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Old 09-12-2003, 08:34 PM   #256
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Default Re: Re: Re: Re: Did I read that right?

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Originally posted by Top Gun 777
As long as burned gases not escape from combustion chamber before exhaust time came-it will not hirt anything
TG I was talking about the compression ratio, rather than the piston/sleeve seal/fit.

I have some very loose fitting engines which run really hard
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Old 09-12-2003, 10:12 PM   #257
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Default compression toruqe

777 you ether misread my last post or diden't understand it! And as far as the few others who dont think compression isen't one of the most important factors providing power let me enlighten you! You are dead wrong!!! There are limits to how much compression you can have but the idea is to get as much as u can with out going into detanation or severe overheating. When you see option parts like supper thin .001 head gasket with a caption that reads increase horse power by simply replacing the head gasket with a smaller one. Are we actually achieving more power by doing this? Yes. So what does it do? (ADDS COMPRESSION) Why are the top engine designers designing there engines with such a close squash band? hmmmmm lets see more compression perhaps? YES!!! The bottem line is you can sugercoat it all you want but when your engine starts loosing compression it will also lose power! Here endeth the lesson!
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Old 09-12-2003, 11:13 PM   #258
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Hellion,

Can you answer me this. From reading your posts I have come to the conclusion that you believe that the harder an engine is to turn over the more compression it has. Do you think this is true?

Do you not think that the engines are harder to turn over due to the friction causes by a P/S fit which is too tight? This is not compression. It is definately friction. Now, I cant see how friction can create torque as you suggest.

Compression will remain the same whether the engine requires grips to turn it over or can be turned over by finger and thumb providing the P/S has a sealed fit.

Quote:
There are limits to how much compression you can have but the idea is to get as much as u can with out going into detanation or severe overheating.
This quote is an example of understanding what people are saying. People could have taken this line as you dont know what you are talking about because of poor thought when writing the sentence. However I know you meant to say that you want to get as much compression as possible without producing pre-detonation or severe overheating.

But I believe your theory is also slightly wrong. For example: It is possible to be running with less compression than you can properly obtain from the engine and still get pre-detonation all because you are using the wrong plug or the engine is running too lean or you are running too high nitro content depending on the ambient temperature. My point. Too many factors have to be taken into account to get the correct compression level to obtain the maximum performance from an engine at any given time.
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Old 09-13-2003, 01:30 AM   #259
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Originally posted by stefan
Nova Rossi based????

Nope, O'donnell based. It's steves brainchild.
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Old 09-13-2003, 02:43 AM   #260
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Default HERE WE GO

Did you really read what I said? Maybe you should read it again! There are allot of things that can cause detonation and over heating that was just a example of what would happen if you had to much compression and I sure as hell don't remember saying the harder it is to turn a engine over the more power you get! With that said I agree the less friction you have the better .HOWEVER... higher compression engines will be harder to turn over and as the engine gets hotter it will be even harder yet ! How bout I try it this way (laymens terms) to gain power you need to intensify the explosion that sends the piston downward ! Do you know what a supper charger or a turbo does. It's simple they are just air pumps that pump more air into the cyl. again adding to the compression and there a ton of factors that involve making horse power but for the last time if you give up compression then you should think about going into electric cars
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Old 09-13-2003, 03:03 AM   #261
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Hellion,

Honestly, you dont have to tell me how engines or anything in Nitro RC works. I gave up on electrics a long time ago. To much hassle keeping them running.

But like I said, maybe you should read all my posts again. Never did I mention giving up compression. I did mention several times that providing the P/S is mated so that no mixtures can escape down the side that the compression will still remain the same regardless if you lap the P/S or not. But each time this was mentioned to you and other things you decided to ignore the facts and carry on ranting about tight fits and compression/torque relations.

But I think we should just let this drop for now. I'm sure myself and TopGun will be more than happy to accomodate you on the track at the Winternats if you plan on competing. This is supposed to be a friendly discussion about engines.
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Old 09-13-2003, 08:47 AM   #262
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Originally posted by blixelX
Hi, any1 here have any comment on the Kyosho engin and the yokomo engin that come with the V1SII and the GT-4? which stock engin (V1SII and GT-4) is better? From the box stated, the yokomo one can up to 100 km/h, is it true? then how bout the V1SII?

Planning to get either 1 of these 2 car? Any comment? Their price are almost the same...
Any1 can give some comment??
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Old 09-13-2003, 09:12 AM   #263
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Having cut my teeth in 200mm Nitro TC I would have to say the yokomo would be a better car in terms of adjustability and strength. But dont get me wrong, when I was racing electric buggies or 1:8th Rallycross (and I guess 1:8th On-road with BMT/Kyosho) I always ran Kyosho cars. Both are great manufacturers and both have there advantages and disadvantages. As for engines. The yokomo engine can be that fast providing the gearing is right and you have a large enough area to run in. But the Kyosho engine is capable of the same if the latter is applied properly also.

The only way to choose a car would be to decide which would offer you better parts support and also which would be better for racing with if you decided to join a club. That one you will have to decide for yourself. I dont know about the Kyosho engine but I know that in most clubs worldwide the Yokomo engine is not allowed because of its size.

Hope this helps
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Old 09-13-2003, 09:59 PM   #264
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Default Re: compression toruqe

Quote:
Originally posted by HELLION
777 you ether misread my last post or diden't understand it! And as far as the few others who dont think compression isen't one of the most important factors providing power let me enlighten you! You are dead wrong!!! There are limits to how much compression you can have but the idea is to get as much as u can with out going into detanation or severe overheating. When you see option parts like supper thin .001 head gasket with a caption that reads increase horse power by simply replacing the head gasket with a smaller one. Are we actually achieving more power by doing this? Yes. So what does it do? (ADDS COMPRESSION) Why are the top engine designers designing there engines with such a close squash band? hmmmmm lets see more compression perhaps? YES!!! The bottem line is you can sugercoat it all you want but when your engine starts loosing compression it will also lose power! Here endeth the lesson!
Hi Hellion. You are absolutly right I can misunderstand what you wrote (my English issue) damn. I've been in USA for 10 years and still can't see the difference between "a" and "z". Sorry abou tit.
I think some how u r referuing to real cars set up and have not too much expirience with Nitro engines ( I might dead wrong on it too). I sad compresi-less is better but I also mentioned reasonble limit. What the limit is, it is up to racer to find his. But power band has nothing to do with compression. You can have great compression in way you see it, but if you make your timing wrong, this compression will not help you at all. I recomend you to find and read some basic principals about 2 cycle engines, I belive Motorman recomend some old book (you can find in his thred). I just want to tell you, I was making engines(modify them and build them ) since I was 14 years old 1977 to 1993. It is not easy to design and build engine, belive me. Much easier to take Novas and do some porting-it will not screw up it anyway. I am ready to discuseabout any 2 cycles engine's desings, but don't tell me I am dead wrong. If I am dead wromg, how come I was many time Soviet union Champion, many time silver and bronze. How come my students were world silver. You kidding me.
I don't want to start any battle with you at all, and I am sorry if some how I insult you, I didn't realy wanted ( my english issue) . I just try to share with everybody what I know and got by my expirience. If it is not acceptable by, that is fin, just stay on your way and I am sure I can live with that, but if you want to listen to me, I can tell you much more about the engines.
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Old 09-13-2003, 10:11 PM   #265
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Default Re: Re: Re: Re: Re: Did I read that right?

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Originally posted by AMGRacer
TG I was talking about the compression ratio, rather than the piston/sleeve seal/fit.

I have some very loose fitting engines which run really hard
Hi AMGRacer. I absolutly belive you and It is right way, loose engine will work harder (till reasonble limit). Compression ratio and compression it is too different things. Compression ratio is how much we compress mixture in combustion chamber and under compression everybody meaning how sealed your piston/ sleeve set is. It absolutly normal to have pretty loose fit, but if you don't loose pressure in combustion chamber-it is perfect. BTW, the hoter engine, the looser fit is, It is designed that way. This is why We have ABC, AAC (differnt materails on piston and sleeve).
Just for exampple, if you have pretty tight set uo but you will have one big scratch on piston-you will not have power couse gases will escape.
I personaly preferd loose set up. ( I tryed in my hobby life tight and loose and normal, everrything).
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Old 09-14-2003, 08:55 PM   #266
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Moddler & top gun777 : I'm not mad at all! A good engine arguement is allways good convo. I have trained allot of high performance techs and if you could give them each (example)$500 to build you a hot engine you would see 5 different ways of doing this. Even though they where trained by one guy. The point I'm trying to make here is every body in this busness will have there own ways of making horse power some right some wrong. And god knows I have never made a mistake (<<<B.S.) lol
And I love hearing other peoples opinions . I myself am learning every day and allways will be!I dont have all the answers. and I hope I didn't offend you! I see allot of future engine modifiers in here and I didn't want them to think that compression isen't that important!To me it's one of the most important parts in achieving high performance goles... So We Cool!!!
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Old 09-14-2003, 09:16 PM   #267
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Everyone has made good comments. Hellion as well as TG.

The one thing that you need to take into consideration hellion is that in the current form we use our 2 strokes they are essentially diesels. Compression(static) is not nearly as important as (dynamic) as this along with the fuel air mixture and plug temprature dictates the ignition timing (not considering dynamic airflow effect/ie port timing or on a four stroke duration and overlap) controls torque and HP more than any consideration of static compression ratio. (albiet that higher dynamic CR makes more torque and lower makes more HP) The most power in our engines is developed with the most effecient dynamic seal with the lowest coeffecient of friction between the parts. all the other factors of torque and HP can be resolved by other means. the BMEP on our engines is so high that currently there is little room for improvement. As TG said its just a shift in the HP/TQ curve. There is some but not much with respect to the higher effeciency recent models.
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Old 09-14-2003, 11:04 PM   #268
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Default Re: Re: Re: Re: Re: Re: Did I read that right?

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Originally posted by Top Gun 777
Hi AMGRacer. I absolutly belive you and It is right way, loose engine will work harder (till reasonble limit). Compression ratio and compression it is too different things. Compression ratio is how much we compress mixture in combustion chamber and under compression everybody meaning how sealed your piston/ sleeve set is. It absolutly normal to have pretty loose fit, but if you don't loose pressure in combustion chamber-it is perfect. BTW, the hoter engine, the looser fit is, It is designed that way. This is why We have ABC, AAC (differnt materails on piston and sleeve).
Just for exampple, if you have pretty tight set uo but you will have one big scratch on piston-you will not have power couse gases will escape.
I personaly preferd loose set up. ( I tryed in my hobby life tight and loose and normal, everrything).
Absolutely agree. My original post to you was that I have found that a lower "compression ratio" (gained by increasing head shims) actually allows the engine to pull more RPM at the expense of torque. I have used this little trick to make my engines pull all the way down a very long straight with very small tires (57mm).
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Old 09-15-2003, 05:51 AM   #269
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Default Nova S5

I have 2 Nova RS12 S5, the first one I bought was a 2003 year production and the recent one is the 2002 production, I bought the 2nd one because I like the performance of the S5, when i disassemble the engine I notice that the crank shaft design is not the same as my 2003 production S5. The Turbo scoop is a bit deeper and the upper part which is usually in triangular shape is a bit round shape also the front bearing is metal sealed rather than rubber sealed of my 1st S5. Is there any performance difference with this 2 same type engine but different production year? for info I bought the 2nd engine was lot cheaper than than the first one at the same LHS.
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Old 09-15-2003, 10:36 AM   #270
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Default Re: Re: Re: Re: Re: Re: Re: Did I read that right?

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Originally posted by AMGRacer
Absolutely agree. My original post to you was that I have found that a lower "compression ratio" (gained by increasing head shims) actually allows the engine to pull more RPM at the expense of torque. I have used this little trick to make my engines pull all the way down a very long straight with very small tires (57mm).
I will try to correct you little bit. To shim up (decrease compression ratio), will help your engine running easier on realy big track, other then that, I would keep clearance as low as possible.
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