PassionRE

Had a great time while it lasted! We'll be beefing up our frame for next year for sure. A ton of fast bikes showed up this year. Met Cam(Redline), Green, and others as well....all great guys...look forward to next year...Jim

Johnny Curry on his Passion/Sniper RZ/DM600 (gas)...Event TOP TIME ! Brandon Hager on his Passion/Sniper yz-85(gas)...class winner! First runs for both bikes...congrats, look forward to the nationals...Jim

A friend contacted me about this post and felt I should reply to it. First and foremost, Ken, I deeply apologize about the wait time on your engine. I also apologize about returned emails etc., for I have just been overwhelmed with phone calls and builds this season. It is by far the busiest season I've had in 15 years, although this fact has nothing to do with the turn-around time on this particular build. 　 　 　 What is truely pathetic, is that the crankshaft that was supplied with your 535 kit that you purchased from another source, was fitted with Chinese rods that would not hold up to the level of power of that kit in its purchased form, not to mention to the level of tune you contracted me to modify it to. The good news is that supposedly the rods I've been waiting on for your build have been released off of backorder...I should be recieving them soon and then I can wrap this build up. If it is any concelation, I will give you these rods for free for your inconvenience and suffering. Your kit supplier should have done the same thing as soon as it was pointed out to them. Rest assure, your 535 will be a dominant force to be delt with....that is a certainty. 　 　 To any of my other customers that are still waiting on their builds, I appolgize for the wait as well, it will be worth the wait. I do not do wham-bam "here ya' go " engine builds. I dont pump out loads of work for instant cash satisfaction... there are multitudes of builders that can satisfy that nich in the market. If your looking for 2 week turn-arounds, some version of Wham-Bam Inc.is always available to supply you with that level of mediocrity. That fact in itself is why I'm so overloaded...if you want the real deal, I will be happy to build it for you. 　 I thank everyone for their support over the years...Jim Smart

You mentioned Sniper first SlyStalker. If your going to continue your mindless drive- by verbage, expect cold hard facts back in your face. RDZ runs, and sells Sniper Inframes....I doubt he's insulted....just a guess.

Rob's logo...our pipe.

Yeah, Rob is smart enough to recognize THE inframe of choice.

Yeah, and he has great taste in inframes too!

Why not, the rings are obviously in great condition, you can tell that by the minimal blowby. If you slight hone, they will just lap themselves a tad and carry on in the same manner as before. The condition of the piston verifies that their is no symetrical inconsistancy..they are as good as new(-.0002") in overall diameter perhaps, you can have that much inconsistancy between 2 different sets of "new" rings...Jim

Slight hone John... I would be willing to bet that if the intake skirt looks like that at 10 hours on a gas engine, their will be slight verticle markings in the bore. In almost every case, cylinders should be slightly honed and cleaned well everytime you teardown.. did you notice, I didn't say re-ring, that should tell you I didnt think it was wasted, it just needs re-grouping, the moly coating and "dry" apearance speaks for itself..Jim

Ok, first of all, it looks like your bore is pretty straight, and rings were doing their job due to minimum ring blowby on piston...looks good. Piston is very clean for 10 hours on gas, this means the oil is either very clean burning, or you may be washing due to slightly over-rich, or a over octaned condition ( if your domes are falling between 15 and 30 m/s sq. velocity, low sv's can look like this as well). The WSM coating on the skirts is a little more worn than it should be with this amount of time on the pistons, and it appears(in the picture anyway) that the pistons have no glossy appearance on the crown or skirts...not good. Lean mixtures can cause no gloss on the crown, but their is no gloss on the skirts, or sign of chalking on the crown.. so, I say its not lean. Instead, I lean torwards a clean burning oil (possibly slightly washed) wiith minimal stiction characteristics..unless its one of these 60-100-1 ratio oils. My Advice...hone, clean well, skotchbrite piston skirts slightly, and change oils. 927 Maxima at 32-1 will have a little more ash on the crown(no biggy,but it's stiction and glossy appearance are much better ,even at leaner fuel settings, and its bearing protection is second to NONE. This observation explains the loss of molybdium coating on the skirts...if its wearing the coating faster than normal, it's wearing everything else at a faster rate than a high end lubricant would...Jim

What cylinder format,what oil, and fuel?....did you clean pistons with cleaner before the picture was taken?..Jim

That would be for duration only.If you want to know if it was specifically set up for a 4mill, the first thing to look at would be if the transfer/ex port floors to see if they are set near 56.25mm from the head gasket surface. The durations can vary a lot depending on who did it and what their goals were..Jim

Yeah, it helps if you have some shade or not be in direct sunlight when checking spark on PVL's..you have to kick the engine over pretty fast too.

If you have a kill switch or button installed...remove it and re-check. Also check the air gap on the stator and flywheel. Should be the thickness of a piece of masking tape. In many cases, I've had to modify the screws for extra clearance on the pick-ups in order to get proper clearance around the entire flywheel due to the holes being drilled slightly off on the stator plate(common problem). If you are using a single kill button, you will have to install diodes on both kill wires going to the coils. If you are still losing spark on BOTH holes after all of this,,,your stator coils, or magnets are weak.. it would be rare that both ignition coils would fail at the same time. Install an additional ground wire from the engine case to the coil mountings under the tank for good measure. It is CRITICAL that you never kick over the engine unless the plugs or caps are grounded to the engine. You can blow your stator easily if they are not grounded....Jim

Degreaser, carwash, wrap in Saran wrap...throw a few of those smelly dryer sheets in the box.

No problem 1shee, some would think a DM is over-kill but if you detuned it from a typical Banshee set-up, you could easily meet the performance goals and not have to run it very hard. Afterall, those 600's can run hard all day long. And yes, it gets pretty expensive to build one...they are a lot of work...Jim

Stock ports and stock bore and stroke at 4600 ft. elevation.........19cc=153psi 18cc= 166psi 20cc= 142psi

927 hands down, especially on methanol.

The main criteria I was looking at when I voiced my proposal was 20 minute solid run times on the throttle. Yes, HP goals could be met on smaller displacement engines, but with power curve requirements, smaller engine sizes would require higher piston speeds(sustained) in order to produce the power delivery styles and top-end speeds needed to be competitive. By over-shooting required displacement slightly, this would allow for HP goals to be met with safe port area margins, lower piston speeds, and increased reliability. Not to mention faster release rates of heat due to larger ex. flanges and lower velocity feeding the expansion chamber. In this manner we can build the power we need, keep piston speeds down ,and outrun the competition with gear ratio instead of rpm....Jim

Cheetah PV's are an outstanding format to start with...expensive, but extremely flexible in power delivery options.

Considering your entire vocational aptitude only qualify's you to make South Park figurines from your own dung, you are hardly a judge Matt. And since you too are a site sponsor, I dont feel the need to pull punches on a chump like yourself...Jim

Simple facts 1. If you make the exhaust port bigger it will make more power. The bigger the more power bottom line. 2. If you are moving gasses out of the engine at a higher rate you need to be letting it in at a higher rate. The transfers are the first bottleneck in the banshee engine. You need to increase the size of the windows and the runners. The runners can be done with a long bit and you have to be sure not to touch the roofs and blend in the cuts. The windows are tricky. This is why people send theirs to a builder. You can easily screw up the jugs if you cut the sides or roofs of the ports. Buuuuuuuuuuuuuuuuuut the floors are a different story. Raising the cylinder and lowering the floors is foolproof. 3. Your next bottleneck is the intake. Open up the intake windows, port the reed cages and add boysen reeds. 4. Next handicap is the compression. Shave .020" or .060" if you ran a thicker base gasket. Just doing these things will get you a solid 15hp on a piped engine. If you open your exhaust port more you can prolly get 20hp, but will have to change your rings every 30-50 hours. If you wanted to do a budget drag engine w/ drag pipes, you could run a .080" base gasket on top of the stock one or a .100" if you can find it or any combination. You would then lower your ports 2mm, raise your exhaust port to 34bd and widen it out to 72-75% of bore width using a 1/2" radius on the corners and a 2mm crown on the top. Put a generous chamfer around the whole port, especially at the top and bottom. open your transfer runners, raise your intake to 70mm from deck and lower it by 2-4mm. Drill boysen ports, widen your boost port, but leave at least 1.5mm clearance from the ring ends. Narrow the intake bridge to 5mm. Port your reed cages, add boysen reeds. Deck your cylinders. You will need to determine what fuel you wnat to run and determine how much to mill for the right uccr. I can tell you that a safe amount to mill at this stage using the .080" gasket plus the stock .020" gasket is .110" for race fuel, you can probably get away with 50/50 race fuel/ premium unleaded. Make sure you check the squish before the milling; there should be .150" or more of squish. If it is less than that say by .005", you should only mill .105" ect. You want at least .035" squish when you are done. Always check for signs of detonation when done, just to be safe; however I believe if you follow these directions you should definately be in the clear if you run race fuel. Prolly get away with 50/50. Mod your timing plate to +4 These recommmendations are somewhat conservative and your rings should last 20 or more hours at this stage. I'd say with cpi pipes and stock carbs you should be at 62-65hp. 34mm carbs closer to 70 THAT is the best bang for your buck. Just for grins, I ran a complete data analysis on this build format, and these are my findings. Keed in mind this is your "average" Banshee cylinder. they vary somewhat in casting accuracy and amounts of casting slag. With proposed ex. area the peak efficiency of ex ports will be right at 9500 rpm... but transfers wont reach peak efficiency untill 11325. This is widening the rear boost port 1.5mm not sure what you had in mind,but it's a good number. This mismatch isn't the end of the world but the engine will be a little slow to build heat, so heavier riders are going to suffer in acceleration and big drag coefficient enviroments are going to tax performance substantially. Also, the mismatch would NOT like updraft porting, especially near the port roofs of the transfers. Opening up the first 10mm of entrance would be a good idea, but nothing past that on this format. The goal on any updraft is "ever increasing velocity"...so the further you go into the updraft section, the worse things are going to get at this level of tune(BMEP) rating. The stock updrafts will support the BMEP level of this engine with only minor modifications to the very first portions of entry on the updraft. All in all, the engine will have pretty decent midrange and respectable top-end ...CPI would be a good choice to help combat the port rpm match defficiency, but will absolutely hate the head mod proposal(read below)... 34mm carbs would be needed to match intake velocity for this level of Time/Area. It would be a decent trail engine in short. Combustion characteristics of proposed head mods are a mathematical disaster.. With this suggested modification to the head, Squish velocity's are going to be in excess of 200% of maximum limits. Flame speed is going to be 41% higher than target goals on this engine. Cylinder pressures are off 20% as well ,so your giving up hp due to that format. These issues will cause major upper mid-range power losses and over-all performance of the engine will be way down compared to where it could have been. Compression ratio, squish velocity, squish clearance, and timing specifications will all have to be altered from proposed build to balance combustion characteristics. This is not a bash, just the facts. Many are looking for good information on these engines...here you go...Jim

I have not built a Serval for Colby. I'm not sure he even has a set of Snipers........ Do you just pull this info out of your ass? << It seems to be your "go to" source for technical information as well.