Ybakoff

Where can I buy a Zac pipe from. I was trying to get one of there modded motor's but I can't find them anywhere.

Thanks

daniz24

A lot of my friends are selling their OS ZAC very cheap (new and used) since JPs have more power bandwidth especially in the bottom. Too bad you are in Australia

markp27

Hi Guys,

I've run my JP FX in and tuned it to the best of my ability (needs some practice, I think!). What surprised me however, was that the gap on the throttle barrel wasn't very big - I see figures of 0.5mm to 1mm often quoted.

My engine is running @ 108 Degrees C after a good 10 laps of hard running. When release the throttle trigger after a flat out section, the revs go to idle relatively quickly (i.e. don't stay high for a few seconds - which I think indicates LSN too rich) and the revs don't increase.

I've used the pinch method (i.e. pinching the fuel inlet tube) to see if the engine is running rich or lean. When I pinch the tube next to the carb inlet, the revs rise for 0.5 to 1 second and then die off pretty quickly. This should indicate an ok tuned LSN, no?

Have a look at the pic attached, you can see my idle gap - let me know if this is ok. BTW: Normally the insert is in, I just took it out to let you see the gap better.

Cheers, Mark.

ziggy12345

Looks ok to me and the explanation shows that its in tune.

I would have thought you could run the engine hotter than 108. What are others running theres at

Cheers

markp27

Cool

I was just at the end of my run-in cycle, so I'm just building the temp up slowly. I've got the JP FX with ceramic bearing, does this mean it can run a little hotter than normal?

No one else is running JP FXs at my track, so I'm not sure what temp I should be running the engine at. Any tips would be welcomed


Thanks, Mark.

Ron C.

iTrader: (2)

Hello markp27,

No, the bearings doesn't mean you can run the motor a little
hotter. On the other hand, ideally, the motor should run a bit
on the cooler side since the ceramics allow the internals to
have more ease and smoothness when in motion.

About the temps..
If you are able to run it at your current 108 C with ample power
and run time, I suggest to keep the temps within that range.
But ofcourse, this number will always differ depending on the
current conditions on the day you are running the motor at.

MrChan

I have been running at my track about 97 C ... give me enough power ..

markp27

Thanks for the info

markp27

Yeah, the power is really great.
I'm running the 3-port version. The other day a guy setup a radar-gun to check the speeds of the cars at the fastest part of the circuit.
A guy running an MRX-3 1/8th got 92 kph, a 1/10th runner with an MTX-3 only managed 60 kph and me, a solid 90 kph

markp27

Is there ever ample power

daniz24

Maybe you could lean your LSN a little bit more. And yes, your idle gap is about the same to us.

Cool. Is that means they now allowed you to join the 1/8th scale racing with your 1/10th car?

markp27

Thanks - it is reasuring that I'm going in the right direction. Ok, I'll lean the LSN a little bit more.


Once I get my old 705 fitted with the Lola body and JP FX engine, I'll be creaming the 1/8th guys

InitialD

It's the car I tell ya...

Geez, are you sure it's the 1/8th scale and not the 1/5th scale lawnmowers?

markp27

D!!!! don't blab about the car stick to the plan remember!!! The car is a piece of junk, made out of glass in fact! It's better to buy something else

The lawnmowers were impressively fast: 72kph

InitialD

Ooophs, apologies Master Mark. Slip of the finger ! Anyway, it's not mentioned in the FAQ to keep silent.

I would rather get hit by a 1/10th scale running at 90 kph than getting hit by a 1/5th scale at 72 kph !