What did you do with your P11 today. he he

I would imagine most P11 owners are spending time looking for parts to restore one. I gave up on that a long time ago. What I do is implement things that could be an improvement for use on the road. So far I've had success playing around with the old P11. It is nothing like a stock P11 to ride. A lot of people would not like it, but I'm not doing it for a lot of people. My toy, my rules.

I finally got around to extending my intake manifolds as far as I can go and still have air filtration for the 35mm FCR carburetors. To do it the coils have to be moved from the stock location, because they are in the way. I removed the can coils entirely and installed a dual coil below the air filters. Actually did that a couple of years ago, but I digress.

My intake manifolds are made up from a set of Commando MkII style manifolds. Tools used were hacksaw, files, sandpaper, and a tube cutter for the last 1/4" section. I could do the same with either the Atlas or Commando style intake manifolds JSM sells. However, he wasn't making them when I started. Now it would be easier to start with Jim's manifolds, but they would still require some modification for use on a P11. I used epoxy to put the rings so to speak together. I also used epoxy to ramp blend up the last piece to go from 35mm to 33mm. My intake port entrances in the head are 31.5mm. The intake manifolds are further blended down from 33mm to 31.5mm. Length of the intakes for the FCR's is 2-3/16" on the top and around 2" on the bottom due to how the intake has to be cut to get a good angle on the carburetor bodies and not hit the frame.

Below is a pic of the naked manifolds bolted to the head: No technical details regarding horsepower, torque, or velocity are known by me. Only thing I do know is there is some minor improvement in the performance at mid-range and beyond when going close to WOT. Midrange is sort of subjective and can mean a lot of things. All I know is the darn thing hauls ass when I get into 3rd gear. I'm a bit afraid to really beat on it because still don't trust the RGM clutch. Story for a different time or never.

Looks nice, look out Allan Millyard! I always found that for street engines, longer intakes make sense for driveability. As an aside, in the case of Japanese bikes, the stock airbox performs better in real-world riding vs pods. Yet people chase the HP and have a terrible time with jetting 4 carbs. What is that plugged (?) fitting on the intake valve cover for? I also like the oil feed lines. I just got some good quality rubber ones, on the N15CS the head stay and orientation of the fittings make it a bit tricky to get right, so I did my best and it's good. That's gorgeous.

Thanks, I do like clean. I have no respect for dirty road bike engines unless the idea is a rat rod show motorcycle. If that makes me a prickly douchebag it's alright with me.

I put Mikuni or Keihin flat slides on the inline 4 bikes I felt like tuning and the Sudco kits all came with pod air filters, like you say. 4 tube mercury sync sticks and a feel for what rich or lean feels like with jets and needles is what I used for tuning. The kits were fairly close. I pulled and saved the air boxes and passed them on to the new owners along with the stock exhausts.

The plugged tube in the intake valve cover: At one time I was letting crank case pressure out up there in addition to at the timing chest. No reed valve solutions were around when I did that. I was using a heavy duty automotive PCV valve. Don't tell anybody cuz they might have a hissy fit, but my steam punk setup worked just as well as the reed valve. Unfortunately, it was a plumbing nightmare taking up too much space and the reed valve solutions available today are a cleaner setup. BTW, Matt of cNw who has done a lot more tuning than I ever will, said he never noticed a significant enough difference (he might have said any difference) letting crank case pressure out of the top if a reed valve was used. It did make a difference with a PCV valve. The PCV valve was more restrictive than a good reed valve.

I keep putting off replacing the valve covers. There is another plugged tube on the left side exhaust valve cover as well.

The top end oil feed is old Commando aftermarket from the 90's. Most of the major Norton parts houses sell similar, and possibly better. You know that though. Excuse the babbling.

The long intake idea can be taken too far.
A friend has a Vincent engine in a Seeley frame. In order to make it work , really long intake stubs were needed.
He said it would eventually rev out and really get going, but wow was that thing slow on the road compared to a regular Vincent twin. I followed him from Manchester to Liverpool and we did some passing along the way. Even loaded two up with luggage we had a lot more power on tap than he did solo on a fairly light bike.

Glen

worntorn said:

The long intake idea can be taken too far.
A friend has a Vincent engine in a Seeley frame. In order to make it work , really long intake stubs were needed.
He said it would eventually rev out and really get going, but wow was that thing slow on the road compared to a regular Vincent twin. I followed him from Manchester to Liverpool and we did some passing along the way. Even loaded two up with luggage we had a lot more power on tap than he did solo on a fairly light bike.

Glen

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Alrighty... Probably so if done entirely for top end.

Fortunately, manifold length is not an issue in my case. Not enough room to make them too long. The manifolds pictured are probably a few thousands shorter than Commando intake manifolds they are made from. My 750 is pooh pooh for short shifting to keep the revs low and probably lacks some low end torque due to being a little over geared and over carbureted as well. One thing it isn't is slow. That performance is a double-edged sword though. It would be easier to ride in town and behind traffic if geared lower.

I have not had the current engine config, gearbox, and gearing out on the Hwy to see how it works in 4th and 5th gear. 3rd is too tall for staying below the speed limit in town, but I've used it a few times.

Probably in no danger of getting the intake length too long then.
I forgot just how long that Seeley setup was-
Here it is

worntorn said:

Probably in no danger of getting the intake length too long then.
I forgot just how long that Seeley setup was-
Here it is
View attachment 114759

Click to expand...

That’s awful !

worntorn said:

Probably in no danger of getting the intake length too long then.
I forgot just how long that Seeley setup was-
Here it is

Click to expand...

Safe and sane.

That Vincent intake manifold arrangement is an example of having to suck it up. Yikes!!

worntorn said:

Probably in no danger of getting the intake length too long then.
I forgot just how long that Seeley setup was-

Click to expand...

That engine cries for fuel injection!

- Knut

worntorn said:

Probably in no danger of getting the intake length too long then.
I forgot just how long that Seeley setup was-
Here it is
View attachment 114759

Click to expand...

Any ice build up on that manifold?

I spent an hour typing up a description of the piece I made yesterday and got cock blocked by the website saying I could not post it because I was not logged in even though I clearly was. Lost it all. Currently I don't feel like typing it up again. Here's what I did. It works.

Schwany said:

Safe and sane.

That Vincent intake manifold arrangement is an example of having to suck it up. Yikes!!

Click to expand...

Built by a plumber would be my guess !

I'm wondering if the inlet tract beyond the carburetor slide or butterfly has an effect on the peak RPM of the tuned-ram at wide open throttle.

I have a 2-inch standoff between the head and carb on my Matchless single, then another six inches of tube before the air cleaner. Also has a Supertrap megaphone/spark arrestor on the end of a 43 inch pipe. It has bags of mid-range torque.

For an additional breather, I used a late 70s VW Rabbit/Golf power-brake check valve in line with a hose off the back of the timing chain case. For the first few strokes you can hear it expelling air till it pumps down the crankcase vacuum. It has almost entirely eliminated oil leakage between the head and barrel and greatly slowed down the oil ending up on the rear chain from the stock breather. When I did this 20 years ago, there were no reed valves available that I knew about. I did that do my Commando too with similar results.

The Vincent setup reminds me of the 60s Chrysler cross-ram 413 V8. The 4bbl carburetors hung out over the opposite side valve cover. Word was they were great for trailer towing. They also made a short cross ram for the 426 drag-race car, which had cast, tuned headers.

Speaking of intake manifolds. Went for a short test ride today. I hit the nail on the head with the length, shape, and whatever else I did on my intake manifolds. Perfect barn yard shade tree imagineering. It runs better than it ever has everywhere. My guess is that ending up with the manifolds about the same overall length as the Commando intakes is what helped. That and the intake manifolds are port matched at both ends, as well as hand blended and shaped by an expert craftsman. It is shaped like a curved velocity stack but on the output side of the 35mm carburetion.

I finally have a handle on belt tension for the RGM belt drive. It's a bit noisy flopping around in the primary case at cold idle but on the money tension wise once the clutch basket expands from heat. Just in time for the fair weather riding in the PNW. I need to make that dyno appointment. More later

That is nice. Assuming what it is... the primary chain adjuster is weird to me. I would think you'd start loose and turn the screw to the desired tension. It seems backward. Per the Chilton's, yank the drive chain with the gearbox bolts loose to pull the gearbox back and tighten the chain with the adjuster backed out. Then loosen it using the adjuster. Having an adjuster that would cinch up the primary chain as it stretches seems more logical. Or maybe I have it all wrong?

The adjuster I made up works more or less the same as the P11 gearbox adjuster. It moves the gearbox forward only and prevents the gearbox from being jerked backward by the drive chain. Gotta own a P11 to know a P11. I have other measures in place to prevent the primary from pulling the gearbox forward, which by the way never happens. The rear chain on the other hand can pull the gearbox back if the tightness of the top and bottom bolts as well as my position locks is not paid attention to.

The primary belt was adjusted the same way as you are describing initially. However it was a little tight, so I simply loosened the bolts and used my adjuster to move the gearbox forward about 1/16" to dial it in.

I gotta go clean up a buttload of crap that was blown out of the Douglas Fir trees around my house. No more time for explaining my mad science work on my relic.

Removed the new and improved RGM clutch rod seal that backed out twice. As it turns out the clutch rod seal is not needed for a TTi gearbox. (Member verified, Thanks.) Gear oil does not migrate up into the bore through the mainshaft for the clutch rod like it did with my old P11 gearbox. I could have been putting too much oil in the AMC box though. The clutch rod in the TTi gearbox stays dry and needs to be lightly greased. In addition, I went back to using the OEM size nut and big lock washer for the hub, and torqued it down to 70 ft lbs. No skimpy circlip on a Manx mainshaft.

Also got around to replacing a manual ball valve without an electrical shut off switch with one that has the shut off switch. No ignition when the valve is shut. Feked sells it. I know people here have made their own. I could have, but it was a lot easier to buy one already made. It looks better than anything I would have come up with. The electrical leads from the switch are connected (spliced into with bullet connectors) to the small dual coil + ground at the coil. It works.



By the way my oil lines run under the gearbox and my stock oil pipe junction block is upside down and has the stock tubes shortened with some shade tree engineered add on pipe for the required pipe curves. It also works in that orientation and the engine is oiled as it should be.

I did a single plate swap on the RGM belt clutch last night. The RGM 4 frictions clutch I purchased comes with a friction plate under the pressure plate. The pressure plate is alloy and really not all that tough if something happens that causes the clutch to slip excessively. There is a note in the install instructions that I missed entirely when I installed the clutch. That note says for greater longevity install a steel under the pressure plate. RGM provides a standard thickness steel plate that can be moved from the rear of the stack to the front under the pressure plate. There is still a thick steel at the very rear against the basket. The clutch seems to work fine with the steel under the pressure plate. I have not ridden the bike yet only tested it in the garage. Drizzling right now, better weather ahead next week.

Short test ride on Juneteenth. I forgot it was a holiday here so turned around before I hit holiday traffic. Tomorrow a longer ride.

The clutch worked perfectly "for me" reconfigured as mentioned in post #18.

I'm very accustomed to shifting and getting the TTi gearbox into neutral now. Works flawlessly. Oh wait, except for that occasional kick start lock up crap. Easy to free up though, so not a big deal considering how much better the TTi gearbox is to me.

I'm done jabbering about my P11 special project. I won't say it is like riding a modern bike with my modifications, but it is close.

Schwany said:

Short test ride on Juneteenth. I forgot it was a holiday here so turned around before I hit holiday traffic. Tomorrow a longer ride.

The clutch worked perfectly "for me" reconfigured as mentioned in post #18.

I'm very accustomed to shifting and getting the TTi gearbox into neutral now. Works flawlessly. Oh wait, except for that occasional kick start lock up crap. Easy to free up though, so not a big deal considering how much better the TTi gearbox is to me.

I'm done jabbering about my P11 special project. I won't say it is like riding a modern bike with my modifications, but it is close.

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These days.... I jump between my '66 N15CS, my '83 Suzuki GS1100E, and either my son's '22 Yamaha Tenere 700, or my '24 Transalp. The new bikes (i.e. the ones made in this century) are just easy & capable and fun. They don't need us but hey, that's cool. Been that way since my VFR days, just ride. I try to neither wax nostalgic nor be a 'fanboy' of new stuff. If it has two wheels I'm in! Keep jabbering, no need to stop. Oh if anyone wants an opinion, take the Tenere 700 over the Transalp. And for that matter, I'd take a P11 over the N15 until I got to fitting it all together at least.