390xp

[parrisw]

Scccccchweeeeeeet,,,, Again very nice work William cant wait to see the vids of this one slinging chips!!!!!

Thanks!! I can't wait either!

Looks good Will. I would leave the intake where it is for now. You might want to drop the cylinder some more. :cool2:

Thanks ya, good idea! But I can't imagine that .003 will make much difference.

 

[wigglesworth]

Machine work is all done. Just did the cyl base this eve. Squish now is at .023, it ended up there, so I figured I'd leave it there, don't want compression to get out of hand.

Post machine work numbers.

EX 97.5atdc 165dur

Intake closes 76.5ftdc 153dur

Transfers 121atdc

Blowdown 23.5

I am really digging them numbers. Strikingly similar to one of my favorite "big" saws, except of course the 390 has quad transfer ports.

If it were mine, I wouldn't change nothin till I ran it.

 

[NORMZILLA44]

Geeze, I had to do some catching up, you have been busy Will.:msp_thumbup:

 

[mdavlee]

Thanks!! I can't wait either!



Thanks ya, good idea! But I can't imagine that .003 will make much difference.

Yeah true. I wonder how the compression will be there? If it's not too high you could drop the jug some more and get more intake and lower the exhaust to around 100°. Just thinking here, I haven't got to try it yet myself so it may have plenty of compression where it's at and not want more.

 

[parrisw]

I am really digging them numbers. Strikingly similar to one of my favorite "big" saws, except of course the 390 has quad transfer ports.

If it were mine, I wouldn't change nothin till I ran it.

Ya, I was thinking that. But as you see my changes were minor. But by all means wouldn't be a big deal to put it together without changes, just widen the ports.

Yeah true. I wonder how the compression will be there? If it's not too high you could drop the jug some more and get more intake and lower the exhaust to around 100°. Just thinking here, I haven't got to try it yet myself so it may have plenty of compression where it's at and not want more.

I'm guessing it'll be fairly stout. We'll see.

 

[NORMZILLA44]

Man the compression talk, you got me thinking of pulling over the 288's. Im sure the 390's are more starter friendly. What is the 390 stock PSI?

 

[parrisw]

Man the compression talk, you got me thinking of pulling over the 288's. Im sure the 390's are more starter friendly. What is the 390 stock PSI?

I'm not sure. I'm guessing at least 160psi, maybe a little more.

 

[RiverRat2]

Ya, I was thinking that. But as you see my changes were minor. But by all means wouldn't be a big deal to put it together without changes, just widen the ports.



I'm guessing it'll be fairly stout. We'll see.

If I was a bettin man I'day it will come in about 185,,, In my book 175-185 is perfect for a good work saw,,,,

will,,,, JFTR,,,,,,, this aint botherin ya letting all of us hooligans in on yer machining techniques????

 

[NORMZILLA44]

I doubt it, he probably wouldn't mind if we came over, and changed all the setting's, and adjustment's on his machining tool's either. That would just make thing's interesting.otstir:

 

[jropo]

I'm not sure. I'm guessing at least 160psi, maybe a little more.

My stock 2yr old 385 pumped up to 150psi cold @ room temp.

 

[tlandrum]

husky saws seem to be a bit lower compression saws than what one thinks they would be. some of them are hard to get compression out of

 

[parrisw]

If I was a bettin man I'day it will come in about 185,,, In my book 175-185 is perfect for a good work saw,,,,

will,,,, JFTR,,,,,,, this aint botherin ya letting all of us hooligans in on yer machining techniques????

Nope never cared, I enjoy showing this stuff.

I doubt it, he probably wouldn't mind if we came over, and changed all the setting's, and adjustment's on his machining tool's either. That would just make thing's interesting.otstir:

Come over anytime! Just don't screw up my stuff! LOL

 

[NORMZILLA44]

LOL! Thought you would like that little buddy! The one husky that is a surprise on the comp being so high though is the 288.

 

[parrisw]

LOL! Thought you would like that little buddy! The one husky that is a surprise on the comp being so high though is the 288.

288's are nice! I've had a few with high comp. My 395 is at 195, it thumps at idle.

 

[Logger4Life]

Nice work Will I'am jealous I have had some trouble this week just had to have me best friend put down yesterday my 3yr old Jack Russels Kiddneys shut down not a good week . But I am trying to completee to same exact build . was wondering how much you took off the base and out of the combustion chamber you took about .025 right I kind of got confused in your post about what the final # was. This is ironic be cause I biult a Makita 6401 with a MCW BB kit at the same time as you also it came out very well I put the HD -12 Walbro on it from a 372 and the HD filter kit it was a HD rental saw beforehand by far the cheapest best running saw per $ I have ever built it was impressive . I also like the 681 Solo's and my other 2 new 7900 that are all ported.
Thanks for your time and thanks for the help. JAY

 

[Outlaw5.0]

My new out of the box 390xp pumped 150 psi. Its possible a broken in one will see 160 psi.

 

[parrisw]

Nice work Will I'am jealous I have had some trouble this week just had to have me best friend put down yesterday my 3yr old Jack Russels Kiddneys shut down not a good week . But I am trying to completee to same exact build . was wondering how much you took off the base and out of the combustion chamber you took about .025 right I kind of got confused in your post about what the final # was. This is ironic be cause I biult a Makita 6401 with a MCW BB kit at the same time as you also it came out very well I put the HD -12 Walbro on it from a 372 and the HD filter kit it was a HD rental saw beforehand by far the cheapest best running saw per $ I have ever built it was impressive . I also like the 681 Solo's and my other 2 new 7900 that are all ported.
Thanks for your time and thanks for the help. JAY

Well I kinda screwed up a little, started with .020, then had to go back to clean up a mistake, and took about another .005. I would not reccomend going by my measurements, check you're squish and go from there. The mathe is simple. Squish was at .028 + .025 out of chamber, now that leaves .053 squish, now machine the correct amount off the base to achieve the desired squish.

 

[RiverRat2]

Well I kinda screwed up a little, started with .020, then had to go back to clean up a mistake, and took about another .005. I would not reccomend going by my measurements, check you're squish and go from there. The mathe is simple. Squish was at .028 + .025 out of chamber, now that leaves .053 squish, now machine the correct amount off the base to achieve the desired squish.

So whats the hold up????:biggrin::biggrin::biggrin:

 

[parrisw]

So whats the hold up????:biggrin::biggrin::biggrin:

LOL, allot where should I begin!

 

[tree monkey]

2 degree angle? all the way to the edge? why?