ENGINE FLUSHING

Generally yes its a good idea to take a look inside , parts id particularly look at are

Cylinder , pop off the head look inside , piston to bdc , flush to exhaust port
Crank case , check for any debris etc ,

Re oil with Parrafin or MMARF oil or Singer Oil

Having said that i pull apart go engines every day and are still to find any debris , they go through a very strict QC and cleaning regiment at the factory before assembly. When i inspected the Assembly room at the factory i had to take off my shoes and put on a hair net, surgical slippers etc , it was like i was about to go into surgery !

BUT still i always check just in case .

M

Go Engine Shimming 101

The Go head button has a step already built into the head button which is .5 mm so whatever you add make sure you realise that it includes the step.

HOWEVER !

the top of piston to top edge of sleeve at TDC is 3.3 mm

from head button step to end of geo dome is 3 mm

so lets say you didnt use any shims your head clearence would be .3 mm

now whenever you add a shim you add it to the already existing .3

eg if you add a .2 your total head squish would be .5 because you are adding to the alreay built in gap of .3

I run .1 in mine to give me .4 total this was after i ran it in , before during run in i ran .4 to make a total of .7 i only ever use 20% nitro in my race fuel.

When the engine is new i recommend for the first 5 litres or first gal and a half ( for imperially impared ) Running .4 to .6 shim

This will save your plugs and give you a better idle , it will also help with relieving tension on the rod when the engine is still tight ..

So lets just talk about head shims VS Nitro % age and assume the engine is run in. Plug choice is next to each one

15 % .2 Hot
20 % .3 to .4 Med hot
25 % .4 to .5 Med
30 % .5 to .7 Med Cold

My set up on my MG66 FT is this

Shim .1mm and 20% nitro, with med plug LRP #6 , 9.2 mm custom venturi 11.5 mins tank time at average tune , 12.4 mins at race tune. 125 ml; tank. EPA wide open. Turbo Head Button.

Shims VS Heat Emissivity.

The more shims you run the lower the comp ratio, less tank time, and the cooler your head will run but this will give you hotter exhaust temps so if you are melting bodies thats why !

Less shims = higher comp = hotter head button and heat sink = Cooler exhaust temps = not melted body , better tank time..

Hope this info helps !

Cheers MM

Great info mark... cheers.....

Nawaf

The stock bearings I agree are awesome. But when I went to replace them I saw that TKO's are very similar in price and at street price actually the front GO stocker is more $ than the Ceramic. I really just wanted to try the rear Ceramic out but my sponsor was all out of both at the time so thats why I am trying them out. And My stock bearings werent bad I still have them as back up.

Hey Mark - that information is MASSIVE
It also explains why my motor runs pretty cool and my body has got big burn bubbles in it !!!
One question so I can get this right.

What are the shim sizes of the standard factory shims in the motor. 2 x thin copper and 1 x thick aluminim

Cheers

no one has an answer to this? I was pretty sure I could at least get an answer from a few people at least. Thanks

here ya go ive never ran the 7 port but i run the 3 and 5 port race and they all run around 220-245 and are very very good running at those temps engines need to stay above 200 to be consistant with power hope that helps thnx will g

thank you sir. I thought was was a bit low. If im getting that low of temps its probably meaning im running rich??????

are you now tuning it on the ground ? if so lean top out 1 hour and see how it runs mostly want to get good power all the way thru the revvvvvvvs and then make sure making plenty of smoke and you can check temps from there

yes sir i dont ever bench tune. I dont believe thats a way to tune a motor.

cool try that what i mentioned and see what it does and what plugs and fuel you using ?

i use 30% byrons with a p3 plug

good deal well give it a try ... remember little at a time should work awesome for you thnx will g

Tagalong, I think most people temp to the plug, it will measure quite a bit lower to the head or with a on board temp guage.

Rex

Hey guys would you reccomend a Go Tech .21 5 port for my friend who is a newbie with nitro( tuning and break-in)