Thanks mate, are they anything like the splitter boxes fitted to bevel twins? Anyone got pictures? WW
I DID split a set of std Mikunis Steve....and bought a set of short Malossi inlet tracts to fit onto the 620 engine.....I ended up using one Malossi inlet tract and one from a 900 ie....as the frame wouldnt allow the second Malossi to be fitted..I also had to cut out the crossmember to allow the carbs to fit.....to be fair, i never had enough time testing to get it set up properly..I used two opening cables off a std 900ss, but had to swap the adjuster to fit the Domino twin pull QA throttle........the bike was running pants tbh, but tahts cos I discovered a serious lack of compression on both cylinders and a damaged fuel pump connector...... I hope to get some time later in the year testing and setting the split carbs up......I'm sure they'll work well.......
I wondered what you were using on your dd bike Nog. They should work ok, they use them on lots of jap bikes on short manifolds. BSB taking all your time up then Mate ?
Well it is taking up more time than any previous season Steve, mainly as we are doing more testing........but I didnt have time to test the short inlet tracts mainly cos of Mum's illness.....and still sorting her affairs out now tbh....gotta get this house sold.......
A couple of points to make here, as for the motor not being able to make power on the long manifolds i strongly disagree, i have a 944 monster on long manifolds with 39 fcr's, the best this has seen is 102bhp and about 82 ft/lb at the wheel on SPR racing dyno, it was consitently making 99-100 bhp, dont get me wrong this did take some work. as for how it is on the road, awesome, without losing too much tractability. i do use this bike and have been on many long haul trips with this setup. as for the short manifolds on the same motor , i am trying to do this at the mo (see other post) as nog says above there is not a proper pair of manifolds to do this job and i have ended up making some from a pair of malossi bevel manifolds, the problem i came across was they point in the wrong direction and i did not want to cut the frame tube out, so by manipulating the malossi's i have got a pair of downdraft fcr41's to fit, and with the float bowls at the correct angle which i feel is most important, now i can set the front and rear carbs the same without compensating on the jetting for a difference in float bowl angle. cables are my next problem.......
Wow, that is serious HP for one of these old air cooled motors. Exactly what have you done to it for it to give those sort of readings? WW
This has been an ongoing project since i got the bike new in 95, i have had three engines up till now and am just working on the fourth. the 100 hp figure was achieved with 944 kit JE pistons that were reworked, carrillo rods and a reworked crank. head mods were extensive with a lot of hours of dyno and grinding here, i actually went through 3 sets of heads to get this right, i tried st2 cams and also vee two both showed merit but for max power the vee two cams won. also as said 39mm fcr carbs ( 41's lost 2 hp) on very reworked long manifolds, termig exhaust, and a silent hektik ignition. the ignition was the most important part as i could not get it right with the std or ducati performance boxes. i actually spoke to Nog yesterday about ignitions and suggested tcip, i may go that way on this new motor. the basis for the idea here was seeing an old battle of the twins racer owned by SPR Racing ( guys whose dyno i use) and figured that that would be brill on the road, they seemed to hit a max of around 95hp and as a side bet i took the 100hp challenge, it was all downhill from there.....
Like it, I'm currently in the process of building a 944cc for my Monster. For now I've got 94mm bores, JE pistons, gasflowed heads, ST2 cams, Ignitech ignition and split FCR 41s on short intakes but other internals are standard. I would love to achieve 100hp but was thinking mid 90s was more realistic. What work did you do to the crank & heads? Did SPR do any of the work? I've heard nothing but good things about them and they're nearby to me, I may have to pay them a visit...
Good questions, as for SPR doing any of the work i will say yes, we are actually working in conjuncton on this, i use the dyno and they gain the knowledge, they are all very well capable mechanics with extensive ducati knowledge and ducati enthusiasts so we all seem to muck in, so to speak. this works well for me. The heads were machined for different styles of valves, these all gave differing results, i settled on a pair of 44mm inlets from ferracci, i used stock exhausts. there was extensive mods to the shape of the port and to the valve area. For my latest heads i have got some 45mm valves from brook henry in austrailia and am going to try these with the short manifolds and fcr's. As for the crank, SPR took care of that with a balance, light polish and slight knife but left at the stock weight. over the years i have found the balancing critical for max power as any vibration is power lost, also at one point we run one without balancing with giocamoto pistons and it split the cases quite badly. I have purposely left out some of the critical detail here with what has been done as these guys do this as a professional service to racers and private customers so there must be some confidetiality. i am sure, ducati or otherwise they would be happy to help any fellow enthusiast with a similar project, and without stupid prices.
Great stuff, I've come to a bit of a stop at the moment as I have all the parts ready to assemble but thinking that I should go a bit 'deeper' now that it's apart and although the bearings etc seem good it is an old engine so would certainly benefit from some TLC, especially neccessary if trying to maximise output. Also I have a lot of 'unknowns' as this is my first attempt at building a 2v Ducati and I wouldn't like to make a any silly mistakes or overlook something important, plus this bike has already cost me a fortune so in for a penny etc... I don't know SPR but they are local and it sounds like they may be just the expertise I'm looking for.
Loving this thread. I'm running a '94 900ss with a CJS tuned engine, blueprinted, big bore (944), HC pistons, ported heads, billet alloy clutch, lightened flywheel and FCR 41's on standard manifolds. It was Pablo Pirates old engine which he had dyno'd at 89 HP with FCR 39's. I'm hoping for around 90 HP once I've had it set up on the dyno. As a road bike it is pretty much flawless as it is but I may go to split FCR's on short manifolds at some point in the future. It would be great to meet up with the owners of other modified 2V engines bikes to compare notes. I organise the DOC Southern rally down in Dorset, in September. Anyone fancy meeting up? WW
Hi Chris, I'm frantically trying to get my 851 ready for the southern rally! I'm struggling to find a front subframe as the one i have (1989) is different to the 1991 onwards one. Steve
