How I modded my F4.6

[Double-O-Zilch]

I in no way recomend trying to mod an eng yourself. This is what I did and I'm not so sure it was worth it. Shortly after modding my sleeve the front bearing began to leak. After that I went and did the crankshaft anyway. It may have actualy worked had the front bearing not started to leak, won't know for sure till I get it all back together and sealed right. For those who wanted to trade me my engine internals for other things, this is why I declined. It was a sloppy job with the Dremel.

I wasn't sure why I did this other than the idea that less material in the crankcase would yeild more room for the air/fuel mixture. I also exagerated the ports only on the carb side.

I can tell you matching the port to the exhaust port in the block is a bad idea! Not good for the way the pipes are supposed to work. I have tried to mod the stock pipe to remedy this and nothing worked.

Here you can see I knife edged the crank.

This angle shows that I exagerated the scoops on the crank.

The last two pics show that I removed the piston skirt material except for what is needed to insure the sealing of the exhuast. This was an effort to decrease rotating mass.

Getting this engine to warm up takes forever! And then the tune is all over the place. Could be due to the front bearing leaking, not sure though. As you can tell I have no idea what I'm doing and would recommend that unless you do, leave it to the pros as I have had nothing but headaches since doing it. Who knows though, maybe I'll get it back together and she'll run like a champ!

 

[Crash]

looks good, lol

sorry to hear it didnt work out.

so is this hobby, live, learn and spend more money.

 

[Jeremy]

At least you tired thats more then I can say I have done

 

[groovethumper]

It takes alot of courage to mod an engine. I'd wait and see til everything is sealed and you've worked through all the little bugs, before you say it's a failed effort. Peace.

 

[HopIt]

Thanks for the lesson !

 

[Double-O-Zilch]

so is this hobby, live, learn and spend more money.

So true Crash! Yeah guys I'm hoping it wasn't a complete loss. As soon as I find a block we'll find out. If it comes to it I'll buy a new F4.6 and throw the parts in there and see what happens. You can bet your bottom dollar I will try this again!

 

[NITRONUT]

Hey Buddy, I give you props for trying it. Most people don't even have the stones to try modding their own engine........I give you rep!

 

[Double-O-Zilch]

I forgot to mention that the Savy was my first nitro vehicle and I did this a month after getting it! All or nothing baby! Learning the hard way always stands out better in your mind anyways.

 

[MotoPsycho]

"E" for the effort Park!

 

[Fx]

Practice makes perfect and I give you props for it.

 

[AIR_RAM]

Whats the word... have you put it together yet.

I have asked around about re-building a Nitro engine but everyone I speak to says rebuilding is not even worth the time... When you do build them they hardly ever run right, they all say buy a new motor its cheaper.

But I wold think it would be cool to know how to actually re-build successfully and then MODIFY one to perform better. From what i have heard... if just a simple rebuild isn't so simple then Modifying must be a PITA.

I would like to hear that it worked well for you. I have built many 4-stroke engines but never a tiny Nitro engine... I cant see what would make it so darn difficult. Heck their are only a couple of parts to the darn thing.

Anyway... good luck and please keep us posted.

SPEED SAFE, AIR RAM

 

[faisalbasha]

is this your first time modding an engine because from the pictures you posted that LOOKS PRETTY GOOD!!

did you fire the engine yet???

 

[Double-O-Zilch]

No guys, she ain't running yet. This is my first atempt at modding. I can tell you what I learned though. As you can see in the pics, DO NOT match the exhaust portion of the sleeve to your port on the block. Between that and the leaking front bearing, she ran crappy. I am going to raise the exhaust port a little on the next go around. That will make the engine run cooler as the exhaust escapes earlier. On the sleeve I just opened up the intake ports towards the top of the sleeve to make the intake last longer. Not more than 1mm. The crankshaft is knife edged meaning the opening is pretty much flush as you look down the carb hole and I exagerated the scoops with a stone to make them bigger. If you're going to try it, good luck and take your time.

 

[svtman]

If you do mod a new sleeve and piston Iwouldnt recomend touching the exaust port. Tha timing on the exaust is very critical for your torque hp balance. by raisng the port you will lose alot of torque. just lighten the crank, piston port the sleeve and polish everything that should make a big difference. I definatley wish i had as agood of hands as yours. There was a article in one of the rc mags that expained the timing if i can find it ill post it. By the way your engine will run cooler but youll lose pressure on yuor down stroke(torque).

 

[Double-O-Zilch]

Makes alot of sense man, thank you. It appears I have some more research to do before my next attempt.

 

[Crash]

Parker,

did the sleeve have tear drop grooves pointing at the exhaust port already?

did the crank have scoops already?

what does it need rite now? front bearing?

the reason for the questions is, I'm getting into modding these little mills and
want to learn as much as possible. Failure teachs us more than sucess does.

IMO on that mill I would of just worked the sleeve over.

and polished everything.

 

[scrogathon]

parker I'm geussing you didnt do any work to the side boost ports? I just noticed that the f4.6 is identical to the force motor I am modding.

 

[Double-O-Zilch]

If I remember correctly, I extended the timing on all ports. How much I don't know as I was just duplicating pics I saw. I think it might have worked out well if I didn't mess with the exhaust port. I have another F4.6 I was thinking about doing to try again but may just sell it to make some money as it's in sort supply!