30Tooth

iTrader: (1)

Of course our brains aren't normal, we're gearheads!

One thing I want to add is that longer stroke engines have less dwell time, can have more blowdown so they are more fuel efficient. The downsides are higher average piston speed and it's affiliates.

NitroVein

There are some good books that covers the basics of two strokes.
Gordon Jennings and Graham Bell books is usually the ones that most start out with.
You'll soon see why a lot of things doesn't matter much.

30Tooth

iTrader: (1)

I've read the Jennings one, advanced concepts for me at the time but I've read it many times to be sure I understood some sections. During the time I was reading the Singh grooves were the rage, if no mistaken Roelof did try something with that concept.

Agreed, we can change the recipe but in the end it's a internal combustion engine with reciprocating piston. The parts I'm focusing is understanding how they can be more user friendly and how to maintain them at their best.

Also...

Roelof

At the end with the many Novarossi engines so far I have seen the timings are in a same range with all different stroke engines. So with a longer stroke engine the combustion stroke before the exhaust opens may be in length longer but in rotation timing still the same although the same length of the rod and the different stroke can give some small differences in the proportions.

NitroVein

Indeed so, just look at other engines. Many modern car engine (full size) that could use a long dwell at TDC to keep the peak pressure longer for more efficiency often run a short rod ratio, and boosted engines that could use less dwell still often run tall rod ratio.
The difference is there, but it's very small and in the end not something that dictates the whole picture.

NitroVein

The subject of understanding could fill a forum by itself...
Lets just say that anyone that say they have complete understanding of engines either doesn't know any better or are lying.
Some aspects of engine theories hold some of the greatest unsolved mathematical "mysteries".
So at this point we are forming theories based on testing to large degree.
That's why F1 teams with an Annual budget of US$ 600.000.000 per car still find improvements all the time.
And it's also why someone with a dyno can get repeatable results, if they use it as a tool to support their theoretical understanding.

But, one has to start somewhere!
Those books cover a lot of the basic understanding and lets you categorize things. You could also read books on 4 strokes, those are usually more up to date, though most do it the other way around.

Roelof

If you read arround these forums about nitro engines then there are people who know some stuf, a lot of people who think they know the stuff and also many people who do not know the stuff, do not want to know it, even think the internals are fragile and let them only be guided by the commercial and sometimes technical bullsh*t.
Like the "new" Novarossi Mantra, it is just a 25 year old model (Nova2000) with a 13mm crankshaft and a square stroke, but because it is "new" it is oh so promising....

The many talks about ceramics, silicone inserts, the amount of ports, the strokes, polishing, scavaning etc does hide what is realy making the engine: the materials and the timings.

NitroVein

I couldn't agree more, the hype around new engines is ridiculous!
And that of Some engine moders is even worse...
But at the same time, that makes it possible for me to buy great engines on sale that is the "older model".

And I would like to see more development in the materials etc that is used!

30Tooth

iTrader: (1)

I don't understand everything unfortunately, mostly the suck-bang-blow and how going one path can affect others and tuned pipes theory.

I'm going to take advantage of having the engine gurus following this thread and present my REDS WR7 Diamond by EBIS and then theorize about it. Posting pics in a couple of hours.

Roelof

There is no EBIS type REDS engine. Probably you mean it is breaked in with an EBIS machine.

NitroVein

I guess what I was trying to say was that it's a sliding scale of understanding.
Everyone has to start somewhere, and you can learn to a degree by trial and error.
But the more you'll understand, the easier it is to adapt to a new scenario. If that makes sens...

30Tooth

iTrader: (1)

Yes the break-in machine, I didn't know if it's spelt break or broke in. Apparently it's run-in.

I understood what you said, no worries.

Alright so here's the pics.
https://drive.google.com/open?id=0B2...3pzRndEcE9EenM
https://drive.google.com/open?id=0B2...0xqQzUzNS1wLVU
https://drive.google.com/open?id=0B2...nV5NTBtZ1VOVDQ
https://drive.google.com/open?id=0B2...XhMVldTTy1DcDA

The rod is so tight I can't remove it! The engine has phenomenal pinch and smooth working. Everything is immaculate.

NitroVein

Get a zip tie around or a small allen wrench behind, pull the crank forward with one hand and swiftly pull the rod of with the other hand. The conrod should be fully seated on the crank or it will just bind.

30Tooth

iTrader: (1)

I'm afraid to do that to be honest, it feels like it doesn't have enough play to come out.

RCTecher12

iTrader: (1)

I had to do that to my Picco P3. They got it in there that way, it has to come out that way. Use a zip tie, get it behind the rod, and put the zip tie end into itself to make a loop. Add a drop or two of oil to the big end of the rod/crankpin with crankpin at the top, brace yourself, and PULL! If you do it quick and fast, it will pop off and be damage free. Don't forget the oil and make sure you pull he crank forward at the same time as pulling the ziptie.