Are ALL Ford 360 and 390 engines internally balanced? What exactly does internally balanced mean? IF they are all internally balanced, would all flywheels from ANY 360 / 390 engine be interchangeable?

 

i'm pretty sure they are all internally balanced, and the flywheels might be different between cars and trucks just count the teeth. You might get a better responce if you post this in the 360 390 FE engine forum.

 

NO, the 360 is externally balanced, so the flywheel is balanced with a weight cast into it.. the 390 is internally balanced so the flywheel is balanced without a weight. If you have a 360 flywheel you can turn it on a lathe and have it balanced to work on a 390.

 

how is that possible ericJ when 360/390's are the same engine with just a crank/rod swap?

 

Going by this chart
http://web.ics.purdue.edu/~stanchfi/specs.html

They are internally balanced

FTE has a FE engine forum for these type questions

 

FE and FT series Ford big block are both internally and externally balanced. All FE engines except the 410 and 428 are internally balanced. FT medium and heavy duty truck engines are externally balanced like their 410/428 FE conterparts. The same can be said for FE and FT series Ford big blocks. Special balancing practices are required if ever you mix parts between the two types. Internally balanced engines don't require the flywheel and balancer be present for balancing. Externally balancer be present for balancing. Externally balanced engines must have the flywheel and balanced and balancer present. When mixing FE and FT parts, all parts must be present for effective dynamic balancing.

The harmonic balancer, aka as the vibration damper, is there to help dynamic balance and dampen combustion pulse shock. Combustion pulse shock hammers the crankshaft with great consistency. The damper or balancer is there to control the vibration or pulsing, which helps increse crankshaft life and smooth out the vibration.

 

Can I have Flywheel from FT 331 machined to a "zero balance" state and will it then work on my INTERNALLY balanced FE 360?

 

the 360 in MY 67 F600 was externally balanced, I swapped in a 390 that came out of a 74 f350, I turned the weights off the flywheel and had it balanced at a machine shop to make it run smooth.

 

all 352 , 360 and 390 engines are internally balanced not external. the 360 in your f600 may have been a 361 FT not a 360.

 

Erij, your F600 truck engine, would be considered and FT engine and is externally balanced.

FE denotes Ford Engine
FT denotes Ford Truck

 

All 360 and 390 FE motors are internally balanced. Period. Flywheels / flexplates are interchangable.

 

It was actually a old Uhaul and was designated a 359 on the u-haul tag, I figured it was a 360 , I don't think I've ever seen a 361, are they identical?

 

The FT engine include 330 cid HD and MD, 359, 361, 389, and 391 cid.
The FE and FT engines are Y-block designs—so-called because the cylinder block casting extends below the crankshaft center line, giving great strength at the cost of weight. In these engines, the casting extends 3.625 in below the crankshaft center, which is more than an inch below the bottom of the crank journals.

All FE and FT engines have a bore spacing (distance between cylinder centers) of 4.63 in, and a deck height (distance from crank center to top of block) of 10.17 in. The main journal (crankshaft bearing) diameter is 2.749 in.

The FE and FT block engines weigh about 650 lbs.

The 410 FE and 428 FE are externally balanced. FT medium and heavy duty truck engines are also externally balanced

 

that would explain a lot. The 359 is a FT and is external balance. It is not a 360 FE.

 

If I recall correctly as I have a 391 flywheel in the garage, it would handle a 12" pressure plate and disc. I was going to mill off the counter weight and use it on a 414 build as the flywheel has more mass than a 390 flywheel. Yes the 414 was converted to internal balance. Better to have the motor smooth internally than just the block feeling smooth with external weights. JMO's.
.....=o&o>.....