Articles & photos


Making a Buell S1 88 CI a reliable daily driver

31-10-2013 - Ongoing project to make a powerful Buell S1 88" last longer than 6000 km

This bike was build many years ago not by us It has lot's of good parts Baker 6 speed, Zippers high flow oil pump, and after a long history of pulling out cylinder studs and eating big ends pins in very short time, the owner was fed up with it, and the bike was put aside for a long time.
We took up the challenge to make it good and reliable and powerful Buell S1. That you can use as a daily driver. 
So stripping the engine, 7 years ago it was already determined there was mayor damage, as the engine oil came out like glitter paint.
The first strange thing we did noticed was the huge amount off play on the main shaft bearing in the Baker 6 trapdoor. That could not have happend in 6000 KM.

The bearing is actually hanging loose in the trap door, and the main shaft is loose in the bearing, bad bad bad.
this can be a cause of being taken apart to many times, This can also be a cause off a very powerful engine and very light flywheels not being able to
dampening the drive force from the engine ?

What also was strange, we normally see the front big end bearing go first, but in this case the rear one has gone first. This is not making sense.               
There where also bad markings on bought front and rear cylinder and on both off the pistons.
Also the cams have a little dammage on it we will replace them to.
Now the next step, heads and piston dome volume measuring to see what the compression ratio was this baby was running at.
We are ready to CC the piston dome
We are almost there
We are mesuring the CC for each cylinder head.
We measured a little differance between the Front and Rear cylinder heads.
The dynamic compression is a little on the high side for a daily driver. The customer told us about the engine was pinging a lot,
this could be a the cause the rear big end is gone as the pistons are in the middle of the piston and not out off center. But so far we have not seen fysical real pinging damage. 
typical markings on the pushrods, they will be replaced by thinner ones made to lenght
one valve seal was loose and was making noise
Pro flow oil pump , did rotated a little difficult , so we took it apart ( not a easy job ) 
a little ware on the presure part 
as exspected much more ware on the oil pump return as it catches the debries first  
main return gears
nice crank and rods,  light and knife edge , heavy duty connecting rods
Took the flywheels apart to see the big end pin 
nice ware pattern, on bottem dead center rear cylinder 
the connecting rod races have little dammage 
race dammage only on top side, the rest off the races look visualy ok, i'm pretty sure there out off rond when we are going to measure theme  
possible culprit , 2 hole big end pin was used
Aluminium rol cages where used, and recces cut in the sideplay washers
the oil chanel alinement is not perfect, a 3 oil chanel pin would have been better
dammage to the rols
you can also see the rolls did not run on the whole surface
some numbers we measured
front cylinder head 69 CC  rear head 70 cc
volume 1 inch down 193,4  ( dome volume - 6,19 cc )
head gasket 0.045"
cams 585
calculated not really high compression ratio, need to measure the squis band to see what is happening there  
Little slow progres, after the holidays catching up with work,

Customer decided to go ahead with a further customizing as taste can change over the years.

Frame new color needs to become red,  cut the pillion seat pegs off the frame

Paint work, cleaning up the electrics , get right off the fly screen

So further strip down was needed


Customer decided to go ahead with a further customizing as taste can change over the years.

Frame new color needs to become red,  cut the pillion seat pegs off the frame

Paint work, cleaning up the electrics , get right off the fly screen

So further strip down was needed


On the engine, still debating the if and watt’s

Measuring up a 2008 xb / XR1200 crank, and see if we can make it fit in there,

( 2008- Xb / XR1200 crank have a 1,5” O.D. crank pin )    

this bigger O.D. big end is making this crank very strong  


frame further strip down

14-2-2013 Little update:
We disassembled the complete engine. After that we found so many stuff that was incorrect, that we didn't even start measuring anymore.

The heads squish band was not set good. So basically it was making two compression zones in the combustion chamber.

This explains the pinging the bike was doing. Strange was it was doing that with basically low static / dynamic compression numbers.

We measured up a 2008 - up  crank shaft but the weight difference between the stock pistons and the 88" pistons  is too much.

So there is a need to balance the crank,  next to the fact lots off machine work needs to be done to make it ready to accept crank bearings,

With no oversize 1.5" big end pins / cages and rollers , pressing apart the 2008-up crank is not really advisable for this solutions.

Update 26 februari 2013
The Frame came back from the powder coater:
8-5-2013 And some more progress to get this bike more relaiable:
For all Buell and Sportster models with 1,25" crankpin ( bolted or pressed )
Developed for maximal roller use and a tight fitting rol in compairement to the old situtation where the bearing rol can move around to much in the cage.
Because the new design off the cage we manage to house 1 rol more in the cage the new rollers are also as longer as the stock roller, there by giving more bearing surface and so reducing the surface destortion from the crank pin, making it last longer.
As always with a repair like this, the outer rod races should be checked for ware , replaced and made to size
In stead off 17 we use 18 rollers. Also the rollers we use reach 30% more surface. The short roller in the picture is the stock version the longer roller is our new version. The roller cage is made of very nice bronze material. 

Update 7-9-2013

Developing and making thing in productions takes time, better make the good the first time , and be very sure about it

So a little update,

Big end cages are ready , so the crank was rebuild

New sideplay bearing shims made in the flywheels, to prefect fit the connecting rods giving theme good side support
New Big end Pin and new cages
Rod races replaced and made to size
looks perfect to me
Update 30-11-2013
Finally everything in the cranck is repaird and it took us a long time. This engine was also the prototype we used to develop the new cranckpin solution. But this has a new bigend bearinga and a rebuild cranck we developed and repaired like we would.
This is a long term project but we get there.