Let's talk reliability of 350 cylinders

[Grande huevos]

As of right now I have been running a esr 330 bolt on and haven't had any issues after 2 years of running it. It has lots of power but recently I've been kicking around the idea of freshening or up and sending out for better porting, OR rebuilding a complete motor with new esr cases, my oem long rod crank with pro x rod, my 01 cr ignition, and my "Neil's" upgraded clutch and Hinson basket, with either a new esr 330 NON bolt on or for an extra $100 switching to a 350 in which I plan to send to Neil for porting.....

So my questions are how reliable is the 350 compared to the 330??

Is the power much more noticeable then a 330??

Would a keihn 38 A/S and esr 5 pipe and silencer  standard mount non BB work with the 350??

I ride mostly open wooded trails and dunes a few times a year and never mx.

[pinned250r]

[MENTION=124]silverlake250r[/MENTION] probably has some decent insight on this.

As far as reliability goes, any engine is as reliable as who built and who maintains it. You should have the same luck with a 350 as your 330

[Pumashine]

My 431 and 412 are as reliable as can be. With more power comes more possibility of problems unless you replace all bearings and clutch components. Any motor over 370cc needs to have the crank balanced. With a good builder you will not have any problems at all.

[etccb]

Reliability would be the same as stated and you will notice a 350 vs a 330.

[Burns363R]

Negligible difference 330 vs 350.  I get a entire MX season out of one top end before i rebuild it usually.  I normally put 20+  racing hours on a top end a season.

[Jerry Hall]

I have seen a few PRO-X 350 cylinders head gasket surface crack around the head bolt holes but never on the 310 or 330s. I am waiting to see if the ESR cylinders are going to crack in this same area since he started machining the coolant passageways in the top of the cylinder much larger than the coolant passageways were on the PRO-X cylinders.  This added machine work makes the cylinders look like a higher quality cylinder but this added machine work only weakens this problematic area and DOES NOT improve the cooling or solve the piston seizures problem this modification is suppose to fix.  The coolant passage way above the exhaust port are now machined within .020" from the edge of the head bolt threads.  This is NOT NECESSARY AND WILL MAKE THE CYLINDER A THROW AWAY when the threads strip on either one of these two threaded holes.  There is not enough material to support a heil-coil or time-sert thread repair.  If one of these thread repairs are attempted, 1/4 to 1/3 of the heli-coil will be hanging out in the water jacket.

[udontknowme]

is it just me or should there of been alittle more thought put into some of these aftermarket cylinder designs ?

[Jerry Hall]

is it just me or should there of been alittle more thought put into some of these aftermarket cylinder designs ?

We are seeing what happens when when a new product or design goes from the drawing board directly into production without adequate testing.  It cost a lot of money to do reliability and longevity testing.


 Some of the American companies have adopted the Chinese methods of product development:

1. The company has an idea for a new product.

2.  The company advertises on ebay, Horrible Freight, or on their web site at a very low price

3.  While the company is waiting for enough orders to justify production (testing the market demand)  the company tells you lies about why you have not yet received your widget.  " We are selling them so fast our production line cannot keep up with the orders",  "We are making some improvements before releasing our marvelous new widget".  "There is a shortage of the special alloy that we use to cast your widget",  "We are waiting for the arrival of our new state of the art CNC machine so that we can offer you unsurpassed quality".

4.  After they receive enough orders and credit card prepayments, the company uses your money to buy machines and tooling to produce your widget.

5.  Now they go from drawing board into mass production

6.  The company selling the widgets lets the customers that have been waiting for and paid for their widget 6 months to 3 years ago test the widget for common flaws and reliability.

7. After using the widget the customers complain about the flaws in the new product.  When the company runs out of widgets to sell, the company starts taking orders again.

8.  If the company gets enough prepaid orders to pay for new tooling to correct the first batch of flaws, they modify the tooling and produce another batch of widgets.

Does this process sound familiar to any of your experiences in the last few years?

[etccb]

What a total out of line attack at a site sponsor and one of the few companies investing into the life of the 250r. Make your own then and stop the repeated bashings. Dont say something is going to happen or what it will do if you havent tested it yourself or truely seen it happen for yourself. Test the newest ones before saying what they will or will not do.

[Grande huevos]

Do any of you own a Esr 350 cylinder?? I'm not sure how much a pro x cylinder that size costs but I would much rather spend a few more bucks up front if it's gonna save me money and headache in the future.  I've looked into led but they are about twice the price of esr after sending the esr to a reputable builder for boring and porting

[udontknowme]

i dont think anyone is attacking anybody.  when your in the business of making and designing cylinders, you better have your ducks in a row. call in outside experts, make prototypes and test them, do what ever it takes to make the product the best it can be. throwing a half ass product on the market and relying on customer failures to inform you where changes need to be made doesnt seem like the correct way to do it.  ive never tried prox or esr cylinders but for the most part im sure theyre good products, im certainly no bashing them. just saying that maybe alittle more time could of went into the design, judging from what ive read on the forums

if im not mistaken and i hope im not but didnt calvin have quit a bit of outside help with his cylinders ? this seems like a good decision on his part. if i were to design a cylinder theres no way i would attempt it without alot of assistance from experts familiar with this sort of stuff

[Hurley250R]

We are seeing what happens when when a new product or design goes from the drawing board directly into production without adequate testing.  It cost a lot of money to do reliability and longevity testing.


 Some of the American companies have adopted the Chinese methods of product development:

1. The company has an idea for a new product.

2.  The company advertises on ebay, Horrible Freight, or on their web site at a very low price

3.  While the company is waiting for enough orders to justify production (testing the market demand)  the company tells you lies about why you have not yet received your widget.  " We are selling them so fast our production line cannot keep up with the orders",  "We are making some improvements before releasing our marvelous new widget".  "There is a shortage of the special alloy that we use to cast your widget",  "We are waiting for the arrival of our new state of the art CNC machine so that we can offer you unsurpassed quality".

4.  After they receive enough orders and credit card prepayments, the company uses your money to buy machines and tooling to produce your widget.

5.  Now they go from drawing board into mass production

6.  The company selling the widgets lets the customers that have been waiting for and paid for their widget 6 months to 3 years ago test the widget for common flaws and reliability.

7. After using the widget the customers complain about the flaws in the new product.  When the company runs out of widgets to sell, the company starts taking orders again.

8.  If the company gets enough prepaid orders to pay for new tooling to correct the first batch of flaws, they modify the tooling and produce another batch of widgets.

Does this process sound familiar to any of your experiences in the last few years?

Sounds alot like the APT smartcarb deal.

[rablack21]

And my Smart Carb goes Braaaaaaaapppppp!!!!!!!!!!!!!! :quad:

[rablack21]

Grand Huevos,
Sorry for getting off topic. Back to your original questions, you will find that most people are happy with their 350s. A couple of things to mention.
The further you get away from stock and the more horsepower you are achieving, you will generally notice a drop in reliability, even though it may not be too bad in this case.
Is the power much more noticeable? Hard to say, how do you quantify this? Again, the bigger you go and the more power you are pushing, yes, you will notice it.
The A/S should work just fine for you. You may want to switch to a big bore pipe though. Chance are, the non big bore pipe will be a bit restrictive, especially on dune trips.

[Grande huevos]

Grand Huevos,
Sorry for getting off topic. Back to your original questions, you will find that most people are happy with their 350s. A couple of things to mention.
The further you get away from stock and the more horsepower you are achieving, you will generally notice a drop in reliability, even though it may not be too bad in this case.
Is the power much more noticeable? Hard to say, how do you quantify this? Again, the bigger you go and the more power you are pushing, yes, you will notice it.
The A/S should work just fine for you. You may want to switch to a big bore pipe though. Chance are, the non big bore pipe will be a bit restrictive, especially on dune trips.

We'll if the 350 is as reliable as my 330 then I would be happy, because I went with the bolt on over getting my cases bored (to save money) lots of guys said its a gamble and other simply said don't do it as well as some that said they haven't had any issues. So I took a chance I guess and I haven't had any issues with it what so ever and I usually ride her pretty hard. So if having the longer piston skirt helps reliability also then I wouldn't think trees much to worry about. I think my biggest concern would be breaking a tranny gear over losing a piston or crank failure. I know there lots of guys out there running  ported 350s and stroked 350s on stock trannys so that's gives me some reassurance!  

As for power difference I'm asking is it a noticeable differenc as in will you feel the difference on the seat of your pants when you ride it? Will it pull you harder? Will it want to stand up easier and so on... If it's one I those things that you would only see on a dyno but maybe not be able to tell the diff from riding it then I wouldn't bother.


My 330 makes me happy and puts a big smile on my face every time I ride it but there is always that voice in my head saying "I want more!!" Especially when I go on my dune trips. If I go 350 I would go ahead and get a new pipe and silencer as we'll. my crank and clutch components are still solid. I haven't put too many hrs on the bike since I've built it.


Guys running 350s what brand are you using who built them??
Is it a higher risk going with esr??? I know they are a sponsor but I'm looking for honest responses rather they are good or bad