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Author Topic: Announcement of 48 hp Bullet  (Read 3543 times)

Ducati Scotty

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Re: Announcement of 48 hp Bullet
« Reply #30 on: January 26, 2011, 04:42:26 AM »
It'll probably be fine with a Power Commander.  It lets you alter the fuel map and has a fairly big range.  If things went really far and you either needed a larger throttle body to flow more air or if the injector just can't deliver enough fuel for the modded engine then you'd have to get more drastic: larger fuel injector, larger throttle body, or maybe even a completely new engine control unit.  I'd guess you can go pretty far with the stock setup and a Power Commander.

The unfortunate part is that unlike a carb where you can swap jets pretty easily and diagnose what it needs, re-mapping fuel injection is best done by a trained tuner with a dynomometer and some time.  You can do it by trial and error but it takes a LONG time.

There are some other fuel map alrering devices that are less precise.  The Power Commander has a huge map of throttle angle and RPM pairs and a + or - for each of them.  There are some that have fewer settings over broader ranges (not available for us yet) that let you tune on the fly with push buttons right on the unit.  They add a certain amount of fuel across the whole low range, a little more in the mid, and yet a touch more when you're at very large throttle openings.  While not as precise as a Power Commander they often do a fair job, are less expensive, and are easily user tunable.

Scott

Ice

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Re: Announcement of 48 hp Bullet
« Reply #31 on: January 26, 2011, 04:57:41 AM »
 As I understand it the stock EFI is mapped up to 18,000+ FT altitude and does correct for  low restriction silencers. Some UCE owners report some popping from the silencer on hard throttle closed decel.

 It has its limits.

Substantial engine changes require a programmable ECU.

Don't give up hope though

 At last  year's ACU National Rally Alan Hitchcock's and crew entered six bikes and took six gold medals. Three were EFI models. One EFI was fitted with a prototype big bore 535 conversion.
 The other two used his modified exhausts and  Dyno-Jet Power Commanders. One had experimental cams.

 About the same time Roberto Totti of Tottimotori in Italy was offering a programmable ECU of his own.

 Forum member Pistone also known as Fabrizio "McDeeb" DiBella of McDeeb custom motorcyles in Italy builds custom UCE based bikes and is rumored to be working on a 535 as well.

  As per the last we got from scooterbob on the powercommander installed in their shop mule, he was tweaking and testing for perfect tune to improve rideabillity first.
« Last Edit: January 26, 2011, 05:40:54 AM by Ice »
I can break it better,,,,at night, in the rain, on the trail,, 20 miles from nowhere.

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ace.cafe

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Re: Announcement of 48 hp Bullet
« Reply #32 on: January 26, 2011, 02:43:35 PM »
Regarding this part of the conversation, I think the approach could go two different ways, depending on what you want out of the bike, particullarly regarding cost.

You could work within the limits of the throttle body and injectors and Power Commander package, and get what you can that way. I don't have any flow-analysis of that head and induction system, so I don't know where those limits are at this point. Perhaps if they are on the big side, such as is the traditional Enfield practice, they might be all you need, or they might even be too big, which could present a problem..

The other way is if we find they aren't all we need, then a new or modded induction system will be needed to go along with the head flowing. That would cost more.

It all comes down to somebody looking at that system(who knows what they are doing), and testing it, and seeing what is there at present. Until that happens, it's all a bunch of shots in the dark.

The first thing that I see is that it has about a 5400rpm rev limit, and going higher than that might present a problem from the hydraulic lifters. That's where Chinoy had his problems when he tried to mod this engine in India.
So, if the ports are small enough, it might be best to work under that rev limit, to keep cost down. Just do a "torquer" mod.
However, if the ports are "optimistically sized", and suited more for a higher rev range, it's very hard to put more metal into the ports, so then the rev range will have to go up to use the port size properly. Or, displacement will have to go up. Or both.

So the first order of business in this idea is to get a baseline on where this thing is currently at, in stock form. All the pertinent data must be measured and analyzed. Then there can be some reasonable assessments made about where it can go and what it will take to get there.

I have the most advanced head-development facility in the world at my disposal, and also the most famous and accomplished head-developer of all time, on site there.
I don't have a UCE to test.
« Last Edit: January 26, 2011, 02:48:00 PM by ace.cafe »
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Ducati Scotty

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Re: Announcement of 48 hp Bullet
« Reply #33 on: January 26, 2011, 03:44:11 PM »
+1 Ace.  I think there will be a 'mild' version with stock head and FI system and a 'wild' version with more.  As to the REV limit, would it be possible to go past that with a different crank or is the head the limiting factor?

Scott

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Re: Announcement of 48 hp Bullet
« Reply #34 on: January 26, 2011, 03:55:50 PM »
Well,you guys are all well past me.But the thing that I do see is that they are not making iron barrels any more.The new bikes are gonna take off,sales-wise,exposure will take care of that.In this country the new ones will soon outnumber the old ones.All of the developement  done on the Fireball modifications can only help on the newer engines.Fuel injection is not a stumble but an asset once an efficient control is devised.Ace,I have to tell you,you are the man to do this,to bring along a kit for the new models.The emissions testing may actually go away for a while as it is an expense not a single state can afford,conjecture,ya.

ace.cafe

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Re: Announcement of 48 hp Bullet
« Reply #35 on: January 26, 2011, 05:03:00 PM »
+1 Ace.  I think there will be a 'mild' version with stock head and FI system and a 'wild' version with more.  As to the REV limit, would it be possible to go past that with a different crank or is the head the limiting factor?

Scott


Scott,
That's a good question.
Piston speed is normally the determining factor for settting rev-limits, and that is determined by the stroke length of the crank, primarily. With a 90mm stroke, I determined that I would limit the Fireball mod to 6000rpm, even with a modded crank and a Carrillo rod and lightweight piston. I did this for reliability purposes for street use. Technically, you 'could' push that 90mm stroke alot faster, as long as you are wiling to take the risks of failure, and reduced lifetime of parts. This is commonly done in racing engines where winning is more important than longevity.
So yes, it is possible to push it higher from a certain point of view, but it gets progressively riskier and shorter-lifetime as you go up the scale.
6000rpm on a 90mm stroke is already well above the Pomeroy Dictum recommended levels for reliable piston speeds in a street engine which expects good longevity.
Bottom end strength can play a part in improving the chances of going up higher, but I seriously doubt that Enfield is putting stuff any better than what is in the Fireball into their stock engines.
But for really pushing the racing lmits, it could be pushed over 7000rpm, or maybe even to 8000rpm, for a short-term life-expectancy.

To give you a basic reference, a 90mm stroke Bulllet at 7000rpm would average 4130 feet/minute piston speed.
A Yamaha R6 with a 44.5mm stroke reaches approximately the same average piston speed at just over 14,100rpm.
So, for all intents and purposes, pushing an Enfield to 7000rpm presents the similar piston speed issues to the engine as an R6 doing over 14000rpm.
And we don't have the same sophistication of design in our engines as the R6 in terms of balance. Plus, our unbalanced system has much longer stroke, so our PEAK piston speeds would be even higher than the R6 would have as a peak piston speed.
And we see that even the Yamaha reaches its rev limit just above that 14krpm level, at 14.5krpm. So, they are limiting it there BECAUSE piston speeds cannot go higher in even that sophisticated engine with all it's hi-tech, and still expect any kind of longevity in the system.
We don't intend to push that far, so I think that 6000rpm or maybe a bit higher, is all I want to be doing in a street Enfield and expect any decent lifetime.

From the POV of valve-train stability, the hydraulic lifters begin to show up potential issues before the 6000 rpm limits that perhaps the bottom end of the engine could withstand. Lifter "pump-up" is a well-known issue in pushrod engines, and is generally expected when rpms get over 5500 rpm - 6000rpm in engines with hydraulic lifters. This is where Chinoy had his problems. There are ways to get around that problem, which typically amounts to essentially using a solid lifter when hi-rev applications are anticipated, and the roller part of the lifter can still be retained with a solid lifter. And there are some high-performance hydraulic lifters available too, but I don't know if any of them are suitable to go in this Enfield.


The next thing is that we see only a ~600rpm gap between existing rev limits and the 6000rpm limit that I felt was the outer limits for a street bike with this stroke length.
So then, we need to determine if we feel that extra 600rpm is worth doing all this tuff to get there, or if it's just better to work under the existing rev limits.

Since rpms are part of the hp equation, we need revs to get a higher hp figure.
Exactly how many rpms is up to the builder and user. Many things can factor into this decision.
However, torque is on the other end of the hp equation, and so increasing torque will also give us more hp, and we don't have to push the rpms up as high to get that, and so it is where most long-stroke tuners spend their efforts.
The Fireball is primarily a "torque build" with some added rev capacity to pull the hp number  up a bit higher, and have enough revs to hit "the Ton" with our typical gearing.

A whole lot to making these decisions.
Many ways to build an engine.
Many types of budget considerations to be thought about.
So, it needs to get focused.
I  made my focus with the Fireball, based on many factors, and it seems to have hit the target right in the bulls-eye. That is what we want to get out of any other build. A bulls-eye for what the desired end results are.

As for the head parameters, we only look at those AFTER we have set the intended rev-range requirement, and then we port and cam to suit.
The head is not really a "limiting factor" unless it's already too big in the ports, or it's not big enough in the ports, and how much the casting wil allow us to do with it.
Of course, there are some basic issues like port angles and stuff, but we are pretty much limited to what's there, unless we're making a whole new head, and even then we still have to fit the thing under the tank, and it's going to be priimarily side-draft no matter what happens.. We can make minor port angle changes perhaps, and do alot with size and shape of the port if the casting allows it, and we can do things with the chamber to reduce valve shrouding and improve flow into the chamber, and alot of things like that, though.
A pertinent example of that would be the Fireball, where we didn't increase the port size at all, and still picked-up 55 cfm in flow at a very moderate valve lift height that wouldn't stress the valve-train system much more  than stock. So we got a huge flow increase of about 35%, improved combustion efficiency by using advanced atomization improvement techniques, and gained alot of power potential on the same basic port size as a stock Bullet. and to go along with it, we redesigned a large portion of the valve-train using high-performance and high-reliability parts, so that it would have no trouble at all with the job we were asking it to do.
« Last Edit: January 26, 2011, 05:48:18 PM by ace.cafe »
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Ducati Scotty

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Re: Announcement of 48 hp Bullet
« Reply #37 on: January 26, 2011, 06:02:47 PM »
Thanks Ace.  I was thinking of shorter stroke/lighter flywheel/bigger bore for 500cc but less piston speed.  Not sure it would be worth the trade off.  I see that if we want to exceed the 5500/6000 RPM range there are a whole host of things to be addressed.  I think a little more torque and power would be nice but I'm not seeking the race engine with high top speeds.  I want a Fireball, a little more umph with good reliability, street manners, and longevity.

This all reminds me of my youth with air cooled VWs.  Those engines are awesome stock and will run forever but if you start looking at mods any one serious mod requires everything else to be modded to keep up.  The stock engine is so well balanced as it is.  I think the UCE has more to give without too much modification and while still being a good daily driver.

Thanks for all the tech geek details ;)

Scott

ace.cafe

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Re: Announcement of 48 hp Bullet
« Reply #38 on: January 26, 2011, 06:18:41 PM »
Thanks Ace.  I was thinking of shorter stroke/lighter flywheel/bigger bore for 500cc but less piston speed.  Not sure it would be worth the trade off.  I see that if we want to exceed the 5500/6000 RPM range there are a whole host of things to be addressed.  I think a little more torque and power would be nice but I'm not seeking the race engine with high top speeds.  I want a Fireball, a little more umph with good reliability, street manners, and longevity.

This all reminds me of my youth with air cooled VWs.  Those engines are awesome stock and will run forever but if you start looking at mods any one serious mod requires everything else to be modded to keep up.  The stock engine is so well balanced as it is.  I think the UCE has more to give without too much modification and while still being a good daily driver.

Thanks for all the tech geek details ;)

Scott

Hi Scott,
Shortening the stroke and enlarging the bore can be a possible route to take.
I have no idea right now how far the UCE bore can be enlarged.

I agree that there are alot of things to consider.
This is why it's important to look at desired end results. Mods can vary from mild to wild, and costs can vary just as much.

If the desired end results can be categorized and some basic ideas can emerge, I can guide people on what costs alot to do, and what can be done cheaper.

Probably the cheapest way to get a little extra, is to do what Enfield is going to do, and bump the displacement up.
You can't really do anything with compression, because it's already at 8.5;1, and that's probably all the available pump gas can handle.
And stroking is a full tear-down with crank replacement.
Hence, the cheapest and easiest way out, aside from external bolt-ons, is an over-bore and bigger piston. I think Scooter Bob is working on that.
Doing a head and cams is not cheap, but there is much more to be gained there in terms of performance, typically, if they are done right.

My hope is that the new UCE bottom end will be sufficient to sustain decent mods for power, and the work/expense could primarily be limited to the performance parts.
The Fireball ended-up with half of the expense being tied-up in bottom-end reliability improvements, which were costly and labor intensive.
« Last Edit: January 26, 2011, 06:21:22 PM by ace.cafe »
Home of the ACE Fireball 535 Bullet,  Ace GP Hi-Lift Roller Rocker Head . Pistons, cams, etc. Highest performance Bullet engine mods available .  AVL mods. Redditch 700/750 Twin mods. UCE kit soon.

Please visit my new website:
http://groups.yahoo.com/neo/groups/AcePerformanceBullets/info

Re: Announcement of 48 hp Bullet
« Reply #39 on: January 26, 2011, 06:32:58 PM »
For the non mechanics among us, does bigger bore mean closer to square than the current undersqare.   You mentioned reduction of stroke (presumably to allow higher revs and thus power)...To my simple understanding stroke = torque.  No? 
Seems to me that the quintessntial characteistic of the Bullet, and what sets it apart from more modern bikes is the disproportioate torque.  Surely it would be a shame to lose this (or even shift it substantially up the RPM curve)  The "Fireball " idea appeals preciesely because it doesn't mess with the stroke.   Even it it were square, I don't think you would sacrifice low end torque, just more explosion throughtout the range, with higher torgue and power , which, seems to me to be competely in line with the Fireball idea :  So a 600 cc would just give you more to work with.   Maybe I've got this all wrong.   But if street and a little more highway passing capability are the goals (as well as pulling a sidecar) then more power without shorter stroke should do it bu making the 600 cc available breather better   Nigel. 

Ducati Scotty

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Re: Announcement of 48 hp Bullet
« Reply #40 on: January 26, 2011, 06:51:31 PM »
Ace,

While a stock bike in India might not take more compression I think it could make a nice mod.  As I recall the bike sent out for magazine review had a prototype high compression piston.  My Monster ran about 10.5:1 and I ran that on 92 octane pump gas, might not be available in India but it is in Europe and the US.  So while these might not make good stock options, they are good aftermarket options.  Here's kinda what I'm thinking:

Stage 1 - High flow air and exhaust with a Power commander to get the map right, smooth and more powerful with no hit to longevity unless you flog it.

Stage 2 - Stage 1 + high compression piston

Stage 3 - Stage 2 + cams

Stage 4 and up - bigger internal mods.

Stage 1 is easy and most anyone with moderate skills could install at home.  Performance increase would be minimal.  Stage 2 takes a little more skill to install but is straightforward and easy to both install and design.  Stage 3 needs some more serious design to restyle the cam profile.  It's only at Stege 3 and up that we really need to start anlyzing what the desired outcome will be so we can determine which compromises to make.  It's also where we'll start realy getting the major increase in power and torque.  Price also starts to climb here.

Am I way off base?

Scott

ace.cafe

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Re: Announcement of 48 hp Bullet
« Reply #41 on: January 26, 2011, 07:15:18 PM »
For the non mechanics among us, does bigger bore mean closer to square than the current undersqare.   You mentioned reduction of stroke (presumably to allow higher revs and thus power)...To my simple understanding stroke = torque.  No? 
Seems to me that the quintessntial characteistic of the Bullet, and what sets it apart from more modern bikes is the disproportioate torque.  Surely it would be a shame to lose this (or even shift it substantially up the RPM curve)  The "Fireball " idea appeals preciesely because it doesn't mess with the stroke.   Even it it were square, I don't think you would sacrifice low end torque, just more explosion throughtout the range, with higher torgue and power , which, seems to me to be competely in line with the Fireball idea :  So a 600 cc would just give you more to work with.   Maybe I've got this all wrong.   But if street and a little more highway passing capability are the goals (as well as pulling a sidecar) then more power without shorter stroke should do it bu making the 600 cc available breather better   Nigel. 

Yes, bigger bore and/or shorter stroke in our case would come closer to "square".
Short-stroke Bullets have been tried in the past by various modders, and none were particularly successful in catching on. Not sure why. I've never actually ridden one, or seen one "in person".

The long stroke does give a longer moment arm, or lever, with regards to torque. So, from that  perspective, it does work as a torque factor. But there is much more to engine torque than just that.

As you mention, part of the allure of the Bullet comes from its layout, and its sound, and loping high-mass flywheel design. To many, any change away from that would  make it "not a Bullet" anymore. There are people who are fanatical purists about just the sound alone. In India, buyers go from one dealer to another, starting up all the Bullets and listening to the "thump", and making their buying decision on the one that they like the "thump" the best. This is serious business in India, and to some extent, elsewhere. Deviation from that can be perilous in some markets.

I didn't want to lose the sound with my Fireball mod, and Chumma is Indian, so we know that the "thump" is not only "right", but even better than it ever was. We nailed the sound perfectly in its improvement.

The 600 would provide more torque and power by virtue of the added displacement.
That works.
The 600 is likely to have an even longer stroke than the 90mm stroke of the normal Bullet. The Iron Barrel strokers are about 102mm stroke, and give 612cc along with an 87mm piston in the combination. I suspect that the upcoming 600cc from Enfield would be something along a similar approach.
They can give good torque and increased power without increasing revs, and they are used for better passing and for sidecar use, and such.
I didn't go that route, because I preferred the shorter(normal) stroke for my purposes.
I got my power in a different way, using the standard stroke.

Stroke length will significantly affect porting and camming, and must be taken into account during the process. To a certain degree, even bore increases will affect it, because there's more displacement, and if the increase is significant, it needs to be fed more by the induction system.

Home of the ACE Fireball 535 Bullet,  Ace GP Hi-Lift Roller Rocker Head . Pistons, cams, etc. Highest performance Bullet engine mods available .  AVL mods. Redditch 700/750 Twin mods. UCE kit soon.

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Ducati Scotty

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Re: Announcement of 48 hp Bullet
« Reply #42 on: January 26, 2011, 07:22:52 PM »
I was thinking that, shorter stroke/larger bore = not a Bullet any more.  I would guess the current long stroke and high mass flyweel are not only characteristic and desireable from an emotional point of view, but also factor in with all the other dimensions of the engine, by design or chance, to create that magical balance that makes the engine so good as it is.

Scott

ace.cafe

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Re: Announcement of 48 hp Bullet
« Reply #43 on: January 26, 2011, 08:08:36 PM »
Ace,

While a stock bike in India might not take more compression I think it could make a nice mod.  As I recall the bike sent out for magazine review had a prototype high compression piston.  My Monster ran about 10.5:1 and I ran that on 92 octane pump gas, might not be available in India but it is in Europe and the US.  So while these might not make good stock options, they are good aftermarket options.  Here's kinda what I'm thinking:

Stage 1 - High flow air and exhaust with a Power commander to get the map right, smooth and more powerful with no hit to longevity unless you flog it.

Stage 2 - Stage 1 + high compression piston

Stage 3 - Stage 2 + cams

Stage 4 and up - bigger internal mods.

Stage 1 is easy and most anyone with moderate skills could install at home.  Performance increase would be minimal.  Stage 2 takes a little more skill to install but is straightforward and easy to both install and design.  Stage 3 needs some more serious design to restyle the cam profile.  It's only at Stege 3 and up that we really need to start anlyzing what the desired outcome will be so we can determine which compromises to make.  It's also where we'll start realy getting the major increase in power and torque.  Price also starts to climb here.

Am I way off base?

Scott

Okay Scott,
Regarding the 10.5:1 compression in your Ducati, we have to understand that is a "static ratio", and the ultimate result that the engine sees is affected by the cam timing. This is how all these engines with these high compression static ratios are running on pump gas. A late closing intake valve causes a shorter swept-volume to build compression after the intake valve closes, so the higher dome on the piston yields an actual working compression of something less than the static ratio would seem to indicate.
Each engine has a set-up which eventually yields a working compression that is within the tolerance limits of the fuel. In the end, they all end up around the same actual working compression levels, with some extra amount possible from good chamber activity and small chamber volume. Some help from an ECU which can retard spark under load and under knocking conditions may also be in play.
We don't really know the limits of the UCE chamber yet, in terms of its characteristics to hold-off detonation at/above fuel limits. Perhaps there may be something good there, but we don't know yet. If it is possible to go higher,  or if we need a bigger dome to compensate for later intake closing event, then we can use that.

So going to the Stages you listed.
They all look viable to me.
I would recommend combining Stage 2 and Stage 3, for the reasons I described above about cam timing having a major effecton the actual working compression of the engine. However, if a person didn't want cams, then a piston should be available which can squeeze as much as practical out of the stock cam timing.

So you are not off-base at all, really.
It all makes sense, and I recommend similar steps.
What I do with the piston situation is to have them get the hi-comp piston, and use a spacer under the barrel to drop the deck-height of the piston in relation to the chamber, and keep the compression lower that way to work with the stock cams.
Then, when they put in the performance cams, they can remove the spacer under the barrel, and use the full compression potential of the piston dome, which will work right with the performance cams I use,which  have later intake closing timing.
You might be interested to know that my cam timing events used in the Fireball are very similar to the cam timing of the Ducati 1000DS aircooled 2-valve twin.

So yes, this is a logical approach toward performance stages, IMO.
And preferably,we want each stage to use parts which will not be obsoleted by the subsequent stages.

« Last Edit: January 26, 2011, 08:23:12 PM by ace.cafe »
Home of the ACE Fireball 535 Bullet,  Ace GP Hi-Lift Roller Rocker Head . Pistons, cams, etc. Highest performance Bullet engine mods available .  AVL mods. Redditch 700/750 Twin mods. UCE kit soon.

Please visit my new website:
http://groups.yahoo.com/neo/groups/AcePerformanceBullets/info

Ducati Scotty

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Re: Announcement of 48 hp Bullet
« Reply #44 on: January 26, 2011, 09:25:59 PM »
Thanks for the explanation of static compression.

Yeah, makes sense to combine 2 & 3 I guess.  I was thinking there might be some advantage to the piston without the cams but there's so much more to be had with the combination.

Scott