[QUOTE=MassiveMods;5558471]Go Engine Shimming 101

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

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..

I checked my engine shims in my MM5 7 port twice and found only 2 x 0.1mm copper shims ..so looking at the above info 0.5 total which with my 25% nitro would be fine ..but I was still melting bodies..Just took it apart again tonight and finally found the 0.3mm aluminium shim that was disguising itself as part of the top of the crankcases..DUH! That would make 0.5 total shims fitted for running in also as detailed above..Maybe I need glasses..

can't wait to fire this up at the weekend..I promise the photo's of me and the circuit will appear this weekend MM mark!!One last banked corner to shape and the circuit is officially open on saturday afternoon..man this winter seems to have lasted forever..

A Os speed and std v-spec carbs are 9mm, the Go is 8 mm, I think that is one of the reasons you notice a difference. I have ran Nova/ Rb carbs and didn't really notice a difference.

Rex

I am sorry even if you run a Holley 6 barrel carb your engine is not going to be faster. It will tune differently and may make it easier for someone to get the full potential out of their engine. I actually have an RB carb on my PTM 5 port, only because I wasnt paying attention with my heat gun and melted it a bit. It still worked after that happened but I didnt want to chance it. I only have that RB carb on there because I got a killer deal on it and I was in a pinch and it was the fastest thing I could get. But I got GO venturi's in there.

MassiveMods Best advise on how to modify a temp gun to give you the best readings for tuning.



1 Get temp gun and place on firm surface
2 Put on safety goggles
4 Select heavy hammer
5 Repeatedly hit the temp gauge till it looks like the pic below
Please refer fig 1A
6 Use temp gun and see how well it takes temps now.


Now that we have modified the temp gun we can use it to help us tune the engine!

Hope this helps !

Cheers MM

That should be a sticky on this forum! I think there is validity into grabbing a temp here and there, but tuning by it, well that's just wrong! Anyone who thinks they must will learn their lesson sooner or later.

Holley doesn't make a 6 barrel! lol
If you can tell a difference between a 7mm and 8mm restrictor you can probably tell a difference with a 9mm carb. We usually run 7mm restrictor to get fuel mileage and we have enough power anyway. The most power doesn't win races usually.

I have never tried an Os carb, I don't really like there products.

Rex

Hi all,

I was looking at the new 3 port R as it looks like a nice little engine with a decent amount of power. As I haven't read much on this thread on that engine I was wondering if anyone is running it and it goes? In other forum I read that it has several issues with the carby, is this just matter of tuning?

Thanks.

i run 3 port race and runs great in buggy has alot of bottom punch and with the dyn 086 pipe or go 0801 pipe it still gives plenty of top end the carb issue is fixed and i personally think it was just alittle finikly to tune with the carb needle that it had ... in fact i still have one with the finikly needle and its in the 3 port race now thnx will g

Yeah I have no idea I was trying to make my point. I ran the 8 and 7.5 in truggy last year and 6.5 in buggy. About the 3 port race this will be my next mill, I like it alot. I have driven 1 of someones before. I just feel that I like mills with smaller amounts of ports I may never have a 7 port. Plus I never run on them wide open 200 ft by 300 ft tracks so I really have no use for it. Plus I like all my engines modded so the 3 will be definetly modified. My PTM 5 port is really too much at times even in truggy I was even thinking about 1 of them Innovative designs 5.5mm restrictors to try.

I have a GO 3 port on the way to my place now, In reading this thread i see the 086 is one of the golden pipes for this engine. I have a 053 here. Would a 053 be a good pipe for this engine? it is the blue headed one. after break in i plan to work the ports a little for better flow.

Thanks!

I think the 053 would really kill the top end of this engine. For $50 get the 086 I have one with less than a gallon on it I'll trade ya for a paint job it's the hardcoated one

i never said it made more speed...it does smooth out the powerband being able to tune the midrange... and i ran a 7mm restrictor

Someone posted a place where you can get the 086 for $41 its back a few pages.

what run time can i expect from a stock 7 port? i have a race this weekend and due to my busy schedule I havent had the chance to time how long a tank runs. i have a dynamite 053 pipe on it and using werks 30% fuel...im just gonna take suggested times and pit in at that time, lol