locogato11283 Posted October 20, 2004 Report Share Posted October 20, 2004 would anyone be interested in my passion racing cylinders, pistons and spacer plate for a 4mm stroker crank? the boost ports have been jb welded shut which has been holding fine. ive been riding it. the cylinders also have a triple exhaust port done to them as well. these things have a ton of top end but not much on the bottom or middle. theyd make good drag cylinders and maybe someone could even get them to run right on the bottom and mid.(i couldnt) im gonna include the pistons and shit for it also. the cylinder walls are fine and they dont really have that much time on them. i think that you could also run these without the spacer plate and a 4mm crank. it may just not run quite as well. if anyone would be interested in these send me a pm. Quote Link to comment Share on other sites More sharing options...
Big Blue Posted October 20, 2004 Report Share Posted October 20, 2004 pm sent!!!! Quote Link to comment Share on other sites More sharing options...
InFlames Posted October 25, 2004 Report Share Posted October 25, 2004 Just a question but whats the purpose of Jb welding shut the boost ports? Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted October 27, 2004 Author Report Share Posted October 27, 2004 bizzump Quote Link to comment Share on other sites More sharing options...
MRMOONEY Posted October 28, 2004 Report Share Posted October 28, 2004 please reply to my pm thanks. i am very interested. Quote Link to comment Share on other sites More sharing options...
Blue Duece Posted October 28, 2004 Report Share Posted October 28, 2004 Just a question but whats the purpose of Jb welding shut the boost ports? thats a great question Quote Link to comment Share on other sites More sharing options...
sredish Posted October 28, 2004 Report Share Posted October 28, 2004 Probably trying to increase the velocity of air at low/mid rpms to help boost the power there. Not sure, I'm not a porter, but the boost ports would unrestric the intake even further, which would slow the velocity and possibly enough at low/mid rpms to reduce power and therefore giving him the on/off powerband and top end only power. Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted October 28, 2004 Author Report Share Posted October 28, 2004 Just a question but whats the purpose of Jb welding shut the boost ports? thats a great question it was for testing only. i was tryin to see if it would help get rid of the dead spot i had. i noticed absolutely no difference either way. the bike ran the same with them open or closed. Quote Link to comment Share on other sites More sharing options...
PassionRE Posted October 28, 2004 Report Share Posted October 28, 2004 Probably trying to increase the velocity of air at low/mid rpms to help boost the power there. Not sure, I'm not a porter, but the boost ports would unrestric the intake even further, which would slow the velocity and possibly enough at low/mid rpms to reduce power and therefore giving him the on/off powerband and top end only power. Good guess Sredish! Blocking the rear boost port reduces the total area of the transfer network and actually increases blowdown PSI... Originally set at 147 they were probably around 160 when done which moves the power band up and narrows at the same time...Jim Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted October 29, 2004 Author Report Share Posted October 29, 2004 Probably trying to increase the velocity of air at low/mid rpms to help boost the power there. Not sure, I'm not a porter, but the boost ports would unrestric the intake even further, which would slow the velocity and possibly enough at low/mid rpms to reduce power and therefore giving him the on/off powerband and top end only power. Good guess Sredish! Blocking the rear boost port reduces the total area of the transfer network and actually increases blowdown PSI... Originally set at 147 they were probably around 160 when done which moves the power band up and narrows at the same time...Jim yea ur absolutley wrong. my compression before doing anything to those cylinders was 180. and i havent checked it since. as for running different, nope it didnt happen. you can try and talk about them all you want but open or shut it ran the same. still the huuuuge dead spot that you claim is a jetting problem. i dont buy it, never did never will. Quote Link to comment Share on other sites More sharing options...
fixitrod Posted October 29, 2004 Report Share Posted October 29, 2004 Probably trying to increase the velocity of air at low/mid rpms to help boost the power there. Quote Link to comment Share on other sites More sharing options...
The Rebel Posted October 30, 2004 Report Share Posted October 30, 2004 (edited) . I think jim was talking about blowdown pressure, not compression. Exactly. What are you asking for them anyway? Edited October 30, 2004 by The Rebel Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted October 30, 2004 Author Report Share Posted October 30, 2004 well it doesnt matter because he is still wrong. it ran EXACTLY the same open or closed. Quote Link to comment Share on other sites More sharing options...
SDD Posted October 31, 2004 Report Share Posted October 31, 2004 Jim can you explain to me how you check your "blow down PSI"? Quote Link to comment Share on other sites More sharing options...
PassionRE Posted October 31, 2004 Report Share Posted October 31, 2004 SDD, blowdown PSI is configured in the design of transfer area vs. total ex. port area. You have to know the math or have software to determine where its going to be at. As a rule though, raising transfers or adding transfer area without ex. port mods lowers Bldn. PSI. Rasing ex. ports or increasing ex. area without touching transfers raises Bldn. PSI. Reducing transfer area without touching ex. ports raises the Bldn. PSI. This moves the powerband up. As far as I know, there is no way to effectively check Bldn. PSI after the fact for it is usually set to a determined number at a specific rpm,usaully approx. peak rpm desired. The goal is to set the ratios of total ex. area to a matched transfer area for the style of power you desire...Jim Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.