Go Back  R/C Tech Forums > General Forums > Monster Trucks
t maxx engine swap >

t maxx engine swap

t maxx engine swap

Old 11-28-2007, 05:32 PM
  #1  
Tech Rookie
Thread Starter
 
Join Date: Nov 2007
Posts: 11
Default t maxx engine swap

hello

i just bought a t maxx with a seized engine. i was looking at new engines on tower hobbies and i was wondering what you guys thought on the O.S. 18CV-RX w/11G Slide Carb. also will this bolt right up or will i need to new motor mounts
dilbert is offline  
Old 11-29-2007, 07:53 AM
  #2  
Tech Regular
iTrader: (15)
 
cheesewhip's Avatar
 
Join Date: Feb 2007
Location: VA
Posts: 452
Trader Rating: 15 (100%+)
Default engine swap

did the original tmaxx have a trx 1.5 in it or the 2.5? meaning did it have a side exhaust or a rear exhaust? looking at your engine choice, it looks like you were looking for a replacement engine for a 1.5. it should bolt on without any issues. you just have to work with the linkage layout and settings a bit. If you are looking to replace the 2.5.. well, the engine will fit without new mounts.. you just have to get a side exhaust header. i would go with engines designed to replace the 2.5 with the exhaust header mounts.. (with 2 screws locking in the header) you may be able to find engines towerhobbies list as discontinued on other sites... but OS 18 TM is a good engine.

i had a tmaxx and 3 revo's, and the tmaxx still has the stock 2.5 in it. i replaced the piston and sleeve two times already from running it so much, and it fires up everytime. i sold the tmaxx to a friend, and it fires up everytime for him too.. i have the os 18tm on one of my revos, and it works great.. i think i still like the 3.3 though.

how old is the original engine, and have you tried using a flathead screw driver to wedge and turn over the engine? have you tried heating it up a little with a blow dryer or a heat gun, then try to turn the engine over? if all fails, i would also put just the engine in the oven, heat it up a little, then try to turn it over. if none of the things above do not work, clean and take the engine apart, clean all the components, relube everything, put the engine back together, see if it fires up. if its broken, its broken. replacing the piston and sleeve is pretty easy and cheap. i would try to fix it before slapping money down for a new engine. i dunno, that's just me. if you find it just easier to start with a new engine, go for it.
cheesewhip is offline  
Old 11-29-2007, 11:11 AM
  #3  
Tech Adept
 
TMaxx-25's Avatar
 
Join Date: Nov 2007
Location: Calhoun, GA
Posts: 100
Default

I have done this swap with the exact engine you are looking at. If you have a 2.5 tmaxx you will need to shorten the crank shaft on the OS to fit. I have been extremely pleased with my OS. For the money you can not beat the motor.
TMaxx-25 is offline  
Old 11-29-2007, 05:01 PM
  #4  
Tech Rookie
Thread Starter
 
Join Date: Nov 2007
Posts: 11
Default

yah its a 2.5 i cam turn it over with my fingers now that i have heated it up but i dont have all the screws for the back plate. how much do you think it will cost to replace the piston and sleeve. also how much will it be to get a new fly wheel and clutch bell and all that. also will a trx2.5r piston and sleeve fit in my trx2.5

Last edited by dilbert; 11-29-2007 at 05:17 PM.
dilbert is offline  
Old 11-29-2007, 07:13 PM
  #5  
Super Moderator
 
roadrashracing2's Avatar
 
Join Date: Nov 2005
Location: Wisconsin
Posts: 67,189
Default

roadrashracing2 is offline  
Old 11-29-2007, 09:39 PM
  #6  
Tech Rookie
Thread Starter
 
Join Date: Nov 2007
Posts: 11
Default

lol sorry if this a really dumb question but what does this mean
dilbert is offline  
Old 11-30-2007, 06:26 AM
  #7  
Tech Regular
iTrader: (15)
 
cheesewhip's Avatar
 
Join Date: Feb 2007
Location: VA
Posts: 452
Trader Rating: 15 (100%+)
Default piston and sleeve replacement

yes 2.5r piston and sleeve will fit the 2.5. it will actually turn your engine into a 2.5r. the 2.5r has a slight port modification on the piston and sleeve that theoretically improve the performance.. although i didn't see any difference. only other difference between the 2.5 and 2.5r is the heatsink head.

for the piston and sleeve, i wouldn't pay more than 50 bucks or so. i think i got mine for 46.00. people will recommend changing out o rings, bearings, conrod and stuff but its not necessary if this is the engine's first piston and sleeve replacement.

Oh, i don't know if anyone mentioned this to you or not but the traxxas website has detailed instructions on how to change the piston and sleeve for trx engines. Also they have an engine replacement thing you may want to check out. www.traxxas.com

i would say flywheel would cost about 10.00 or so, clutch bell about another 10.00, clutch shoes and springs about 5.00... you can check tower or give your local hobby shop a call.

i don't really know what means. rotating tire??? i guess its people's way of bumping the thread to the top of the thread list.
cheesewhip is offline  
Old 11-30-2007, 10:14 PM
  #8  
Tech Rookie
Thread Starter
 
Join Date: Nov 2007
Posts: 11
Default

thank man i was trying to fingure out what i could do lol. yah it would be its first piston sleeve replacement. lol i got a deal this truck. all aluminum front and rear nd with a blown engine for 40 bucks
dilbert is offline  
Old 11-30-2007, 10:21 PM
  #9  
Tech Rookie
Thread Starter
 
Join Date: Nov 2007
Posts: 11
Default

thank man i was trying to fingure out what i could do lol. yah it would be its first piston sleeve replacement. lol i got a deal this truck. all aluminum front and rear nd with a blown engine for 40 bucks
dilbert is offline  
Old 12-01-2007, 11:14 PM
  #10  
Tech Elite
iTrader: (4)
 
pinky2252s's Avatar
 
Join Date: Nov 2007
Location: Broomfield, Colorado
Posts: 3,278
Trader Rating: 4 (100%+)
Default

you might not want to use aluminum a arms but every thing else it fine!

you could do os 18 tm, if you can find one
pinky2252s is offline  
Old 12-01-2007, 11:44 PM
  #11  
Tech Rookie
Thread Starter
 
Join Date: Nov 2007
Posts: 11
Default

why not with the aluminum a arms
dilbert is offline  
Old 12-03-2007, 05:50 AM
  #12  
Tech Regular
iTrader: (15)
 
cheesewhip's Avatar
 
Join Date: Feb 2007
Location: VA
Posts: 452
Trader Rating: 15 (100%+)
Default alum a arms

alum a arms may not break but they will bend, rendering them useless. rpm makes beefy plastic arms i haven't yet been able to break, and they flex just enough not to break when i hit something.

also, sometimes rather than bending, alum a arms will transfer the force of the impact to the bulkheads and kingpins. you could go with alum bulkheads and titanium kingpins, but then we are talking about a little bit of a weight gain here, in addition to the already heavier a arms.
cheesewhip is offline  
Old 12-03-2007, 03:06 PM
  #13  
Tech Elite
iTrader: (4)
 
pinky2252s's Avatar
 
Join Date: Nov 2007
Location: Broomfield, Colorado
Posts: 3,278
Trader Rating: 4 (100%+)
Default

plus, RPM makes it so if you break the arms they give you the broken one for free if you send the broken one in
pinky2252s is offline  
Old 12-04-2007, 01:38 AM
  #14  
Tech Regular
iTrader: (2)
 
fhm555's Avatar
 
Join Date: Mar 2007
Posts: 457
Trader Rating: 2 (100%+)
Default

If you swap out the TRX 2.5 or 2.5R for an OS CVR with an SG crank, you will need to shorten the crank just a hair and you will also need to get a new clutch nut. The threads traxxas uses on their crank is different than the threads EVERYONE else uses so it's not just an OS motor that would require a different flywheel nut. I used a flywheel nut from a nitro TC3 when I did mine. If you get the stub crank version of the CV-R, you will need a Traxxas pilot shaft nut and you will have to trim the crank a bit as well. The only OS that's a direct swap for the T-Maxx is the 18TM.
fhm555 is offline  
Old 12-14-2007, 12:06 AM
  #15  
Tech Rookie
 
maxximizer's Avatar
 
Join Date: Dec 2007
Location: canada
Posts: 10
Default t-maxx engine swap

first of all, don't put a new piston and sleeve in it, it is not worth it, a new piston/sleeve is about 75-80 bucks,but if the crankshaft is shot it is not worth it cause you won't have the same power as buying a new motor. A new 3.3 motor is about 150-200bucks, but if you want to get the best the NEW O.S21 is the way to go, expensive(about 250-300bucks, canadian$) but it is the best motor and a direct drop-in for the maxx trucks!!!!!!(btw-the O.S18tm is not available anymore, the 21 replaces the 18) but if you find the 18 it is still a potent motor for the maxx, but to make perfect use of the motor you should also upgrade your throttle/brake servo(a faster one) and the PHANTOM tuned piped( i did and well, WOW)
maxximizer is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.