J-Madd

Squish clearance is not to make sure the piston hits the head; it's to get the correct MSV (Maximum squish velocity). As mentioned, you need squish band, angle, piston angle, combustion chamber volume, etc, etc, to calculate MSV. That being said, I have never calculated MSV. It usually takes software to plug in all of the variables.

What do you mean have them build the motor back? So you don't have the cases that go with the topend? I'd assemble it, check the specs, and run it before I'd re-port it. I've made that mistake before. Also, how does Kim know he can get more out of it if he hasn't seen it? There's probably a little more to get out of a lot of motors, but who's gonna spend 100 hours to get that last 5 - 10 % (other than for their personal motors)?

Install crank in the cases before putting those gears on and see how that works out.

I reallly dont think that he does. But who knows. He dont build his own drag chassis. BUT he is always secretative as shit on stuff. I saw some odd stuff that led me to believe he was purging is carbs to get nitromethane in them a few years ago, but they supposedly dont run that.

ll l'll address a few things here: If an off the shelf 421 Cub cant run 3.8s there is something wrong with the setup. That being said, this motor runs about the same e.t. as my brother on my 421, but I weigh 20 lbs more. Dave, I ran against your bike with a non lightened stock chassis, and the guard beam was off so who knows, (as you know) but it ran good. The Snipers did run relatively same times as the Shearers on the Passion motor on back to back passes, as did BB Shearers. The Snipers weren't exactly tuned at the track, but were on the on the dyno runs. The record Cub has a power to weight ratio(with rider) of about 0.3 to 1, and has a clutch setup that I havent seen and NASA couldnt build. And he runs some RDZ pipes that came as an unwelded kit, and he made the to his specs. He is currently making from scratch his own pipes. The bike has wentt 3.58 btw, not the mentioned 3.61. The passsion 10 mil did hit 109 hp but that was a different day, and lean as hell on Shearers. Matt Shearer ports for who?? The big dogs that have records do their own porting, but Im not sure who ports Packards motors, but he runs CPIs>

What does your motor run at the track?

Who are you ban421shee?

Really not much difference??? Well, everyone can go back and check, but I'm sure that I've said a few times that I think Snipers would be the best pipe for a Passion build. Yet..... Once again here we are with Snipers best effort at building a pipe for your specific motor vs. Shearers basic off the shelf SB pipe........and I'm not seeing the +10 HP we keep hearing about. So that's TWO DYNO POSTS NOW from owners of Passion motors who don't show anything close to a +10HP advantage over the Shearers. People were worried that guys were going to put these pipes on motors that were "Built to favor Shearers" and that the biased results were going to reflect negatively on the Snipers. Here we have the Sniper mounted on motors that are clearly built to favor the Snipers and I've yet to see the promised performance. Truth. Chew on that for a while. Jim?.......Gary?.....Hello?......This dyno run is over a year old. Would you care to post the updated runs where ....You easily tuned it to make the +10 HP? Or did you not get around to doing that for this customer yet. Wait....one last question. Is this an alky motor? I'd assume so with the OOF pipes, but I thought I'd check.

Dammit this crap has went on long enough. Here is a dyno chart of Sniper "built for my Passion 10 mil Cub's specs" vs Shearers. There are three runs. One with the Snipers "as is", and another where we inserted a pipe in the stinger to make it longer, and a run with SB Shearers. THese are all OOFs. There's not really much difference. These are in the same day at the same dyno.

I've never ran them, but you should be able to look at the screen and just let off the gas if the temp gets past what you consider safe.

There's no rev limiter on a Banshee, so anything that calls it self a "rev box" I'd avoid. Just run the timing plate. If you want to try different curves get a Dyna FS. Beware, they will fry without notice, so keep a spare CDI on hand.

Fair enough. How about coming to a Pro Sand Drag event and I bring a few Cubs and Sniper pipes and if you show them to win, that will be an asset for the Snipers. Leerjak race Labor Day weekend.

We run methanol, if that makes a difference; but when a motor is rich it ALWAYS moves the curve to rhe right on back to back runs. This is dyno max hp, not meant for the track. This is on Jason Menz dyno, his 397 Cub has run 3.57 in3 00 ft. Most motors twice that size struggle to get there. He makes his own pipes, btw. JIM -NOW you're talking about overrev?

This would be better asked in the drag forum. How fast do you wanna go?

It has been my experience that when its jetted correctly (for the dyno) that the curves should overlay on back to back pulls. If its rich, it will shift right, if its lean, it will shift left.

For a drag Bike, what exhaust port duration would be optimal for these pipes? I have motors all over the range but only tried them on 1. If they were built by softwae, what does the software say? I have a hypothetical dyno chart with these pipes exact specs (outtframes) on a given duration motor, but the results were not optimal. So the ex duration must not have been optimal.

On bigger engines with non Banshee based reeds, they sometimes don't last very long. On Cubs, though, I've ran the same for years. It is hard to tell if they are wore out sometimes. There will be just a bit of fraying at the ends of the petals. From the symptoms of your engine, it sounds like that bad reeds may be a possibility.

The carbs being out of sync will make it cut out on one side at part throttle. I agree about the TORS for WOT problem.

Just pull 1 plug wire off, it'll be fine.

No other pipe is claiming a 10% (or whatever) hp increase over another. That's why this always happens.

Well the main thing people don't do is run a good ground. You want to run a ground strap from the black wire on the coils, to the motor. Most just run a motor to frame ground. I still don' t like them. Bought 2 motors with them, and went back to OEM on both. A good racing buddy of mine ran PVL for years. He said the only difference he could tell vs. stock was that his right shoe/boot lasted a whole lot longer with OEM.

A twin Saber would be a Scimitar. The piston is the same. That is not a motor you'd want to build for anything other than a 100+ wheelbase drag frame. And yes, it's on spreadbore Mattoon Cases. Not sure why its monoblock instead of separate cylinders, though. Maybe due to the transfer area on the monoblock, not sure.

Don't forget wrist pin bearings. I'm bad about forgetting to add those and they don't automatically come with pistons.

Times? Did it run with those tires that are on it? Its a 967 cc Nick.