Results 1 to 27 of 27

Thread: Best engine?

  1. #1
    RC poster
    Join Date
    Oct 2018
    Location
    North devon UK
    Posts
    19

    Best engine?

    What would be the best engine to go for if and when my trx 3.3 goes pop? Thanks.

  2. #2
    RC Qualifier Rich2's Avatar
    Join Date
    Feb 2014
    Location
    Western New York
    Posts
    622
    Quote Originally Posted by Nitronut 78 View Post
    What would be the best engine to go for if and when my trx 3.3 goes pop? Thanks.
    What I've noticed is if this is your first nitro engine it probably won't last as long as your
    next new engine.With that in mind I chose to stick with the Traxxas 3.3 and have 3 of them.
    This way you can refurbish them while still running one. It's a matter of having similar parts. Also, Traxxas can't be beat for getting parts and I've been through that dilemma. On the other hand, if Your a Pro the sky's the limit.

  3. #3
    Marshal Double G's Avatar
    Join Date
    May 2008
    Posts
    13,279
    Depends on what you want. You could go with a big block Picco but that would necessitate going to a different mount, upgrading the entire drive train. Or you could go with an OS .21TM that drops right in - others have reported transmission issues but to date (2+ years) I haven't. There's also the Dynamite Mach 2 .19 that are a hit or miss - at least when they first came out but I don't hear much about them at all. There were reported fitment issues even though they were "designed" to be drop-in.

    Another route is get a Losi 3.4 carb and a different pipe and install them on the 3.3.
    The Super Derecho

  4. #4
    RC poster
    Join Date
    Oct 2018
    Location
    North devon UK
    Posts
    19
    Thanks for your replies guys, definitely not my 1st nitro but my 1st traxxas. I have read quite a few stories of these engines going pop after only a short period of time, whether that's down to poor running in or poor mixture I'm not sure, mine seems OK at the moment I'm just looking to the future.
    Another TRX 3.3 engine is a good option as there readily available but what pipe would you run with it? I've read people say about a THS tuned pipe? What would you recommend? And is the losi carb a good upgrade over the stock traxxas carb?

  5. #5
    Marshal Double G's Avatar
    Join Date
    May 2008
    Posts
    13,279
    The 3.3 is a decent engine, IMHO. Many cut their teeth on tuning with it so that may cut into its life.

    There was a quite a write-up and debate years ago and a rush for many people putting the Losi carb on the Traxxas. I did it as well and it was impressive. THS pipe woke it up too.
    The Super Derecho

  6. #6
    RC Racer
    Join Date
    Dec 2014
    Location
    Adirondacks
    Posts
    152
    Installing a bigger carb definitely makes a difference in my opinion. Acted like a whole new engine. More forgiving in its tune(easier to tune) and seemed to run better and cooler. Never had a THS pipe but read good things about them. I drilled out my stinger a little bit instead of new pipe. With this combo I was very happy and would do it again. I did buy a 21tm to try but I have yet to start break in so I cannot compare the two. I bought it because direct drop in and I got a good deal on it.

  7. #7
    RC poster
    Join Date
    Oct 2018
    Location
    North devon UK
    Posts
    19
    Do any of you guys have a link for this write up and also know the part number for the losi carb at all? I'll definitely be looking into this then. Thanks again.

  8. #8
    RC Racer
    Join Date
    Dec 2014
    Location
    Adirondacks
    Posts
    152

  9. #9
    RC poster
    Join Date
    Oct 2018
    Location
    North devon UK
    Posts
    19
    No where in the UK (that I can find) sell the 3.4 carb for reasonable money. But I have just seen a post for a complete losi 8 350 engine for sale, would that carb work OK?

  10. #10
    Marshal Double G's Avatar
    Join Date
    May 2008
    Posts
    13,279
    You'll have to do the research and determine the ID and OD of the throat and see if it will fit in the 3.3 block.
    The Super Derecho

  11. #11
    RC poster
    Join Date
    Oct 2018
    Location
    North devon UK
    Posts
    19
    Had a quick read up about it and that engine doesn't have an insulated carb so when it gets hot it causes vapour in the carb and struggles to run and start again untill it's cooled down. Won't be buying that then.

  12. #12
    RC Racer
    Join Date
    Dec 2014
    Location
    Adirondacks
    Posts
    152
    I believe the stock Traxxas carb is 13mm outside(part that goes in crankcase) and the inside is 5.5mm. I used a carb from a picco engine, reduced the outside diameter on a lathe to fit and the inside is 7.5mm. Mine doesn't have a insulator and I haven't had any problems with vapor lock. I also run on the rich side. If your into and able to modify a carb you could make one fit. The losi 3.4 carb would be easiest for install if you don't have the tools to modify a carb to fit.
    Notes of carb sizes:
    Traxxas carb 5.5mm ID/13mm OD
    Losi 3.4 carb 7mm ID/13mm OD

  13. #13
    RC poster
    Join Date
    Oct 2018
    Location
    North devon UK
    Posts
    19
    I bought a force .28 carb last night as I couldn't get a losi one here in the UK without importing it in at quite a high price. I do have the use of a lathe if needed.

  14. #14
    RC poster
    Join Date
    Oct 2018
    Location
    North devon UK
    Posts
    19
    Well the force .28 carb turned up over the weekend so I took it into work last night stripped it down and set about machining it down so it would fit into the 3.3 engine. All went well with that so I'll put it back together again later and see how it performs later. I also found an old ofna hyper 7 .21 engine in my shed which I'll use the carb so I'll see if I can machine that down to fit in my jato 3.3

  15. #15
    Marshal Double G's Avatar
    Join Date
    May 2008
    Posts
    13,279
    Let us know how they turn out. I know with my Losi carb I used Losi's stock carb settings to get the engine running. Traxxas's settings would not work at all.
    The Super Derecho

  16. #16
    RC poster
    Join Date
    Oct 2018
    Location
    North devon UK
    Posts
    19
    Well it's in and fits nice and snug but the throttle hits the terminal for the ez start system. So need to have a look at that 1st before refitting the motorand encountering the next few problems. Biggest one will be connecting the throttle up to the linkage.

  17. #17
    RC Racer
    Join Date
    Dec 2014
    Location
    Adirondacks
    Posts
    152
    I was able to fit mine by rotating carb slightly to clear ez-start. You can also rotate throttle arm on carb after rotating carb to clear ez-start. I also moved throttle linkage bell crank on motor mount cradle out to outside hole to allow full throttle movement.
    The other issue I ran into was the air filter rubbed on the spur gear, I fixed that by bending the filter mount wire so it gave me the clearance without rubbing the gear.
    Last edited by grizzly03; 05-29-2019 at 04:13 PM. Reason: airfilter

  18. #18
    RC poster
    Join Date
    Oct 2018
    Location
    North devon UK
    Posts
    19
    Do you have any pics of the throttle linkage etc grizzly?

  19. #19
    RC Racer
    Join Date
    Dec 2014
    Location
    Adirondacks
    Posts
    152
    linkage[/IMG]
    linkage2

    If your having trouble with throttle arm fitting in slot you could file ball end down to make it a straight shaft.
    Forgot that I also sanded down on the inside of the roll bar where the linkage rubbed against it. I only had to trip the lip down flush. You will see where when it's together if you need to.
    Last edited by grizzly03; 05-29-2019 at 09:01 PM.

  20. #20
    RC poster
    Join Date
    Oct 2018
    Location
    North devon UK
    Posts
    19
    Thanks for the reply grizzly, I'm sure I'll see what you mean when it comes to fitting it. ��

  21. #21
    RC poster
    Join Date
    Oct 2018
    Location
    North devon UK
    Posts
    19
    Grizzly your throttle linkage mount is different to mine. Yours is mounted to the engine whereas mine is mounted to the engine cradle.

  22. #22
    RC poster
    Join Date
    Oct 2018
    Location
    North devon UK
    Posts
    19



  23. #23
    RC Racer
    Join Date
    Dec 2014
    Location
    Adirondacks
    Posts
    152
    Same mount, I just took a bad picture. I know it took me a while to get the linkage where I liked it.
    It looks like the arm on the carb is shorter than mine, that could be where its binding.
    Last edited by grizzly03; 05-30-2019 at 09:38 AM.

  24. #24
    Marshal Double G's Avatar
    Join Date
    May 2008
    Posts
    13,279
    Switch to a pull or roto start and you don't have to worry about the starter motor getting in the way.
    The Super Derecho

  25. #25
    RC Racer
    Join Date
    Dec 2014
    Location
    Adirondacks
    Posts
    152
    Quote Originally Posted by Double G View Post
    Switch to a pull or roto start and you don't have to worry about the starter motor getting in the way.
    Try taking EZ-start off and adjusting carb and linkage to see if you can get it to work better without it in the way. After that then you would see if EZ-start will fit without interference. You might need to switch to a different starter. After the headache I went through I felt it was definitely worth it for the bigger carb.
    Now that mine is tuned to the carb I wouldn't hesitate to put on a pull cord. It starts better than when it was new.
    Maybe I'm biased into using a different carb. But I had very good luck and was very impressed with the way the motor ran and would do it again, even on a new motor.
    Last edited by grizzly03; 05-30-2019 at 10:32 AM.

  26. #26
    RC poster
    Join Date
    Oct 2018
    Location
    North devon UK
    Posts
    19
    I'll have another look at it tomorrow now as I've had to come into work. I've had it running and I can already feel a massive difference in pick up and it still needs tuning properly. Really looking forward to getting it running now.

  27. #27
    RC Racer
    Join Date
    Dec 2014
    Location
    Adirondacks
    Posts
    152
    Another thing I forgot to mention is that I changed out the bushings in the throttle bellcrank to bearings which helped. You can use Traxxas #5114 or 5x8x2.5mm size bearings.

Posting Permissions

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