Wanna Talk About Port Shapes?

[Mastermind]

You have plenty of saws to excite you.

 

[cgraham1]

You have plenty of saws to excite you.

Is that what they're for??

 

[SquareFile]

That was the 4th 064 of the week.....

Sounds like a lot of 064's come across your bench.

For a saw that has been discontinued for about twenty years.

I can't wait until mine does.

 

[nmurph]

No......this one is heading to Washington State.

You guys jugs are carbon copies though.

I believe I recognize a cylinder in the OP???

 

[Mastermind]

No Neal.......I've not used that one yet. The one in the OP is a Mahle jug.

 

[Mastermind]

Here's what great guys hang out on these sites.

I mentioned needing an 064 jug. Three arrived in a few days.

 

[SquareFile]

Randy, have you worked your magic on many 056 mag II?

If so are the gains good?

 

[Mastermind]

I've ported a couple of those units. They are not as easy to get big gains from as the newer epa, stopped up stuff. Some gains are there though.....just not the big gains will see in newer engines.

 

[cgraham1]

No Neal.......I've not used that one yet. The one in the OP is a Mahle jug.

The one I sent was a Mahle jug.

I've heard that the KS jugs are better, but after porting is there any noticeable difference?

 

[Mastermind]

I checked and double checked Clint.......no difference in port timing at all. The KS jug does have a much nicer finish, and that is likely why in stock form they seem to out perform the Mahle.

After port work.......I doubt there is any difference at all.

 

[moosejaw6401]

Pp.

 

[Mastermind]

I agree completely.

 

[wcorey]

When the transfers first crack open, you want to be fully flowing across the entire area of the port.

What’s the benefit of keeping it flat (or am I completely misinterpreting that that's what you mean to say...)?

I seem to recall the more northern monkey mention angling the upper transfers up a bit toward the exhaust side so as to give that end a head start to help get the entire charge over to the intake side at more somewhat the same time. Or something like that…

Is this only an advantage in particular cylinders and/or circumstances?

 

[PA Dan]

Hey Randy thanks for sharing all this info! You answered questions I didnt even think of asking yet! Can't wait to get my 064 to you! Sure glad you had all those other 064's to practice on!

 

[maico490]

No.....here's a set of finger ports......with bridges. Done by Dennis Cahoon.

I reckon he was laughing when he ported that. Hahahahaha!

 

[Terry Syd]

If DC sent you that jug for you to learn something, I wonder what it was. First thing I noticed was the rear finger ports were not equidistant from the centreline of the cylinder. If they work, they would be tilting the flow to one side. I would have liked to see the flow pattern in the head before it got machined out.

Assuming they work, then what was he attempting to achieve. Looks like it may have been an attempt to increase the time/area of the transfers without raising them too much. Being as it is a dual port jug, there is a limit to how wide the transfers can be, so he may have gone with the rear boost ports to give the transfers more area. THEN, he may have noticed a disruption of the flow from the angle of the ports, so he put in the ports below them to correct the flow.

That's all conjecture without his R&D input - however, if I've learned anything from modding it's - 'what works is just that, what works'.

 

[Chris-PA]

I don't have that many cylinders around to look at, and some of them are Poulan clamshells - but the only one that has a flat lower edge on the intake is a GZ4000. How common is it on higher end cylinders from the factory? And if it's not, then why not? It certainly would be easy for them to make that shape anything they wanted it to be.

 

[bryanr2]

You have plenty of saws to excite you.

I know right?

 

[dl5205]

Thank you Randy, for taking the time to make a great thread.

 

[Mastermind]

No problem my friend.

I enjoy making these little engines perform better.......I figure I'm not the only one.