Which would you recomend?

[Badaxe]

So I'm trying to decide which engine to go with to replace the original in my Terra Crusher. New Era big block kits are non-existent any more, so trying to narrow down what would be best..............

HPI G3.0

OS .18 CV-R

Traxxas 3.3

 

[Greywolf74]

ID say the OS .18 CV-R is the best engine out of those three but its discontinued so replacement parts are expensive shoudl you need them.

 

[alpinehyperlite]

Os .18

 

[Phins Fan]

Its ben a great motor for my Maxx but Greywolf has a point - parts location/surplus has proven to be a little difficult. You can still get em but at the steeper prices.

 

[Badaxe]

Tower shows em' in stock, and there are several on e-bay right now. I know the stock muffler design was an issue(with stock motor) should I look at a pipe too

 

[Phins Fan]

I run an aftermarket pipe anyway for more torque

 

[olds97_lss]

IMO, OS engine parts are expensive regardless if the engine is discontinued or not. Carbs that have been around for 5+ years are $60-$90. $25 OWB... don't get me wrong, OS engines tend to last forever, but it stinks for a Traxxas guy to have to spend $60+ for a better carb. lol

That said, OS18CV or if you can afford it, the OS18TZ, but would require a different pipe/header of course. Not sure a rear exhaust header would fit on that, so you may be stuck going side exhaust. Just by nature, side exhaust engines put out less power than a engine with rear exhaust just due to flow.

You could at least snag a better flowing side exhaust header than what I'm seeing on the stock terra crusher.

 

[Badaxe]

The LHS recommended an OS .21 small block(?), and felt the 3.3 would also be a perfect fit with plenty of power. Rear shock tower does require mods for rear exhaust, but can and has been done.

 

[olds97_lss]

Well, if you go with a 3.3, you can use a traxxas t-maxx header to clear the tower like the t-maxx does.

I don't know the truck, but if it had a typical 15 in it, the 3.3 should be considerably more power than what it had. I'd venture to say the 3.3 has more grunt than the OS18CV-R as well. You LHS may be suggesting the OS21 because it's a $300 engine... not a bad choice mind you, but selling a $300 engine vs $150 engine would probably be better for them.

Ok... not $300, but considerably more than you will pay for a 3.3 on ebay.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXRTM1&P=ML

I think I bought my 3.3 on ebay for right around $100 shipped.

 

[Badaxe]

The 3.3 is definitely more readily available. I need to find a engine with a rotary carb though. All conversion kits(big block and slide carb) are nowhere to find. That or if by some odd chance if I can come across a TNX 5.2 chassis, the bulkheads are a direct swap and obviously big block ready.

 

[olds97_lss]

If you can, post up some photo's of your rig with the engine and linkage on it so we can maybe help you figure something out. Just because it has a rotary carb now doesn't mean we can't help get a slide carb working for you.

 

[mrbones]

The 3.3 engine runs good but you will probably have to spend an extra $40 to buy a connecting rod that will not break because the one in the stock engine is probably going to. ( of which I have discussed this with Traxxas and they feel it's not that much of a problem to be concerned with!). So probably your best choice is the OS. That engine will run great. It has almost as much power as the 3.3, it holds a tune real well and idles great. I don't have anything good to say about the HPI engine so I just won't say any more than that.

 

[moe7404]

i have lost 2 con rods in 3.3s. i have a O.S. 21 in my jato. and it has held up fine. if you buy a 3.3, just buy a aftermarket con rod, and sleeve / piston to keep in stock. cause if you drive hard, and who doesn't, the 3.3 rod WILL break. R B mods makes a tuff con rod, that fits a 2.5 and 3.3. its made with 7075 T6 AL. both ends have bronze bushings, a 3.3 stock rod only has one end bushed. some where i have a 3.3 with a R B mods con rod, i think i ran it a while, no trouble. not only do i run my cars/trucks hard, i run 50% nitro.

 

[SchrodeMode]

i have a O.S. 21 in my jato.

Hey Moe, what header are you running on it? I'm thinking about grabbing an OS .21 for my Jato and Rustler.

 

[moe7404]

my 21 was a true bolt in, i use the traxxas EZ start, with mods. i use a RD logics . twin ext pipe for jato- blue. 61940B. but there is a trick, some say the pipe doesn't have enough pressure, this may be true, i dont know. to make it work get a sullivan check valve s756, put it right next to the pipe, to hold pressure in to the tank. AND put a tee fitting next to the tank, with the stright part going from the pipe to the tank. then use JB weld to block the 90 degree fitting, then drill it with a .030 inch to .040 inch drill bit. this will release some pressure, and soothes out the pressure in the tank. NOTE: that pipe is loud !! but it is FAST. all so getting the pipe alined up is not easy. go to office depot and get some very big paper clips 620-883. cut them in two to hold the pipe, to the shock tower, use collars around the wires, insteed of screws. this makes it more adjustable. as you can see, thinking out side the box helps a lot.

 

[mrbones]

i have lost 2 con rods in 3.3s. i have a O.S. 21 in my jato. and it has held up fine. if you buy a 3.3, just buy a aftermarket con rod, and sleeve / piston to keep in stock. cause if you drive hard, and who doesn't, the 3.3 rod WILL break. R B mods makes a tuff con rod, that fits a 2.5 and 3.3. its made with 7075 T6 AL. both ends have bronze bushings, a 3.3 stock rod only has one end bushed. some where i have a 3.3 with a R B mods con rod, i think i ran it a while, no trouble. not only do i run my cars/trucks hard, i run 50% nitro.

I talked with Traxxas about this and they say it's not enough of a problem to be concerned with. They told me there are thousands of these engines in service and not very many of them have failed. ???? Really! Enough have failed that someone is making a bunch of money selling upgraded rods! I told them that they don't want to address it because it would cost them money.

 

[moe7404]

my idea is that its a bit like a regular car. if you mistreat it you will have trouble. with a stock Jato if you use some common sense youll be ok. jumps, cracks in pavement, over reving, need caution. i have striped out my single speed gear two times doing the same thing, going at speed with full power over a crack in the pavement. they are NOT indestructible.

 

[Badaxe]

Ok I finally got around to some pics.....













When I was first googling, waiting for the truck to arrive, I did come across a photo of the slide carb adapter but failed to save it. And of course can't find it again.

 

[Badaxe]

The LHS thinks a good nitro bath will help the engine, not locked up but no glow plug upon arrival. Problem is I don't have the electric starter. So lets say based on a 3.3 swap....do I go with the Traxxas starting system or rely on a pull start and glow plug.

I have come across the big block mounts for the late model 5.2 version, but it's a different chassis. Not that custom mods are unheard of in our line of fun. Also managed to find a not-so LHS in the UK that carries a good supply of Tamiya parts, and have a few on order.

 

[Badaxe]

So any suggestions, electric start or pull? Any experiences with .21 Wasp engines?