Hi Reto!!!

I can't wait to test out the spec 3 engine.Thanx to design a reliable engine of us to race.Smell some good stuff for the engine.Maybe we can share tunning setup for spec 3.Send my best regards to Michael Gaul,Andy and for u.

what's new in the spec3?

Afiq, Ularlidi Ipoh still in progress of breaking in the engine - 3rd tank. More to go...

New crankshaft, new liner, new conrod, new backplate, new burnroom. Engine has different timing, it makes basically more power everywhere...

I have a Mega ZX12 currently and both the LRP & Mega engines are Picco based so i have a few questions for you:

Have there been any leaking issues with the LRP from around the carby area etc?

Is there any tuning issues during longer races with the carby and people have swapped the carby as a result?

Look forward to hearing from you shortly...

BB

Air leaking tips from P. Morganti (Serpent- Mega USA)
The 2 cams that you use to fix the carb at the crankcase, in some cases are some tenths too long, and so even if you tight the screw all the way down, still the carb is not really tight and some air leaks from there.
To solve this, you need to take out the 2 cams, grind a little bit and then the problem is solved.
Another tip is the "o" ring inside the crankcase (there is an internal o ring inside the crank where the carb is located). In some cases the fit is so tight that when you install the carb you strip the o ring and the black parts goes in the crankshaft making a mess (not a big problem, is easy to solve).

Tuning for long mains (from several posts on this thread and on the Mega Thread)

Engine works better on the rich side (HSN) and normally needs more than a couple of laps to reach the operational temp. Start on the rich side (HSN) and after 4 or 5 laps tune the engine. Doing this process on the bench (or starter box) normally overheats the engine driving you to a wrong tuning and maybe causing a damage (this is not only in our engines, is for all). Start here:
HSN: 4 1/2 turns out
LSN: 5 3/4 turns out
This is very close to factory setting.

Regarding LSN, Run the LSN a little bit on the rich side and still the engine has a good idle (Very low rpm idle, is better for fuel consumption and handling of the car after off throttle).
After pre-heating a little bit the engine, open your throttle fully for 2 sec. than back off and let the engine idle for 30 second than just pinch the fuel line and the rpm should remain the same for 4 to 5 second and then the engine revs up and shuts off. That’s the best option for a large track with long straight away. If the track is really short, and full of hairpins, LSN need to be more lean, because the engine never revs up for a lot of time and so if you keep the same setup described before is always rich out of the corner.

Regarding HSN, Set the engine a little bit rich (if you progressively open the carb, the engine responds quick but at 3/4 rpm becomes rich (not really 4 stroking but rich) Then at the track after several laps (at least 5) if the engine is still rich lean it.

In general, if the engine does not keep it’s tune and starts to lean out after a few minutes of racing, the bottom end needle needs to be richened. That happens quite often and it is always the first thing to check when tuning the engine.

You tend to lean out the bottom end during static setup of the carburetor. In most cases, the engine has not warmed up completely (including chassis and all other aluminum parts) thus it is changing its tune during driving.

If the engine is still cold, or it was only warmed up in the pits, then set the bottom end a tiny bit too rich in order to compensate the above behavior.

If you use a Nova carburetor you'll be unable to restart the engine once it has warmed up entirely. That's because it has no thermal isolation between engine and carburetor like Picco based carburetor have.

This is also the reason why you have to start with richer setting when using the Picco based carburetor, it simply takes a while to warm up!

Experience running Picco based engines dictates that before your heats you need to warm up the engine first. Try to refuel not more than half tank and then tune the engine. To check your low end, try to idle the engine for 30 second and punch max. If you find that it screams to loud, richen a bit. It should bog a little but not shut off.
Check the temp, the best is 105š C
Plug No. 7 for heats. Plug No.8 for a 1 hour final. (on 20 -25% Nitro)
For final try to tighten a bit your 2 speed and tune your engine around 100š C.

AFM

Hey amigo, onde voce esta correndo (altura do nivel do mar) para usar .62 de shimming einn ? ... abraįo amigo ...


Hey ... where are you rinning (mts over the sea ?) to be using .62 of shimming ?


cya !

Hey Pato...how are you

He Ąs probably using 0.60mm of shimming, because the Picco, Mega and LRP engines have 0 mm difference between piston at TDC and head button, so chamber volume is direct related to shims in this engines.

From the factory they come with 0.40mm (0.20 + 0.10 + 0.10), which is good enough for 20% Nitro. For 16% Nitro you may get away with 0.30mm. For 25% nitro 0.50mm and for 30% nitro 0.60mm, and I know some drivers even use 0.70mm with 30% Nitro to be on the safe side and with more high end.
Of course all of this measurements at sea level altitude.

AFM

Hi, I have a question. I know the z12 Race (not team) motor is made by SH. Is it a good motor to replace my stock GXR-15 in a fw-05? in my LHS the dealer said it has the same perfomance as the gxr-15. is this true? I'm planning on buying this since I dont have the money for the more expensive "team" motor and to train myself with .12 motors...

Actually "internal clearance" is 0.05mm on our Spec.2 and Spec.3, which means if no shim is used itīs 0.05 and if 0.40 shims are used itīs 0.45mm.

@deceiver: the Z.12R Race is a very good engine too, you canīt go wrong with it. Very good value for the money!

@burito: how much better is the race spec2 than the old version? I found a good deal for the spec 1. Is the spec2 faster/stronger?

thanx for your reply

Obviously the Z.12R Race Spec.2 is slightly faster, but the difference is not day and night. If you got a good deal for the Spec.1, then go for it!
Reliability is obviously be the same between the 2 versions.

I made a radical test this weekend and all the carb problems on the ZX12 dissapeared, and on top of it my lap times dropped.

What I did is got a Nova carb and took it to a lathe, reduced size of throat that goes on to engine to 10mm ext. dia, then made a sleeve from Teflon of 2mm and put it on the carb so i't has 12mm ext. dia. like original, so it acts as an insulator (like the OS or Orion), ...and BINGO...all problems gone, carburation is precise and stable, I made a 25 minute non stop run and pitted every 5.30 minutes...no flame outs and at the end the engine was at 115šC idling like cat's purr..
This engine has tons of torque and good top end, I kept my pace with the JP'S, Sirio's and the likes with no sweat.....now I'm ready for the race this coming Sunday.

AFM

the Z12R is a good motor as it is picco.
The rest of the LRP linup is SH which are junky motors, not to mention they snap cranks and throw rods as if thats what the were designed to do.
They make lots of torque but the power curve of the motors isnt broad at all, you cant expect much from a 140 dollar engine really. Its about like the CEN .46, makes alot of torque cause of its large displacement, power curve is very sad and makes no HP.

my .02

which company is SH?