Home Forums Rotax Max Lettered Cylinder

This topic contains 10 replies, has 6 voices, and was last updated by  Samir Shah 8 months ago.

Viewing 11 posts - 1 through 11 (of 11 total)
  • Author
    Posts
  • #63161

    Ambrose Buldo
    Participant

    What is the difference in performance, durability and elidigability from a lettered and non-lettered cylinder? Engine is a SR ROTAX MAX with EVO Upgrade kit used for Sprint Racing exclusively.

    #63306

    David Cole
    Keymaster

    Test

    David Cole - eKartingNews.com Managing Editor -
    @DavidColeEKN

    #63328

    Steve piggott
    Participant

    Our Rotax series you can no longer use non letter cylinders, it must be letters so check your area

    #63551

    Samir Shah
    Participant

    Has anyone figured out what the letters mean? Has anyone tested the lettered cylinders and are they consistent and similar, so that we don’t have this race to spend the most money on engines?

    Samir

    #63554

    Ambrose Buldo
    Participant

    I’ve not done any back to back testing. I thought I had the latest cylinder, apparently not. For me, motor performs more than fine, thus not spending the huge money to change. When it comes time for my rebuild, if it approaches $2,000 for rebuild + cylinder head, I may consider another motor. As much as I like the Rotax the prices for parts are out of line. Have you priced a radiator or exhaust recently? Prices for those components for other engines are typicialy about 1/3.

    #63575

    Christian Fox
    Participant

    The letters are the production batch codes. They vary by year, and they vary in performance, sometimes by a lot. Many thousands of dollars are spent on dyno time trying to find the good ones. No one is going to just tell you what the good ones are. Once good ones are sorted out, they fetch a lot of money. The top ten in Junior at any National event are all likely on the same cylinder batch.

    #63653

    Samir Shah
    Participant

    Hi Christian. I thought one of the reasons for change to the lettered cylinders (and evo engines) was improved production tolerances, thus levelling the playing field. I was wondering if they achieved that.

    #63656

    Mark Traylor
    Participant

    lettered cylinders have been around since 2011. still good and bad ones.

    #63659

    Christian Fox
    Participant

    Hi Samir, like Mark wrote, lettered cylinders have been around since 2011. Prior to that they were numbered by year, so a “9” stamped on the cylinder indicated a 2009 production year. Every few years Rotax mandates that certain parts will be phased out. Last year, for Micro and Mini, 2010 cylinders and older were no longer legal. Many good 2009 cylinders were taken out of circulation, so everyone began hunting for good lettered cylinders. As far as Junior and Senior, the original plan was to ban numbered cylinders this year, but although it’s not been made official, I’ve been told that numbered cylinders are going to be allowed again for 2016 for Junior and Senior. The latest batches of cylinders from 2015 have proven to be quite even performance-wise so far, the problem is they aren’t as good as lettered cylinders from 2011 and 2012.

    #63705

    Samir Shah
    Participant

    That’s annoying. I just took off a very nice numbered cylinder from my spare 08-bottom Jr engine to put on a lettered cylinder to prepare for this year, doing an unnecessary rebuilt ($$) at the same time.  If we don’t need it, I’ll have just wasted money. And next year, we may want to be in Seniors. Guess I’ll just sell the fresh engine if it comes to that.

    What letters are stamped in 2011-12? Any one have a list by production date?

    Samir.

    #64065

    Samir Shah
    Participant

    Is a ‘0’ numbered AB size cylinder a good one, an OK one, or a bad one? Thanks, Samir.

Viewing 11 posts - 1 through 11 (of 11 total)

You must be logged in to reply to this topic.

Karting's News and Information Leader ekartingnews | an HMG publication