Horsepower #'s on Cub

[ONTHAPIPE]

You posted a dyno sheet on your motor and I had a few questions. What was your exact setup for that dyno run.....you said you had t-5's and stock carbs, was the crank stock or stroked? Was the bore stock or the 68 mill? I would be very happy with hp numbers in the 80's and I want to build a cub. Also Who makes the best 68 mil pistons if I do go that route, My gut tells me to keep it at stock bore so I can use Yamaha pistons for reliabilty. I have ridden/rebuilt many motorcycles and I am less than happy with wiseco pistons. How many ponies difference are we talking between stock bore and 68 mill? Also is it absolutely necesary to true and weld the crank...I dont want to split the bottem end if I dont have to? One last question...What is an apropriate dome for getting the most out of 50/50 110 race gas and 92 octane? I truely appreciate any help anybody has.

[jbooker82]

Just so you know Yamaha pistons are cast, while weisco's are forged aluminum. Forged pistons can take way more abuse than cast pistons.

[Capone]

I would bet green money that stock pistons in a race bike would last longer than wiseco's. I have seen wisecos grenade more than once..

 

If wiseco's 'nade its not the pistons fault its the builders.

Edited September 27, 2006 by Passion99

[dawarriorman]

As far as pistons go, every type out there has failed. Stock probably more than any, only because its been used in every banshee made. Cast vs forged isn't really the issue, quality control is. A good set of cast pistons will last just as long as forged. That being said, most people still use wiseco.

 

As far as hp #s on cubs, if you have pipes, with everything else bone stock, you'll still be probably be at least 80 hp on cubs. You don't have to worry about hp with them. You have to worry about getting it to the ground.

[2003LimitedBanshee]

Cast vs forged isn't really the issue, quality control is. A good set of cast pistons will last just as long as forged.

 

I guess in part I would agree with that, but not really. The problem (which you sort of mentioned) is that you cannot, under most any circumstances, get the same quality from a cast piston, as you can from a forged piston. The process of creating each type of piston inherently makes a cast piston less durable than a forged piston. Inclusions, voids, etc. all contribute to weaknesses over a forged piston. I can guarantee that no performance based application would run a cast piston when a forged piston was available.

[Animalman294]

I highly recommend that you true and have your crank welded over 50-60 hp. You put any more power to it than that and you are way asking for trouble. If you are considering building a cub I hope you have your money saved up because there is a lot of things you need to do to the motor and the bike to take that kind of power increase from stock. The amount of power that you are looking for isn't going to be cheap, so don't even think about it if you are going to skimp in vital parts of the rebuild. For example the stroked crank and longer rods along with the larger bore allows the rod angle to be decreased so that it doesn't put a lot of stress on the rotating assembly..........

 

Just do it right....................... :beer:

[badassbanshee479]

where do you do most of your riding?? why do you want to build a cub?? that dyno run of daves was stock carbs t-5's 68mm bore and a 4mill stroker. Just to let ya know jeffs aggresive dune port with cpis and 35mm carbs is making right around 75-80hp and it will cost you about half as much as it would to build a 4mill cub. I have personly rode my buddys dune port bike and that thing rips!!! its reliable holds its own on the drag strip and its just plain fun to ride.

 

what you are trying to do is take a top fuel dragster and detune it so you can drive it on the street. just remeber its still a dragster in the end.

 

one more thing, ask dave what he has on that cub now. shearers and 35mm pwks. and now he is going to lock up, alky and an over ride. he figured out that its not much fun trying to detune a cub.

 

I am sure he will get on here and tell ya the same thing.

[banshee364]

Just to let ya know jeffs aggresive dune port with cpis and 35mm carbs is making right around 75-80hp and it will cost you about half as much as it would to build a 4mill cub.

 

Who does this port job and how can I get a hold of him? How much does it cost? And what setup are you, or whoever has this, running? Clutch? Heads, etc? I was going to build a cub this winter, but if this is producing nearly the same amount of power for half the price, I am interested in how much. Thanks.

Edited September 27, 2006 by banshee364

[dajogejr]

where do you do most of your riding?? why do you want to build a cub?? that dyno run of daves was stock carbs t-5's 68mm bore and a 4mill stroker.

 

Exactly.... Sorry to get back so late. 421 Cub, which...as said, is a 4 mil stroke crank with the 5 mil longer rods (115mm). They are big bore blaster pistons, 68mm.

I bought my cub from Jeff, and all he did was clean up the flashing and castings imprerfections on it.

I have a Noss head, not sure of the dome size...but, my compression is in the 185PSI range.

 

This was on stock cages with boyseen reeds, stock carbs, T5 pipes, and 100% bone stock ignition with the timing set at +12. (Plate maxed out)

 

I would bet just about every top builder uses Wiseco pistons...

 

ON that....

I thought I could make my cub a trail bike by leaving the stock carbs and T5 pipes on it.

I was wrong. BigRed said it best by saying "You'll have all kind of the wrong kind of power" when it comes to trails. You'll spend as much time locking up the brakes as you will being on the gas.

So...I went the other way. Strict dune and drag bike, hence the 35mm carbs and inframe drag pipes.

 

Soon, it'll be alky, cut trans and lockup....

 

 

If you're not going to be in the dunes or the drag strip most of the time, I'd agree and get a good strong port job on your cylinders.

 

Don't get too caught up in a dyno number.... It's really only good for comparing mods back to back....

[FASTOYS]

Very well said!

We have found that cast pistons do not hold up to the high rpms that a high perf. Banshee attains. YOu will find that most every builder out there uses Forged pistons in a high perf. application wether it be cars, boats, or Banshees! We have been using Wisecos and had no trouble with them for many many years. Most piston problems are bore related or self inflicted like jetting, dirty filter, air leaks etc..

The crank needs trued/welded even on a stock Banshee! We have seen a few bone stock bikes come through here and they had cranks seperating!!

YOu would be very surprised what a Good port job will do for you on stock cyls. :wink:

[dajogejr]

Also...

Once you build a cub, be it stock bore/stroke or Big Bore stroker...you're gonna have to think about a longer swingarm, longer chain, etc....and most definately...Jeff's clutch.

 

Then...suspension to get that all to the ground!!

[badassbanshee479]

The setup is a members on here, he goes by bigcrewduramax, dont post much but he is around now and then. he has jeffs (FAST Racing) aggresive dune port, 19cc domes with a noss machine head, +5 timing 35mm pwks on race gas, cpi small bore inframes, and v force 3's, with a 6 over arm, and 9 paddle paddle brats, we where puttin a good ass woopin on all the 4 strokes and a tyson 404 big bore kit with a 80 lb jockey over labor day weekend at the dunes. best part is it makes awsome power every where and brent trail rides the crap out of the bike. oh it also has a nology coil and wires. I am sure there are a bunchs of odds and ends I have forgot but I will have him post anything else majoir I may have forgotten

 

porting was like 350.00

jeffs clutch and shift mods.

 

 

jeff is on here as FASTOYS or you can call him at 785-364-5325

 

I would put this bike up against any none drag piped under carbed cub anyday.

Edited September 27, 2006 by badassbanshee479

[ONTHAPIPE]

I have looked into the porting and it runs like 500 bucks for a dune/drag port. I am building this bike mainly for sand mountain, and it feels like you could always use more power in that deep dry sand. I just cant see paying that much for a port job, when for 900 you could buy a cub. I understand there is other things to buy for the install, but there is for the port job as well. And also, I know that t-5's are not considered drag pipes, but my god, you make it sound like the cub wont even work at all with them. I am not trying to run a de-tuned cub motor, I am just trying to get one going for around $1500. I am sure it will be "pipey" and have a "powerband" but WTF thats why I bought a banshee and not a 450. I also read on here that it would be very hard for anybody to do a port job that would make as much power as a cub right from the box. I am not trying to argue, "I just wanna go fast" I dont want to spend three grand.........p.s. I have the tools knolwledge and friends to do any of the tear down/install work down to the crank.

[dajogejr]

Nope...not trying to say it won't run with T5s...it surely will.

But...I'd kind of liken it to having a top fuel dragster, with cherry bombs on it.

Yep, it'll work...but, you'll be missing out...that's all.

 

900 for cubs (maybe a bit less) crank welded and a fresh top end is gonna run you 1200 or so.

Doesn't leave much for a longer swingarm (which...you'll definately need for hill shooting" and a clutch to handle it....

 

I think with the few hundred you'd save by getting your own cylinders ported, you could spend that on other items you're gonna need ...

 

Jeff will tell you, same thing he told me. It'll run with T5s...but, it'll run better with Shearers or CPIs...that's all.

[ONTHAPIPE]

Is The cub really the most power in an aftermarket cylinder? What about the T-Rex and the Vitos Monoblock???? Also....Why does stroking the motor, Which would increase the displacement and up the power, make it more reliable?? It seems that the farther you deviated from the stock design the less reliable it would be??