1026

hauge

Well, time flyes.
I was colecting parts for 984 engine to my strada. However I ended up as a part owner on a st4s with a friend who needed some other parts, wich gave me a complete engine.
I´m going to use the left side on the engine from my 888 (alternator, cover, etc) and a "My Ecu" computer. Using the old alternator means I don´t have to replace the wiring loom.
The heads are sendt away for porting, bigger valves (32/38) and new guides. I´m going to put tb´s from 996 wich i will take out to 48mm. Not sure if I can use the 996 tps thugh. I got a spare as well so i might try to make larger butterflys and take it out all the way.

I had some problems finding the right timing gear for my old 907 ie crank (6 splines). The newer gears has bigger diameter on the crank. Gears from an ss600 would fit but does not have the sensor thing on it and does not have the same angels on the teeth.
I did find a new set of timing gear from an early 900ss wich has exactly the right gears except for the sensor. The sprocket from the pair in the 888 does fit though. I guess it wouldn´t be any problem whith not use a matched pair??

I´m going to Cartagena for 5 trackdays in march. Í don´t have time to finnish the engine before that as I have somother things to do with the bike as well.
WP fork, crasch bodywork, etc.

Some pics to be seen here
http://picasaweb.google.se/laverdahauge/Spritmotor#
(from now on I will write in english)

Cheers
Thomas

greenmonster

And Spritmotor means ethanol engine. 😏

What`s the problem w the 996 TPS?

lb980316

Nice Job , are you selling the front forks of the ST4 ?
Cheers,
MarcVSt

hauge

lb980316 wroteNice Job , are you selling the front forks of the ST4 ? Cheers, MarcVSt

I´ll check with my mate. I only bought the engine from the bike. It seems though that even the st4s fork have the dodgy rebound damping as the ssie bikes have.

Cheers
Thomas

marvin

The TPS from a 996 is the same as 888 TPS.

marvin

hauge wroteI´ll check with my mate. I only bought the engine from the bike. It seems though that even the st4s fork have the dodgy rebound damping as the ssie bikes have. Cheers Thomas

That dodgy rebound damping can be "fixed".

Desmoquattro

1026... hmm I don't think you will get more that 127 bhp... Then I will laugh in you face as I pass you doing a wheelie on my 848😝 😎

griff851

The heads are sendt away for porting, bigger valves (32/38) and new guides. I´m going to put tb´s from 996 wich i will take out to 48mm. Not sure if I can use the 996 tps thugh. I got a spare as well so i might try to make larger butterflys and take it out all the way.

I had some problems finding the right timing gear for my old 907 ie crank (6 splines). The newer gears has bigger diameter on the crank. Gears from an ss600 would fit but does not have the sensor thing on it and does not have the same angels on the teeth.
I did find a new set of timing gear from an early 900ss wich has exactly the right gears except for the sensor. The sprocket from the pair in the 888 does fit though. I guess it wouldn´t be any problem whith not use a matched pair??

Cheers
Thomas[/QUOTE]

We just had a talk about the size of the and the taper in the throttle bodies last week. Be careful, the tapered section is important. Bob has done the 1026 conversion on a 748, and has bored out the bodies to 46mm I think. The taper effects the smoothness of the transition as you open the throttle up.
As for the timing gear, it is pretty important that they are matched pairs. The teeth have been lapped together to give max contact with minimum back lash. If you use non matched, they will naturally lap themselves, and you will spread the case hardened filings all through the eng. You could get them professionally lapped, which is done in a special machine which high pressure injects the lapping compound. If they have the same number of teeth as 851/888, try Stefan in Germany he may have a set lying about. I just got a set for my SP4 crank, after looking into the whole matched pair bit I decided it was the best option. I did get a set of 748 gears but the big gear doesn't have the sensor tang.

Griff

brad black

any 907 or early 851 timing gears will fit - i think '91 was the update. or get a spacer sleeve made up for the 888 set. pete smith made one for me that i sold to phil costin that may now be with the guy in the uk who bought all phil's stuff. you just need a tall key.

hauge

brad black wroteany 907 or early 851 timing gears will fit - i think '91 was the update. or get a spacer sleeve made up for the 888 set. pete smith made one for me that i sold to phil costin that may now be with the guy in the uk who bought all phil's stuff. you just need a tall key.

Gidday!
seems as i have 4 options then. Find a set of gears for 907/851 or modifie the early ss gear kit i have (add the "sensor thing") or mix the ss/888 gears or make a sleve.
Absolut easiest is to mix ss/888 gears. Quite easy to modifie the ss kit. Making a sleve could be done in the "house" but im concerned about hardening.

Cheers
Thomas

hauge

griff851 wroteWe just had a talk about the size of the and the taper in the throttle bodies last week. Be careful, the tapered section is important. Bob has done the 1026 conversion on a 748, and has bored out the bodies to 46mm I think. The taper effects the smoothness of the transition as you open the throttle up. Griff

I´ve heard about people taking the bodies out to 48mm. I friend of mine had his tb modified with larger butterflies (54mm) and 50mm bodies.
I havn´t talket to the guy who is dóing the port job yet so I will se how it turnes out.
I do have a spare tb that i can play around with. Since im not going to race with the bike im not interested in losing any power in midrange.

Cheers
Thomas

brad black

the sleeve doesn't need to do anything, so it won't need to be hard. there's only movement there when the alt nut comes loose.

it might be cheaper to get some 749/999 throttle bodies if you want to go bigger and make them fit. or get the 54mm blades out of them and get yours bored if you want to stay with old ones. i don't know if you'll find any advantage tho.

hauge

brad black wrotethe sleeve doesn't need to do anything, so it won't need to be hard. there's only movement there when the alt nut comes loose. it might be cheaper to get some 749/999 throttle bodies if you want to go bigger and make them fit. or get the 54mm blades out of them and get yours bored if you want to stay with old ones. i don't know if you'll find any advantage tho.

The sleve is an easy option then. Thanks for the advise.

Fixing my tb:s is only a matter time (have a lathe). A freind of mine has a watercutter in his business so the blades is no problem either. A guy here in Sweden is a about to test his 996 heads in a flowbench (ported, 32/39mm valves, 54mm tb, etc.) so I can get an idea if I need it or not.

Cheers
Thomas

hauge

Got the pistons and rods in the mail yesterday. Just sendt i away with the crank for knifegrinding, polishing and balancing.
Also had som parts made modified with a watercutter.
Rear disc and caliper holder, fotpeg brackets and som sprocket lightned.

hauge

hauge wroteGot the pistons and rods in the mail yesterday. Just sendt i away with the crank for knifegrinding, polishing and balancing. Also had som parts made modified with a watercutter. Rear disc and caliper holder, fotpeg brackets and som sprocket lightned.

Forgot the pictures......😱

hauge

Finaly (after siezing (?) my crank bearings) I`ve spendt some time in the shed. The bottom end is now completed and is a mitch match of parts....
st4s crankcases with: 907 crank, carillo rods, 749 gearbox on 851 shafts, 749R and DP slipper clutch ss 600 alternator and st4s starter clutch, etc. The slot for thr closer shims where a bit low so I had to grind most of the closing shims down a bit.
I made a fixture for the lathe so its not that big bother.

Cheers
Thomas

griff851

Hi Thomas, brilliant. Putting the grinder on the lathe. Love it.

Griff

marvin

Hi Hauge,

Looks great! I would cover the lathe bedways up when grinding, very abrasive to the bed!

hauge

marvin wroteHi Hauge, Looks great! I would cover the lathe bedways up when grinding, very abrasive to the bed!

Yepp!
I just made a test since the shim kit i got is only step by 0,1mm and want to be able to get it as good as possible. I might need to improve my fixture. So far I have only tested the closing shim. I guess i need to make a new fixture for the openers.

Cheers
Thomas

hauge

I finaly (after a kithen and a hall rebuild) started to fiddle with my 1026 project again. I did get the engine in the frame in august but it wouldn´t start. It did backafire and I assume that the ignition timing is not corect due to the several differnt parts for the time gearing (old 6 splines 907 crank).
Anyway, I also had an oil leak at the transmision cover. I thougt it had to do with my gasket. I usual glue a gascet to the case and not to the cover. This makes it easy to remove and put cover back without any mess with liquid gasket.
It turned out the the later engines with pressure ragulater in the oilpump is slightly bigger tha the old ones so I had to mill a bit off the cover.

There is a 4 brush conversion for the Zane laverda starting engines. I thought I would make a similar conversion with mine. I turned out not to be as straight forwad as i thought. To get it good i need new brushes with longer conector wires and i also need to move the springs and mill of or somthing in the housing.
Mean while I´m going to use a later version of teh starter engine. They are about 10mm taller than early types. Any one knows how much more power they have??

I also made up a new bracket to be able to grind the opening shims in the lathe also.

Better get the bike running soon, going to Cartagena in mars again. I prefer to ride the 888 instead of the "Rain bike" 900ssie, even if its a good track day bike.

Last picture shows later version cover.....

Cheers
Thomas