porting the 044. what to do with intake and exhaust port

[blsnelling]

i figured i was safe staying about even ith the lower transfer. think i should try for more or call it good?. both those transfers took all of 20 minutes is all.

i thought youd say i took out to much.

intake scares me because its comeing in off center and dropn alot out of the carb.

well see what happens

thanks for the great tips

decided i didnt need to know what stock 044 is like. and i was scared the 359 would make it look bad

Check where you rings end. Make sure you leave some wall for the ends to ride on as they go past the transfer.

Ignore the angling of the intake. Just look where the edges are and how far you have to go to the edge of the skirt, just like the exhaust. I shoot for the same 70% rule here as well. Remember it's the bottom of the intake you care about. You can go squarer here than you would on the exhaust. the rings never have to ride over it.

 

[Evan]

so your saying the exhaust shape should be more rounded due to piston dropn below it. does this help keep the rings from hangin up. but in that same note your saying a squarer port is better than round.

i might widen the transfers alittle more just because its quick and easy. it sounds like id be safe to take alot more out but i fell ive already taken out quite abit, 1/4" wider or so and blended back. that should make a pretty big difrence from stock(whatever that is)

im not sure i understand about what you mean by the bottom of the intake. i thought i didnt want to lower at all. from what i understand on the intake. you want to go wider and stay square as much as possible. is this right


Brad
your gona hate me but this porting has got me thinkn about the 084. and what could happen there. with bigger cylinder the porting should be easier

 

[blsnelling]

so your saying the exhaust shape should be more rounded due to piston dropn below it. does this help keep the rings from hangin up. but in that same note your saying a squarer port is better than round.

Yes and yes. A perfectly square port would give the most flow and therefore performance. However, it must be rounded to prevent snagging the ring. On the exhaust, both rings have to travel past both the roof and floor of the port. On the intake that's not the case so you can go flatter. If flat, the full width of the port is opened immediately. The more rounded it is, the farther the piston has to drop to get the port wide open. It's a balancing act between performance and reliablity on how square you go.

i might widen the transfers alittle more just because its quick and easy. it sounds like id be safe to take alot more out but i fell ive already taken out quite abit, 1/4" wider or so and blended back. that should make a pretty big difrence from stock(whatever that is)

If you've already widened 1/4", I'd probably leave it. Keep in mind that you're not only widening the transfer for increased flow, but also angling them back towards the intake to direct the fresh charge at the rear of the cylinder and help the scavenging process of forcing out the exhaust.

im not sure i understand about what you mean by the bottom of the intake. i thought i didnt want to lower at all. from what i understand on the intake. you want to go wider and stay square as much as possible. is this right

Exhaust flow happens as the piston drops from TDC and opens the top of the port. Therefore, it's the top of the port where most of the flow happens. Raising the exhaust roof increase exhaust duration, but also lowers compression. I don't raise the exhaust unless I have to to get a good port shape.

Intake flow happens as the piston rises from BDC and begins opening the bottom of the intake port. The floor of the port is lowered to increase intake duration, just like you raise the roof of the exhaust to increase duration. I often lower the intake 1*-2*. I also widen the intake just as I do the exhaust.

Brad
your gona hate me but this porting has got me thinkn about the 084. and what could happen there. with bigger cylinder the porting should be easier

Reguardless of what you do with your 084, you need a 046/460!

 

[Evan]

well see.

what i need first is an 044 10mm piston. i dont think meteor makes 10mm piston for the 044. might have to suck it up and get stihl piston

thanks again for all the help.

ill be grindn tommorw

Evan

 

[parrisw]

If you'r dropping your jug, you might not want to lower the intake floor, since lowering the jug is also increasing your intake duration. Something to think about.

 

[Evan]

im not going to lower the floor,

i dont know enough to mess with duration il just stick to dropn it the thickness of the gasket and make everything wider.

im pretty exscited to see how this thing runs

 

[Evan]

my pot of coffee is about gone im awake now and off to grind on exhaust. blend transfers just alittle bit more and maybe grind on the intake to then im done porting and might come in and order a piston.

 

[blsnelling]

Sounds like a plan. Don't forget to work the windows of the piston over when you get it. And remember that you work the angles for flow from the inside out.

 

[Evan]

my little man woke up right as i was going out to gargage. ohhwell.

i didnt think i was going to work the piston over, ive never messed with piston other than cutting a square in kx125 piston in the intake side i wonderd about doing this on the 044 piston but i have seen any one do it on saws.

i id the kx 125 becaue kawasaki posted porting specs for theyre bikes. actualy they sent them to you if you aked.

 

[Evan]

finaly under way. widend exhaust to just past the factory chamfer. im tryn to hang on to the shape that factory had as close as possible. i feel much better about this time around almost kinda feel like i know what im doing.

thanks to you guys.

 

[Evan]

what ive got so far.
widend intake to just past the chamfer, widend exhaust farther, pick doesnt look like it.

still have more work todo.


intake

before grinding

 

[Mama Tried]

you still using the dremel with the stone? or something else?

 

[blsnelling]

Taper the widened intake port all the way back to the opening.

 

[volks-man]

thank you very much for the reply.

i will widen some. im just gona grind till i think it looks good and call it good. i just ground till it looked good on my 359 twice. think it might have a 3rd time comeing when i get bored

i have the cylinder here and man im lookin at the upper tranfer and ill leave it alone i can see me accidntly getn the cylinder wall. need little 45deg angle grinder it looks like

thank you again for the reply

thanks

Evan

you may be able to get at them with a flex shaft attachment. my flex has a long pencil-end that i could get to the transfers with a cutting wheel to angle forward. i have not tried this yet though.

 

[Evan]

yeah just useing the dremel still.

have some that go wide down to a fine point then a rounded tip one kinda big blunt shape.

i did get the upper transfers with biscit shapped grinder on the dremel wided about 1/4" abd blended to the intake.

blsnelling
i did blend the rest of the intake. though that side that you noticed was almost done already i wided to what i felt was safe and the way it blended out out around the bend the rest was wider. i ended up blending all the way out to were the intake boot clamps on.

the intake is wider than the exhaust, what are your thoughts on this. i can still widen the exhaust quite abit intake i widend to just past the factory chamfer on the port i feel that i shouldnt go anymore there

went to easter dinner and left my camera there so ill have to wait to post pics of what ive got so far.

 

[Mama Tried]

take some pic of the tools too please.

 

[Evan]

cameras at my grandparents place. kinda SOL for tonight

 

[Evan]

these two are what i use mostly i use the msller point getn in tight places

used this in the upper transfers

 

[Mama Tried]

cool I think I have those and a flex shaft. thanks.

 

[Evan]

i have a flex shaft but it broke first time i used it.