Too easy, Teeks and I ain't even an engineer.
California bearing ratio - Wikipedia, the free encyclopedia
but what does it have to do with water injection

 

Hueristic,

The use is for supercharged or turbo applications. When you start packing in air/fuel mixtures under high pressures, the compression pressures increase and higher octane is required. Also when compressing the mixture, it raises its temp. and an inter-cooler may be required. The water injection does two things, 1-cools the mixture, 2-acts as an octane booster.

Injecting water into a non-charged engine will produce ill results.

 

Stock compression ratio is 10.5:1

I run 91 octane almost exclusively in my bike. Some people say they can get away running 87 without pinging.

I think I'm with TBT on this. The water injection is necessary for the increased pressures and temps of a supercharged motor but probably wouldn't be effective on a normally aspirated engine.

If it were, wouldn't it already be a common aftermarket add-on for N/A applications?

I do see the advantages of cooling the mixture. Vapor will expand at higher temps and contract at lower temps. Cooling the mixture can pack more fuel/air per cubic inch of volume in the intake mixture, giving you more power. But cooling it too much (dew point) can convert it to a more liquid state potentially causing over-rich and fouling problems. Using a vacuum operated or push-button switching mechanism to apply the water/alky injection for high power demands could give you some boost in power but if that's the case why not just go with juice?

 

the compression pressures increase and higher octane is required.
Water is not compressible, so in effect all you're doing is reducing the "squish" area of your pistons - same as if you took 25 thou off the head - increasing compression and giving you more bang for your buck(s) That's what I'd do - I'm not keen on variable amounts of water in my cylinders at all at all
I'm told that some Mercedes vehicles have water injection but can't be sure of that.

The cheapest form of instant "bang" is still a nitrous conversion - sounds mad, but it's not - the amount of nitrous is infinitely variable, depending on how much "bang" you want. It runs cooler too. We fit them to caravan towcars here and it makes a great addition on the long hills.... and a cylinder the size of a tyre repair kit or can of spraypaint or a sodastream cylinder will fit neatly in front of the CDI unit and give you quite a few "shots"

 

Searching for water injection results in diesels with water injection systems to reduce temps due to supercharging.

I knew a guy who drag raced and he had better times on a cool humid Friday night then on a hot low humidity Saturday afternoon.

Converting water to steam in the combustion chamber could net more torque but injecting water into a 10,500 rpm engine is not going to get you steam engine results.

"Hey guys, I've got to stop for water again." simply won't fly with my riding group. Methanol is not sold at the pumps either.

Interesting LINK

 

Wouldn't have to stop often for water Tim, 'cause at sea level and 212 F the ratio of water to steam is about 1 to 1600. i.e. 1 pint of water produces 1600 plus pints of steam (water saturated air).

I looked at doing this for my Diesel Landcruiser as I noted how well it went in the thick foggy air we get up here often in winter. The way I was going to do it (probably still will when time allows) is have a small pressure revervoir (for the water), closely wrap copper tubing around the length of one header tube and attach the closest (top) end to the inlet track with a fogger jet. The water in the tubing turns to steam and is self injected (due to the pressure in the closed system) into the airstream entering the combustion chamber. May work??

Personally, I wouldn't do it to my bike though.

Cheers, SB

 

Wouldn't a closed boiler system w/o a pop-off valve be courting disaster?

Also the system would still be pressurized even after you shut off the motor Then you would need a condensate return system otherwise you'd be pumping pure water into your intake at start up

 

Yeah, yeah!!! I'd probably work all that out Woof after I detonated the first motor.................

No, I had thought of a pop off valve. As ususal, too many projects/jobs/PhD's to finish to get this one to the drawing board just yet. ( I did just buy a lovely binocular dissecting microscope though )

Cheers, SB

 

What I mean is there is a equation or a set of equations to find the volume of H2O that would be required to increase the compression of the cylinder from 90lbs to say 140lbs. That would be good to know so that I could at the least have a minimum starting point so that the first nozzle I try will be well within spec and as not to over pressurize the cylinder and destroy a linchpin/rod.


Not sure where they are supposed to be bu the valves were horrible from what I could see. you can see the pics I took of them in the "on the side of the road" thread. I'm pretty sure the water decarb I did cleaned them aout a ton but I don't know what the pressure is ATM. I'll check that out when I put the new coil sticks on.

see above.

LOL, no sheet.

Well I got her registered today and put about 50 miles on her. She's weak and that's more than likely the low compression. I'd hoped the low compression was valve sealing issue from carbon buildup. I'm still not sure I've got all the carbon out though. I may do a seafoam douche. But at least she didn't leave me on the side of the road today!

baby steps.

 

Not true, Although it is indeed used for that it is not exclusive to that.

And the (I'll add this to your list) 3- acts as compression increaser (yeah not really a word but suffices) thing it does may well come in handy for a low compression engine.

Juice is added to the water if you so wish.

I'm really interested in doing this mod for 2 reasons. 1 steam clean all the years of garbage in the head and cylinders and 2 increase the pressure that has been lost. I have no inclination to tear the engine down and replace the rings. hopefully when all the gunk is cleaned out of this poor thing i'll get some compression back and then can make a more conventional decision.

I'll check that link out tomorrow.

Yes, 1700 is what I had read so that is the reason I'm concerned about the size of the nozzle. Of course I will experiment on one cylinder first just to see the compression increase.And if it goes Boom I'm only losing an engine that is in need of a rebuild anyway. Well that's my thoughts on the issue as it stands.

not if it's a switch controlled system. If you read my posts you will see
I have already thought of this as well as a plethora of other factors I am weighing. Pretty much why I started this thread. To see what your guys thoughts were on it. I will think hard on this before implementing it. I never jump into sketchy **** without forethought.

Man I want one of those. Just not enough to pay for it!