Porting the 046-D Jug

[drf256]

Yes. My buddy John has a 1st yr 046d that he barely touched. Very impressive

The 460 was the more impressive jug. Maybe they changed to jug to keep power up and still meet EPA requirements.

Maybe Mike can post some pics. If it didn't have factory bevels with plating over them, I woulda sworn it was rubbed.

The D 046 had a smaller chamber and tighter uppers.

 

[drf256]

The timing on the 460 coulda been crap, who knows.

The 046 was Mahle. The 460 a "Stihl" branded jug. I guess from the period they started making they're own.

 

[Keith Gandy]

Id have to look but I wanna say Johns is KS

 

[drf256]

The 460 with a popup (yeah, I said it) would make a mean saw out of the box with some simple machine work on a lathe.

 

[drf256]

I remember some other builder, name escapes me right now, using a lot of popups and using one specifically in his 460 Hybrid. I'm wondering if this is why.

 

[Keith Gandy]

The 460 with a popup (yeah, I said it) would make a mean saw out of the box with some simple machine work on a lathe.

Ya I think that would work in johns too. Already has great torque . Add alil rpm and fuel in there and it would get serious

 

[Keith Gandy]

I remember some other builder, name escapes me right now, using a lot of popups and using one specifically in his 460 Hybrid. I'm wondering if this is why.

Pretty sure some saws it would suffice and some not. 660 for instance with the high factory exhaust

 

[drf256]

Pretty sure some saws it would suffice and some not. 660 for instance with the high factory exhaust

I'm sure you're right Keith. I didn't measure this one stock.

After .030 off the band, I had to raise the exhaust ~.100 to get to 102*.

Maybe it's low already, but as you know, the relation of band cut to port raising is non linear because of rod angle changes.

 

[mdavlee]

I still like a flat top in case you get a dose of bad gas or something crazy. No machining another piston if you have no way to do it yourself.

 

[drf256]

Mustang Mike is all about torque. He could care less about RPM.

I think the smallest bar he wields on his 046's is a 32"

 

[drf256]

I still like a flat top in case you get a dose of bad gas or something crazy. No machining another piston if you have no way to do it yourself.

I fully agree. But it just seems that it would be an easy "poor mans" port job.

I've done a few 044 (10/12), 026, 028, 036 and this was the most variation I have witnessed in ports on the same model.

KS 10mm has larger ports than a similar Mahle, but not to this extent.

 

[drf256]

Mustang Mike is a super guy too. Brought me so much stuff and paid for lunch.

He probably woulda saved $50, and had better work done, if he'd sent it out to be done.

We had a lot of laughs though, and he's gonna help me drop a tree this year that, quite frankly, I don't have the balls or experience to do.

 

[Keith Gandy]

Mustang Mike is a super guy too. Brought me so much stuff and paid for lunch.

He probably woulda saved $50, and had better work done, if he'd sent it out to be done.

We had a lot of laughs though, and he's gonna help me drop a tree this year that, quite frankly, I don't have the balls or experience to do.

Thats awesome u helped him out and yall had a great time!! I know he is tickled to death to learn and see this porting first hand

 

[drf256]

Thats awesome u helped him out and yall had a great time!! I know he is tickled to death to learn and see this porting first hand

To bad he learned it from a garage hack like me, LOL!

 

[Keith Gandy]

To bad he learned it from a garage hack like me, LOL!

Man u have a grip on this thing way over my head!!

 

[MustangMike]

Al, Thank You again, this was probably the best way for me to learn, if the process went too fast, there would not be time enough for it to penetrate my thick skull!

I'll get some pics of the 460 jug. As you said, the intake port looked almost perfect, and the other ports were all larger than the D jug, but not finished as nicely. The casting marks were all removed on the D jug, but not on the 460 jug. Although the D jug has a smaller combustion chamber, I think the squish was tighter on the 460 jug in factory form. (And as Al stated, the base on the D jug was notably thicker)

I'm thinking there is a large variation in stock 460 jugs that really influences how people feel about them. I wish I had the jug off the 460 that went to Big Chris (the one that needed a new clutch) next door at the same time to compare them. We put that one back together unmolested, base gasket & all, and he is ga ga about how it runs.

Hopefully, Chris will be able to attend the Upstate GTG again with me this year. But being NYPD, it is never certain. Chris is the big guy standing next to me in the 6th pic that Jeremy posted of last years GTG. He is 6'6" & 350 lbs.

Yea, I like torque! While I may often run a 24" bar on the 460, it will also likely see some milling, and occasionally run a 36" bar, and I like to be able to lean on them a bit.

 

[Canadian farm boy]

Sounds like you guys had a good time and are building a strong friendship. I think this is awesome. You both are helping each other out in different ways. I'm planning on attending the NY gtg this year and I hope to meet both of you in person.

 

[MustangMike]

Likewise!

 

[MustangMike]

Yes. My buddy John has a 1st yr 046d that he barely touched. Very impressive

If you get a chance, check if it is a KS jug. I'll bet they were ported more aggressively, just like the 10 mm jugs.

 

[drf256]

If you get a chance, check if it is a KS jug. I'll bet they were ported more aggressively, just like the 10 mm jugs.

It's very possible that the D jug has better timing numbers.

The timing makes a huge difference in performance Mike, IMHO.

Bigger ports don't always make a saw more powerful. It all has to work together.

It seems like these saws like low blowdown. They must have good case pressure and relatively small transfers-I think. The tunnels dont look much bigger than an 036's to me.

I'm still trying to understand this concept. If anyone cares to explain this, I'd appreciate it alot.

So when you have high case pressure you can:

Raise the transfers more because the flow and pressure will overcome whatever exhaust pressure is left?

Keep them lower because the pressure would allow them to fill the cylinder better?

A combo?