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OS .35AX

Old 10-11-2011, 07:24 AM
  #26  
airraptor
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Default RE: OS .35AX

The very best of these "25" sized case engines is the Irvine 39 hands down bone stock. Then do a few mods to get correct timing and they will spin a 9x8 APC at 17,300 !!!
Old 10-11-2011, 02:45 PM
  #27  
Strykaas
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Default RE: OS .35AX

a few mods
Could you please elaborate ?
Old 10-11-2011, 04:51 PM
  #28  
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Default RE: OS .35AX

If he DID elaborate, would you promise to DO the mods...?

Are you equipped to carry the mods out..?

It takes considerable time to go into detail about this sort of stuff and after offering this type of advice, plans, molded parts, etc. on these forums for several years.....I have NEVER seen ANY of it bear any fruit.

Old 10-11-2011, 07:30 PM
  #29  
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Default RE: OS .35AX

yes it is very hard to explain to someone if they havent ever modded an engine.

I will say that all most all engines of the same bore and stroke will turn almost the same rpm if everything is very close.

the main thing we have discovered is that you need .100 blow by for every 20 mm of stroke.

so if only a 10mm stroke you need .050.
and if 30mm then you need .150 blow by.

alll of that is a very small part of the equation though. you have to measure your transfers, boost ports and exhaust ports. find out where you are at. it is best to have an engine with very low transfers so you can work your way up.

you have crank timing, piston/sleeve timing, crank hole size, carb size, cumbustion chamber shape and size, commpression ratio and even the plug can change things.

we usally look for .015-.020 from head/head button to piston (start at .025) for 5% nitro. if your oil is clear you can raise compression, if its dark then might be to high
carb if your needle is very sensative then its to small for your combo you have open it up. With carbs though YOU HAVE TO KNOW WHAT YOUR DOING to open them up. you just dont drill them out. you have to use a dremel and slowly grind to open the Dia. just a bit then reinstall and see where your at. if you go tofar it will never idle again.

then there is exhaust port shape and transfer shape also. usally the exhaust is narrow at the bottom then tapers outward to around 155-165 degrees then do a arc to the top to get your desired timing you need. once there you need to raise the transfers to get your magic .100 = 20mm ratio.
Old 12-08-2020, 10:00 AM
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OS 35ax I ran 60% nitro and it hauled ass (I know that was dumb) now my engine is pulsating and full throttle it revs up and down? Do you guys not what could be wrong?
Old 01-12-2021, 12:41 AM
  #31  
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Originally Posted by 3Doutlaw View Post
OS 35ax I ran 60% nitro and it hauled ass (I know that was dumb) now my engine is pulsating and full throttle it revs up and down? Do you guys not what could be wrong?
HAHAHAHAHAHAHAHAHA!!!!!!!

Replying to a 9-year old thread.
THATís whatís wrong.
LOL...
.

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