I sure hope Ferret sees and replies! ;-)
Just watched the video review comparo of the CB, the R9, and the Triumph Bonnie 1200. I've always enjoyed reading John Burns, and I remember Evans from his past work at CRUISER magazine when I began my bike search in 1998.
Anyway...John mentioned the compression difference between the Honda and BMW as the primary difference in hp, and then said how easy it would be to up the compression in the Honda motor. Easy? Really? And what about the air cooling? How do easy and inexpensive correlate in this endeavor? I really have no idea, but he did say it, so it made me wonder.
I really don't mean for this to be _another_ thread about "How do we get more power from our 1100's" or "WHY didn't Honda put more hp in my bike?"
I'm just curious about his offhand comment that makes it all sound so simple.
(08-22-2017, 02:05 AM)Olyrider_imp Wrote: [ -> ]I sure hope Ferret sees and replies! ;-)
Just watched the video review comparo of the CB, the R9, and the Triumph Bonnie 1200. I've always enjoyed reading John Burns, and I remember Evans from his past work at CRUISER magazine when I began my bike search in 1998.
Anyway...John mentioned the compression difference between the Honda and BMW as the primary difference in hp, and then said how easy it would be to up the compression in the Honda motor. Easy? Really? And what about the air cooling? How do easy and inexpensive correlate in this endeavor? I really have no idea, but he did say it, so it made me wonder.
I really don't mean for this to be _another_ thread about "How do we get more power from our 1100's" or "WHY didn't Honda put more hp in my bike?"
I'm just curious about his offhand comment that makes it all sound so simple.
any chance you have a link to the article?
Raising compression is not difficult, but it is difficult.... if you get my drift. There is no magic button, the motor must come out and get breathed upon by someone that knows what they are doing. If he said it would have been easy for HONDA to do, he is right, but that is not what Honda chose to do in designing this motor. If he said it would be easy for YOU to do, I am surprised.
In order to raise compression you have to decrease the space in which the gas compresses. That is usually done my milling the cylinder head (or using thinner head gaskets..or higher domed pistons) making the dome of the cylinder closer to the dome of the piston creating less space for detonation therefore upping the compression ratio. Make the gap too small however and the pistons slam into the valves when they are open. Don't mill it flat and you take the chance of creating a gap or leak of compression or oil. Personally I am mixed on this when it comes to streetable bikes and the CB1100 in particular. I certainly wouldn't want to do anything to my engine which would make more heat, which raising the compression ratio would do, however I think Honda has over built these motors and doubt a small increase in compression would hurt anything. You would also have to use an octane of gas more appropriate for a higher compression motor, which again produces more heat.
The thing for me is, this is such a lovely motor, with IMO the right power, right where it needs it, that I see little benefit and much risk from changing how Honda designed it. Unless you did intake work, exhaust work, cam work, valve work I can't see where just raising the compression would have very much effect. You are certainly not going to go from 88 hp to 104 hp (or whatever) thru just a boost in compression IMO. Performance is a chain and adding one link doesn't make your chain much longer... a bunch of new links are required to make the chain very long.
But that's my opinion.
A serious HP chaser may have an entirely different outlook and opinion.
(08-22-2017, 03:04 AM)The ferret_imp Wrote: [ -> ]Raising compression is not difficult, but it is difficult.... if you get my drift. There is no magic button, the motor must come out and get breathed upon by someone that knows what they are doing. If he said it would have been easy for HONDA to do, he is right, but that is not what Honda chose to do in designing this motor. If he said it would be easy for YOU to do, I am surprised.
In order to raise compression you have to decrease the space in which the gas compresses. That is usually done my milling the cylinder head (or using thinner head gaskets..or higher domed pistons) making the dome of the cylinder closer to the dome of the piston creating less space for detonation therefore upping the compression ratio. Make the gap too small however and the pistons slam into the valves when they are open. Don't mill it flat and you take the chance of creating a gap or leak of compression or oil. Personally I am mixed on this when it comes to streetable bikes and the CB1100 in particular. I certainly wouldn't want to do anything to my engine which would make more heat, which raising the compression ratio would do, however I think Honda has over built these motors and doubt a small increase in compression would hurt anything. You would also have to use an octane of gas more appropriate for a higher compression motor, which again produces more heat.
The thing for me is, this is such a lovely motor, with IMO the right power, right where it needs it, that I see little benefit and much risk from changing how Honda designed it. Unless you did intake work, exhaust work, cam work, valve work I can't see where just raising the compression would have very much effect. You are certainly not going to go from 88 hp to 104 hp (or whatever) thru just a boost in compression IMO. Performance is a chain and adding one link doesn't make your chain much longer... a bunch of new links are required to make the chain very long.
But that's my opinion.
A serious HP chaser may have an entirely different outlook and opinion.
100% agree with you the Ferret. I was on a ride this sunday where i was all over the motor in 2nd 3rd and 4th (after regearing only the top of 4th hits the governor) and it was amazingly fun and i was keepign up with much faster bikes with no issues (you can only go so fast on the road and the cb1100 keeps up in that range with most everything else), and im like 260 so probably one of the heavier riders. Since the motor is overbuilt ill be able to ride it like a bat outta he** for years and years and it will ask for seconds. a great ride to be sure.
The hassle of trying to build the motor for more power (other than bolt on stuff) is the heat as the Ferret said. I could see bumping it slightly and the motor would probably hold but then youd be needing to change the synthetic oil more often because of higher heat murdering the magic lube. I would still love to get a legit oil temp gauge setup so i know whats normal and if when im on the motor harder i can adjust the oil change intervals as needed. I religiously use the oil temp gauge in my cars and value its data. now to find a place to tap one in.
Good post ferret, right on the money on all counts - but others will have a different opinion. It's whatever "floats your boat" as they like to say around here on the Atlantic coast.
I'm always a bit dismayed when a motorcycle is purchased and then they complain about the horsepower. I saw a lot of that when the Triumph Bonneville came out.
If the customer wanted more power and speed why didn't they buy a bike that already had all of that in the first place?
Turning the 1100 into a power monster would take a lot of money and great skill by the builder - and there are plenty of speed shops that can do that. Speed and power costs money, how fast do you want to go they will ask.
The purchase price of a road rocket off the showroom floor would have been the cheaper way to go and the engineering has already been done at the factory. Just turn the key and ride.
My CB900F (919) is much lighter and has a lot more power than the 1100. When I feel the need for speed I take it out for a rip, but truth be told, it's the 1100 that I choose most of the time because it's such a joy to ride.
^+1
Where's the "like" button again?
I don't think the OP is "complaining" about horsepower. I'm pretty sure he is referring to an article he read by an author he respects saying that an increase in compression could have been or could be easy. He was wondering why and how.
Look. People like to tinker, it's a fact. Not everybody wants a sport bike for various reasons. Ergos, looks, stigma, etc. So the constant arguement on this forum about "you bought the wrong bike" is not a valid one. People love this bike and that is why they bought it. What's wrong with wanting a little more? My stock Bonnie was 55hp at the rear. It's now 69hp. Very little effort and $ to achieve a pretty decent gain. Is it better? To me, (and that's all that matters) yes. Did I ruin it? Will it grenade? No.
It "seems" that when somebody posts about adding a little more pep to their beautiful CB the same folks come out to shame them for it.
Sorry for the rant.
If anyone who posted above this was referencing MY need for additional horsepower...then shame on you!! Please go back and read the last part of my post. Anybody that wrote anything in this thread about forum inmates complaining about the power in our bikes has way-below-average reading comprehension skills, IMHO.
Rant off!!!
Here's the link to the video. It is not an "article". It is a video.
http://www.motorcycle.com
****Then look for the "Videos" in the menu. This comparo will be the first one. I couldn't get it to copy & paste. Sorry!
If you are ADD (like me!) skip to the seven-minute mark and be patient. It is a "discussion". Three knowledgeable guys discussing stuff. You will hear John Burns (the fellow on the right) say "It wouldn't be difficult".
From this simple review came my question to the forum...
