How to modify engine port?
 

Hello,

How to modify engine port?

what should be pay attention to when modify an engine's ports?



TKS

Re: How to modify engine port?
 

To moddify ports on any engine you can use any tool whch will be suitable for that work-needle files, Dremel with dimond bits etc.
The most important thing you have to pay attention is-what do you want to achive by modding.
Good luck.
Edward

Re: How to modify engine port?
 

My How-to is to send my engine to the Engine Master! Bmodified forever RULES!

who might the engine master be???

Kondo sensei.

I'd say it's DINO san.:D

dino san now is on a different mission.

DNA specialist, mod baby to become world champ :D

I think he mods too much that it leaked out. The result stands as proven.

DNA specialist? Shot ten months ago. It is too late now.....:deathstar

I would like to know that HOW TO MODIFY CHILD?:(

that'd take more than a lifetime.

Bmodified rocks!

hi adsl
what you can do is blueprint the motor. make sure that when the piston is at BDC [bottom dead centre] the top of the piston is level with the bottome of the exhaust port. if the top of the piston comes down further than the bottom of the exhaust port, make the bottom of the exhaust port longer until the top of the piston and the bottom of the exhaust port are flush.

just be careful that you don't brake any IFMAR, ROAR OR AARCMCC rules by doing this.

i hope this helps. :)

If piston is not in flash, how does it affect the engyne performance? What is happening there when it is not in flash?
Just recently been proven, that if piston goes further down then bottom line of exhaust port works better. How much further-0.5-0.6 mm. anything else will not work ( 12 Novas based engines). The same with boster and transfer, but numbers are different.

Do you mean, instead of raising the top of the exhaust port, you should extended it by taking materal (0.5 -0.6mm) off the bottom of the exhaust port?

sorry i'm kinda think :sweat:

No,that is not what he mean.

Mp 777 means that lower the port is wast of time as it is prooved that it is better for engine if piston goes .5-.6 mm lower than exhaustport in BDC. You should remeber one moore thing. If you lower ehaust port to much you can have a problem with fresh gasses going past piston and out in exhaust system while piston is at TDC. Never mesured it but it can happend.

I was talking about that, if piston goes below bottom line of exhaust port it will not hirt at all ( but should be certain number).
Exhaust timing will have nothing to do with that ( exhaust timing counting from top line of exhaust port).
Actualy underpiston induction ( when gap is open at piston in TDC position) is using widely in couple classes in airmodeling ( if they not prohibited). In cases where carb diameter is restricted-underpiston induction is very good solution. In our case it will not unfortunately work due the presents of idle.

THanks for clearing that up guys, i get it now hehehe :blush:

I also have another question regard exhuast port height. if you raise the exhaust port hieght on the sleeve, then you would have to raise it also on the crank case right? What happens when i replace the sleeve to a new one with the stock exhaust height. THat would meant that the exhuast port height on the crank case would be higher than that of the sleeve. Would that jeopardize the engine's longivity or reliabiliy or power? Would the sleeve start to warp or blow out at the top of the sleeve exhaust port because there's no reinforcement from the crank caes due to its exhaust port being higher than that of stock? Have i lost you guys yet?:sweat:

I glad that we were able to help.
How much higher exhaust makes sence to raise? 0.1 mm is equal 2 degree. Even if you raise 10 degree exhaust it is only 0.5 mm-don't touch crnckcase, leave it as stock, nothing will change.

I would try that ^^^^^

Please if you try that, don't forget to compencate pipe lenght. It is sort of issue with raised exhuast. Exhaust timing must to be compancated by pipe lentght, otherwise pipe will be too short.