need info on porting

[wedge]

what exactly do i need to do and where do i need to do it. ive done it on car v8's. but what needs to happen to a saw? please help

 

[tony marks]

well first u go inare somewhere around the intake and open it up.. a can opener will do,, put in oversized jet.. then go to the hine end o the thing.. u grind out the exhaust port a good bit.. dremel tool will do.. thein u gets 2--1 by3/4 copper adapters an weld on the muffler fer good looks. then uputs it on ebay and sell it fer a fortune .. as u packing u bags to move..cause u done found out this sucker wont run a lick.. sorry wedge ,,
its just me cutting up.. have a good day bud.. somebody will help uhere..

 

[Dennis Cahoon]

Wedge, you need to go learn the basic's about 2 cycle engines. Get a book, or find some threads on this site for some basic information. If you don't, you'll probably wreck your cylinder, but if you feel lucky, just start grinding. Have you ever heard the saying biggers better? Good Luck! Dennis

 

[wedge]

ive done it alot on muscle car motors and a few bikes. i was just wondering if theres and certain places that need a lot of material removed or just a general smoothing will do. i have a complete set of grinding stones and carbide bits. im just looking for a lil insight.

 

[jokers]

Wedge,

You no doubt understand the effect of the camshaft in a car`s engine, consider how the two stroke engine operates without a cam. You`d better know what you are doing before you start grinding.

BTW, what saw will be your first victim?

Russ

 

[tony marks]

lowes got saws, u could practice on pretty cheap.. just til u got an idea what works.. i well remember the firstun i got rite.. oh itus a thing a beauty..only problem is ,when i throw it in,, it got so much plastic,, it floats along side the boat..
i got no idea why this subject is bringing out the worst in me..i aint even had my wine today... yet. goodluck therewedge

 

[wedge]

i figure id get a used but running homelite or poulan and get to work. im laboring under the dilousion that air flows the same in a chain saw as it does in a car v8. so porting should be similar

 

[tony marks]

lets see we ll callit the wedged 346 xp.
call me at br 549 i gottus some marketing ideas.

 

[Crofter]

Wedge;

I almost think you are trolling, if as your profile says, you are a mechanic. Read Jokers post. In a four stroke porting doesn't change induction and exhaust timing. In a 2 stroke it very well can as well as the likelyhood of allowing the rings to fall into the ports and self destruct.

Frank

 

[wedge]

to be honest im new to 2 stroke engines. i usually just change parts on em. to be frank i think 2 stroke engines are a strange breed of motor and im amazed they work. im much more framiliar with 4 stroke motors. by the way what the heck is a troll?

 

[treeslayer]

For a close look at a troll, go brush your hair.

 

[wedge]

whats that supposed to mean? still dont understand what a troll is.

 

[jokers]

Well Wedge, a troll in this case is someone who is trolling, as in passing through dangling a baited hook and waiting for someone to jump on it. If you still claim to not understand, I will know beyond all doubt that you are in fact trolling. Did it seem odd to you that noone responded to this thread sooner? I think everyone had the same thought. Nothing personal.

Russ

 

[Jacob J.]

Also it would be a good idea to check out macdizzy's site on motorcycle and watercraft engines, that guy is amazing. As these guys have pointed out, there are many, many good books out there, most of which can be read free of charge at your local library, on tuning 2-stroke engines. You need to know the relations of port shapes and timing and their effect on the capabilities of what you're building an engine for.

You need to look at the entirety of the motor and visualize the flow, as a 2-stroke engine is basically an air pump. If you look at macdizzy's site he gives some good numbers to start with on porting, he also shows the use of a degree wheel, depth dial indicator, and graduated cylinder for measuring cc's of squish area, combustion chamber, and compression ring.

The absolute best way to learn is to start with a good design ( like the stihl 066 ) and improve upon it. Some engines are naturally condusive to modification through their design, some aren't. Some are just too much work to be worth it.

 

[wedge]

thank you fellas for answering my questions. i thought it was simply a matter of improving airflow/efficency by removing all the unnessasry obstacles,rough spots, restrictions ect in the intake and exhaust areas of an engine. thats the porting im used to. ive not had much wrench time on a 2 stroke. just a parts changer. i must be the most ignorant s.o.b. in the world because the whole troll thing escapes me. i was just asking for info. not my balls squashed. thanks again to those who helped me out by giving me a direction to go.

 

[jokers]

Hey Wedge,

Sorry if you feel like I`m squashing your balls, that`s not my intent.

Maybe I`m assuming way too much about you, but since you are a mechanic and I believe you have stated that you have built hi performance auto engines, I assumed that you knew exactly what each component of an auto engine does. Now there may not be a direct correlation between every component of a multi cylinder 4 stroke engine and a single cylinder 2 stroke, but I figured that you knew that intake and exhaust timing and duration, valve size, and lift for flow are important, and that somehow this has to be accomplished in a two stroke engine which has no cam or valves. Some elements of internal combustion engine operation are universal. Consequently it seemed as if you were trying to pull someones leg with an overly simplistic outlook and question about porting a two stroke.

There is actually quite abit written on this site to get your feet wet and the site that JJ mentioned is a good one. Check the archives for "piston ported" or "two cycle theory" and see if you find anything. There has also been alot written in threads seeking troubleshooting help, describing how strokes operate. The info is out there, but in order to be able to use it, you must first understand how piston ported two strokes work.


So you still don`t understand the troll thing huh?

Russ

 

[ray benson]

Hi Wedge,
Here are a couple of sites to steer you in the right direction- you
will see there is quite a bit to it.
http://www.macdizzy.com/cyl_primer.htm
http://testfly.0catch.com/homelite/enginemod/cylindermod.html
Regards
Ray

 

[Jacob J.]

Modern chainsaws are lot more complicated than just improving the flow, remember there has already been almost 70 years of engineering in the 2-stroke motor so a lot of the bugs have already been worked out. By modifying a chain saw engine you are basically pushing it beyond a point that the manufacturers are comfortable with, and also bypassing manufacturer's cheap production methods. You can actually ruin a good engine by giving it too much flow.