Just bought this Cylinder . . . Good or bad ?

[250R4EVR]

I just picked up this cylinder off this site. Anyone know anything about this kind of cylinder, who makes it. Ever heard of elsberry performance(ppl who ported this mother) It looks like a big bore cylinder, but from what i was told it has a stock slleeve and its on its stock bore. Aftermarket head ? im thinking so beacuse of the bolt on watter port thing. i guess ill find out when she comes in the mail

I know these cylinders have the full water jacket around the exhaust flange for better cooling.

If you know anything else about this, any information would be awesome. Thanks Evan

[methyman]

Thats a Pro-X jug and are good cylinders. How good is the porting it the question to ask.

[wilkin250r]

As for the big-bore vs stock sleeve, you should easily be able to get a set of calipers and measure it to answer this question.

[250R4EVR]

If you were going to buy the cylinder what would you think would be a good deal for it? I bought the cylinder, head, and a new piston. Was told it was a new sleeve and Brand new piston?

Do you think it would be smart to upgrade to a new head, something on the lines of Esr or Coolhead. Or should the one on it work fine ?

[wilkin250r]

Originally posted by 250R4EVR
If you were going to buy the cylinder what would you think would be a good deal for it? I bought the cylinder, head, and a new piston. Was told it was a new sleeve and Brand new piston?

Do you think it would be smart to upgrade to a new head, something on the lines of Esr or Coolhead. Or should the one on it work fine ?

Much of the value depends on the porting, and the bore. A cylinder on it's last bore isn't worth much, and a good port is worth substantially more than a stock unported cylinder.

As for the head, it would really depend on it's specifications. If it's been rechambered to work specifically with this cylinder and porting specs, I don't see much need to get a new one.

[250R4EVR]

I guess ill have to wait and see what i got when it comes in the mail. If the porting doesnt look good, whats a good company that you would perfer to have it done by? I thought that i heard that when you buy cylinders from, companys such as Ct, ESR, LRD . . . ECT. To buy them unported because there porting is sketchey or sloppy.

What would be a good company for a Good MX low-mid range porting ??

[wilkin250r]

A large company like ESR, CT, and LRD didn't get their success by shipping out crappy products. True, they are often "cookie-cutter" port jobs, a few standard templates with very little flexibility or options, but that doesn't make them "bad". They do a lot of R&D on their port jobs, so their standard packages are generally fairly decent.

A smaller company doesn't necessarily do it "better", but they generally are more customized. They are generally more willing to adjust the boost port angles for more midrange power, or shape the top of the exhaust port to give you a sharp powerband, or use epoxy to decrease the size of passages in order to increase the velocity of the gasses passing through them.

You generally cannot get this type of customized building from the larger shops, but that doesn't mean they put out junk products. Just because you don't get as many options doesn't mean their standard templates are poor quality.

[250R4EVR]

Alright, thanks for all of the information. Ill just have to wait and see what i got when it comes in. I've still not decided if i want to put it on my 89 lower end, and run the 86 piston w/spacer plate. or put it on my 86 lower end w/o a spacer plate.
Whats you suggestion on this one ?

Also i was told to up your compression. To take a stock head gaskit, and cut the tabs off the sides. Then to use one of the thin metal peices? Good idea, or a bad idea. In my R right now i have a paul turner National 265 Kit ( power head, ported cylinder ) i figured the extra compression wouldnt hurt because i already run torco 110 mixed 32:1 w/amsoil dominator.

Once again i thank you for all the Tips. Thanks Evan

[wilkin250r]

I'm not a big fan of chopping gaskets to increase compression, unless the engine calls for it.

There are more things going on inside your cylinder than just compression. There is a squish height, squish angle, and squish band thickness, as well as the dome shape. These factors influence your squish velocity and turbulence, which can determine your spark advance and detonation.

Does it sound like I'm speaking greek?

You don't necessarily need to know about boost port angles and blowdown duration in order to use a ported cylinder.
However, you DO need to know about squish and it's effects before you start playing around with your gasket thickness.

As for the spacer plate, that's your call, but I can tell you the effects. In generally, the short rod will rev a little faster, but the long rod will live a little longer.

[250R4EVR]

I'm thinking that you should just write a book on all these tips and send it right to my door Lol. Seems that ive got a lot to learn on all these motor mods.

Would a CR-250 ignition upgrade be a good idea or not necessary?

I see that your running a duncan Pv 340, witch im assuming would be the PC 2000 cylinder? Is it really worth that kindda cash. It crossed my mind to buy one of them, until i seen the Price.

Ive heard that a PV cylinder has its pros and cons because of the smooth powerband. On the other hand it takes away from that sudden Rpm Jump and Powerband streanth. Is this True or do i have it all wrong? Am i understanding this correctly ?
Pv- MX, trails
Non Pv- Dunes

[wilkin250r]

You've got it right. The powervalve takes away that sudden "hit", and smoothes it out. This is great for racing, because that "hit" can cause the tires to spin and break traction. However, it when riding recreationally, especially the dunes, that "hit" is half the joy of riding. You're certainly not worried about wheelspin in the dunes, because it's unavoidable no matter what you do.

The CR ignition is a common upgrade, but I've never done it, so maybe I'm not the best to give advice on that particular mod.

The PC2000 is indeed expensive. I actually got mine off ebay as a complete motor, so the price wasn't bad.

[250R4EVR]

Are there any differences between any of the 250r stock cylinders? I have a stock 85 cylinder laying around and was going to put it on here and try to get rid of it. I'm just not sure if its different than an 87, 88, 89. I know that on the intake side on the 85 and 86 dont have "bridges", other than that is there any difference ?

[wilkin250r]

There are some slight differences in the porting, and the bridged intake, and some other minor details.

However, although the porting and bridge may be slightly different, they are all interchangeable. You can put an 85 cylinder on an 89 bottom end, and use an 88 head.

[jst]

EP Racing did a-arms and complete engine kits some time ago.They came with a handmade cone pipe/silencer/cylinder/head and a few other items I can't remember.I belive the "fasttrax" was the name of the kit.You will have to measure the bore to find out what size it is.