What's the difference between a 360 and a 361? Or was that just a marketing scheme? A friend was over the other day and we were looking at the 360 my 72' F100, and he said he had an F600 dump that had a 361 in it.

 

As far as actual cubves go they are exactly the same. Ford just threw the 1 on the end to signify it is an FT. The 361 had a forged steel crank with a larger snout. The block was stronger also. The heads are very restrictive. Do a search here for FE vs. FT or something and you will get tons of info.

 

Thanks!

 

Well their might actually be the extra 1ci, Shoe found that with how the tolerances were different on the 391 it actually could measure out to 391ci so the 361 could actually have that extra 1/2ci or so to make it a 361

 

The 391 crank is actually .006 bigger than the 390 on the stroke but the 360/361 have a 3.500" stroke from the info that I have seen.

 

Fact or myth: They are actually called 360 and 390 I's, the I signifying Industrial, so they would have been called 360 and 390 industrials, but over time the 0 got replaced by the I and they were called 361's and 391's. I heard this somehwere.

 

I would say myth but it sounds feasable enough. Maybe this would be better answered by some of our resident geritol consumers. The older guys are full of this kind of info.

 

I was under the imoression that the 1 cube cam from the larger dish in the piston they used to reduce the compression from 8.6:1 down to 7.4:1. Maybe I am wrong.

 

That's where I heard this, from an older gentleman. He's a mechanic at one of my friends shop.

 

I kind of doubt it since they were called FT's since the mid 70's at least so they wouldn't have been called 390 Industrial

 

Displacement comes from the swept volume of a certain bore size going a certain distance so the lower compression wouldn't change the displacement

 

Yep, Bore and stroke are the only figures used to calculate displacement or swept volume as FE427TP more scientifically put it.

 

I am not trying to be difficult, but explain one thing to me. I know the bore diameter or stroke length don't change, but there is still physically more volume inside the cylinder due to the larger dish on the head of the piston. Why doesn't that account for more cubic inch displacement? Maybe a better question is, what is the difference between static volume inside the cylinder and swept volume inside the cylinder?

I trust what you say; I just like to soak up as much input as I can get.

 

the compression of an engine is scalled by how much volume is squezed into a known amount of area. that is were you get 10 to 1 this means you are putting a certain amount of air fuel mixture into an area 10 times smaller hence 10 to 1.

cubic inch is the size of the piston and the distance that the piston travles to get it there, simply put, there is actually a mathematic equasion to help figure ci out wich I dont have at this time.

compression and cubic inch's are two different thing even though they can complement each other or hender each other.

Only cubic inches have Horse Power Potential, vrs compression.

 

Just to join in the fun, with the books I have on Ford engines, they say that the 390 and 391 / 360 and 361 have the same displacement and that the 1 was to distinguish between a motor used in a truck. Also, I have a friend that has a 390 in his dump truck so you have to know they will put out some tq.

That is my .02, but I'm still learning!!