Raising compression ratio

[G-Man]

Greener

The 4-ring pistons were used on 1960 C72 and C77, I think. May have been used on C71 / C76 too. I have a single NOS C72 one.

G

[teazer]

Ford Guy,Anticipated miles will be nearly all divided four-lane highway.I believe the higher compression will be more efficient, allowing a crisper response for passing(when necessary) .Greener

If that is where you want to be, you may be starting from the wrong place.

That's not to say that you can't improve performance, but that bike was never designed IMHO to operate in modern traffic conditions on a highway. It's ideal for trips to Starbucks or gentle rides around quiet lanes. Not so suitable for commuting on major roads.

[Greener101]

The speed limit on the route is 55 mph and will require the bike to sustain that speed for approximately thirty minutes(one way). I plan to thermal coat the valve faces piston tops,as well as friction coat the piston sides.I could see stepping into yesteryear during these jaunts.Teazer,are you saying these bikes cannot endure this?Do they require a constant up and down of rpms?If so,why?Greener

[teazer]

Good question.

I'm not saying that a CA77 Dream is not capable of doing 55 for 30 minutes but in this neck of the woods, a 55 limit means close to 70 in traffic and that's a bit punishing for the old girl. I'm sure it can do it but it's running fairly hard.

For the odd summer run, sure, but as a commute that might be pushing it.

The other way to look at is that it's an over engineered Honda that should be able to put up with enormous abuse for years on end and a short jaunt should barely tax it.

I'm sure that Dream owners have some ideas as to its suitability for the purpose. if it were me, I'd probably get an SV650 or EX500 or something similar with with more in reserve for when it's needed.

[Greener101]

I believe a good number for the 55 mph usage will be about 95 percent of the time.Honest.The bikes you mention would probably be more suited for the commute.The Dream would definitely make those miles a little more tolerable.Just some biscuit crust to chew on.Greener

[jensey]

Hi,

I see you want to use this bike as a daily rider / commuter bike. It may seem important to have more power or torque, but it's not, unless you're planning to do highway at long distances.

I went trough this phase too, and I like you to consider the following information as I took the time to write down my experience's :

The engine is very reliable, as long it is in good condition. extracting more power out of it will make the engine less reliable, that is not only subject to the dream, but in general.

I did flow the head, put a CB77 carb on it, but the impact of the bigger carbs wasn't noticed until I changed the mufflers (for early stainless ones). Like I mentioned before somewhere, flowing the intake is worth every penny. Please keep in mind that you have to re-jet the carburetor, the CB77 carb alone is too lean. Bigger valves, smaller valves, it all doesn't give much more power, unless you want to turn it into a high revving bike, but that's almost impossible with a normal budget. The CL72 / 77 cams are a good and cheap swap, but again re-jetting will be necessary.

The electrical system of the bike is much better then the CB72 / 77's and that's because the dreams have different rotors and different stator's. A good add-on is a modern rectifier.

But, and there' always a but :

I went for a dream as a rider, but I rarely use it as a rider, and that's not because the engine doesn't perform, but the reason is the rest of bike itself.

The handling is not good, the steering isn't direct, the suspension (front and rear) is very comfy, but won't do it's job when going a little faster, actually, it's getting dangerous at high speeds. And when the engine is delivering more power, you think the bike is ready for the highway, but it's not.

Then the brakes, the single leading shoe front brake is a good brake, as long you don't doing speeds above 30 / 40 miles an hour, but going any faster you have to use an anchor too stand still in a normal situation. Don't forget, because of the swing suspension on the front, the bike will lift up, and putting weight on the rear wheel, thus taking weight from the front wheel.

Actually a good adjusted front brake can make the front wheel scream on tarmac (even with modern tires), but that says everything about the wrong geometry then about the way the front brake is functioning.

The frame isn't any good too, it wobbles and moves around while riding it, and sometimes you wonder if you don't have a soft or flat tire.

I know it seems negative, but that's not. This bike is not up too modern traffic and modern cars. If a car in front of you is hitting the brakes, and you are braking too, you see the gap between your bike and the car getting smaller and smaller until the moment that even air is not fitting in between.

I don't know how buzzy the traffic in your era is, but I live in the Netherlands, and here the traffic is heavy.

It doesn't mean I don't take the bike out for long trips, but only on Sunday's on twisty roads and nice weather. I really like it's looks, a very classic bike, and a real head turner.

I tuned the engine a little and it is in very good shape, it's doing almost 100 miles an hour (no, that's not a yoke), but it is really scary with those 16 inch wheels, the "seeking for direction" front wheel, the rear suspension looking for travel, the frame that bends in all kind of directions, etc.

Really, it's one of my favourites, very comfy and very relaxing, but not for daily use (at least not in the Netherlands). It would be as you swap the dream front fork for a CB77 fork, put some Hagons on the frame at the rear, and weld some extra material in the frame for that extra rigidity.

But without the dream forks it isn't a dream any more, so, many years ago, I decided to take my CB72 as a daily rider, but I had my scary moments also on this bike, but never felt it as out of control, but the dream was sometimes.

And last two years I took my bomber on longer trips, letting the CB72 garaged. This winter I will work on a few details, and take it out for the next summer,

Jensen

[G-Man]

Jensen

Nicely put. These bikes were built 50 years ago and designed a while before that. I did a nice 350mile round trip on my 1958 BSA Bantam 125cc over a long weekend but I have never repeated the feat.

It was fun to do once just because I'd restored the bike and I enjoyed the nostalgia.

G