440, 426, or 416 for the dunes?

[carlj75]

I just got my motor taken apart today. I only ride at the sand dunes and was wondering what bore would be best. I'm thinking the 440 would be the best but wondered if anyone had a different opinion. I'm also going to be getting a cam and some head work done.

go with the 440 :D

[Pappy]

what compression are you wanting to run? that will make the most difference...not just bore size

[sweet300ex]

465:D

[Baley69]

Ive emailed a good majority of engine builders with the same q, they all seem to say a strong 426 is a good in between for reliability and hp. All depends on what type of dune riding you do. I mainly stay away from racing straits, I enjoy uphill much better therefor I need more low end.

[buckeye400ex]

I think someone, who at least sounded smart, once said, "There's no replacement for displacement." :D

Like others have said the compression level is the #1 reliability factor. Crank it up too high, like I did and your chances of blowing a head gasket (like I did) are greater. I know numerous guys with 11:1 pistons in there and they are fine. Past a 440, I'm pretty sure you'll have to stroke it, so I don't know how that would affect reliability. Many people on here have strokers though.

[rhandw69]

416!!!!
Call and talk to a few people at engine builder shops. It all depends on what you want your bike to do.
I set my bike up for straight out dragging and idiot hole running. It really depends on where you want the power.
I have a freind with a stroker kit 440. I love the bottom to mid power that it gives. Awesom torque. However on a sand dune drag, i always beat him. Yet when i take his bike in the idiot holes, i like the way it torques its way through the rough stuff. Basically with mine, i have it set up to run like a 2 stroke. Hi revs, and great mid to top end. Im in the middle of rebuilding mine and the only thing im doing differently is putting a hotcam 2 in it versus the xr cam.
Call C&D racing and get theyre input. I like the fact they have first hand experience on theyre own 400s. But I like dealing with them as well as POWROLL. Most of my motor work has been done by Trinity, but i buy all parts through C&D.

[carlj75]

Ok, thanks for all the replys. Im leaning towards the 426 JE piston with the hotcams stage 2. The guy thats going to do the bore keeps telling me that I shouldn't put in a new cam without hardfacing my rockers even though hotcams says that you don't have to. rhandw, did you hardface your rockers or get new valve springs when you did yours?

[rhandw69]

Not with the XR cam. Yesterday I talked with Colby at C&D and he explained to me that since it is a billet cam than hardfacing the rockers is what deteriorates it. Er something like that anyways. I kinda think im not going to touch the rockers. If anyone else on here has some more information on the pros or cons of doing it perhaps they can lend some assistance.

[GlamisEXRider]

Go with the 440
Thats all i run is sand and i beat raptors all day long

[Silverfox@C&DRacing]

Hardfaced rockers will ruin a hotcam... Springs are personal preference but not needed.

for the dunes you should really think about a stroker motor. Ask oynot or norcalatver on their opinions on their FDO 493's

[rhandw69]

In my opinion,
When you start with the 440s and the strokers, you need to keep in mind that our 400s are just air/oil cooled. We dont have the luxory of running water cooled to keep the temp down. As far as the stroker goes, it all depends on what kind of dune riding you do. There are some that spend all day on the open flats and there are those who ride in the crazy idiot holes and there are those who just like to putt around. If you are going out there to race the comp hills up to 400ft, i believe you are going to be better off with the smaller CCs yet build it for a top end application. Besides in short drags you want quickness and the ability to get up to top end speed faster. My bike now, is kinda slow off the line, however usually by the bottom of the hill i can get a 2-3 bike length lead. Ive raced 426s, 440s, predators, DSs, and raptors. Now i wont claim to be beating alot of those built bikes after say 500yards, but from 300 - 400,,,,im very very happy with it. All i need to compliment it now is a +4" swingarm.
But really it all depends on where you like to ride. If you like hill climbing, and i do, and quickness isnt a top priority, than perhaps a larger bore 440 would do. I do however think that a 426 is a good in between motor. Good torque and still reliable. I was debating on doing that to my motor, but i still like the ability to really rev it out high.
Good luck, when in doubt regardless of what size motor, just give it more gas!!!

[norcalatver]

I've had my 493 for 2 weeks now. Before the 493 I had an LRD 440 w/13:1 compression, fcr 39, big valves, LRD pipe, pretty much everything you could do to a motor it had it done. I've ridden the 493 twice since I've had it, once on dirt trails and moto cross track, the other @ Pismo beach. The first time I was breaking the motor in.The second time, at Pismo, I was able to open it up. This motor has so much power that I find myself shifting very quickly. With the 440 I would rev it out but with the 493 it likes to be quick shifted. At competition hill and on the flats no one on a four stroke beat me. No one was even close! The four strokes I went up against were 2 yfz 450's, 440's, raptors, kfx 700, and suzuki 400's. The guys on the yfz's came directly over to me after an approximate 10 quad length whoopin and asked what I had done to my motor. The biggest problem I am having is keeping the front end down. I never had that problem with the 440.
As far as overall duning, this motor rocks! It performs Exceptionally well at every thing. My family nad I are going to the Oregon Dunes for Sandfest in a couple of weeks. I can't wait to ride it again!
As far as cooling I have Mickey Dunlap's cooler and a Pingry tank. My 440 lasted nearly 4 years before the connecting rod broke. Back in early 1999, the engine builders didn't know about the connecting rod being a weak link. I was one of the guinea pigs for engine testing for LRD.

[400grl]

I think I have found me new bore size.......did you have the room in the head to bore it out that much? Or was it all in the sleeve?

I have a 440 (11:1) kit, but so far I am still running a stocker carb and stock oil cooler (one coming from JEGS very soon, however!) - stock springs and stock rockers.....I have more power, but there is alot more I can tap into......

I didn't know you could bore a 440 out that high! You have given me hope!!!! :devil: heheheheheh

[Dune Surfer]

I had a 416, then a 426. I really liked the 426, good power and it reved quick. One thing to keep in mind is sand sucks up your power. If I were to do it over again I would recomend a 440. Only because of the sand. Go with a ross 440 kit with a hotcam2 and porting. Change you front sprocket to a 14t and use mobile 1. I think you will be very happy with that set up.

[norcalatver]

400grl, the 493 is a stroked crank. Mike @ FDO built the motor for me. 740-967-1078.

[DEAL]

I think it makes a diffrence how big of a guy you are, a larger guy would want a 440 and a smaller guy would want the quicker revving 416 or 426