I realize this is a somewhat silly question and rhetorical in nature and the same thing could be asked about other engines but what was Ford trying to accomplish with the 360? They already had the 352 and the 390, why did they bother sticking a 352 crank in a 390 block to come up with this combo? I suppose maybe since they were discontinuing the 352 (why bother) they decided to use the remaining crankshafts possibly? The engine came out pre smog IINM so why didnt they use either a longer rod/taller piston pin height and get some compression? Or did they want low compression? Also, you will come across literature that states the 360 had "heavy duty internals" for pickup truck use, anyone have any idea what these "internals" they refer to are?

 

One line of thought is emissions, back then when they were trying to figure it out, and I'm not sure that it is yet. De-stroking, timing retarding, among other things were tried.

I am sure there are other better comments.





John

 

I think it was to use a common bore block. Easier for production and cheaper. One set of molds for both. Same machining steps and sizes.
In my opinion the thing that made the 360 heavy duty was the low compression.

 

I agree with everyone plus....it put the cid's just a few ahead of Chev/GMC & matched Dodge- for those buyers that were "CID" impressed.

 

But they already had the 390, well above in cid the "mid size" engine dept, I think Fordman's same block theory is the closet to the truth but still, the 360 seems superfluous. the only theory that makes sense to me is Ford wanted a low compression engine for their trucks and this was how they achieved it.

 

But they had the 428! Why even make the 390?

Ford makes a dozen engine displacements. If they I think the fact that the 360 is barely bigger than the 352 the point, it replaced the 352, with a common block, one less part on the shelf, still have a midsize engine.

 

The 390 came before the 428 and outlasted it as well. Thats kind of my point, they already had the 390 when the 360 came along, whyd they bother. Besides, the 390 was a workhorse motor where the 428 was much more a performance motor. Also, the 360 was never put in anything besides a truck, a 428 was never put in trucks dunno why they didnt just use the 390

 

My take on the situation. They had the blocks available, along with all the rotating parts.
By combining 390 blocks & pistons with 352 crank and rods, they had a lower compression "entry" level engine, that didn't cost any real money to develop.
The engine came along at the same time the 390 got the compression dropped, which served 2 purposes, improved emissions and lower octane fuel needs. It was just an added bonus to Ford that they were able to use parts they already had the tooling to make, in order to achieve the end results, thereby giving the engines almost another decade of life.
The bottom line, they took existing parts and developed a "new" variation of the engine that saw use in many trucks over the next few years. EPA was pacified, and the bean counters were pleased. Not a common combo.......

 

That makes sense Wolff, until a Ford beancounter from that era joins FTE that is probably as close to the truth as we will ever get. I know the 360 gets a bad rap from many and while its not my fav powerplant I will say that the two I have owned, were both dead reliable, smooth running problem free engines. The one I have now has never been apart and no idea as to the real miles on it but it purrs, has a horrible gasoline addiction though!

 

I think the common bore idea is probably one of the biggest reasons, same reason a lot of 90 degree V6s share specs with V8s, cost. A whole lot of Detroit's desicions are based on cost. Emissions may have played a part also, but again, cost to certify an engine family rather than a new engine becomes a big piece, look at what Ford replaced both the 360 and 390 with, the 351M and 400, give me a 360 any day over a 351M.

 

The 360 is considered a bit of a dog, as far as FE's go. But, when compared to the other ~5.8L (+/-.1L) engines of the same timeframe, they're actually pretty respectable. The power output was well below the design limits of the components used to build it, so the stress factor was rather low.
Take a 360, bump the compression ratio into the mid 9's, add a decent cam and induction/exhaust, and it starts to be a respectable powerplant. True, the 3.50 stroke is not optimal for torque, but the 352 shared the same stroke, and still had respectable numbers.

I would have to agree with that last statement. I'd much rather have a 360 than a 351M.

 

I agree with most eeveryone in that they already had the parts, tooling, and molds. I have owned many 360's and 390's as well as the new models '351 combos'. Never had a prob with a 360 or 390. But i think it had the a lot with new emmisions and that a 360 weighs a couple hundred pounds less thann a 390 and had a quicker "rpm speed". About the time of the 360, ford. Changed production and materials ( faster build time and lighter trucks). 352's and 390's were heavy powerhouses. The 360 was lighter, quicker, and had satisfactory performance. Ford just used time proven parts and designs and made a lighter duty engine with the epa's new evolvinvg egr program. AnywAys, part truth part theory......

 

The 360 was intro'd in '68. Smog equipment at that time was limited to PCV, smog pumps and lean(er) carb settings. Compression ratios were not an issue--witness the 10.5 and 11 offerings from all manufacturers at the time.

Those were the days of "all new..", so using the 390 block with the left over 352 crank and rods and 390 car pistons was, as previously noted, a way of making something "new" for nothing.

Now the post above says the "...360 was lighter, quicker..." and states the 360 "...weighs a couple hundred pounds less thann a 390...".

How could a 360 be even 20 lbs lighter than a 390 when they are identical save for the crank and rods? I doubt they are 5 lbs different, as the difference in crank throw is only .142"--not a lot of material.

Quicker? As issued in PU trucks, I doubt you could tell the difference without a load. Both are low compression, low rpm motors. As has been said about the 360, they "don't make enough power to hurt themselves...", thus the long life.

EGR didn't show up until '73 if the info I found is correct.

As for "lighter trucks":

1968 FORD F100 Information Specifications Resources Pictures

vs.:

https://www.ford-trucks.com/forums/5...rb-weight.html

 

I was an automotive machinist for a long time. There is a bis weight diff between the 360 and 390. There may only be. 173 diffrence in throw but what u are not considering is that once. You start changing things out, balance comes innto play. A 390 crank is balanced for longer heaver rods, heavier pistons and bearings. Therefore to make a 360 out of it, it has to be rebalanced to the differnt rotating parts. Shorter rods, ighter pistons and bearings. Its just like a Gm 305 v8 s almost the exact same engine az the 350. The only diffrenceu is rods Nd pistons, but if u just threw a 305 crank in with the rods and pistons of a 350. First time u started it. ( if it even started) if it got over 800 rpm, all hell woutld break loose! It would mechanicly explode!
Yeah, part for part on a scale tbe 360/390 would weigh about the same. But until its balanced, it would never run. And in the process of rebalancing u loose a lot of material. Resulting in a very noticable weight diffrence.
Not many people realize that all theze socalled 'interchangable engines' are quite modified internally. Same would hold true with a 390 and a 428..
And there proves my other point, 360 being "quicker" than the 390. Less weight and a shorter throw means a quicker get up and go.

 

Also, i didnt mean to get into such specifics, the point is, the 360/390's are both great engines. Would take a 390 anyday of the week. But the 360 held ots pwn as a lighter duty ranch/ street engine and was a ligtle more street friendly than the 390 ( and i have a dozen zets of tires to prove it ). Why they quit with the 352's? Have to write ford on that one.... Lets just all be happy we are FORD GUYZ AND GALS!!