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Author Topic: Engine design and modifications Q/A thread  (Read 2044 times)

ace.cafe

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Engine design and modifications Q/A thread
« on: October 17, 2013, 12:35:53 AM »
If anybody wants to ask some questions about the design of engines, or their workings, or about performance modifications, then ask away, and I'll do my best to answer them or address your points of interest.

When I was just starting out, nobody ever bothered to explain anything to me, and I had to learn everything the hard way. So, if you ever wondered about something, I'll try to answer to the best of my ability.
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:
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single

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Re: Engine design and modifications Q/A thread
« Reply #1 on: October 21, 2013, 03:46:18 AM »
Obviously,we are all pretty sure of ourselves.
Nice offer,Tom.

D the D

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Re: Engine design and modifications Q/A thread
« Reply #2 on: October 21, 2013, 02:21:00 PM »
I think you'll find they need your help on specific things.  Sometimes questions don't pop into our heads unless we have a problem to fix.
D
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Chuck D

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Re: Engine design and modifications Q/A thread
« Reply #3 on: October 21, 2013, 04:04:59 PM »
Tom, I think maybe it's time to dig out a few of those instructional threads from a few years ago. Y'know, the ones that began "Let's talk about...". Those were great.
« Last Edit: October 21, 2013, 06:09:39 PM by Chuck D »
2006 Bullet Sixty-5 w/ Ace "Fireball 535" Kit (#10)
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ace.cafe

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Re: Engine design and modifications Q/A thread
« Reply #4 on: October 21, 2013, 05:05:01 PM »
Hi Chuck.
I'm going to have some exciting news for you later today.
I'll email you later with some pics and the news.
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://autos.groups.yahoo.com/group/AcePerformanceBullets/

Chuck D

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Re: Engine design and modifications Q/A thread
« Reply #5 on: October 21, 2013, 06:08:25 PM »
Hi Chuck.
I'm going to have some exciting news for you later today.
I'll email you later with some pics and the news.
I'm on tenterhooks.
2006 Bullet Sixty-5 w/ Ace "Fireball 535" Kit (#10)
Ace "GP" head in the works.

'76 Honda CB550Four K(sold)


"What's so funny 'bout peace, love, and understandin'?"

RGT

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Re: Engine design and modifications Q/A thread
« Reply #6 on: October 21, 2013, 06:40:13 PM »
I was wondering if the factory 535 cylinders are just standard cylinders bored out to their maximum like the Fireball's or are they able to be bored oversize?
Thanks,
Roger

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Re: Engine design and modifications Q/A thread
« Reply #7 on: October 21, 2013, 07:42:32 PM »
OK. I'll take a stab......Here you go Ace:
With the hi-lift rockers and Magnum cams in place, just how much more can you 'fill' the cylinder i.e. how close to 535cc at 1 barr at sea level. I am guessing it will vary with rpm.

ace.cafe

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Re: Engine design and modifications Q/A thread
« Reply #8 on: October 22, 2013, 02:39:49 AM »
OK. I'll take a stab......Here you go Ace:
With the hi-lift rockers and Magnum cams in place, just how much more can you 'fill' the cylinder i.e. how close to 535cc at 1 barr at sea level. I am guessing it will vary with rpm.
The hi-lift hi-port head can flow about 25% more at it's max lift than the regular Fireball head can flow. The highest efficiency of the flow comes at torque peak rpm, and the torque peak rpm of the hi-port head is at a higher rpm than the Fireball head.

We don't have the engine quite finished yet to do a dyno test of it, but it should be capable of 110% to 115% volumetric efficiency at torque peak. In other words, the cylinder should have a compressed load of 10%-15% more than the displacement. Somewhere around 600cc in a 535 cylinder.
Here's the port which flows 241 cfm at .600" lift.


Here's the first viewing of the new Ace hi-lift roller rocker system for the India-made Bullet 500 head.


Another shot.

« Last Edit: October 22, 2013, 02:42:14 AM 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://autos.groups.yahoo.com/group/AcePerformanceBullets/

ace.cafe

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Re: Engine design and modifications Q/A thread
« Reply #9 on: October 22, 2013, 02:49:42 AM »
I was wondering if the factory 535 cylinders are just standard cylinders bored out to their maximum like the Fireball's or are they able to be bored oversize?
Thanks,
Roger

Roger,
All the barrels are the same. The "factory" 535 ones are just the 500 barrels that are bored larger. The wall thickness is not any thicker than the ones we bore for the Fireball. Same thing.
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://autos.groups.yahoo.com/group/AcePerformanceBullets/

singhg5

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Re: Engine design and modifications Q/A thread
« Reply #10 on: October 22, 2013, 03:25:32 AM »
Well Tom another one from me. 

The piggy back ECU (I think it is Dynojet Power Commander) programmed for Suzuki ATV450 has been used on EFI REs to improve its performance with open pipe or other head/cam work. That ATV is also single cylinder 4 stroke engine but can rev way higher than G5, C5. Perhaps close to 11,000 as compared to 5500 or so for G5, C5. 

So question is what makes Suzuki engine safely rev so much higher and produce almost double HP than RE though both are about same volumetric size.

I mean what are the engine design features of Suzuki that are different from RE engine design that result in so much difference in them.
« Last Edit: October 22, 2013, 03:32:50 AM by singhg5 »
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ace.cafe

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Re: Engine design and modifications Q/A thread
« Reply #11 on: October 22, 2013, 03:34:11 AM »
Well Tom another one from me. 

The piggy back ECU (I think it is Dynojet Power Commander) programmed for Suzuki ATV450 has been used on EFI REs to improve its performance with open pipe or other head/cam work. That ATV is also single cylinder 4 stroke engine but can rev way higher than G5, C5. Perhaps close to 10,000 as compared to 5500 or so for G5, C5. 

So question is what makes Suzuki engine safely rev so much higher and produce almost double HP than RE though both are about same volumetric size.

Hi Singh,
The Suzuki engine has a much shorter stroke, which reduces the piston speeds dramatically, so that it can rev to that much higher rpm. It also will have a bore size that is much larger than the Bullet, since it will need that to have that size displacement with the shorter stroke. This allows bigger valve area for more flow.
So, basically, since hp = torque x rpm/5252, the more rpm we can reach, the higher our hp will be, as long as we can hold on to our torque at that high rpm. The shorter stroke's slower piston speeds allow this torque peak rpm to be pushed up the rev range, because it won't reach it's maximum piston speed until much higher in the rev range. This also typically will weaken the lower rpm torque to some degree, which is usually what we see in the higher revving bikes. They like to wind it out at higher rpm speeds, while our thumpers like to cruise along at lower rpms. It's a different kind of ride.
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://autos.groups.yahoo.com/group/AcePerformanceBullets/

Arizoni

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Re: Engine design and modifications Q/A thread
« Reply #12 on: October 22, 2013, 04:50:51 AM »
The short stroke reduces the dynamic stress in the connecting rod and crankshaft.

Basically, the mass of the big end of the connecting rod is traveling around a smaller circle around the main bearing axis so the centripetal forces are less at any given speed.
 That allows the upper limit of the rpm to increase before the stresses in the rod and crankshaft began to tax the materials strength.
Jim
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RGT

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RGT

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Re: Engine design and modifications Q/A thread
« Reply #14 on: October 23, 2013, 07:28:04 AM »
"One thing that's needed to know about ratio rockers is that the effective duration between the .050" lift points is extended, and this will lower your working compression some. So be prepared to make a compression increase when using this package.  With the Ace Magnum cams, the .050" duration is extended by about 24 degrees, with 12 of those degrees on the inlet closing side. That is probably going to drop the compression test psi by about 10 psi. You can reduce the thickness of your barrel base gasket stack, or you can use the 3-way timing pinion to advance the valve timing by 4.5 degrees, to help compensate the compression. Advancing the cams also changes the lobe center angles, and will affect power curve characteristics on a peakier way, and you need to watch out for valve/piston clash when doing that. A test during the build,  of slowly rotating the engine by hand, with a thin(.060") layer of soft clay in the piston's valve reliefs is the usual testing protocol. " From Ace in his new parts thread

I have been thinking about my Fireball back in the states and I rebuilt it just as I had been running it at 4500' with not plate and just one cylinder base gasket. Now that I have my bike in Boston which is pretty much sea level I am wondering if I may end up with too much static compression. I copied Ace's write up above as it got me thinking that maybe if I end up with too much compression I can switch to the Shotgun 410's which by extending the valve timings a little might reduce my static compression so that I don't need to add an extra gasket or spacer. And get a performance boost as well.....I had been thinking of these rockers for after I get the engine broken in again but if I find when I get back to it that I am over compressing it this might be a good option....