Mugen MBX-5

im getting a LRP .28 zspec. is there anything i should know about it when starting it for the first time??

ive heard that you DONT want metal to metal contact with the piston when starting it?? is that true?

ive also heard to get the engine warm before starting it, preferably with a hair dryer or something like that?

any other tips/suggestions. im sure there will be some in the instruction book (when i get it) but i just wanna hear what you guys think.

jatoman1992

iTrader: (4)

1. true
2 you dont have to heat the engine before starting but its easier on the internal motor parts.

tip: if you have a bumpstarter... try not to spin the engine backwards.

Charles Godwin

iTrader: (2)

When i started my engine from new i put a few drops of after run oil down the glow plug hole and that seemed to help as well as using a hair drier. Before starting it blow down the exhaust fuel line so it then pushes fuel into the fuel line straight away instead of waiting for fuel to get to engine whilst it's on the starter box

Chaz

ezveedub

iTrader: (17)

I recommend heating the motor up first. This helps to keep the rod bushings from taking a beating with a tight piston/sleeve pinch on first few tanks. You can use after run oil through the glowplug hole or through the exhaust port if the pipe is off to make sure it is well lubed, but I prefer castor oil personally. And also blow through the pipe or the line to the tank to get fuel right at the carb so you don't spend a lot of time trying to get it started up. Hair drier may only make it to about 160deg which is OK. I prefer the heat gun and get it to 200deg instead though. What fuel are you running it in with. It should be a high oil content for breaking in.

rltanner

iTrader: (2)

me and my buddy did a heat cycle break-in and it works awsome

Mugen MBX-5

ok, i usually blow through the line to start it anyways. how would i avoid the metal on metal contact upon first start up??

how to i avoid spinning the motor backwards?

and im not too sure what fuel im using, i think its like sidewinder or something.

ezveedub

iTrader: (17)

What they mean by metal on metal contact is running it dry on first start up cold. Thats why I shoot a bit of castor oil into the engine and heat the engine to 160+ so the sleeve/piston are not so tight. You can lock an engine if you rotate it cold and not broken in yet. That pinch in the sleeve that locks it up will be a lot less & looser when hot, so you won't wear the sleeve down as much during break in if you heat the engine first. If you can get it to 200-220 your good, but not actually needed. You'll notice the engine is easier to turn over when hot. By doing this, your break in wear will be minimal and your to piston to sleeve will seal much better after break in and last a lot longer. After each tank, make sure you bring the piston down to BDC. Don't let it cool down with the piston half way up the sleeve or higher, because when it cools down, it will shrink down and may lock onto the piston and ruin your piston/sleeve assembly.

Also, if I am not mistaken, you engine should rotate counter clockwise (facing the engine from the front)

Mugen MBX-5

i was also gonna let it idle 1 tank through it, then i just take the next 2 or 3 tanks super easy on the engine or what??

ezveedub

iTrader: (17)

I would take the first 2 tanks at slightly above idle speed. You usually have to do this to overcome the friction of break-in. Then the next 3 tanks you can run a higher idle speed and you may have to adjust the idle screw because it may high idle. From there on, you can run the car, but limit the throttle to about 30-50% in short blips for the next 2 tanks. Then run the next 2 tanks at 50-70% throttle max. Then the next 2 tanks about 70-80% throttle. Remember to keep an eye on temps. Try to maintain a 210-240 F temp. I keep glowplugs of different heat ranges around as the engine starts to break-in. You'll encounter that when then engine is getting close to fully breaking in, you'll have to lean it more and more to keep temps UP and good response. I personally like to run castor based oils during break-in. Castor smokes and gives you a good visual of how rich you're running. Most newer synthetics lubes don't give you that good blue smoke on accel, so the temp gun is more critical when you run these types of fuels. I'm old school and like to see the nice blue smoke plume on accel. Its nice to run the newer synthetics based lubed fuels for more power, but I'm not racing with a sponsorship behind me, so if I blow an engine, I don't have a sponsorship to give me an engine for free. Its out of my pocket. I good break-in fuel to use is 5-10% nitro with about 16-18 oil content. I run Omega 10% with castor based oil. It seems likes much to do, but the engine will last you much longer. Remember nitro is corrosive, so the higher content, the more you erode or wear the sleeve/piston. Try to look up Ron Paris's engine tips PDF. Its an older tip sheet, but its based on castor based fuels like Blue Thunder. One way to know when your full broke in is to remove the glowplug and rotate the engine. If you feel the piston gets stuck or feels scratchy when it gets closed to TDC, you still need to break-it in some more.

Mugen MBX-5

sweet, thats what i was wondering. thanks a lot for all that info. i dont have a temp gauge though. do those come with the engine or electronics or what??

ezveedub

iTrader: (17)

You gotta get one separately. You can find them at LHS. There are some pocket sized infrared temp thermostats available for about $30 and up that should work fine.

Jason Halvorson

iTrader: (22)

i use the duratraks one for 20 bucks and it works great...

Mugen MBX-5

damn, those are a lot cheaper then i thought. ill have to get one. how exactly do they work??? its got a piece of metal that touches part of the engine, then goes to some sort of electrical box (powered by seperate batteries, not my receiver battery thingy) or what?? how do i mount it??

Charles Godwin

iTrader: (2)

If you want a temp gauge i recommend the O'Donnell one. Takes temp in *F and in *C and also doubles up as a stop watch

Chaz

ezveedub

iTrader: (17)

No, you just point it into the head at the glowplug. I point and move it around in the head to get the highest reading. You can easily get an off reading if you catch the side of the head instead of the center or hottest point.