What do you think: balancing crank needed or not?

hauge

Have a ST4s bottom with siezed big end if anyone is intersted, nut sure how complete.
Also have a complete st4 engine with pankl h-profile rods and HC pistons (balanced togheter..), might also be for sale.

jakepeewee

brad black wrotethe cases are the same casting. the difference is the machining for the cylinder stud spacing/cylinder spigot. 2001 onward cases are better, you'll need matching oil pump and primary drive gears.

Brad, thanks for the info.

Do I understand you correctly in that the primary gears and oil pump in my SP3 won't fit in the 2001 onwards cases? Will they fit in the < 2001 cases?

jakepeewee

hauge wroteHave a ST4s bottom with siezed big end if anyone is intersted, nut sure how complete. Also have a complete st4 engine with pankl h-profile rods and HC pistons (balanced togheter..), might also be for sale.

Thomas,
ST4s cases won't be of use for me since the stud spacing is too big for my 888 cilinders. I decided to go for the carrillo rods, so I am on the look out for a set of ST4 cases. But just the cases, not the rods and pistons. Well, perhaps the primary gear and the oil pump 😉

hauge

jakepeewee wroteThomas, ST4s cases won't be of use for me since the stud spacing is too big for my 888 cilinders. I decided to go for the carrillo rods, so I am on the look out for a set of ST4 cases. But just the cases, not the rods and pistons. Well, perhaps the primary gear and the oil pump 😉

hello!
I can split the engine for a resonable offer. I can check the engine number this weekend so we can see what year it is from.

brad black

the later oil pump has the pressure relief valve in the pump body, not between the cases. plus the 2001 pump spins a lot faster, with the speed difference in the drive gear and its matching part of the primary drive gear.

2001 has the large plug in the oil pick up screen and silver covers.

jakepeewee

Thomas,

You've got a pb

Regards,
Jacco

ajcorse

S4 crankcase

I used for my race 888 with 955 engin case from S4. There sure muss be used also oil pum from S4 and next problem is with flywheel. If is in case S4 crank from 851\888 and also complet flywheel and rotor then is small problem with size "width" flywheel. Flywheel need modify width min -2 mm becouse otherwise is nothing space betwen flywheel and bearing watterpump in cover.

Rest is okay. this case is strong an fine for race engines.

hauge

jakepeewee wroteThomas, You've got a pb Regards, Jacco

engine number:
ZDM916W4C*000590

stiglarsenDK

22520451A , ST4 from 2000

Have a NOS case set from st4 2000 (22520451A).. what the difference with 2001 ?

jakepeewee

hauge wroteengine number: ZDM916W4C*000590

How do we know what year the engine is?

hauge

jakepeewee wroteHow do we know what year the engine is?

I know its from an st4.
Otherwise there are desmoquattros with swing arm bearing in the case from moster s4 or st4.

ZDM916W4C*000590
916 is capacity, w is for water cooling, 4 is for 4 valve
I dont know about the "C"

brad black

c is the variant, the third of the 916 engine series.

#590 i would say is a 99 model.

jakepeewee

hauge wroteI know its from an st4. Otherwise there are desmoquattros with swing arm bearing in the case from moster s4 or st4. ZDM916W4C*000590 916 is capacity, w is for water cooling, 4 is for 4 valve I dont know about the "C"

Thomas,
Thanks for going through the trouble, as I understand it looks like a 1999 build.
At this early stage I will first try to locate used 2001 cases. I still got plenty of time. First I need to buy the carrillo's and get the crank balanced. I am in no rush especially since the money coming my way is sort of time related 😁

jakepeewee

Now I am feeling really stupid .....
I just saw a couple of pictures showing a single sided swing arm on the monster S4.

Now that would mean that these S4 cases won't fit the 888 chassis with the DSSA, or am I wrong? What am I missing?

stiglarsenDK

jakepeewee wroteNow I am feeling really stupid ..... I just saw a couple of pictures showing a single sided swing arm on the monster S4. Now that would mean that these S4 cases won't fit the 888 chassis with the DSSA, or am I wrong? What am I missing?

S4 shared swingarm w 851/888 ... will fit.. (S4RS has a single swinger)

nine16

S4R had a SSSA. S4 should be double sided.

brad black

all monster engine cases use bearing in engine style swingarm pivots, so all will fit the 888 swingarm. difference b/w s4 and st4 engines is the inlet cams. year for year everything else will be the same. st4 is variant c, s4 is variant d.

the 916 on sbk, mts and hm all use bearing in swingarm style pivot, and the back of the case is narrower at the pivot as well.

jakepeewee

Thanks for all the info and help. Just bought a pair of 2002 S4 cases from ebay.
As I understand S4 primary gears and oil pump are the same as from a 996, I can get a matching set of those here in Holland.

So now saving a little money for the carrillo's and the balancing and then hopefully the pricey stuff is dealt with 😁

BTW
Right now I use 15/39 sprockets for the final drive. Since the S4 will have a primary drive ratio of 1.84 in stead of 2.00 I will compensate this by going to 41 teeth at the rear. Gives me a little more top speed but no too much. And what a wealth of info on Brad's website, really really great!

brad black

you need 2001> primary drive and oil pump gears to spin the pump faster. not 1999 or 2000 996 or any other of those years.

jakepeewee

brad black wroteyou need 2001> primary drive and oil pump gears to spin the pump faster. not 1999 or 2000 996 or any other of those years.

Brad,
Thanks.
Just checked, gears and oil pump are from a 2001 996S so it should be fine (1.84 ratio).

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