Home Porting ?

[carl]

Okay, I have had no luck in finding a sutible person to port my cylinder. So i have thought about porting it my self and was wondering if any of you have done this to yours?. I have the correct tools to get the job done but i do not know how much will be best to take off.

Any help will be greatly appreciated.

Thanks Carl

 

[1997blaster]

i would just try top find cheeper shipping to the biulder uwant to port it cuz i u mess it up ur gonna have to buy a new one then have it shipped to u so youd be better off finding cheeper shiping or find a local enine biulder

 

[4cfed]

you could do it your self BUT id buy the 2 stroke tuning guide before doing so..

see if any of these help you out

Aptec Motorsport

Cylinder Repair and Cylinder Plating Services

motorcycle engine tuning and performance centre - FW Developments

Two-stroke Performance Tuning: Amazon.co.uk: A.Graham Bell: Books

 

[carl]

i would just try top find cheeper shipping to the biulder uwant to port it cuz i u mess it up ur gonna have to buy a new one then have it shipped to u so youd be better off finding cheeper shiping or find a local enine biulder

True but to ship to a porting company i can trust WILL cost a minumum of £75 each way. and for that price i am prepared to take the risk

 

[carl]

you could do it your self BUT id buy the 2 stroke tuning guide before doing so..

see if any of these help you out

Aptec Motorsport

Cylinder Repair and Cylinder Plating Services

motorcycle engine tuning and performance centre - FW Developments

Two-stroke Performance Tuning: Amazon.co.uk: A.Graham Bell: Books

Yes! Thanks alot man, rep given

 

[4cfed]

Yes! Thanks alot man, rep given

no problem man.. granted i live in the states BUT i can still find most things for other places... i know 2 strokes are the big rage in the uk, and europe (sp?) seen alot of stuff online with some nast fast 2 stroke scooters ( mopeds here) so i know there is a market for it and performance available there

 

[carl]

no problem man.. granted i live in the states BUT i can still find most things for other places... i know 2 strokes are the big rage in the uk, and europe (sp?) seen alot of stuff online with some nast fast 2 stroke scooters ( mopeds here) so i know there is a market for it and performance available there

Yeah, the people over here do seem to love there mopeds but most people ride them illegally lol. Back when i was younger i had a Derbi Senda 50 and put a big bore kit, 21 mm carb , performance reeds and much more on it and she flew burnt every other moped i could find to race lol.

 

[ROCKSTAR]

my cousin had a derbi!!!
BB stroker, carbon exhaust...

anyways...porting is a risky thing..i understand shipping overseas is a big issue...but you have to do A LOT of research. have to get the port timing right, the port angles, the correct port durations.....hope you understand the workings of a 2 stroke...cuz you'll need it, for sure.....not only that, but you have to find a pipe that will work with your portjob also. and you have to figure out what port design makes teh right range of power so your pipe and engine work together.....(i.e. mid range port and low-mid pipe) that way your not putting a drag pipe on a mild trail port or vise-versa.....theres a lot of info you'll have to research...

idk your backround, so im just saying....

 

[StrokedTater244]

if you can fully understand about 85% of graham bells guide to 2 stroke tuning you will have no problem making a decent running 2stroke motor...if you dont send it to someoen who knows what they are doing..

 

[OConnor Racing]

The Mac Dizzy web site has a very detailed page ( Blaster Build ) where he gives all of his porting specs. He even made a spacer plate for the bottom of the cylinder. I built the same engine for my wife. Works great and make a ton of power. Works even better when you go to a larger carb and do a 4 degree advance. She's running a Toomy B1 pipe.

 

[carl]

Okay thanks for all you help people i am now going to start doing all the research i need to help me do this.

Just wondering by just polishing them will i gain any noticeable performance?

Many thanks carl

 

[370]

carl.. the thing for you thats gonna be the trickiest is getting into the transfer ports.. now you can change the ex port duration rather easy with simple tools and some time. BUT.. you have to watch how much because the relationship between the exhaust port opening and the transfer port opening is critical.. this is what is refered to as "blowdown" your gona have alot of homework to do.. my advice is start small.. then you always can go from where you've stopped.. porting takes time to do correctly.. even for someone like myself thats got alot of time with a handpeice in my hand it still takes time.. keep things stright and even.. transfer ports at different heights with big nicks in the corners and such do nothing to help the performance of your project. get a degree wheel.. that will help you alot as well.. some guys are gonan say nah just use this program for your computer and measure down to the port roof.. that how i started out too... thats not nearly as accurate. if the top of the cylidner has been decked in the past these measurements are out of whack.. it also doesn't figure for things like base gasket thickness.. not all base gaskets are the same.. and anytime you move the cylinder up or down you change to port timing.. if you've got any question feel free to PM me and i'll help you out..

 

[Wildcard2]

I will never discourage someone from learning to port their own cylinders, it can be very fun and rewarding. There is a wealth of knowledge to be had from some of the publications listed in previous posts. There is a noticeable amount of gain to be had just doing some work in the exhaust port as 370 mentioned. But be very mindfull of shape, width and blowdown timing so you don't ruin the cylinder or make it too "peaky". But, if this is just to save some money I can assure you that it will be cheaper in the long run just to send it out if you plan to get the same type of power gains as some of us builders do. The required tooling for the transfer port work and head modification isn't by any means cheap.
-Brandon

 

[Blasterdude27]

When I started to get interested in this area I picked up as already mentioned above "Two-stroke Performance tuning" by a. g. Bell's.

That might not be the biggest book filled with papers and papers of german research, but it covers EVERYTHING you need to know to get started, from reeds to the pipe it covers it all in a well organized book.

 

[370]

When I started to get interested in this area I picked up as already mentioned above "Two-stroke Performance tuning" by a. g. Bell's.

That might not be the biggest book filled with papers and papers of german research, but it covers EVERYTHING you need to know to get started, from reeds to the pipe it covers it all in a well organized book.

the pipe section of that book is lacking.. not saying thta bell was wrong.. just at the time when he wrote that book 2 stroke expansion chamber design was still somewhat of a mystery. there have been many many advancements in the design and construction of 2 stroke expansion chambers in the last 30 or so years.. but even today that infomation is not exactly "commong knowledge" being that it's alot more cost effective to buy a mass produced unit and set up the engine around that pipe..

 

[370]

I will never discourage someone from learning to port their own cylinders, it can be very fun and rewarding. There is a wealth of knowledge to be had from some of the publications listed in previous posts. There is a noticeable amount of gain to be had just doing some work in the exhaust port as 370 mentioned. But be very mindfull of shape, width and blowdown timing so you don't ruin the cylinder or make it too "peaky". But, if this is just to save some money I can assure you that it will be cheaper in the long run just to send it out if you plan to get the same type of power gains as some of us builders do. The required tooling for the transfer port work and head modification isn't by any means cheap.
-Brandon

i def. agree with you on the fact that to get the power gains that the experianced guys do it would be more cost effective.. and also on teh fact that i'd never discourage someone from wanting to leran how to port their own cylidner.. that said.. i have much respect for a guy that has the dedication to do it.. or rather the dedication to do the reasearch and give an honest try at doing the job correctly.. and going into it knowing that the first try is not going to be on the level as those with years of experiance and knowledge on the topic but is also dedicated enough to further his knowledge and eventaully expand on his capabilites.. so i guess you and I are on the same page here.. if he's expecting professional results the first try.. then rely on a professional to do the work... but if he's into this not only to port his cylinder but to also learn how they work, how to modify them and further his intelligence on the subject of 2 stroke performance then i say READ UP BRO..

 

[carl]

Okay right, i appreciate all the help and the problems which might occur during porting. Im sorry to say but i am not prepared to pay over £300 (around $550) for a port job.I know the risks involved and i know i am going to need to learn alot to make it successful but like you said 370 it is a process of learning, i can only learn from my mistakes. If it all goes tits up i will just have to buy a new cylinder which will not cost alot.

So once again thanks for all your help Carl

 

[Blasterdude27]

the pipe section of that book is lacking.. not saying thta bell was wrong.. just at the time when he wrote that book 2 stroke expansion chamber design was still somewhat of a mystery. there have been many many advancements in the design and construction of 2 stroke expansion chambers in the last 30 or so years.. but even today that infomation is not exactly "commong knowledge" being that it's alot more cost effective to buy a mass produced unit and set up the engine around that pipe..

I agree it does give you a good general idea and the basic formulas.....
But the section is lacking. I think that unless its a custom application and your willing to try and fail many times before you get the results you want there is no need to make your own pipe, like you said its more worth while to set your engine around the pipe.