Bheezy27403_imp
Road warrior
Well done sir. Some actual testing done in the correct order. So often you see these things done willy nilly. Looking forward to the rest of the results.
Any interest in cams?
- Thread starter PowerDubs_imp
- Start date
PowerDubs_imp
Road warrior
Thread starter
I honestly do not think there would be any benefit to straight timing the cams.
The stagger is only on the intake cam, the exhaust is already normal.
It would be an awful lot of work for probably a difference of one or 2 hp while loosing the wonderful sound the engine makes the way it is currently designed.
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The stagger is only on the intake cam, the exhaust is already normal.
It would be an awful lot of work for probably a difference of one or 2 hp while loosing the wonderful sound the engine makes the way it is currently designed.
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beardyweirdy@me.com_imp
Been there
Actually, why would the ign timing be delayed for Cyl 1&2?
If they are evenly spaced no the crank shouldn't they fire at the same point?
Unless they are off set on the crank... just thinking...
If they are evenly spaced no the crank shouldn't they fire at the same point?
Unless they are off set on the crank... just thinking...
PowerDubs_imp
Road warrior
Thread starter
I'm going to guess the crank timing and TDC is the same across all 4, but only the factory knows for sure.
While a normal engine times the ign across all cyl a certain degree BTDC, changing the cam timing can change where optimal ign timing is set. But just like the cam timing being slightly mismatched, having the ign timing off a bit in either direction isn't a big deal- unless you advance enough to detonate (not pre-ignition).
You can rock most settings slightly- cam timing, ign timing, fueling rich or lean to little effect.
Heck, for all I know just by changing the duration and lift- therefor effecting the charge pressures, maybe overlap, scavenging, etc- it is possible the factory ign curve will no longer be optimal as is. I don't care- and wouldn't expect it to make a huge difference anyway.
There are soo many variables to engine design, operation, modifications, tuning. Luckily in modern computer designed engines as long as you don't stray far from what the factory designed not much of that matters in the real world. It is when you start pushing the limits that it really takes on a whole new world of complication.
Example- I am leaving the cam timing alone. I am not putting in huge cams. I am not raising the rev limiter.
So- I shouldn't have to worry about valve float, valve spring coil binding, piston pocket clearance, but stuff still changes- cams allow more air, which needs more fuel, but I am *possibly* also lowering my dynamic compression ratio at lower rpm (static will stay the same)..and might be increasing it up top due to scavenging and velocity. All depends on overlap which I admittedly haven't bothered to delve into.
I could spend a LOT of time doing all sorts of calculations and measurements, tearing my engine apart or buying pieces off Ebay for benchwork- but I've been doing that for decades and luckily have learned enough to know when it matters and when it doesn't.
This is by no means a race bike. There are plenty of bikes now if you want 200hp.
For what I am trying to achieve- just a more natural old school engine breathing before emissions and cats required very mild cams and lean fuel limiting both power generation and cooling purposes on our air cooled.... nothing extreme is needed.
I think 100whp will be broken though.
While a normal engine times the ign across all cyl a certain degree BTDC, changing the cam timing can change where optimal ign timing is set. But just like the cam timing being slightly mismatched, having the ign timing off a bit in either direction isn't a big deal- unless you advance enough to detonate (not pre-ignition).
You can rock most settings slightly- cam timing, ign timing, fueling rich or lean to little effect.
Heck, for all I know just by changing the duration and lift- therefor effecting the charge pressures, maybe overlap, scavenging, etc- it is possible the factory ign curve will no longer be optimal as is. I don't care- and wouldn't expect it to make a huge difference anyway.
There are soo many variables to engine design, operation, modifications, tuning. Luckily in modern computer designed engines as long as you don't stray far from what the factory designed not much of that matters in the real world. It is when you start pushing the limits that it really takes on a whole new world of complication.
Example- I am leaving the cam timing alone. I am not putting in huge cams. I am not raising the rev limiter.
So- I shouldn't have to worry about valve float, valve spring coil binding, piston pocket clearance, but stuff still changes- cams allow more air, which needs more fuel, but I am *possibly* also lowering my dynamic compression ratio at lower rpm (static will stay the same)..and might be increasing it up top due to scavenging and velocity. All depends on overlap which I admittedly haven't bothered to delve into.
I could spend a LOT of time doing all sorts of calculations and measurements, tearing my engine apart or buying pieces off Ebay for benchwork- but I've been doing that for decades and luckily have learned enough to know when it matters and when it doesn't.
This is by no means a race bike. There are plenty of bikes now if you want 200hp.
For what I am trying to achieve- just a more natural old school engine breathing before emissions and cats required very mild cams and lean fuel limiting both power generation and cooling purposes on our air cooled.... nothing extreme is needed.
I think 100whp will be broken though.
beardyweirdy@me.com_imp
Been there
Roger that... looking forward to the results coming in.
just throwing this out there.
I read that during development of this engine they had a problem with the heads cracking because of the heat from the top of the combustion chamber. their fix was this oil cooler cooling the top of the combustion chamber in the head. I am wondering if more HP would result in a cracked head ? i would love to hear about HP gains as i love that stuff but would never consider it myself as it would definitely rob my off the bottom straight up torque curve i love so much. I generally shift at 2500 RPM anyway. keep us posted , like i said i like to hear about advancement and engineering.
BTW - the largest HP gain i have seen posted comes from the wyvern 4 into 4 exhaust with 90.8 HP at the rear wheel posted on samurider cb1100 website
I find it hard to believe that a 13 HP gain is made by these pipes myself but mine is a very strong runner
I read that during development of this engine they had a problem with the heads cracking because of the heat from the top of the combustion chamber. their fix was this oil cooler cooling the top of the combustion chamber in the head. I am wondering if more HP would result in a cracked head ? i would love to hear about HP gains as i love that stuff but would never consider it myself as it would definitely rob my off the bottom straight up torque curve i love so much. I generally shift at 2500 RPM anyway. keep us posted , like i said i like to hear about advancement and engineering.
BTW - the largest HP gain i have seen posted comes from the wyvern 4 into 4 exhaust with 90.8 HP at the rear wheel posted on samurider cb1100 website
I find it hard to believe that a 13 HP gain is made by these pipes myself but mine is a very strong runner
PowerDubs_imp
Road warrior
Thread starter
I don’t expect to loose much, if any low end power with what I am doing.
I also don’t expect to have any reliability issues from heat for 2 reasons- I will not have to worry about staying lean or the cat.
Since I do not have the limitations Honda did- no emissions, I can cool with fuel just like in the old days.
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I also don’t expect to have any reliability issues from heat for 2 reasons- I will not have to worry about staying lean or the cat.
Since I do not have the limitations Honda did- no emissions, I can cool with fuel just like in the old days.
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emullick_imp
Running like a top
My shop manual for '13 and '14 CB 1100 shows cam timing:
Intake Opens at 1 mm 5 degrees ATDC
Closes, # 1 and 2 28 ABDC
#3 and 4 38 ABDC
Exhaust opens 42 BBDC, closes 10 BTDC
Strange, but making changes will affect many other things.
Personally, I will not try to re-engineer the engine.
There are lots of other bikes to choose from.
On my CB 750 I had Yoshimura 812 pistons, new cam, and he flowed the head.
Back then there weren't nearly as many bikes to choose from.
Intake Opens at 1 mm 5 degrees ATDC
Closes, # 1 and 2 28 ABDC
#3 and 4 38 ABDC
Exhaust opens 42 BBDC, closes 10 BTDC
Strange, but making changes will affect many other things.
Personally, I will not try to re-engineer the engine.
There are lots of other bikes to choose from.
On my CB 750 I had Yoshimura 812 pistons, new cam, and he flowed the head.
Back then there weren't nearly as many bikes to choose from.
PowerDubs_imp
Road warrior
Thread starter
I’m not reengineering. Just adding a little more lift and duration. Easy Peasy.
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PowerDubs_imp
Road warrior
Thread starter
Might as well keep my power updates here since the cams will be the main end result.
Now that the baseline is done- are we having fun yet?
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Now that the baseline is done- are we having fun yet?
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PowerDubs_imp
Road warrior
Thread starter
Just heard back- "They had to make new
tooling in order to grind these cams, it's a head the goes on the end of
the cam to drive it on the machine for grinding. It will be about
another 10 business days before shipping our of here. I super apologize
for the delay, but we're almost there."
SOOO- the headers are on- and yea, when I fired it up to check for leaks there is definitely an increase in decel popping. Currently installing the power commander and auto tune. Will block pair.
Modified velocity stacks will go in at cam install time.
tooling in order to grind these cams, it's a head the goes on the end of
the cam to drive it on the machine for grinding. It will be about
another 10 business days before shipping our of here. I super apologize
for the delay, but we're almost there."
SOOO- the headers are on- and yea, when I fired it up to check for leaks there is definitely an increase in decel popping. Currently installing the power commander and auto tune. Will block pair.
Modified velocity stacks will go in at cam install time.
Chrisvillar98_imp
First service completed
You're doing Gods work, powerdubs. I'm following with interest.PowerDubs_imp said:
PowerDubs_imp
Road warrior
Thread starter
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PowerDubs_imp
Road warrior
Thread starter
So... while waiting for my cams to ship to me, I went back to the local dyno again for a final baseline before cams #, and more importantly curve.
The difference between these runs is I added a arrow header, my modified velocity stacks, and fuel with the power commander / autotune that I am still playing with.
Amusingly I am running a little leaner 7k+ now even with my (clueless) tuning.
I will be fixing that once my POD300 shows up and I can see what the real world data is while riding.
Going to try to get the number closer to 13 across the board, but not concerned about fine tuning now as it will all change once the cams are installed.
Anyway- the best modifications are the ones with no losses (wot)...
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The difference between these runs is I added a arrow header, my modified velocity stacks, and fuel with the power commander / autotune that I am still playing with.
Amusingly I am running a little leaner 7k+ now even with my (clueless) tuning.
I will be fixing that once my POD300 shows up and I can see what the real world data is while riding.
Going to try to get the number closer to 13 across the board, but not concerned about fine tuning now as it will all change once the cams are installed.
Anyway- the best modifications are the ones with no losses (wot)...
Sent from my iPhone using Tapatalk
Aussieflyer
Been there
Hey Josh that's an excellent result. A near 10% improvement to HP and a glorious linear power delivery, the bike should drive exactly like before but now with extra punch above 6k rpm. I'm really curious about your fuel table to see how the Autotune worked throughout the rev range at WOT. Any chance you could post a picture please?
Great project, I'm a keen observer.
Great project, I'm a keen observer.
:banana::beerchug::biker:PowerDubs_imp said:So... while waiting for my cams to ship to me, I went back to the local dyno again for a final baseline before cams #, and more importantly curve.
The difference between these runs is I added a arrow header, my modified velocity stacks, and fuel with the power commander / autotune that I am still playing with.
Amusingly I am running a little leaner 7k+ now even with my (clueless) tuning.
I will be fixing that once my POD300 shows up and I can see what the real world data is while riding.
Going to try to get the number closer to 13 across the board, but not concerned about fine tuning now as it will all change once the cams are installed.
Anyway- the best modifications are the ones with no losses (wot)...
Sent from my iPhone using Tapatalk
nice results! cool bike too!
Bheezy27403_imp
Road warrior
:clap:
riggies_imp
Running like a top
Awesome thread, PowerDubs, we all owe you a beer.
PowerDubs_imp
Road warrior
Thread starter
Aussieflyer_imp said:
More punch both at low and high. Here is a show with the tq difference shown. Nice tq gains both down low and up top.
Fuel trims are a work in progress. Still tweaking and waiting for my POD300 to help dial it in. Subject to change at any moment (I have been playing with it alot) and the cams will totally change it anyway.
Heck- who knows, if I richened up the top end as is I might hit 100whp...as it appears my peak hp was running at 13.5ish...
My cams will definitely be interesting!!!!
Makes me wonder if I sent the ECU to Guhl to have him change the ign timing and remove whatever the factory limitations are..
