916 motor to 851 Frame
 

Ok, another project I'm starting - but has anybody here fitted a 916 motor to an 851 frame ??? if so would you mind if I picked your brains - ta very much...
you know - p7 to p8, single to twin injectors, did fitting twin injectors have a major affect on the airbox, who made up spacers & bearings and did the machining on the 916 cases etc etc....
and no I don't want to sell the 851 and go buy a 916 :D

The ST4S engine has been made to fit, that I do know.
Don't know if the vertical head on the 916 will clear the suspension rocker - I think that's why the 4S engine was used as the exhaust cam is 20mm lower on that engine for just that purpose - the ST frame is a modified 888 one.
HTH
Andy

Yep,Rj is correct,St4 Mota is the way to go.

If you're doing it I've found out that the ST4S engine has the same valve sizes as the 996 SPS... swap the cams over & that could be fun!
Not that I've thought about it of course..........

I spoke to a bloke at popham who had a 916 lump in his 888 chassis actually.
Didnt talk about how difficult/easy though.

I have a 916cc motor in my 888, but it is done with a 916 crank and pistons in the original 888 cases. (Big end failure on original crank - no rev limiter you see!)

The 916 cases don't have bearings for the swingarm pivot while ST ones do.
I had to use 916 (ST4 actually) pistons as the 888 ones are the same bore but have a 1mm higher crown which would cause valve clearance problems. Valve sizes, cam spec etc is identical on 888 and 916 Bip.

This all used the original 888 wiring, injectors and P8 ECU, albeit with an FIM chip for an early 916 Strada and the whole bike is for sale if you want to copy it :lol:

If you have a read on the FIM website you probably don't want twin injectors unless you are going the full 955 SP/Corsa/120+ bhp spec.


Rob has put the ST4S motor in his 888 chassis and will probably be along with comments soon!

Paul

Neil,

What do you what to know. Easy job, well easy once you've cracked all the small issues. Get the ST4s engine from Jim at Bike Enders, and party on. Give me a call to discuss. 01202 693523

Yep..ST4s...Rob was kind enough to give me they keys to his bike for some spirited 'A' road action and the motor was fantastic in the T8 chassis..recommended.

Nat

mmm, typical me I've gone down a totally different route !!
just bought a new 916sp motor !!
Cases are going down to Baines for machining / inserting to allow the swingarm to run off of the back of the cases.
I'll fit up the 955 corse barrels and pistons, fit up a set of new twin injectors and it's sorted - just like that.
I still need a P8 though so if anybody is aware of anybody with a secret stash, let me know and I'll try to get them to part company !!
Boy am I looking forward to spring 06'
yeeeeehah

if it's a proper sp motor you should be able to bolt the barrels straight on. the cases are already machined to accept 2mm over barrels as std on sp's.

yup, you are correct the barrels bolt straight on - the machining I'm on about is at the back of the cases, they need machining for fit up of spacers/bearings to allow the swing arm to be mounted / pivot, as the 916 motor pivot point is totally different to the 851/888.
Baines do a kit for this and that's where the cases are going to for the swing arm pivot modification.
cheers

Neil

I would be interested to hear how it goes Neil. Roughly how much does the kit and installation cost?

I am planning on putting a 996SPS spec. engine in my SP3. I had thought of an ST4S engine with SPS cams, but if a modified SPS engine would work it might save some of the cost of buying upgrade engine parts.

Thanks,
Mike

you obviously have to take the motor apart as the machine shop only want the cases - so if you don't do it yourself there's a strip and rebuild cost at the very least + the bearing/insert kit which includes machining, Baines have quoted me £200 (only for the kit + machining).
I'll keep you updated as she progresses.
cheers

Neil

Please, forward your own experience ...
I'll stay attentive coz I didn't know about Baines modifications !!! Moreover £200 quoted is quite interesting !!!

That means an important modification of the original characteristics.
Does it mean that you're allowed to ride your lovely on the open roads regarding the insurance regulations or do you intend an exclusive use on circuits ???

the 916 engine will bolt in as the mountings are the same. there is no clearence issues but the swing arm will not fit. the 851 crankcases have an extra piece wich has bearings pressed into it. the 916 doesnt so the only way to do it would be to use a single sided or a 999 arm wich uses its own bearing system or fabricate the missing pieces onto the 916 engine.. the best way would be to keep the 851 cases and install the 916,996 crank shaft piston and heads. the 916 heads flow more than the 851 heads.... i once mated a 916 top end onto a aircooled 900 monster 2v bottom end and used an elctric water pump

What, what what ??? Sounds intriguing!

916 heads on aircooled barrels or 916 barrels and heads on 900 crankcases :puzzled::puzzled::puzzled:

You can use 888 SP 5 crank cases on the 916 996 lump seen it done several times. I know a lad with fully kitted 955 corse lump in his 888 and all I can say is YEAH BABY!!!!

yup, that's another way to go - use the original cases, which is just what I did originally. I had the cases machined to take the 955 barrels and pistons and ran her with a 916 crank, rods + 916 heads.
The issue was that I'd been looking around for a set of 916sp heads and just happened to come across the full sp motor. Having spoken to Baines I became aware that they could machine the 916 cases and insert some bearing/sleeve (?) to allow the motor to not only bolt straight into my 851 frame but also to allow the original swingarm to run straight off the back of the cases. Buying the sp motor has got me a close ratio box, pankl rods, nice crank, nice cammy heads and twin injector throttle bodies (my originals are single injector).
When I get the cases back from Baines I'll post up some pics.
In the meantime I've got some kit to sell:
motor, throttle bodies, wheels, forks, P7 ecu, full SP2 exhaust system.
I'll put up a seperate post with prices - no takers and the lots going to e-bay.
cheers

Neil