RK Tek Posted November 23, 2003 Report Share Posted November 23, 2003 Jason, This is not sayin that a set of "standard" domes are better or worse than "custom" domes, but for stock cylinders the standard would do just fine. Can we agree on that? I do not think we can agree on that. For several reasons. Let's look a few points 1) The Banshee engine is .. What? 20 or so years old with the same cylinders. So.. say a guy picks ups a screaming deal on a 1988 Banshee . He was told that the engine is stock. Does this new owner know for sure that it is, indeed ,stock? Now, if it is still on it stock bore. .then that would be a miracle for 15 year old engine. SO... if the engine is overbored at all.. then the jugs have been off to SOMEBODY and who knows if they had to deck a few thou off the base or top? 2) Installing the aftermarket domes , I've seen, on a stock engine will probably cause a power loss.. not a power gain. Depending on the compression ratio selected. Installing a set of domes designed for a stock engine can yeild some performance gains.. but most of the combustion chamber designs (based on flat plate volume) that I have seen are not going to add much in the power arena IMHO. 3) Let's look, very briefly, at the internal combustion 2 cycle engine.... Every other stroke is a power stroke. thatis why it can make great power.. But there are many factors working against this process which robs power. For example... pumping losses, frictional losses, volumetric losses etc etc... Correct exhaust systems can aid in reducing these losses... Now.. think about it.. Where is the power being made in the engine?? What causes the "work" on the piston and its attached components??? Is it the pipes? NOPE! is it the Carbs?? NOPE! is it the reeds? NOPE! Hmmmm what actually causes the push on the piston? COMBUSTION!! While the carbs, pipes, and reeds all work together to help supply the required elements for combustion to take place... they are not doing anything that directly creates work on the crank train! All this is done in the Combustion Chamber Hmmm.. so it stands to reason that anything we can do to optimize the combustion process will add performance. Can we agree on that? It also stands to reason that anything we do to upset the combustion process will reduce performance. Now... combustion is not all about compression. There are countless things going on inside this process. It is KAOS! Some if this kaos is somewhat controllable. Other parts are not! The "key" is knowing enough about the controllable portions to be able to optimize it. This is not about compression!!! It is about squish action, cooling action, active radicals, flame front propagation, heat disappation etc... So.. the point being...proper compression ratio with improper squish action, flame propagation etc. will result in less than optimum combustion and can cause MAJOR stress on the entire crank train. So, IMHO.. changing flat plate volume is not the way to improve the combustion process.. The chamber's design is what will improve the process. Most of my chambers come in WAY under in terms of compression ratio compared to what people are/were running before. What makes the power is the design of the chamber and trying to controll as much KAOS as possible. Like I said in an above post.. Many of the crank failures people are experiencing are due to the head design. Bottom line... In the head is where the work is being performed. This is the area that needs MAJOR attention.. not MINOR. Just because the part raises compression numbers does not mean there will be added power. And if there is added power.. there could be unfavorable results down the road. Other bottom line.. on ANY engine that has been disassembled at ANY time in its life.. there exists the possibility of internal or external modifications being performed.. So, just because you have been told that your engine is not modified in any way.. does not mean it is true. Again.. those of you running those low cc domes.. are losing huge power!! If you want to read a snipit on cranking compression.. you are more than welcome. It is located on my webite under the "Tech Articles" section Kelsey Quote Link to comment Share on other sites More sharing options...
94BansheeRider Posted November 24, 2003 Author Report Share Posted November 24, 2003 Ok, so back to my question... I have had some porting done on my jugs. Are 18cc domes ok for this setup? And will they be ok with 28mm carbs and Vforce3 intake? I have been told that porting will reduce the compression, and the smaller domes will compensate for this (18 vs 20). Is this correct? You guys should really quit arguing amongst yourselves Can't we all just git along!!! Peace, Quote Link to comment Share on other sites More sharing options...
94BansheeRider Posted November 24, 2003 Author Report Share Posted November 24, 2003 Duece, Thanks for the response. I currently run about 170 lbs. I run 110 octane or a 50/50 mix to stretch my gas sometimes. Also my crank is welded. I am really looking forward to getting the carbs and intake installed. Will probably wait till after Turkey day, so I can get some riding in over the long weekend. I have a friend of mine that has pretty much the same setup as I do. The only difference is he already has the Vforce intake. He claims to have around 220 lbs. I think he is full of s**t personally. Peace, Quote Link to comment Share on other sites More sharing options...
RK Tek Posted November 24, 2003 Report Share Posted November 24, 2003 Duece, Like I said,, some only hear what they want to hear and the rest goes out the other ear. I explained why a lower PSI engine can make more power. I also gave out other pertinent info regarding combustion and the internal workings of a 2 cycle engine. I also did not make reference to selling ANYBODY a dome in ANY of my posts. Please check for yourself.. There are no "selling" phrases. Screaming Banshee asked for some explainations of some aspects of combustion and I provided just that. Like I said.. no selling, NONE! just some information that, apparantly, most choose to ignore because they do not want to hear. I can show you a lower PSI engine making much more power then one with tons of cranking PSI but you probably would not want to hear that either. I'll tell you what...Ask Forcefed his cranking PSI and then ask how many races he loses. I mention him because he is one you know. Believe me, there are many others. Once again, Duece. THERE WAS NO SELLING GOING ON IN ANY OF MY POSTS!! I came to the conclusion ,,LONG AGO, that the BHQ people much prefer "Shiney" over "Powerful, Reliable, and Shiney" so, believe me, coming on BHQ with the idea of make a sale or two is FAR, FAR from my mind. And once again, Duece.. I thank you for keeping it civil this time. I do appreciate it Kelsey Quote Link to comment Share on other sites More sharing options...
Blue Duece Posted November 25, 2003 Report Share Posted November 25, 2003 I can show you a lower PSI engine making much more power then one with tons of cranking PSI but you probably would not want to hear that either. yes i would Kelsey, id love to hear all about that..... and as far as selling, be my guest, your head which can only run your domes is around 340.00? head and domes, i would suggest anyone wanting a custom dome go with your services or patriot who can cut a dome for a noss or pro design head, but if we took 2 stock motors and you made domes for one and i put domes on the other that gave it 100PSI more than yours, yours would dyno with more power? everything i thought i knew about a engine just went out the window..... but im not doubting your knowledge what i know about combustion you shit out this morning, but when i upped my compression by 65PSI it sure woke my banshee the fuckk up, can you explain why? Quote Link to comment Share on other sites More sharing options...
RK Tek Posted November 25, 2003 Report Share Posted November 25, 2003 Duece, First off... my head is not $340.00 it is $310.00. If you buy another aftermarket head and have custom domes made you are at the same price. As for PSI.. All I can say is that explained in this thread and HERE you can read more on why what I say is true. Or you can go to the SAE website and download, at a cost, 1000's of papers on internal combustion (like I do) and read it for yourself I am not State drag champion because I run high compression and advanced timing. I run lower compression and retarded timing. Go figure... In any case. If you really wanted to be convinced you would allow some of this info to sink in and not be dismissed because you do not completely understand it. If you have poor combustion chambers to begin with and then you up compression a bit and still have a poor combustion chamber then you may see some power increase but usually this increase only appears in the lower rpm range not in the upper band. In any case... if you are happy with the way your bike runs.. then that is cool. If you do not wish to improve it even further.. that is your call. Kelsey Quote Link to comment Share on other sites More sharing options...
Bense Posted November 26, 2003 Report Share Posted November 26, 2003 I am very interested in your thoughts Rk. I race drag boats and I have seen this over and over. Now raised compression with the proper combustion chamber will ultimatly give you the best results. I would like to hear more if you have more to offer. By the way, what head do you make and where are you out of? I would like to check it out some more. Quote Link to comment Share on other sites More sharing options...
RK Tek Posted November 27, 2003 Report Share Posted November 27, 2003 Bense, I am in Idaho Feel free to phone me if you wish to discuss combustion Kelsey Quote Link to comment Share on other sites More sharing options...
BSPolice Posted November 27, 2003 Report Share Posted November 27, 2003 RK TEK, Ive never seen so many blanket statements in my life. And then you go on saying your supplying information, when you say absolutely nothing. Not only are you a total loudmouth, half of what you say is total BS. Your websight is a joke and you are dead wrong about proper combustion being as much or more important than porting in reference to performance and hp gains in 2 stroke engines. Combustion is afterall really just hot air... I guess you are the expert! Quote Link to comment Share on other sites More sharing options...
Blue Duece Posted November 27, 2003 Report Share Posted November 27, 2003 RK TEK, Ive never seen so many blanket statements in my life. And then you go on saying your supplying information, when you say absolutely nothing. Not only are you a total loudmouth, half of what you say is total BS. Your websight is a joke and you are dead wrong about proper combustion being as much or more important than porting in reference to performance and hp gains in 2 stroke engines. Combustion is afterall really just hot air... I guess you are the expert! here we go...... Quote Link to comment Share on other sites More sharing options...
RK Tek Posted November 27, 2003 Report Share Posted November 27, 2003 Oilsmoke.... I don't quite understand your question or statement: If a properly design head is made to increase horsepower not octane Or maybe I do.... The head design does not increase octane.. It may increase the octane requirement of the engine (is that what you are trying to say?) The Cranking PSI does not tell you octane requirement. I have several engines that crank over at 140-150 PSI than will not live on anything less then 110 ocatane BSPOLICE.. Nice!!! you joined today, or should I say... came up with another alias from your everyday BHQ name, just so you could post a thread and not have people know who you really are!!! GEEEZ.. I wonder who you could be? WOW... that is one smooth operation... Nice job!! By the way.. about my website.. Glad you hated it.. It is like I have been saying all along... if you want you want something that is the best you call on an expert in that field!! I am definitely no expert in the field of website design.. but I still can make one and it works! But there are better sites out there. Kelsey Quote Link to comment Share on other sites More sharing options...
Oilsmoke Posted November 27, 2003 Report Share Posted November 27, 2003 OK on my shee it runs cold @145 and is ported and runs great with 91 pump gas at 4300 feet. I torn it down and the heads is stock but milled to the point that the water jacket was cut into. I would like a new head for it. I was thinking of one with inchangeable domes.But I don't have a Guage or a way to judge my choice. How do I as A none engine biulder make this choice as so to Increase my power output? If i spend big money for a New Head I want it to make more power not less so if it runs ok with old setup would a 19cc dome be a good starting piont and I can run higher ocatne if need. Quote Link to comment Share on other sites More sharing options...
dlnoss Posted November 27, 2003 Report Share Posted November 27, 2003 Just to get my 2 cents in... Kelsey, I'm sure you build fast motors and know what you are doing. I'm also sure that there are a lot of engine builders that build motors slower, faster, and comparable to yours using similar and radically different methods. Your posts come across that you are the only one who has knowledge which can't be true. I've learned a lot over the past several years from reading Blair, Gorr, Turner, and others, and I've designed some chambers that aren't like anyone else's I've seen (although I must admit I haven't seen many designs). I intend to continue learning and trying innovative ideas. I don't agree with senseless bashing of people. I generally don't say (or type) much unless it is positive or productive in some way. I, like you, would rather not see posts like the one you are referring to. EVERYONE, Have a great Thanksgiving. All of us obviously have stuff to be thankful for. -David Quote Link to comment Share on other sites More sharing options...
RK Tek Posted November 27, 2003 Report Share Posted November 27, 2003 oilsmoke.. 1st you need to decide what octane you want to run. Then you can decide on a compression ratio that will accomodate that ocatane requirement. 19cc?? who knows... Think of this... say you engine has a negative deck height of .015". That can ad between 1.225 and 1.3 cc's to your overall trapped volume..So.. now, your 19cc dome just became a 20.225 or a 20.3cc dome depending on your bore size. You just lowered your compression ratio quite a bit(over 2.3 points) and , more importantly, you just upset the squish effects of the engine to a point where you MAY have detonation issues. OK.. take that the other direction.. you have a positive deck ht of .015" now your 19cc domes just became 17.8 (roughly)cc's and you raised lowered your trapped volume and raised compression ratio up at least 2.3 points on the compression ratio scale, possible more depending on the bore size. NOW, you may have serious reliability issues or it could run like a scalded dog.. ya see.... it is NOT about the flat plate volume of the domes.. it IS about what is added or taken away due to the engine specs and how these engine specs effect the combustion process in terms of squish action, heat, and flame propagation . Make sense? Kelsey Quote Link to comment Share on other sites More sharing options...
RK Tek Posted November 27, 2003 Report Share Posted November 27, 2003 dlnoss... Your posts come across that you are the only one who has knowledge which can't be true This is the problem with forums.. people cannot hear the tone that is in the typing. Everybody hears a different tone and you hear a snotting tone when, I can assure, you that is not the intended tone. Inotherwords... I in NO MEANS stating that I am the only on on here that knows anything about combustion. What I am saying is that I DO know something about it. The BHQ people may want to ask themselves why there are not many (if any) full fledged performance shops posting on this site. If you go down the posters in this forum you will not find many (if any). IMHO.. it is because anytime somebody posts something they get these type of responses. It seems ironic because the ones that know and FREELY post informative threads can only help improve the knowledge of those who did not know. BUT they get "flamed" because they do so. For example... The last fiasco with me on here.. You realized that your compression PSI chart was incorrect and changed it. You also realized that the porting of an engine effects the PSI of an engine and, consequently; you added this info in your webite.. Ya see.. information was exchanged and mis information was fixed. Now you seem to ask about the porting state of the engine before you recommend a dome size where before you did not. So, that whole fiasco became a positive for you. If it had not happend.. your PSI chart would read as it did before. My point??? It is NOT to talk down to you.. It IS to point out that if people would listen without predjudice... then there could be a good information exchange(on ANY subject) between people. But instead it seems to always turn into a bashing session. Kelsey Quote Link to comment Share on other sites More sharing options...
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