Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 851 / 888 > 888 questions ...

[Mr.R]

Hi, This has been one of the best threads for a while. Must i agree with lads who said building it yourself is 1/2 the FUN, although probably more than that for me, engine building has been my thing for a long time.
Mid 130s bhp motors? I must agree with Ains et al,likening them to a hand grenade with the pin 1/2 way out or a tune to far. Great FUNif someone else is paying for the upkeep. Having said that both Neil and Rob B wisely used latter/stronger cases/motors.
When Raymond Roach won his WSB champinship, it was said that they got through 30 YES 30 sets of c/cases!!!!!!!!!
With this in mind i set about tuning my "92 851 strada.I wanted sp4 type power with a broader spread and peak below 10,000rpm.
Despite all the bhp claims for these models,the real world figure is around 82rwbhp! (still enough for 150/1 or 2 mph).
A 916 set of heads....same valve sizes,but better/cleaner ports,
916 barrels,
853 pistons-lighter than 888/916 items,
851 steel Pankle rods-lighter/stronger than 916 items,
Ballanced 916 crank,better oil feed to the l/hand side of the motor,as in it's got some!!!!!
916 water pump-same 888/926/955 corse item,
916 oil cooler,
Alloy flywheel*,stm slipper clutch + plates,1/2 time wheels (sp4/5),V-TWO vernier adjustment camwheels,
V-TWO 604 cams-996sps rip-offs,
54mm single green top feed injectors,
Feul pressure bumped upto 4.5 bar,
Inlet stubs matched to suit,
Full 50mm spaghetti GIA-CA-MOTO high rise spaghetti system,
955 corse roller main bearings (not to sure about these now),
Full blue print,
FIM 916 open pipe chip-fim 061?,
Dyno set up by Steve "H" at Moto Rapido.
So how did i do???
All work by myself except Dyno set up and crank,pistons and rods.ballancing....J+J's of Swindon-----Very GOOD!!!!!!!
Well i said i would be happy with a strong 110bhp and i would be over the moon with 115bhp...........Well i'm not over the moon,but she made the base line at 7,100rpm,100 at 8,400,105 at 8,800 and 110 at 9,500 hanging on to that till 9,800 then tailing off to 105 at 10,700rpm.a dead straight line from 3,000 to 9,500rpm! Max Torque 65.5 at7,250 with a good spread till 9,250
Not the star ship enterprise......but i'm quite chuffed!This was with a standard 851 airbox....Top removed, ITG foam filtre
The mk2 is now on the bench...Sp5 heads o/size valves 35/31, long stroke 900ss crank,Ti Pankle( 748sps) rods and 748 close gearbox,works carbon airbox and "x" shape runners.955 pistons giving 984cc.
Well that's the short version....2 other Dukes to keep going and 6 children and ONE very understanding wife.
Steve Robins S.W.

[TP]

Originally Posted by Mr.R

Hi, This has been one of the best threads for a while....

I'm glad I can do SOMETHING positive on this website!

Still, thank you all for your input so far, it's one of my favourite threads ever. Heaps of good info.

I appreciate it

[jgriff]

My crowning moment on the S2 was taking out an R1 on the mountain, poor guy didn't know what was going on. Ah these young fellas with their new fan-dangled machines.
Yes I'm after a set of 748/916 heads for my 851. I'll just keep searching ebay, the best I've seen is US$280 for a complete set a few months ago. I already have 888 cases and SP2 gearbox, and balanced crank. And one day I might even put on 888 barrels. Oooooo!
Right now my mission is to build a machine be able to get past Blob (115kg vs my 75kg) on his 135hp 748. I think I have him on power to weight ratio.

Griff

[Mr.R]

This is a bit of a p.s anybody want to borrow my wife ? She's a star,she never blinked once.....
Steve

[851neil]

aha, Steve - got that 3 piece airbox fitted up yet ?? or is that part of your stage 2 project.
This is a really good discussion, from all of the chats I've had with peeps on / off the forum it's always been my intent to have a motor with a slightly lower state of tune - as such I have the 916SP cams in storage and will soon have a fresh set of heads to play with. I'll take these spares to the same valve spec as my current motor and have them re-shaped / ported but run softer cams. If push comes to shove I've then got some options to play with, next insurance policy will be a set of cases.

[851neil]

Steve, If your missus has done your engine work then she's more than welcome in the sunny NEast - take it she's leaving the kids at home then lol

[loony888]

g,day again guys,
for those interested, here's a run down on what's going on to my 888 donk as we speak.
FBF 12.4 pistons
carrillo rods
lightened and balanced crank ( with pistons, rods,primary gear,flywheel)
sps flywheel
STM slipper clutch
36mm inlet and 30mm exhaust ferrea valves
SPS T1 cams
portmatched and tidied up heads
1.00mm squish
3 piece c/f airbox with carbon ram tubes and ITG filter.
48mm ID "daytona" termignoni spaghetti system.
varijet regulator set at 4.5 bar
power commander and FIM chip for seperate cyl mapping.
i'll let you know what it's like when it's back together.
cheers,
paul

[loony888]

oh! if anyone is interested, my 888 strada had pankl sp H style rods fitted std, the motor did 23 thou klms and they are in perfect condition. i bought carrillos expecting to find ordinary macchi rods in there!!!

[851neil]

Paul, with that spec she should go really well !
Give me a clue about the fuel pressure though - are you going to run 1 or 2 injectors per cylinder ?

[loony888]

Originally Posted by 851neil

Paul, with that spec she should go really well !
Give me a clue about the fuel pressure though - are you going to run 1 or 2 injectors per cylinder ?

only 1 per cyl, i couldn't find an original twin set up so to overcome the shortfall in fuel req./injector open time i decided to up the pressure. typically, 888 and 916s on one injector can lean out at peak revs and with the max open time exceeding the available time the only other way to get enough fuel in there was to up the pressure.