This is the LRP Nitro Engine ZR.32 Spec.4 Pullstart Nitro Engine. The LRP ZR.32 Spec.4 Pullstart is based upon the very popular ZR.32. In order to be able to again increase the enormous power of the .32 monster, we build in a completely constructed carburettor that has an additional notch for improved adjustability and that provides an even more efficient fuel-air mixture.
This leads besides an improved idle speed setting, also to better responsiveness and more torque. The already known Heavy-Duty CoolDown- Max cylinder head provides sufficient cooling for this power unit.
Features:
- MASSIVE Big Block size - You cannot replace displacement with anything… but even more displacement!
- New CoolDownMax cylinder head - Improved cooling and higher efficiency through new cooling fin arrangement
- XTEC PowerCarb3 15S-2 carburettor - Flow optimised carburettor with built in 9.0mm venturi for maximum power
- Universal fit - Fits all major .21 engine mounts
- 5 + 1 Ports
- FREE PLUG - FREE LRP Platinum / Iridium R5 glow plug included
- Standard burn room - Guarantees easy adjustment of the engine in all conditions
- XTEC T6 engine housing - Especially reinforced heavy duty engine housing for toughest offroad action
- Massive con rod - Extra reinforced con rod. Specially adjusted for .32 engines
- Ultra strong pullstart - Pullstart specifically developed for big block engines
- Power Start capable - Prepared for the use of the LRP Power Start for starting the engine at the push of one button
- Torque you can barely handle
Specifications:
Cubic capacity: .32 (5.24 ccm)
Bore: 19.80mm
Hub: 17.00mm
Power: 4.37 HP*
RPM: 33.300 RPM*
Number Channels: 5 + 1
Glow Plug: LRP Standard R5 (No. 35051)
Carburetor: XTEC PowerCarb3 15S-2 with machined in 9mm venturi
Weight: 420g
Class: 1/8th Offroad Buggys/Truggys
* Figures may vary depending on used fuel, muffler and tuning
This product was added to our catalog on October 4, 2018
Once I got it to startup and began the Break-in process,, I gradually found that the "low" needle needed to be turned almost the entire way in until it bottomed out, and then only back out about 1/4 to 1/2 turn in order to get it to start, and idle, and run correctly... very far from the factory recommended setting of about 4.5 turns out from bottomed.
Initially while attempting to start with the stock settings on the carb, it was so rich and so out of tune, that due to the extended and constant attempts to get it running and keep it running - it ended up breaking the one way roller on the pull start. So before I could finish and run the first tank of fuel through it, I had to already dissemble it and swap the one-way roller that luckily I had from other similar motors that fit and worked the same.
I've now had the motor up and running for a couple of weeks and no matter how much I mess with the carb tuning, the low needle is only about 1/4 turn from bottom. And the high needle is close to recommended default settings. Its impossible to reach out to anyone from LRP for help on this, so I've simply left the carb as is, and it actually runs very good like this from idle to off-idle and into wide open.
I've tuned and worked with as many as 25+ Nitro motors in cars, truck, airplanes and even RC boats since the mid 1980's,, I consider myself very experienced and knowledgeable and a very good carburetor and Nitro tuner, and have never seen a carb do this before in these applications.
Once broken-in and deciding to leave and work around the low needle at the nearly bottomed settings.... I have to say this motor is extremely powerful and tugs along great in a Savage XL. Tons of off-idle TQ and great top speed also. This motor is much louder as far as exhaust goes then anything I've seen/heard that are the typical .28, .25 and .21 and etc.
Pre heated the engine to 200 degrees, put the igniter on and it fire right up. Minor adjustment and I was on my way to break in. I have 8 tanks through it before the snow came in. It is awesome and as smooth a break in for a long time.
Amain's service was awesome as always and it came early. Thanks for your quick and easy service to get this engine to me.
I found closing the high speed needle 1/4 - 1/2 a turn and the low speed needle about 1.5 turns in from "factory settings" got the car to start.
In a break in, I typically close the low speed needle 1/4 a turn at a time until the car will start and stay running up to about 1/4 throttle works pretty well to keep the engine at 160-200 degrees F (70-90 C), although I did have to alternate between closing the low speed needle a very little (1/4 turn) and high speed needle (1/4 turn) for every two adustments of the low speed needle to get the engine to idle and run to 1/2 throttle. (Always slow pulls of the throttle, run for a short time then let go back to idle)
Once this was completed, I was able to close the high speed needle in 1/4 turns after each tank of fuel ran through it during break in until the engine was running approx. 180 F(~80 C.) and very rich at full throttle. (The engine was extremely rich at this point, but at full throttle was approximately 60% of "full speed")
I actually wound up richening up (opening) the low speed needle approx. 1/4 turn at this point, and the car still ran and idled fine.
The engine is almost fully broken in now, and waking up in the top end.
I tend to just close the high speed needle 1/8 of a turn after each tank at this point in most situations until the motor is consistant and crisp.
In summary, it is imperative during break in to not run nitro engines lean. If the engine is too rich, it will not start and idle. An easy way to combat this situation is to continue leaning out the bottom end until the car starts. BUT sometimes the high speed needle is way too rich and can cause over leaning the low speed needle to get the car to run, so it is a good idea to close the high speed needle 1/4 turn for every two 1/4 turns (or 1/2 turn total) of the low speed needle until the car starts and idles, and then continue to close the low speed needle very little, or 1/8 of a turn, until the engine will start, idle and get up to 1/4 throttle without cutting out.
This method sucks, as the engine will shut off and need to be restarted often to get to this point. The benefit is that this works with ANY nitro engine, even if the factory settings are unknown so long as the engine is TOO rich on both top and bottom AND one does not need to worry about running a new engine lean.
Anyone that has ever owned a German made automobile (think VAG, BMW or Benz) knows that German engineering is difficult to work with, but I am giving three stars for having to restart the engine 8 or 9 times before it would allow me to start the break in process.