gregrob

Then we also have the Chariot design with just 2 "segments" or whatever instead of 4

First thing to do is get your budget lined out, then figure out how far you can go. Building a 4mil right isn't cheap. I spent a little over 1500 for my 4mil setup and I put the motor together and port matched the cases myself. That doesn't count carbs, pipes, reeds, etc etc

Are these hillshooters or comps? How much ride time on them

I'm thinking about switching from the prodesign intakes I have now to the white knuckle design w built in crossover. One less place to have an air leak. Is there any advantage or disadvantage to this design though? Both the built in crossover and the segmented openings in the manifold? I assume it's like that to help smooth out the airflow, but does it actually work or just cause a restriction? TIA Greg

If you're going to have one of them port the cylinders you should just buy everything from them and they can tell you what you need. You will gain hp and efficiency by port matching the engine cases, but it isn't necessary. You can do it yourself or have them do it. You have to have the cylinders "modded" obviously (porting). and you'll also need a cool head so you can get offset 4mil domes for it, or have your stock head rechambered. Kevin has a stock cyl 4mil package listed here: http://herrjugsracing.com/Porting_Motor_packages.html That's what I would go with. You'll end up spending that much or more trying to piece it together from different sources. I couldn't be happier with my HJR porting, he does a badass aggressive dune port. My drag ported FAST bike runs awesome too, but they're different kinds of porting.

http://www.fireball-racing.com/billetball.htm

Mine is awesome too!!! I swear it's as fast as my fast drag port on methanol. With the fast drag port currently on gas my HJR duner kills my other bike!! and the other bike has a lighter frame and an override. It was out in front of a K&T ported 4mil on meth this wknd, a hopped up raptor (piston, kenz ported head, barkers, etc) and the K&T ported bike is about the same or a little quicker than bonbon's 485 cheetah on gas. I am SUPER impressed with how the thing runs. It truly amazes me for just a dune port, it still has tons of mid range. It will power wheelie in 3rd and 4th on my +4 swinger. I'm actually gonna start looking for a +6 cause it's tricky keeping it down on a hard launch now. To anyone considering HJR porting you will NOT be disappointed if you can set it up and tune it right! Awesome guy to work with as well.

And to further eliminate any confusion, NO a straight override is not any faster than a duneable... In a drag race they will both perform the same. The duneable is just more forgiving and allows you to downshift if you need to without coming to a complete stop. Which you can do with a straight override too, just never let it backload.

People install straight overrides because "duneables" haven't been out as long as straight overrides. A lot of the big name builders will tell you there's no such thing as a duneable tranny. A lot of them put the springs that help prevent damage when backloading in it and still don't call it a "duneable". WCR is the one who has been marketing a "duneable" as seperate than a straight override. The difference is that if you backload a duneable your not going to slam gears into each other and explode your transmission, if you go around backloading the shit out of it though you will still bend and wear shift forks badly. If you are primarily drag and can ride the override like it's supposed to be ridden when you're "trail riding" or duning, otherwise I'd say go for sidecutting the gears, shift star mods, and roller shift segment and call it good. You can still backload that tranny all day long and it won't hurt it. If you can be careful though, an override is awesome and you can make one live a long healthy life, just learn how to ride it.

When my duner was fresh the 19's gave me 160 psi. This was out 6k ft, where I live. Thats why I was thinking 18's would probably get me at least into the 170's. Bigreds little kt bike has 180 with 17cc domes up where he lives at 7k ft. Its more of a drag port than mine though I think. Kevin kept my exhaust duration pretty conservative for my weight elevation pipes fuel choice etc at the time. Walden @ 8500 is just one of the places we ride, and is definitely the highest.

Doesnt really matter. I put the bung in the left cylinder and mounted the pump on that side as well when I was running one Get a longer screw for the flywheel cover and secure one of the mounting tabs then make a bracket for the top, or just do like I did and use zip ties on the top. At least to get it mounted and tuned, then you can make it nicer in the future if you want.

We need to see what were comparing here. An as-cast cub compared to a ful blown drag port 4mil stock cyl, I'd go with the stock cyls every time. My stock cyls dynoed 100hp at sea level, ported by jeff at fast. Not a lot of even ported 4mil cubs get into that territory, from what I've seen. Now a max effort ported cub in the hands of the right builder is probably gonna be faster than 95% of the stock cylinders out there. Get your stock cyls in the right hands and they can be serious contendors, but by the time you pay for that kind of port job you can have a ported cub for not a whole lot more I know kim at K&T does great work with the cubs and I've seen some impressive stuff from kevin at hjr on them too. I know kevins porting on my stock cyls runs amazing and its still just a dune port As per your question on pipes I would run small bores on any 4mil combo out there unless it was something close to the 500cc range or bigger, like a big cheetah or DM.

This has been beat to death. But, ATF type F here. If you want something better than type F, use Dexron III / Mercon Synthetic. That stuff will work great too and hold up a little better than Type F I certainly dont change it twice as often, but it does break down faster than a gear lube. I like using it because of the light viscosity, frees up resistance in turning over the motor, which means hp, and my bikes always shift great.

About 10 mins total ride time after I putted up the road to the dunes to let it warm up. We made a few runs drag racing a long stretch and on about the 5th run is when it let go. Kinda hotlapped.

How do you check/calculate UCCR? I take it this is similar to what we call dynamic compression ratio in the smallblock chevy world. I'll check the squish band on the good cylinder before I tear the engine apart. Methanol domes from Kevin are what will be going back in it. Probably 18's, shooting for 170-180psi cranking(static) at this altitude.

Thanks for the input daj.

No boost bottle but I do have the prodesign intake w crossover tube. I have always double checked that the clamps are tight but I'll look it over closley when I tear it down

Cool.

I run maxima castor 927 @ 32:1 on gas and alky. I wouldn't go less than 40:1, and I like 32 because I feel it really slows down the wear as opposed to a numerically. I got a friend in oregon who runs 32:1 and he says he gets hundreds of hours out of a build and it looks perfect on tear down. He rides trails so reliability for long long rides is more important to him than the little extra performance you could get out of 40:1, and I tend to agree. 50:1 or higher is just rediculous IMO.

That main jet is too lean at sea level unless he has a very very lazy signal on the carbs. What size carbs, stock?

No, that's opposite the nature of a stroker crank. 240 sounds extremely lean to me on a 4mil. My stock stroke was at 270mains all the way at 6000ft elevation. I had T-5's and pod filters. He needs to get the jetting right. Do a plug chop and get that main jet where it needs to be. Then he probably needs to work on the pilot jet. The wrong size pilot will make it doggy on the bottom. That and check the compression and squish clearance. If the compression will low it will be lazy and if the squish band is way too high it will too, as well as having lower compression than it should. If it's hard to start, that's your first clue the pilot jetting is off. And if that main is as lean as I think it is it's not getting any fuel to have any torque.

The aerosol can of Aircraft Stripper from walmart works well.. Either that or the gel will do the trick. I like the aerosol just DO NOT breathe it. Seriously, I usually dont worry about breathing in a little vapor if I'm using spray paint, etc but this stuff is hard core and will take your breath as well as causing who knows what kind of damage to your lungs. I'd grab some cheap paper face masks to use with it if you use the aerosol. And rubber gloves as mentioned if you get the gel stuff in the can/tub.

Do you have a lockup or not? If yes, just get a cheap tusk clutch off of RMATV. They hold pretty good with a lockup on a good running 4mil. If you don't have a lockup I would do an FZR clutch. You need FZR 1000 clutch fibers and Barnett steels for a banshee. Jeff at FAST sells something similar and people have good luck w his heavy duty clutch. You can put it together yourself but it will be more expensive than if you just buy it from Jeff. Vitos hd one is an FZR clutch as well I believe.

QUOTE (C&B @ Jun 21 2009, 04:05 PM) <{POST_SNAPBACK}> I solved the prob with bearing from NTZ. Heavy duty sob, well worth the money IMO . Havent had a problem yet. and i run straight cuts as well. What problem were you having with the stock bearing?

It refers to how far the center of the wheel that bolts from the hub is to the outside edge of the rim. A higher off set number, will have a deeper "dish" which will increase the width of the front end. Running +2 offset wheels has the same effect as running +2 wider a-arms on stock wheel offset.