LRP ZR.32 Spec 2 Pull Start Engine

Words: David Harrington

LRP is very well known for their electronic power systems but were you aware that they also produce a line of big block nitro engines? Their range of engines starts at the standard .21 and goes from .28 and .30, all the way up to a massive .32. Putting out 4.34hp, it is truly a beast of an engine. You may be wondering who would need such a monstrous engine with such a huge power output. I’ll tell you, anyone looking for over-the-top performance from their 1/8-scale vehicle will appreciate an engine like this. In particular, I feel this engine is especially suited to extra-large and heavy monster trucks, which is why I will be installing it in my Savage XL for testing. Let’s take a closer look and see how this engine develops such monster horsepower, and what that power does in action.

THE GOODS
• If your motto is, “There’s no replacement for displacement,” then this is probably the engine for you. At .32 it is one of the largest aftermarket engines available.

• The new CoolDownMax cylinder head is specially designed to maximize heat dissipation. The fins are spaced to optimize air fl ow between them. Heat rises, as we all know, and the fins are swept upwards to help the heat escape. They have been drilled to increase surface area and air flow through the head. With all this functionality, it also looks great with its blue anodizing and laser etched graphics.

• The XTEC Power Carb 2 is an aluminum slide carb. It uses a 9mm insert to maximize the power and adjustability.

• This engine is a standard fi t to any big block engine mounts and should drop right in your 1/8-scale buggy, truggy, or monster truck.

• The engine housing serves the daunting function of keeping 4.34hp contained. To do so it’s is manufactured out of a T6 alloy and it has been specially reinforced. It is also anodized in black to maximize heat dissipation.

• The connecting rod has to transfer the massive horsepower to the crankshaft . To do so and make sure it continues to do so it has extra reinforcement just for the .32 engine. It has knife edges to help it cut through the fuel and gases that may be in the chamber. It is aluminum to keep the weight down, and it rides on double bushings.

• The crankshaft is triple turbo scooped, which helps create fl ow in the crankcase to keep the fuel and exhaust pumping in and out.

• Such a large piston can create a lot of inertia, but this piston has been specially lightened. It is made of a high silicium alloy.

• It can take quite a bit of force to turn over a huge .32 engine like this. So the pullstart is an extra strong unit specially designed for big block engines. It is compatible with LRP’s power start system but unfortunately I was unable to fit HPI’s roto start for my Savage.

• The ZR.32 uses standard glow plugs, which is good because they are readily available and much cheaper than turbo plugs.

THE WORKS
To test the motor I dropped it in my Savage XL. It dropped right in, only taking me about 45 minutes to make the exchange. Since the stock motor turns higher RPMs but less horsepower, I stuck a smaller 45-tooth spur in to compensate and convert that extra horsepower into speed. I used my Buku pipe with it. The manual recommends you use fuel with 25 percent nitro content. That must be a European thing, because in the U.S. we commonly use 20 percent or 30 percent. So I used some 30 percent VP Powermaster fuel. Just keep in mind a higher nitro content means more power but also faster wear on your motor. Initially it did not want to start. I was ready to start cursing pullstarts but I kept my patience and began trouble-shooting. I gave it a little throttle to start up and it revved up and then died. It seemed to me like it was leaning out. So I pulled the glow plug and confirmed the chamber was bone dry. I referred to the manual and reset my needles to the recommended settings. I found the low end needle was a whole turn from where it should be. So it might be a good idea to double-check your needle setting before starting. With the needles in the proper setting, the engine fired in one tug, a half a tug really. Then it just sat and idled without interruption. That’s more like it! Every nitro motor is different so I always follow the manufacturer’s directions when it comes to break-in. In this case the manual stated not to break it in on the bench. So aft er giving a few minutes to idle and build up some heat, I started running it up and down the road to break it in. Even though the motor was in rich, blubbery, break-in settings, and I was only pulling half throttle burst, I could tell this motor was ready to make some serious horsepower. After running five tanks it was time to start leaning it out for performance. I only needed to take a tiny bit off the low end, then I started leaning the top end 1/8 turn at a time until it started making power. Once it was tuned in I had to back the idle screw off a tad to keep it from creeping forward at idle. Once it was tuned in, wow, just wow! The horsepower from this motor is truly monstrous. With the changed gearing, the speed was on track with the stock motor, which is no slouch, but the power and acceleration are greatly improved. I think I could easily go with a larger clutch bell to increase top speed, and I think it would still out-accelerate the stock motor, but as it is, it was clicking through the gears and by the time it hit third it was actually a little scary seeing a 14-pound truck coming at me so fast!

WRAP UP
This is a great motor for bashers and beginners because while it incorporates some race level features to make awesome performance, it is really easy to tune and super reliable, starting right up in one tug every time. Its price point also makes it friendly to the same aforementioned group. It is actually a little cheaper than replacing the stock motor in the Savage XL and gives me greater performance. Plus, the price is right on track with many lesser motors, making this the obvious choice when looking to upgrade your monster truck or truggy.

LINK
LRP America, lrp-america.com, (949) 276-6060