Engine project

[Jeff H.]

I've had the Duc in pieces all winter having the engine rebuilt and some other stuff done. Thought I'd check in with some info on the progress so far.

The cylinders were sent off to Millennium to be bored out for some Pistal 944 11.5:1 pistons. Heads were sent to Jeff Nash at AMS to be ported and polished. The crank and rods were sent to Nash as well for lightening, balancing and polishing. We kept the stock cams, but degreed them properly. The shop had an older DP full stainless system, for a Monster, that we ended up installing. The midpipe had to me modified, but I think they got it just about perfect. Nichols engine bolts were installed as well.

The jetting and ignition timing still has to be sorted out, but I took it for a spin around the shop a couple times and it really scoots. I'll be sure and post dyno numbers once we do that as well.

I hadn't intended for the project to get this extensive, but it seemed like we kept finding things to do and parts to toss in the mix. I had been saving up for this kind of project, so I feel OK just getting it all done at once. I've had the Duc for going on 10 years now and I think it's the perfect bike for me...especially now! Here's a couple pics I took with my camera phone when the exhaust was finished...this is right after we discovered that my Ohlins had sprung a leak over the winter. Doh!

I got a lot of helpful advice over the winter from Bruce Meyers, Nash, BCM, Ducshop, MBP, Ducati Seattle and Chris Kelley. Awesome resources!

Regards,

Jeff

[mellocervelo]

Originally Posted by Jeff H.

I've had the Duc in pieces all winter having the engine rebuilt and some other stuff done. Thought I'd check in with some info on the progress so far.

The cylinders were sent off to Millennium to be bored out for some Pistal 944 11.5:1 pistons. Heads were sent to Jeff Nash at AMS to be ported and polished. The crank and rods were sent to Nash as well for lightening, balancing and polishing. We kept the stock cams, but degreed them properly. The shop had an older DP full stainless system, for a Monster, that we ended up installing. The midpipe had to me modified, but I think they got it just about perfect. Nichols engine bolts were installed as well.

The jetting and ignition timing still has to be sorted out, but I took it for a spin around the shop a couple times and it really scoots. I'll be sure and post dyno numbers once we do that as well.

I hadn't intended for the project to get this extensive, but it seemed like we kept finding things to do and parts to toss in the mix. I had been saving up for this kind of project, so I feel OK just getting it all done at once. I've had the Duc for going on 10 years now and I think it's the perfect bike for me...especially now! Here's a couple pics I took with my camera phone when the exhaust was finished...this is right after we discovered that my Ohlins had sprung a leak over the winter. Doh!

I got a lot of helpful advice over the winter from Bruce Meyers, Nash, BCM, Ducshop, MBP, Ducati Seattle and Chris Kelley. Awesome resources!

Regards,

Jeff

MAGNIFICENT! ! !

I Love that bike...

[1fast750ss]

Lookin good Jeff. Can't wait for the results on the dyno. Did you end up doing the short inlets and FCR's(or singles), or am I retarded and missed that in your post?

BTW, I really dig the 5 spoke Mag's on this model. SWEET!

[Jeff H.]

Thanks guys! I'm really looking forward to getting the Duc back on the street and seeing how she goes.

I ended up keeping my current FCR 41's on the long manifolds. I received equal parts advice for staying with the linked FCR's on long manifolds and going with singles on short ones. In the end, I think I went with simplicity and kept what I already had in place. I was willing to sacrifice a few potential horsepower for convenience and $.

Jeff

[BrianK]

Beautiful bike Jeff. Nice work. I'll be interested in those dyno results.

I can only think of one further improvement you should make....






Paint it the faster yellow color!

- BrianK

[Jeff H.]

Hi Brian. I just saw your post...she is staying RED!

Well, the dyno is scheduled for July 7, so I'll have numbers then. In the meantime, I'm just getting the engine broken in and becoming re-acquainted with the Duc. After only 1 ride I can tell you that she is much quicker than before. When I roll on the throttle, she accelerates right now and the engine is extremely smooth. Must be the lightened/balanced crank. Whatever it ends up being on the dyno, my seat of the pants meter says it should be perfect for what I'm looking for. I'm really happy. My wife could see my sh*t eating grin from her car as we were heading back from the shop. Good times!

Regards,

Jeff

[BrianK]

Well, okay Jeff, give up those last 5-10 HP/TQ for the sake of paint, up to you.... ;-)

Glad to hear you're happy with the mods. That's what counts.

Ride fast and safe; and enjoy. - BrianK

[Jeff H.]

Good to hear from you Brian! Are those Heli bars still working for you?

[BrianK]

Funny you should ask Jeff. I was out on the Duck all day today. Came home and my sit-bones were aching - but NOT my back! Prior to the Heli-Bars, I couldn't ride the Duck more than 45-60 minutes without a backache. So in a word, YES, they work GREAT!! Thanks again!

PS, I may have mentioned this before but when I put in 11:1 pistons, I had to retard my timing 3* and I now use 93 octane, whereas before it was happy with 87. But I don't regret the change!

I'm still sorting out the FCRs - I have two sets (35mm on my Norton and the 41s on the Duck) and both came jetted WAYYYY rich. I'm a little further ahead with the process on the Norton, and so far I have dropped from 152 to 145 mains (and thinking of trying 140s, and moving the 145s to the Duck for an experiment), raised the needle clips 3 slots (from position 5 to position 2), turned out the slow air screws from 1.0 to 1.25 turns, and turned in the slow fuel screw from .75 to .5 turns. And it's still a bit rich! - B

[Jeff H.]

Good tip about the timing. The feedback we got from both Bruce Meyers and Jeff Nash was anywhere between 2-4 degrees of ignition retardation. I think my mechanic went with 2 degrees. I have to say the engine is smooth as h*ll and very responsive. I like it! We haven't touched the jetting on my FCR's yet, so I'm curious to see how close we are once I get it on the dyno.

I recall we had a few conversations about the lightweight flywheel last year and I was going to email you again about it. I'm so happy with the engine now, especially with the lightened/balanced crank, that I'm not sure I want to do anything more to it. I'm sure I will at some point. It never stops does it???

Jeff

[BrianK]

Stop?!? Of course it never stops!!! There's always One. More. Thing. that just HAS to be done.

We're up to six bikes in the garage now (wife accounts for two) and I came *THIS CLOSE* to buying a 69 BSA Lightning on eBay today....

I like the lightened flywheel. As I may have mentioned I got mine cheap, second hand, as a result of a posting on this board (I posted that someone was selling another one, that did NOT fit my bike, on ebay. Well, I was accused on being a scammer, but in defending myself mentioned the bike I have (not one the flywheel in question fits - hence my post) and someone else said "hey, I have one to fit that, if you're interested...." Anyway, bought it, like it, don't find it a major difference (I occasionally stall it out starting from a stop, if I'm being stupid...which I am, occasionally!). Worth what I paid, but not sure if it's worth full freight... not a waste of money though, and if you've lightened your spinning parts a bit already, it might make all that more difference. Not as much as a nice yelllow paint job, but hey some folks CANNOT be taught....

Hope all's well. Ride safe, Jeff - Brian

[Jeff H.]

I suspect I'll try lightening the flywheel at some point. I'd prefer to try a lightened stock flywheel before spending the $ on a really light Nichols. My '98 has a 3 phase charging system though, so spare 3 phase flywheels seem to be a little hard to find. I'd like to keep my original one intact in case I have any "issues".

Now it seems that my front rotors are approaching the min thickness. They're stamped for 3.6mm and my calipers read 3.8mm. I don't know what the original thickness was for the Brembo "round hole" rotors, but .2mm doesn't seem like much material left. Might be time for some Braketech Axis rotors. May have to advise my better half that it's a "safety issue" requiring immediate attention. We do have an anniversary coming up...

[BrianK]

Update: I've put in 91 octane the last few tankloads, and haven't heard any pinging. And, I swear this has to be wrong (I did lean out the jetting somewhat, but this is ridiculous...), but I got 52 MPG on the last tankful....not highway, just my usual 30-50 MPH backroads! I think I may have been a little easier on the throttle as I had just rejetted and was conscious that the next fuel stop would be interesting, but sheesh! Great if it's true.Strangely, ALL of my bikes have improved their mileage lately (maybe it's gas prices - a subconscious thing feeding from my wallet, through the cerebellum, to the wrist?) Almost makes up for all the gas I've spilled on the garage floor pulling float bowls to replace jets....

[1fast750ss]

Originally Posted by BrianK

Update: I've put in 91 octane the last few tankloads, and haven't heard any pinging. And, I swear this has to be wrong (I did lean out the jetting somewhat, but this is ridiculous...), but I got 52 MPG on the last tankful....not highway, just my usual 30-50 MPH backroads! I think I may have been a little easier on the throttle as I had just rejetted and was conscious that the next fuel stop would be interesting, but sheesh! Great if it's true.Strangely, ALL of my bikes have improved their mileage lately (maybe it's gas prices - a subconscious thing feeding from my wallet, through the cerebellum, to the wrist?) Almost makes up for all the gas I've spilled on the garage floor pulling float bowls to replace jets....

It happens. My 750SS gets about 15mpg MORE since I built the motor. I get about 50-55mpg and have watched my real time MPG(I have a data analyzer in my dash) show as high as 71mpg while on the freeway doing about 70mph. My bike averages about 230 miles per tank.

27,000 miles and still going strong. I love my SS.

[Jeff H.]

Keep up the good work Brian!

My mileage is holding steady at about 40mpg. It's actually been a bit lower since the rebuild because I've been wringing the engine out harder than before. I've been using 91 octane only and haven't noticed any pinging.

I did do a couple other little mods in the last couple days. I removed the old 8 gauge wire that ran from my starter relay to the starter motor. I replaced it with a high quality 6 gauge wire that was about 5 inches shorter as well (something about Ohms law from college ). The bike starts way easier than before, almost jumps to life. I was going to upgrade the batter y cables as well, but there is a kind of switch attached to the positive one that has a second cable running off of it. I couldn't figure out where it went so I decided to leave well enough alone.

I also installed a little oil temp guage that screws on where the oil fill cap goes. I think it's made by a company called moto detail. (I've had a couple beers so my fingers arent' following directions) I ordered it from a company called Monsterparts. Really fast shipping and the temp guage works great. She seems to run staeady between 90-95 C. Idling at a light will creep to 100 C pretty quick.

I think she's about done for a bit. Dyno day on Monday!

Cheers,

Jeff

[droopy]

Nice Bike ! Reminds me of mine Except mine's a 96 SP . I never have been able to get mine (944 with Doug Lofgren portwork) to run without pinging on pump (93) gas . Yes the timing has been retarded . Might not have the squish set right . But since it needs to come apart anyway to fix the frame cracks , and I picked up a good used set of Carillos , and it has always bugged me that the reciprocating assembly has never been balanced properly , and I may have the infamous oil galley plug backing out , I suspect I have yet another impending project on my hands . Yes I wrote that run-on sentence on purpose At least I don't have to worry about whether or not I'll like the bike when I'm done . After 9 years , waaay too much money and all sorts of problems , I still love it . Hey BrianK , I've got a '75 Commando on the way . Might need to chat with you about the FCR's on it and some other stuff

[BrianK]

Best of luck with the Snorter Droopy! Happy to help if I can.

Lots of good info here too:

Norton Commando Motorcycles.

BritBike Forum: Norton Bulletin Board

Norton Commando Workshop Manual

[BrianK]

Including the never-ending saga of my rejetting experiences on the Snorter's FCRs:

Jetting Keihin FCRs

[Jeff H.]

I'm dropping off the Duc tomorrow for a bigger main jet and some more dyno work. It looks the head porting and bigger exhaust left the engine running way lean. Hope to have that sorted out by Monday. Is this the kind of thing I could do myself if I had one of those gunsten gas testers?

[BrianK]

Sure rejetting is easy. You don't even have to take the carbs off the bike. I don't have any EGA or other measurement tools. Just make be systematic, keep track of what you're changing - one change at a time - and see how she runs/how the plugs look.