DanielSon

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DanielSon

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rrgt_kid

yeah!, well in my opinion ive seen totaly better! but atleast youve tried!!!!!!!!!!

jeremy.

Corse-R

Danielson:

Don't take me wrong, I told you in the past what seems to me the crank (that in fact, despite to the cuts on the counterweight seems stock to me). I could be wrong, but in the photo the intake window of the crank isn't touched and this is one thing that modifies the powerband and output of the engine.

Seeing those cuts on the sleeve. I expect that you have modified the internal porting of the block, because you removed too much material from the sleeve and the internal capability of generating pressure and vacuum to push the mix thru the ports to the combustion chamber. Not to say that now this sleeve is more prone to warping due to the channels on the ports.

Have you used fillers to put another time on the normal dimensions of the channels block?

Porting an sleeve isn't only a matter of making the holes and the channels bigger. Is a matter of velocity of the mix travelling on the engine (I bet that with the loss of pressure the mix velocity has decreased a lot) and a thinking a way of putting more mix on the combustion chamber in the same time and evacuating the gases after the combustion more quickly for being replaced by fresh fuel on the next piston travel. But remember: Bigger isn't better ever.

Modified many complete engines, but never saw anything similar to this, please that I doubt that this works unless I see with my own eyes (Probably Dennis Richey and Smeltz agree with my points, but is quite difficult that Motorman see this, smetz could be).

FREAKAH

That's quite an increase in crankcase volume.

Not good.

Manticore

Not good.
Not good.

racenut123

iTrader: (32)

Was Jonathan lei using one of these motors?He wasnt any faster than anyone else last weekend in stockton.Matter of fact he had lots of problems.Anyways,good luck.

rod_b

Is that the boost port? It's too large to be the boost port. It looks like the exhaust port. If that's the exhaust port, that engine is history.

DanielSon

hahah douchebags

Corse-R

All engine modifiers by the fact of grinding sleeves and cranks (me included) are enlarging the actual crankcase capacity, thus reduces the internal pressure, thus reduces the flow speed. The ideal porting should be the one that removes unwanted flow blocking, provides better flow speed.

Main problem is that you made some cuts to the crank and sleeve that enlarged the capacity thus reduced two important factors on the engine (compression/vacuum capacity and flow speed). This directs to problems of tunning the engine. A good porting job doesn't need to remove much material.

JUN

that's something different.

stefan

What would concern me most about this crank (I don't see a pic of the sleeve anywhere) is the reduction of the counterweight.

You are taking a huge amount of metal of that thing and in my experience, the engine is going to run very rough and put a lot of strain on the bearings (crank and rod)

If you take this much off one side, you need to compensate on the other.

Also, will that counterweight stay where it is @ 37,000 rpm?

DanielSon

opinions, opinions everywhere

...the brain dead trying to formulate an original thought....

modellor

I dont see how you are using the fan style cuts to create pressure.

I am of the understanding that a fan sucks air in one side and forces it out the other at a greater speed. From your pictures, you dont have any slots in the front of the shaft and case so it cant do this.

All you are doing is swirling whatever air/fuel mixture is in the crank creating turbulence at the wrong point.

I design model aircraft myself and I understand what you are aiming for with the sleeve but I am not sure it is working how you are wishing. The idea at that point is to get the most efficient flow to the chamber and if the mixture is being blocked by any obstruction at all you are defeating the purpose.

Data

I agree with you but you are trying to explain your design to us average hobbyist, and unfortunately, not every one of us are rocket scientist from Sandia National Laboratories, so please forgive me if I could not ask intelligent questions.

Assuming cavitation does occur and fuel does vaporized further (by the way, if you know the vapor pressure and flow pressure of the fuel mixture at the point of inception, would you let me know? I always wanted to know what the values are out of curiosity) at the tail end of the six airfoils (2 on each port, 2 mm H X 1 mm W X 2mm D), how many percentage of the fuel mixture pass through the ports got vaporized further? (I hope this is intelligent enough) The way I see it, the height of the airfoil is only about 1 mm at most, it might not have enough surface area to create enough turbulence to make a difference. For the wing on an airplane to create enough lift to be of any use, it got to have enough surface area. Besides, cross section area of the transfer port tunnel is much bigger than that of the two airfoils; I expect most of the fuel mixture will just travel through the port tunnel without ever hitting the two airfoils.

Also, I think the airfoils are a bit too close to the combustion camber, the flow of the fuel mixture has to change direction already as soon as it leaves the tail end of the airfoils, the turbulence created by the airfoils might not be as effective as it should be. Move the foils to a lower position might help (just a guess).

Is there anyway to polish the EDM surface? I think it really would slow down the flow.

I see you spend a lot of machine time (time spent on making the electrodes, time spent on actual burning) on the sleeve, wonder how much you are charging for all the works? And if you have some any kind of test data (performance, mileage etc), would you publish them? Hope that is not too much trouble.