I think my Revo 3.3 motor blew up today

[erxrevomonster]

Hey Guys,

I was doing some high speed runs today and my truck just shut off. Now it won't turn over at all and the flywheel won't rotate. I pulled the glow plug and it was shot, even though it was brand new. I think I may have over heated the motor by leaning it out too much. I just finished my 1st tank of Top fuel 20% and started using Byron's raceblend 20% when this occured.

Here's my question, do I rebuild my motor or get a brand new one? Or, do I spend a little more and get something better and more powerful? What motor upgrades work best for the Revo 3.3 (5309)?

Looks like I need some help, please I need advice.
Thanks in advance

[Rock0utRC]

Well you can start with taking the engine off (either way it's gotta come off) and stripping it down to see what's broken and tell us/post pictures. Then we could tell you what you need.

The O.S. 21 TM I think will bolt right up to the stock 3.3 engine mounts, more people here probably know more about better engines then I do.

[erxrevomonster]

Your right, I need to take the engine off and inspect it. I won't be able to do this until this Wednesday, and I will post some pics of the damage. Just spoke to my LHS and the options I was given were: #1 Get a replacement 3.3 engine w/trade in program for $120, or #2) Upgrade to the OFNA Picco .26 for $219 + another $20 for the correct OFNA engine mount for a total of $239. Obviously option 2 sounds good, but it's twice the price of a stock 3.3. Is the OFNA Picco .26 really worth twice the price of the stock mill? I love my Revo, and I know that this is an expensive hobby, but this thing is really starting to become a money pit

What would you guys do in my situation? By the way, my best guess is that the connecting rod split and locked up the engine. I will see if my guess is correct on Wednesday.

By the way, this may sound like a dumb or noob question, but here goes...What kind of top speed can I expect if I do upgrade to the Picco .26. If it were like 60 mph I might say screw it and just get it.

[Double G]

Many people don't realize what the costs associated with going to a much more powerful engine--such as the Picco--versus the 3.3 really are. Sure it would be a little more for the engine, buy a mount but the rest of the drivetrain has a good chance of being torn up too. The Picco has loads of power, don't get me wrong, but it is not always the best choice. You could go with an O.S. .21TM which has a little more power, fits right in and has nothing but rave reviews from a large majority of the RC community.

[fallonguy]

Some times rebuilding cost almost as much as a new engine. Look on ebay you can find a 3.3 for around $100.00. I have a OS .21Tm in my revo and really like it.

[Rock0utRC]

My picco is beast lol. But I've never tried the 3.3... I had a 2.5r Revo and on my slayer I bought it used with a picco 26 max. Huge jump lol. I'm not sure what my top speed is. I'm sure with longer transmission gearing and a bigger clutch bell and a smaller spur gear it would hit 60, but I like the take off more than top speed. With the picco you will probably have to get a header and tuned pipe as well.

I say see what's broken, price it out on the parts you need on ebay (toss it in your wish/watch/make your own list) then decide if you want to rebuild it or buy a new engine.

[Redsawacs]

someone once told me - if you're driving at high speeds and it just stops, check the flywheel. If it rotates 360 without resistance, dont attempt to start it. You probably snapped the connecting rod. If you try to start it, you'll do more damage and typically ruin the block.

Sounds like you have some shrapnel inside there....I hope not. Post some pictures, I enjoy a good "frag grenade" (I use to build real cars and engines)

[BlackpoolAndy]

Screams of the dreaded conrod.. good luck and whack the picco.26 max in.

[Revo gene]

Conrod for sure. Been there and done that. I lucked into a package motor deal a few weeks back. $220 for two running 3.3's and a fairly new picco max .26! I will say this, the picco is a huge difference. I did have to find a header and pipe for it and go waaaay up on the pinion gear (18 tooth) and down on the spur to a 36. Buku clutch and I'm seeing huge power and speed improvement. Check eBay......there r great deals out there.

Now I did clean up my 3.3's and re-sleeve, Davis connecting rods, and ceramic bearings in all of them. Backed them up to a ERCM pipe, dropped gearing back to 15-40 and my truck is pulling just as hard as the picco in the short run but does not have the top speed.

I do have rr trans gears and traxxas steel shafts throughout. With any power/speed gain = upgrades of other parts. Just a fact of life in this hobby.

[erxrevomonster]

Hey Guys,
Well as promised, I would investigate what happened today with my engine and was asked to post some pics of what I found. This feels like a postmortem after an autopsy after a really bad death

Last night I pulled the engine out of my Revo and cleaned up the chassis, and broke the engine down as much as I could and took pics along the way. I think what I found and you are about to see is one of the worst internally damaged TRX 3.3 engines.

Here they are.....




EDITED****


Well if I can't upload the pics because this site is not cooperating. So I'll try again later.


So..........As you can see the Connecting rod split all the way down from the top of the piston wrist pin and down to where it attaches to the crank shaft, and shot the top of the connecting rod right through the top of the piston! Oh my god, what happened? I must have ran it way too lean, and it must have reached 100,000 RPM.

I think I'm going to have to be much more carefull with my engines in the future, and avoid high speed running in this thing unless I know it's tunned correctly. My dilema now is...Get another TRX 3.3 or something better like the Picco .26 JL Red dot, or the O.S. .21TM. What would you guys suggest?

I will post more pics of the crank, piston, and connecting rod when I can get the flywheel off the engine.

[erxrevomonster]

My pics aren't loading, how do you suggest I load them?

[dougrevo26]

[dougrevo26]

Richt click the photo, then select properties, highlight the url and copy.
Click on the Image icon and paste that url into it.

[erxrevomonster]

Thanks Dougrevo26. I'm a goof ball I can post them now that they're on Picasa but you got the best ones up for me.

Thanks, you're the man.

[Revo gene]

Ouch!!!!!!!

[erxrevomonster]

I know right! Ouch! I think I have decided to get the O.S. .21TM engine. Sounds like it has a great reputation for decent power, ease of tuning, and reliability. Can get one for $230 right now and I think it's going to serve me well. I was going to get the Picco .26 JL Red Dot, but it sounds like it's a bit tough to keep tuned and needs a better pipe to really make power. I want a direct drop-in motor that meets or exceeds the TRX 3.3 and I think this is it.

[Jake C6R]

Another one bites the dust. It's happened to many of us, but it will make you a better person! I have the .26 red dot but have heard nothing but good things about the .21! I think you will like it!

[Rock0utRC]

Yeah I got a picco .26 max it's kind of a pain. Real fast engine and I got a lot better a tuning lol

[Revo gene]

I have had no tuning issues with mine. It was a headache at first getting it going but after dialing it in.......it runs perfect every time. Found a good pipe/header combo for it and it is my favorite setup now. I have 4 other engine setups and I still most often run it. You will be happy i am sure with yours as well

[erxrevomonster]

Well, it's official! I went with the O.S. .21 TM engine. It's on it's way from Tower, and it should be here this tues/wed. I will try to get it installed asap, and then break it in. I will post some pics when the Revo has been resurected

[erxrevomonster]

Well the O.S. .21TM is IN!!! Installed new clutch as well and this Sunday is break-in day. This engine is a thing of beauty and the quality is awesome.

[detoboy1]

+1 on the quality side of this motor. they look fantastic and are certainly a little pocket rocket of a motor! just so you know (which you probably already do) but from my experience these motors have a fantastic capability to stay idling even with super rich settings. this means that during breakin you can run it really really fat to accentuate the valuable lubricating properties of the fuel without the motor flooding and dieing out. you may need to wrap with the head in alfoil to keep temps up.

[BlackpoolAndy]

Exactly how my conrod went on my less than 1 gallon trx 3.3.. man i was peeved ...

[newrcaddict]

Any updates on your new OS .21?

[Sniffin' Nitro]

Well the O.S. .21TM is IN!!! Installed new clutch as well and this Sunday is break-in day. This engine is a thing of beauty and the quality is awesome.

Just curios, what fuel are you running? OS wants no less than 18% oil content in there engines. Byron RTR is 14% syn blend thats equivelent (sp) to 18% oil. Thats what they use at OS when an engine comes back in for any reason. If you still have some Top Fuel use that eventhough some may disagree, even OS. But after speaking with the Engine guy from OS for some questions I had about my .21, his words were Top Fuel has enough oil content to be somewhat comparible to what they recommend. I'm using VP Master Basher 14% syn blend which is 18% comparible and love this stuff at around $20 bucks a gallon. Another thing is keep the operating temps right around 200 during break in, this is what OS wants. After your broke in, about 6-7 tanks. Temps should stay in the 220-230 range on the high side to get the most engine life. Prefferably lower around the 210-220 range.

Other may disagree with this and more than likely will, The info I just gave is straight from the engine guy at OS, not a tech. If you plan on just racing you can use a lower oil%, but for bashing and just overall fun stay in the higher oil percentages. You can expect temps in the 230-242 range using Top Fuel this is what temps my .18 runs on TF

Heres a breakin link http://www.osengines.com/faq/product-faq.html#q590
One more thing, stay with an OS LC3 plug or Duratraxx LR3 for the best performance, the plug should stay in the silvery or very very light bronze color to know that your tune is right. Anything darker and your way to rich.

Hope this helps.

Good luck, you'll love this engine!

[fallonguy]

I have the 21TM too and really like it a lot add the BUKU pipe and this thing is fast I first put it in my slayer but it was so fast it was hard to control so I swap it into my Revo.

[newrcaddict]

I just ordered a .21tm and it will be here Wednesday. I'm excited to try this engine out. I debated this or a pico .26. I still have about a gallon of top fuel 20% that I guess I will use.

I'll show you the reason why I ordered a new engine - This rod/engine had about 3.5 gallons through it

[fallonguy]

Ouch that will do it. You're going to love the .21tm I know I do. I use Traxxas 20% all the time .

[newrcaddict]

Don't want to threadjack...but I think I will love this new os .21 mill too! My lhs had 2 trx 3.3's and I decided I wanted to spring for the OS engine instead of the trade in because I don't trust the rods in the 3.3's no more, especially after seeing so many with rod damage exactly like mine and believe it or not, the motor was broke in, tuned and treated like it should have been. Oh well, it's an excuse to upgrade!

[tree11]

Yep 3.5 gallons and mine did the exact same thing today. I am going to just install a new connecting rod for now and see how that works. Everything else in in the engine looks great. Eventually the O.S. will go in it.

[danyvw]

I'm not so sure but hear that OS discontinued the .21TM, today I was looking for a crankcase and is discontinued on Tower and other web stores. I don't know the reason and in the OS website there is no info about it. Will do more research.

[tree11]

Well that sucks! I just use my two Revos to bash with my son so I really don't want to go the big block route. Besides from what I have seen, the stock power is more than what most of the parts on these trucks can handle. **** near have to build a whole new truck for a big block. Anyways let us know what you find out.