Results 1 to 8 of 8
  1. #1
    RC Racer Nitrocrazy66's Avatar
    Join Date
    Jan 2016
    Location
    Colorado
    Posts
    186

    Broken connecting rod

    Well today I blew up my first nitro engine. This engine is 1 1/2 years old not sure how many gallons I have put through it. I understand it's the nature of the hobby for things to break but trying to get an idea of what happened to this 3.3

    I did run this thing hard after proper break in. The last few gallons was 30% nitro and my temps were always a bit high around 270ish but always had good trail of smoke. This engine is from the first nitro car I owned so there was the learning curve of nitro tuning with this engine. Anyways her is a couple pics let me know what you think happened.








    "Drive it like you stole it"

  2. #2
    RC Qualifier westoakmech's Avatar
    Join Date
    Dec 2011
    Location
    Woodward, OK
    Posts
    861
    It looks like it has been hot, and or lean a few times. Like you said though your first one is always the shortest lived.
    The 3.3 has a little less wiggle room for error. I think the 3.3 is great engine, it just won't handle the extreme variances like a 2.5 will. If maintained, and tuned properly, you can get many gallons out of one. I run nothing but 30%, and have had several engines go into the 8 plus gallon realm.
    Rusty 2.5R,T-max 2.5 & 3.3,Summit VXL Nitro 4-tec

  3. #3
    RC Turnbuckle Jr. Nitronaught's Avatar
    Join Date
    Oct 2005
    Location
    South Florida
    Posts
    19,413
    +1 That was ran pretty lean for a while.From the sound of the post I am wondering if the LSN was tuned using the Pinch Test.

    If the LSN is not set right you will always experience high temps, smoke trails and not top performance. As well as premature engine life.

    Tuning is not something you just pick up, it's a developed skill. Very helpful if you have someone around who understands this skill. For those who do not I suggest going over this. https://traxxas.com/forums/showthrea...ul-Tuning-tips

    90% of all people new to nitro end up with their first engine not lasting as long as there others as the engine usually has to deal with periods of time when it is operating out of tune.

    Hope this helps.

    Once tuning is conquered, 6-8 gallons on most engines. I have gone as far as 12, but at 8 it was not performing up to par... Just wanted to see how far it would go...
    All Lives Matter
    United We Stand, Divided We Fall

  4. #4
    RC Racer Nitrocrazy66's Avatar
    Join Date
    Jan 2016
    Location
    Colorado
    Posts
    186
    I did use the pinch test.

    Pretty much chalking it up to first nitro tuning learning curve. I am alright with getting 1 1/2 years out of it being my first nitro.
    Anyways life goes on and it's off the the LHS to hit up the power up program and get a new motor
    "Drive it like you stole it"

  5. #5
    RC Turnbuckle Jr. Nitronaught's Avatar
    Join Date
    Oct 2005
    Location
    South Florida
    Posts
    19,413
    Quote Originally Posted by Nitrocrazy66 View Post
    I did use the pinch test.

    Pretty much chalking it up to first nitro tuning learning curve. I am alright with getting 1 1/2 years out of it being my first nitro.
    Anyways life goes on and it's off the the LHS to hit up the power up program and get a new motor
    FYI
    A full rebuild to include piston, sleeve and new ceramic engine bearings is around $110.00
    $60.00 for piston, sleeve and conrod pulled from a new TRX engine.
    $30.00 for Avid ceramics
    Putting $20.00 extra for any shipping and taxes.

    All Lives Matter
    United We Stand, Divided We Fall

  6. #6
    RC Racer Nitrocrazy66's Avatar
    Join Date
    Jan 2016
    Location
    Colorado
    Posts
    186
    I was gonna do a full rebuild but found a crack in engine case. New engine on power up program is $110 seems like best way to go and since my LHS has them in stock no shipping cost. I also have some avid bearings that I bought to keep on hand so I may just install them after I pick it up.
    "Drive it like you stole it"

  7. #7
    RC Racer
    Join Date
    Apr 2012
    Location
    Roan Mountain, TN
    Posts
    215
    Yea just look at the piston skirt, the chipping away of the skirt like that is a sure sign of a lean run engine.

  8. #8
    RC Racer
    Join Date
    Apr 2012
    Location
    Roan Mountain, TN
    Posts
    215
    I would break-in the new engine before you install the avid bearings. That way if you have any problems during break-in traxxas can't say it was because the after market bearings being installed.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •