cleaning engine internals

[Buttanic]

Re: cleaning engine internals

Rodbolt, you and I have similar backgrounds. I started working on lawnmower engines in grammer schoolback in the 50's. From there it went to car, motorcycle and boat engines. I did some drag and circle track racing. Always built my own engines.<br />I read every word I could find on engine theory and operation. Right now I have one on the engine stand that I am building for a Chris Craft Cutlass I am restoring.

 

[Peter J Fraser]

Re: cleaning engine internals

They still have missed the point on water and NOS injection.<br />They dont raise the comp ratio by any significant amount unless you over supply.<br />All that happens is the engine burns the extra oxygen that is carried in with the supplemental "fuel" and that alone increases the thermal efficiency of the normal fuel.<br />Get more oxygen into an engine and you can burn more fuel. Exactly what rodbolt said regards fuel / ratio.<br />If you put more oxygen in by whatever means then you must increase the amount of fuel or you get a lean burn and engine meltdown.<br />Those rules do not strictly apply to diesel engines as the fuel / air ratio is a totally different matter.<br /><br />Peter

 

[jimmythekid]

Re: cleaning engine internals

"but like it was posted, with todays fuels and oils there is no reason for water injection now."<br /><br />rodbolt: I may have over simplified the explanation,I am a simple guy after all, in my reference to cylinder compression/volume. However before the ignition system fires the plug, the water will reduce the volume of the cumbustion chamber a BIT albiet a very small bit which will raise the compression a BIT.(probably immeasurable) Once the plug fires, the water flashes into steam which has much greater volume and raises cylinder pressure like you said.( probably immeasurable) They may have gotten the idea from the steam engines used on the railroads of the day. Thats how single and compound expansion steam cylinders work, the highly presurized, superheated water is recieved in the cylinder, which is close to normal atmospheric pressure, and instantly flashes to steam, which we all know takes up much more room in a givin space, which drives the piston outward providing the power (and lots of it) last but not least the main reason for water injection, I believe, was to reduce combustion chamber temps. Yes it will keep the upper cylinders clean which is a side benefit. Modern engines? Lots of later model Ford pushrod truck engines (92-98 4.0,5.0,5.8 engines come to mind) get rebuilt because they have a (rod knocking) when actually the carbon buildup on top of the piston get so bad the piston (now taller because of the carbon buildup, hits the head causing the knocking noise. All caused by the crappy fuel we have to live with today. Todays fuels are far worse than those of 30 years ago IMHO. Contamiated fuel is also common. (Anyone ever work on Gm Multec fuel injectors used on the 3100 engines?) They get away with it because eletronic engine controls due a far superior job of fuel management. All works well and good, until the Service Engine Soon Light comes on. There is a definite need for periodic engine decarbonizing, as "modern engines" are much more sensitive to carbon buildup than those good ol V8's of the 60's Not much has changed internally in an engine since the 50's aside from some changes in materials used, just electronic engine management which is better by leaps and bounds over carbuerators, although more sensitive. If you find that term paper I would be kool to read. Sounds like your an engine guy you might like this- http://www.deadbeatdad.org/eliptoid/menu.html

 

[jimmythekid]

Re: cleaning engine internals

oops I meant not much has changed internally talking about pushrod engines, which is what most boats use.<br />although the overhead cam engines aren't that much different than push rod engines, just how the cams get driven.

 

[lakelivin]

Re: cleaning engine internals

jimmythekid,<br /><br />you've got me curious, why would you convert a lawnmower to a nitrous system?

 

[jimmythekid]

Re: cleaning engine internals

because I can, no really I worked in the lawn care industry, and I took a 20 hp kohler v twin and hopped it up, balanced all reciprocating parts. It would turn 5500 rpm and I tried a turbo but couldnt get it tuned right, so I made a dual injection system for it and added nitrous. It went on an Exmark 60" commercial mower. I did it during the winter, I was living in Michigan at the time. It was just a show piece. Had alot of fun with it. The biggest problem I had with it, was at that high RPM, the plastic fan on the flywheel kept exploding because of centrifugal force, we did it to the school bus just to do burnouts and try to blow the engine. They say Nitrous is a poor mans supercharger, but when things go wrong (like fuel pump failure or running out of gas) it becomes more expensive than a bad crack habit. So Im told