 conrods:
small-end: 16mm
big-end: 32mm
heart to heart length: 93,5mm
yamaha fzr600 conrods i have lying around:
small-end: 16mm
big-end: 32mm
heart to heart length: about 113mm

also the gsx400f conrods are wider at the big-end then both the other 2

problem is my pistons have 16mm pen's so there are a few solutions:
- use the gsx400f conrods. they would have to be bored (there is enough flesh since the outer diameter is the same as standard B4 rods) to become 16mm. since the rods are 3,6mm longer and the pistons would go 2,4mm higher (thanks to the longer stroke) the cilinders+head would have to be raised 6mm. now my pistons are 1mm shorter so that makes 5mm for me. this is not difficult to do, but i need to check if the camchain is long enough.
- use the gsx400f conrods and use a 14mm pen with 2 outer "busjes" (english name:bushes thanks Banditmax) to get the 16mm piston to fit on the 14mm piston-pen. same things happen as option 1 but also there are more difficulties.
- use the standard B4 conrods. problem is they dont fit and there is not enough space to enlarge the big-end. the crankshaft big-ends could be cut smaller to make it fit, but this would make the crank alot weaker. big advantage of this solution is the the big-ends could be cut excentric to increase the stroke even further to a possible 48,2mm which would give 527cc with 59mm pistons. something for you Jay?? cilinders+head would be have to be raised 3,9mm (or 2,9mm with the pistons i use)
- use the yamaha fzr600 conrods. nope cant be done. same problems as the standard b4 rods but even longer.
- get other conrods which do have to correct sizes. anybody know any rods with 16mm small-end, 35mm big-end and a heart-to-heart length of about 93,5mm?? maybe rvf400 rods would be good?? titanium would be nice aswell  
- or i could get pistons with a 14mm piston-pen, which means i would have gotten these pistons for shit and i would have to search much more. but if someone knows any (more or less) 59mm pistons with a 14mm small-end. let me know

a picture of the standard B4 conrod


two pictures of the pistons.
the left one is standard B4 piston and the right one is my 59mm piston.


if i were to only mount these 59mm pistons, the compression would go down to 1:10,9 thanks to the fact that they are 1mm lower.

update 2:
i took the head and cilinders off my engine and saw how much the head can rise before the camchain says its too much...
the camchain would allow maximum of 3,5mm rise to be made as you can see on the pictures


3,5mm isnt enough to use the gsx400f rods except if i were to shave some 1,5 mm of the pistons.
it could be done but i would have to find out if the valves wont touch the pistons.
another and better option is to extend the camchain. increase the size by 1 link which will enlarge it about 1cm which means it possible rise-distance will increase half of that  
btw camchain 20 links are 141mm, service limit is 143mm. does anyone know what it is with a new camchain?

the boring of the cilinders to 59mm will be done next friday. and friday i will get my old engine (which has blown up) at the workplace to make everything fit without having to take my good engine further apart yet.

now the engine looks like this:


anyone know of another camchain which is longer but has the same other measurements? maybe gsx400f or a gk71b? i dont have the manuals...

[gsxr400 racer]

this should be interesting but i think your gonna shoot your self in the foot with the rvf swinger

[Bartjan]

who knows    
it will take quite some time before i start working on that anyways and if i dont like it i can always go back to the original

[Bartjan]

update 1: see 1st post

[Banditmax]

How about turn some bushes for the piston pins to take the hole in the 59mm piston down from 16mm to 14mm? Then use 14mm piston pins into your rods?

[Bartjan]

yeah thats what i meant with the 2 outer "busjes" (option 2)

problem is the rings that keep the piston-pen from leeving the piston wouldnt stop a 14mm piston-pen. so these rings would have to be bend inward.
and in the bushes there would have to be holes for lubrication.

it can be done, but removing some "flesh" from the gsx400f conrods has my favor because there is less that can go wrong.

update 2 done

[Bartjan]

the same type of cam chain that fits gsf400/gsxr400 (215 FTH) isnt the one that fits the gsx400f (SCA 0412 DHA).
so i need cam sprockets that go with it before i can proceed, which isnt a problem but is gonna take some time...

in the meantime ill go 442cc and ill see what the crank does in my (old and broken) crankcases.

updates will follow

[Bartjan]

as you can see the gsx400f crank hasnt got much problems fitting in the gsf400 crankcases.

however 2 more problems have risen...
- the sprocket going to the clutch is wider and touches the crankcase. this can be easily solved by grinding 2mm's from the crankcase.
- the tooth on the sprocket going to the clutch have a different angle so the gsx400f clutch basket is needed (and im gonna hope it has the same diameter as the gsf400 has)

i will update this in the 1st post when i have more time

[Bartjan]

was searching the internet for a gsx400f clutch basket, but found something more interesting.
so last saturday i bought a complete gsx400fw engine for the same amount of money a clutch housing would sell for  
the gsx400f is suzuki's 1st 16 valve 4 cilinder 400cc machine and it was aircooled. the gsx400fw is its successor and its liquidcooled. the gk71b engine is the gsx400fw successor and then we have the gk71f and after that the gk73/B4 and the 76 after that (i think).

only thing ive done so far is look in the cilinderhead to see which camchain it used and i saw it used a different chain from both the gsx400f and the gk71f/73/76/B4 engine.
but i now have both the correct cam sprockets and clutch housing to go with that crank. so tomorrow im gonna take that engine apart to see if its going to fit

[Bartjan]

while taking apart the gsx400fw engine i saw it had the same angled tooth on the crank, so i figured it would work with the original clutch.

but then  

i found out Jay and me made an error while measuring cranks and it turns out the gear on the crank have different diameters...
cant use the gsx400fw clutch cos its way bigger, cant use either gsx400f or gk71b clutches cos those are the same big-ones.

so 1 option remains:
put new teeth on the original clutch-housing  

interesting crank facts:
- gsx400f has the same crank (and rods) as gsx400fw and gk71b, except for the smaller diameter sprocket and the angle of the tooth on the sprocket.
- gk73/B4/gk76 (40,4mm) crank has even smaller diameter sprocket then gsx400f crank has.
- bearings distances are all the same
- the 45,2mm cranks have bigger and wider big-ends and the conrods have 14mm small-ends
- gsx400fw and gk71b have the same angle on the sprocket as the newer 40,4mm cranks, but it doesnt matter cos there gonna have to be new tooth on the clutch-housing for it to fit with all 3 cranks.
- there might be a crank available which would be even longer. it would make 600cc possible, but im gonna investigate it some more.

since i bought some crankcases ive got enough parts to build a 2nd engine, so i can insert the 59mm pistons and drive while working on the longer crank in my 2nd engine.
takes the time-frame away i was working in  

[gsxr400 racer]

i found out Jay and me made an error while measuring cranks and it turns out the gear on the crank have different diameters...

Well that sucks but we both know its possible as there are people running on the street this way and thats how suzuki dominated factory racing in japan in the 400 series.
cheers
Jay

[Bartjan]

well like i said ill calculate (finally using my education properly) some new teeth for the clutch housing and ill have to find some company that is able to make it.

crank/clutch-gearratio will be longer though, but thats not a real problem since the extra cc's will favour a longer gear  

in the meantime the 59mm pistons are in the engine and the B4 is almost ready to fire up again

[VinCBR900]

Progress?

Is the GSX550 crank a possibility also?

[gsxr400 racer]

Progress?

Is the GSX550 crank a possibility also?

i always thought so the piston pin diameter was the same i just never had a 550 crank in my hand

[Chris H]

www.staniforths.co.uk/catalogue
If you click on chain& sprokets there is a section at the bottom of the page covering cam chain that may be of some use.