differences between 360 and 390 (external)

[SteveC]

duckryder is correct and put it the best. sorry if i confussed you

[convincor]

You can distinguish between a 360 and 390 if you have an automatic trans and you are willing to pull the cover plate that gives you access to the bolts that connect the flex plate to the torque converter.

The 360 has a big half moon shaped cutout on the crankshaft flange.

The 390 does not.

Tim

Like this-


But I was told that the later 390's had it also.
Havn't seen one that has yet..

[sideoilerfe]

...#6 ain't easy to get to.

What???

Yes it is.

Are we gonna do this again?

No it ain't,

I have 3 F250's with FE engines AND power brakes. I have NO problem getting to the # 6 spark plug hole, period.


I'm not going to argue with you. He's got is information by now, this thread is done.

[kaptnkaos]

See guys... that's why I use the same one...
I can't never 'member if it's #4, #6, or #11
If I use da same hole it don't matter which one ya use...
Bring the chosen cylinder to da top.
I always use #1 'cause it's easy to count to, and there's them little lines on dat thingy stickin' out the front to tell ya when it's at the top of the hole.
Put da stick in da hole 'n' make a mark on the stick.
I leave the stick in the hole and watch it go down as I turn the crank
(power disconnected of course so it don't start on ya)
When the stick starts comin' backupatchu U know you hit bottom so turn it back just a hair to bottom it out again.
Put a line on the stick then pull the stick out and measure the space between the lines...
Make sure ya put the plug back in and hook up all da wires so ya don't feel goofy trying to figure out why da ting won't start...

KaptnKA S

[rjewkes]

perhaps i can help i think you two are arguing about the wrong hole.

no 6 is right behind no 5 it is the second cyliner on the driverside from the front of the motor now no 8 is a tiny pain to get to its the one way at the rear on driversiide.

[DuckRyder]

I have NO problem getting to the # 6 spark plug hole, period.

Getting to the spark plug hole, and getting to the spark plug hole with a long wooden dowel is two different things.

[rjewkes]

took this from the did you know section.

hope it helps anyways.



Did you know? The 360 and 390 blocks are identical externally. The only way of differentiating between the two, since there are no external markings to tell you what you've got, is to measure the stroke. Simply rotate the crankshaft around until the #1 cylinder is at TDC (top dead center) as indicated at the timing mark. Remove the spark plug and insert a wooden dowel into the cylinder until you hit the top of the piston and make a mark on the dowel. (Use the valve cover lip as a constant reference source.) Then remove the spark plug from the #4 cylinder (when #1 is TDC, #4 is BDC) and make another mark on the dowel. Then measure the difference. A 360 has a 3.50" stroke and a 390 has a 3.78" stroke.

[DBossMan]

You can distinguish between a 360 and 390 if you have an automatic trans and you are willing to pull the cover plate that gives you access to the bolts that connect the flex plate to the torque converter.

The 360 has a big half moon shaped cutout on the crankshaft flange.

The 390 does not.

Tim

Like this-


But I was told that the later 390's had it also.
Havn't seen one that has yet..

YES!! That's a great pic. Thanks for posting it. My understanding is the flange was cutout like that to enable machining. Not sure why a later 390 would have a cutout like that. I've never heard that, but it could be true.

Tim

[convincor]

I can't see why they would either, but that's what I was told.