Engine porting

[Error401]

Anyone know of a good source of info on porting engines? I'm gonna upgrade my engine and really want to try my hand at doing a port job on the stock 21bb.

 

[NCNitro]

Here ya go,

Engine Porting

Heres one that shows how to do it on a pro 15 but it may help you out anyway.

TRX Porting

 

[Error401]

Thanks. I'll check it out now.

 

[HugeGuy]

I ported my trx .15.. talk about a boost..wow! The only downside is that doing so, made it not idle well at all but it had GOBS of top end power.

If you have run some fuel through your engine, you will see the dark marks inside the cylinder. That is where you need to remove aluminum from. Try to get your "cuts" the same "thickness" as the existing ports. There is also no need to get them perfectly smooth. In fact, a little roughness will help the fuel atomize better.

I would not recommend grinding away on the sleeve as it is to easy to mess it up. Although, if you are getting a new engine and have nothing to lose, go for it..

 

[Alein]

Hmm some interesting thing to porting the other parts of the engine. Might have to look into doing some of those mods.

 

[Digital Liquid]

Has anyone tried porting or polishing up the Nitro Star S-25?

If so, what were your results?

Did you have any problems doing it?

 

[Hypedonrc]

Those are some good links NCNitro!

 

[newnitrofan]

Error do share your results when done. I have a spare 21BB layin round and would love to see a difference out of it.

 

[Error401]

I never got into porting that mill. It ended up being too far gone, so I just got a hyper 21 8 port to replace it.

Man, this thread is ancient. I think PeeWee is porting his 21BB, so ya might hit him up about it.

 

[newnitrofan]

OH crap I didn't even see the original post date. Ehh I am pretty much giving away my spare 21BB with the buggy I am selling so it's just as well.

 

[pee wee]

Yes, I'am porting the 21bb. It was in way to good of shape but it was just sitting there so, why not lol. I'll let you know if or when I get it running. I'am about half done right now. Later boys.

PW