390xp

[parrisw]

how mutch did you cut from the squish?

.025" should of gone more, but I hear people say they are getting over 180 with just base gasket pulled??? WTF

 

[tree monkey]

what is your in dur now?

 

[parrisw]

I want to try to put 6 tanks through it, check it again, then tear it down, and check it over, maybe machine some more out of the chamber. Just don't want the intake to get out of hand.

 

[tree monkey]

I want to try to put 6 tanks through it, check it again, then tear it down, and check it over, maybe machine some more out of the chamber. Just don't want the intake to get out of hand.

thats what i was thinking.

 

[wyk]

.025" should of gone more, but I hear people say they are getting over 180 with just base gasket pulled??? WTF

My 385xp went to 170psi.

 

[parrisw]

what is your in dur now?

after machine work it was 153° duration, but when I ported I slightly took a little off the bottom, so probably no more then 155° in fact probably didn't even go that high.

 

[parrisw]

My 385xp went to 170psi.

Well, that makes me feel a little better.

 

[tlandrum]

in? ex? blowdown?

 

[tree monkey]

after machine work it was 153° duration, but when I ported I slightly took a little off the bottom, so probably no more then 155° in fact probably didn't even go that high.

then you have room to cut squish and base more. take another .020 and check comp before changing ports

 

[parrisw]

Post machine work numbers.

EX 97.5atdc 165dur

Intake closes 76.5ftdc 153dur

Transfers 121atdc

Blowdown 23.5

My thoughts, ex will stay were it is, just widen.

Intake maybe bring up to 155-156dur close to 80ftdc

Transfer maybe raise up to 119?? little unsure about the transfers still.

that would leave 21.5blowdown

in? ex? blowdown?

See above Terry.

then you have room to cut squish and base more. take another .020 and check comp before changing ports

Cool, thanks Scott. I've heard the 390's don't like allot of intake? Maybe not though?

 

[tlandrum]

i see a need for more in duration , but the rest looks good. takes fuel to make power. some are afraid of slow spooling with too much intake but im not worried too much .

 

[Meadow Beaver]

i see a need for more in duration , but the rest looks good. takes fuel to make power. some are afraid of slow spooling with too much intake but im not worried too much .

More intake is better in my opinion as well, intake channels are my prefered work to the intake.

 

[SawGarage]

aaaarrrrrrrrrrrrrrrrrrggggggggggg

thats it? come on, cut the car in half, ya ya ya :msp_w00t:

Easy Beavis, easy....

 

[SawGarage]

More intake is better in my opinion as well, intake channels are my prefered work to the intake.

uhhhh?? with a wet intake, wouldn't this cause puddling?

pictures? as I have had thoughts about something similar...

 

[parrisw]

i see a need for more in duration , but the rest looks good. takes fuel to make power. some are afraid of slow spooling with too much intake but im not worried too much .

That was my first thought Terry. I usually don't go under 160 on most of my saws on the intake, but heard these 390's like different numbers. So I left it alone, and decided to run it as is and see. Easy to go back in for more, then to go too far and think FUK, I went too far. So, its going to get run like this for at least 6 tanks, then come apart again.

 

[parrisw]

Ok, this compression thing was really bugging me. So I remember last year my gauge acted up, so I went out and tried again, I just couldn't accept 160psi. So when I check it again, sure enough I watched the gauge real close while I was pulling my guts out, everytime I stopped I saw the needle drop a bit, so the highest I saw this time was 170psi. But now I can't even trust that.

 

[NORMZILLA44]

What is the issue Will just seem low?

 

[parrisw]

What is the issue Will just seem low?

Ya, there is a leak in the gauge somewhere. I just couldn't believe that it was only making 160psi. I can live with 170 now, we'll see after a few tanks and a new gauge.

 

[NORMZILLA44]

Yep, gotcha it's a husky she will climb! t least you got a comp release. I pulled a few 288's. Woulda been afraid to guess the comp. 170 sounds really good. I know how you feel though if you are anything like me, if a saw is having an issue or something is stumping me it will keep me up at night.

 

[parrisw]

Yep, gotcha it's a husky she will climb! t least you got a comp release. I pulled a few 288's. Woulda been afraid to guess the comp. 170 sounds really good. I know how you feel though if you are anything like me, if a saw is having an issue or something is stumping me it will keep me up at night.

YUP, it wouldn't leave my mind till I went back out and checked.

I checked it against my 371bb, and either its a fluke it worked right, or that saw is pulling some serious compression, it hit 190psi.