Magnum 5.9 piston crown thickness

-
TT5.9mag said:
Blueprint spec 6.125
Click to expand...

Is the magnum rod 6.125 ?
Factory SBM rods were 6.123 ,,,,,at least all the old stuff was .

Do you need to cut both valve notches,,,or just intake ?
Either way,,,,I believe what you did on the piston in the pic will be fine.
Looks good,,,,,I think you will be in good shape .

Tommy
 
Last edited:
TT5.9mag said:
I’m 100% sure and I’m cutting them if I need to. I’ll wait for final valvetrain stuff from B3 then decide how much to cut em. Thankfully most of the material will come out of the thickest part of the crown then just kiss the thinnest part.
Click to expand...
Yeah, now that's a smart thing to do. Mike is a legend genius. Once you get the rocker shafts right, you'll know for sure.
 
RustyRatRod said:
What was the clearance with that cut? If it was enough, it might be ok. But I wouldn't cut those crowns very deep at all. They aren't too thick to begin with. That's a failure you don't want, Beavis.
Click to expand...
I didn’t measure anything for that cut. It was a test to see if I could effectively fly cut the piston. It’s a spare piston.
 
It sounds like a fun project so keep us posted.
 
Desoto291hemi said:
Is the magnum rod 6.125 ?
Factory SBM rods were 6.123 ,,,,,at least all the old stuff was .

Do you need to cut both valve notches,,,or just intake ?
Either way,,,,I believe what you did on the piston in the pic will be fine.
Looks good,,,,,I think you will be in good shape .

Tommy
Click to expand...
It’s just the intakes that I’m worried about as the valve size is a big step up from a stock magnum, 2.055 vs 1.88 stock. But I will for sure measure both when the time comes.
 
RustyRatRod said:
It sounds like a fun project so keep us posted.
Click to expand...
It’s been fun. I had all this old stuff in my garage for 25 years and @Turbo440Dart has convinced me to use all of it finally. It’s coming together nicely and I will post progress. It’s going in my 70 dart so it will be on my build thread.
 
TT5.9mag said:
It’s been fun. I had all this old stuff in my garage for 25 years and @Turbo440Dart has convinced me to use all of it finally. It’s coming together nicely and I will post progress. It’s going in my 70 dart so it will be on my build thread.
Click to expand...
I've really mulled over a turbo on Vixen, but now that I've just gotten the headers on and hooked up I'm leaving it N/A. I'm sure a turbo would be fun, but I'm having a blast like it is.
 
RustyRatRod said:
I've really mulled over a turbo on Vixen, but now that I've just gotten the headers on and hooked up I'm leaving it N/A. I'm sure a turbo would be fun, but I'm having a blast like it is.
Click to expand...
Ive told you before, don’t do it. You’ll never want an NA engine again. I have a Sickness and everything I own is turbocharged.
:lol:
 
TT5.9mag said:
Ive told you before, don’t do it. You’ll never want an NA engine again. I have a Sickness and everything I own is turbocharged.
:lol:
Click to expand...
I'm sure you're right. I love N/A stuff and I don't want that to change.
 
TT5.9mag said:
Yea I know how to measure for it. I’ve mocked it up a bunch already and and it’s very close with the cam in at 109.5, it won’t have more than .020 on the intakes right at the edge of the dish. Before I got too crazy I wanted to know how thick the crowns were and how much they’d need cut.
View attachment 1716277208
Click to expand...
Seeing where the test notch is landing on the piston, I am now wondering if you plan to cut one of your broken pistons halves 90 degrees to your first cut so we can maybe see where the top ring land will be in relation to the intake valve notch?
 
Bobzilla said:
Seeing where the test notch is landing on the piston, I am now wondering if you plan to cut one of your broken pistons halves 90 degrees to your first cut so we can maybe see where the top ring land will be in relation to the intake valve notch?
Click to expand...
I can do that today.
 
@Bobzilla here is the second cut on the piston you asked for. 90 degrees to the first cut, through the pin boss.

8B00A9D1-2064-4DD1-822B-1512DBB0F5D2.jpeg
FB98B0BE-7FF0-4D42-A481-AD01DD90B2AC.jpeg

73003D4D-DFB0-4D26-B5E5-B3FF0094A87B.jpeg
 
@Bobzilla it was this dimension I believe you were wondering about, ring land to dish, correct?
3FFD9B2D-52A1-4029-BF77-5DAD9D0C2397.jpeg

If so that is a valid concern and the actual measurement is .190.
 
Since your talking, how much RPM's & boost are you planning on running? :thumbsup:
 
moparlvr166 said:
Since your talking, how much RPM's & boost are you planning on running? :thumbsup:
Click to expand...
Haven’t got that far yet. But it will be a stick shift (T56 magnum) 10 inch tire, dual fuel (e85 and pump gas) car and I hope to run 9.50s or so on drag week.
 
TT5.9mag said:
It’s been fun. I had all this old stuff in my garage for 25 years and @Turbo440Dart has convinced me to use all of it finally. It’s coming together nicely and I will post progress. It’s going in my 70 dart so it will be on my build thread.
Click to expand...

I just mildly suggested repeatedly that you finally used the stuff. I cannot be held accountable for anything after that. :steering:
 
Turbo440Dart said:
I just mildly suggested repeatedly that you finally used the stuff. I cannot be held accountable for anything after that. :steering:
Click to expand...
So what are you sayin? You gave him a little nudge? lol
 
You must log in or register to reply here.
-

Back
Top