Post up your ported cylinder Artwork

[Bigmac]

You talking about taking care of the lip on the lowers?

Epoxy! Ftw

 

[Canadian farm boy]

357xp cylinder. No new tricks here. Just case matched the lower transfers and blended them in. Adjusted the port shapes and timing. Waiting on a couple small parts and I’ll get the saw back together and tested.

 

[huskyboy]

357xp cylinder. No new tricks here. Just case matched the lower transfers and blended them in. Adjusted the port shapes and timing. Waiting on a couple small parts and I’ll get the saw back together and tested.View attachment 285146View attachment 285147View attachment 285148View attachment 285150

I’m noticing your exhaust side transfer staggered higher than your intake on this cylinder and your 390xp you posted as well. Are you doing that to flatten out the power delivery? I tried that on my 572 fairly recently by sloping the exhaust side roof higher than the intake since it’s only a dual port. I really noticed the difference in the “forgivingness” of the power compared to having them open flat. I forgot who mentioned it on here originally that inspired me to try it. I’m sure it’s been a known method for a while but I haven’t really seen it be mentioned on here. I know there are other ways to get torque, but it was a yet another way to skin a cat I guess.

 

[Canadian farm boy]

I’m noticing your exhaust side transfer staggered higher than your intake on this cylinder and your 390xp you posted as well. Are you doing that to flatten out the power delivery? I tried that on my 572 fairly recently by sloping the exhaust side roof higher than the intake since it’s only a dual port. I really noticed the difference in the “forgivingness” of the power compared to having them open flat. I forgot who mentioned it on here originally that inspired me to try it. I’m sure it’s been a known method for a while but I haven’t really seen it be mentioned on here. I know there are other ways to get torque, but it was a yet another way to skin a cat I guess.

I stagger the primary and secondary transfers 3-4*. Primary ports are aimed as close to the spark plug as I can safely get them and the secondary are flat and aimed at the cylinder wall above the intake port. My thinking is that I fill the top of the cylinder with fresh charge and then use the secondary ports to push the spent charge out the exhaust. I find it makes for a nice wide and flat torque curve. Imo that’s important in a work saw since everyone’s cutting style is different.

 

[Moparmyway]

I’m noticing your exhaust side transfer staggered higher than your intake on this cylinder and your 390xp you posted as well. Are you doing that to flatten out the power delivery? I tried that on my 572 fairly recently by sloping the exhaust side roof higher than the intake since it’s only a dual port. I really noticed the difference in the “forgivingness” of the power compared to having them open flat. I forgot who mentioned it on here originally that inspired me to try it. I’m sure it’s been a known method for a while but I haven’t really seen it be mentioned on here. I know there are other ways to get torque, but it was a yet another way to skin a cat I guess.

Magic happens

Just depends on
well..........


lots of things

 

[Dolkitafreak]

A friend challenged me to build a fast 7900 big bore, I never like Chinese stuff, but this top end was decent quality! Took some tweakin’ but it ran decent. Not better than a ported 7900 due (imo) to the tiny lower transfers but close. I wanted to add some finger ports but didn’t make the jump.

 

[Mycamaro_68]

View attachment 285268 A friend challenged me to build a fast 7900 big bore, I never like Chinese stuff, but this top end was decent quality! Took some tweakin’ but it ran decent. Not better than a ported 7900 due (imo) to the tiny lower transfers but close. I wanted to add some finger ports but didn’t make the jump.

I have a 7900 big bore top end that I am planning on practicing on. I had read peoples thoughts about too small of transfers and was thinking about doing bridge ports. Do you think fingers would be better than bridges? I have zero porting experience, just trying to soak up as much info as i can before i attempt anything.

 

[MustangMike]

Bridge ports are certainly easier to do, and I'm very pleased with how some of my saws with Bridge ports run (including a MS460 and Asian 660).

I won't comment on which may be better ... but I definitely think that Bridge ports can make a difference and address the problem you are concerned with.

I've heard various opinions and don't know if anything is CONSISTENTLY better (bridge, fingers, or neither).

 

[HYPERSAWS]

500i that I might have gotten carried away on lol

 

[HYPERSAWS]

 

[HYPERSAWS]

 

[jacob j.]

View attachment 286302 View attachment 286303

Where are you gonna put all the JB Weld at?

Edit: I think I see some in the intake...

 

[Moparmyway]

Did you block off the stock lower transferr ?

 

[HYPERSAWS]

Did you block off the stock lower transferr ?

I have not got to that yet, been running like this for a few weeks to see how it acts. Next on this project is to block it off from the case tunnels up.

 

[Moparmyway]

I have not got to that yet, been running like this for a few weeks to see how it acts. Next on this project is to block it off from the case tunnels up.

Impressions so far ?

Will you be doing anything else to it when you block off the stock transferr tunnell, or do you plan on seeing if doing that alone makes any difference ?

 

[HYPERSAWS]

Impressions so far ?

Will you be doing anything else to it when you block off the stock transferr tunnell, or do you plan on seeing if doing that alone makes any difference ?
View attachment 286346

I like it, its a fun little zippy saw with a lot of power. I'm going to bring the intake to 83 and plug her off and see what that does.
When I do another one I will have it machined. I didn't leave much room on this cylinder probably have to ditch the bottom ring if I machined this cylinder

 

[Ketchup]

Strato Thing. If I touch those air ports it’ll be a Freeport Thing.

 

[qurotro]

View attachment 286856
Strato Thing. If I touch those air ports it’ll be a Freeport Thing.

Does it cut wild?

 

[Ketchup]

Does it cut wild?

I hope so. Still in pieces. Probably won’t be cutting until Monday or Tuesday.

 

[Ketchup]

Impressions so far ?

Will you be doing anything else to it when you block off the stock transferr tunnell, or do you plan on seeing if doing that alone makes any difference ?
View attachment 286346

What angle are you cutting your piston at? Really nice.