fixitrod Posted November 6, 2004 Report Share Posted November 6, 2004 BanchettaI noticed on your stroker motor, you have a dip right before it comes on the pipe. Were you ever able to get rid of that dip with jetting changes? I can feel the dip on my ported stock stroke motor. If I roll on the throttle, the dip isn't nearly as bad, but when I go wfo on the throttle when I'm off the pipe, it'll hit that dip. It just sorta sputters until the motor revs past the flat spot. Do you know what is causing this or how to get rid of it? I ended up taking off my stock modified head for the stroker and had Dave at Noss make me some stroker domes. I increased my compression from 158psi to 185psi and had a different shape dome put in for a broader powerband. I haven't put the shee on the dyno since my head change, but it definately made a huge difference. I told Fixitrod about this and he bought a head for his stroker to. Fixed his problem and then some. Not to say thats your problem, my shee only fell on its face at that rpm, if I kept the rpms up, then I had no problem w/ response, but when I let the rpms back down and hit it. It'd fall on its face and piss me off...as you can see w/ my originally graph, I'm not used to dead spots.... A lot of times a lean needle will cause that hesitation before powerband like your saying. Have you tried raising the needles? Also, most high rev pipes or dune porting changes the port timing which will make your power move to the higher rpms causing that dip before the powerband since the port timing is no longer matching the pipe....increasing compression can help get the port timing back in play w/ the pipe. The increased compression accelerates combustion speed and will change the timing of everything....Its the one thing that a lot of builders don't compensate for which in turn should tell you something.... so if you ever want to see how much builder knows then ask him what he needs for info from you to build you a motor....he should be asking you what kind of fuel your running, compression you want to run, compression he suggest, riding style, what kind of pipes your running, carbs, timing, etc..It ALL plays a part. Sorry for the book... Don't forget we tightened the squish up to Banchetta. I had almost .060 and didn't know it until I measured it. Went to .035 by a calc that Jim at passion did for me. He was dead on. Quote Link to comment Share on other sites More sharing options...
sredish Posted November 7, 2004 Report Share Posted November 7, 2004 OK, let me ask you all a question I thought of while driving around today. If I make a slight jetting change, like 1 main size and gain a few hp, does that mean that's the better setup or will I still have to worry about being too lean? Like, if I lean my main 1 size or even 2 and gain hp over the base reading, does the more power tell me it's right on or will I then have to double check that I don't have it too lean? Jetting on a dyno is new for me as well and this might be a stupid question, but I don't want to totally rely on my dyno readings unless there is no worries as long as there is power gains. Dunno, later fellas. Quote Link to comment Share on other sites More sharing options...
00BANSHEE Posted November 7, 2004 Report Share Posted November 7, 2004 sredish, from what I have learned from playing with the dyno, it is safer to leave a couple hp on the table to be on the safe side of jetting. You will get the most hp from running right on the very edge of being too lean which is Ok for someone setting their bike up just for a few passes down the dragstrip. But I think this is a little to lean for someone that wants to go out riding for the day. So my answer to your question-- "Like, if I lean my main 1 size or even 2 and gain hp over the base reading, does the more power tell me it's right on or will I then have to double check that I don't have it too lean? Would be yes you do need to make sure you aren't too lean. I have heard alot of guys say their bike ran the fastest right before it blew up. I'm certainly not a know it all in the jetting department, just my .02 hope it helps you out. Quote Link to comment Share on other sites More sharing options...
sredish Posted November 7, 2004 Report Share Posted November 7, 2004 sredish, from what I have learned from playing with the dyno, it is safer to leave a couple hp on the table to be on the safe side of jetting. You will get the most hp from running right on the very edge of being too lean which is Ok for someone setting their bike up just for a few passes down the dragstrip. But I think this is a little to lean for someone that wants to go out riding for the day. That's definitely how I was going to approach it, I just wanted to bring it into "open discussion". Appreciate the comments. Quote Link to comment Share on other sites More sharing options...
fixitrod Posted November 7, 2004 Report Share Posted November 7, 2004 You have to remember though, a dyno may make you jet a little rich because of the resistance of the dyno. It's like going uphill. Quote Link to comment Share on other sites More sharing options...
Ducman Posted November 8, 2004 Author Report Share Posted November 8, 2004 Well I took off the head this weekend and the domes didn't have the CC size written on them. I talked with Mr. Noss today and he is having me measure the squish, dome size (using a seringe and alchohol), and distance from the bottom of the dome to squish band (since 4mm sroker piston goes above the top of the cylincer and I don't know the thickness ofcylinder base gasket). Then we can see if squish clearance is part of the compression problem and figure out what size domes to run. The bike ran great this weekend and seems to be jetted really well, just runs real "top endy" and I'm sure that with more compression it will feel stronger on the bottom end. Not that it was real bad on the bottom end,but the power just hits like a ton of bricks the instant it gets on the pipe no matter what throttle position. Got to look at the tripple port inside the cylinder too. Thats some seriously trick looking tunneling work that comes out just about all the way on the side of the cylinder in its own little square port opening. As far as the dyno, if it has a sniffer to measure the A/F, that will tell you if you are getting too lean probably better than by doing plug checks. On cars (or Ford Llightenings ) that are supercharged or turbocharged if you modify them to make more boost you have to tune them for the added boost to insure a safe A/F and to not add more boost w/ no HP gain due to running way to rich, or because you went off the stock fuel curve and you computer has to shut off all fuel because is doesn't know what to do. The only way to check the tune and A/F is with a sniffer on the dyno. Quote Link to comment Share on other sites More sharing options...
00BANSHEE Posted November 8, 2004 Report Share Posted November 8, 2004 The bike ran great this weekend and seems to be jetted really well, just runs real "top endy" and I'm sure that with more compression it will feel stronger on the bottom end. Not that it was real bad on the bottom end,but the power just hits like a ton of bricks the instant it gets on the pipe no matter what throttle position 278486[/snapback] Ducman, A set of V-Force reeds will take that "top endy" feeliing right out and smooth the powerband out quite abit broader. I couldn't believe the difference they made on a couple of shees that I rode after they had been ported. They went from real peaky to real smooth without losing any power after we switched out the boyseen reeds for V-Force. Quote Link to comment Share on other sites More sharing options...
Ducman Posted November 8, 2004 Author Report Share Posted November 8, 2004 Ducman, A set of V-Force reeds will take that "top endy" feeliing right out and smooth the powerband out quite abit broader. I couldn't believe the difference they made on a couple of shees that I rode after they had been ported. They went from real peaky to real smooth without losing any power after we switched out the boyseen reeds for V-Force. 278512[/snapback] Thats what I'm runnin I just haven't updated my signature, as it is in a period of rapid flux. Quote Link to comment Share on other sites More sharing options...
roosthrower Posted November 9, 2004 Report Share Posted November 9, 2004 banchetta thanks for the book. I guess I'll have to take a serious look into getting a new head. My problem is just like the one you described. The power lags only right before it comes on the pipe. I've toyed with needles long enough. It only runs worse when I go richer on them. Quote Link to comment Share on other sites More sharing options...
Banchetta Posted November 11, 2004 Report Share Posted November 11, 2004 banchettathanks for the book. I guess I'll have to take a serious look into getting a new head. My problem is just like the one you described. The power lags only right before it comes on the pipe. I've toyed with needles long enough. It only runs worse when I go richer on them. 279002[/snapback] Good luck, I hope it works as well for you as it did for Rod and I... Quote Link to comment Share on other sites More sharing options...
Banchetta Posted November 11, 2004 Report Share Posted November 11, 2004 OK, let me ask you all a question I thought of while driving around today. If I make a slight jetting change, like 1 main size and gain a few hp, does that mean that's the better setup or will I still have to worry about being too lean? Like, if I lean my main 1 size or even 2 and gain hp over the base reading, does the more power tell me it's right on or will I then have to double check that I don't have it too lean? Jetting on a dyno is new for me as well and this might be a stupid question, but I don't want to totally rely on my dyno readings unless there is no worries as long as there is power gains. Dunno, later fellas. 278082[/snapback] I've always read my plugs before I went to the dyno, checked them on the dyno and always got max readings w/ the plug color that I liked. So I trust that the perfect and most hp reading on a dyno will give you your best air/fuel ratio...Besides, a dyno will create more of a load than the actual field, causing you to be running richer in the field than the dyno....since more load requires more fuel.. Quote Link to comment Share on other sites More sharing options...
InFlames Posted November 14, 2004 Report Share Posted November 14, 2004 Bigblue>>>I have the exact same setup as you except i run 34 pjs....what kind of gas was used in that dyno run? thanks.. Quote Link to comment Share on other sites More sharing options...
Big Blue Posted November 14, 2004 Report Share Posted November 14, 2004 Im running phillips b32 it is 110. Quote Link to comment Share on other sites More sharing options...
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