Interesting information regarding the 4.9L six cylinder...

[1986F150Six]

Yesterday, I shared with Gary and Jonathan [Ford F834] a link to the FTE forum where this was being discussed. I shared with Jonathan because he, too, likes this engine and Gary was included due to his quest for accurate information regarding all aspects of our trucks.

It was suggested that a link be provided so all can see.

https://www.ford-trucks.com/forums/1566039-some-interesting-history-on-the-300-a.html

 

[grumpin]

That is interesting.

[85lebaront2]

Funny thing, the 460 is damn near as long as the 300, there is 5 1/4" from the end of the waterpump shaft to the radiator core on Darth and barely room to get your hand behind the heads. If crash worthiness was a criteria, maybe that was part of the reason for killing the 460 and replacing everything except the 4.2L V6 with mod motors. V10 isn't short either. I would suspect emission requirements played a far greater role than crash tests.

As for moving the power band up, my son's V10 Excursion with 3.73 gears, needed to drop clear down to 2nd coming across the Blue Ridge Mountains towing his 1986 F150 5.0L 4WD on a trailer, I can take a similar load with Darth and never drop below 3rd with 3.55 gears. Mod motors need rpm to develop torque, even a very low compression 460 has more low end grunt than that V10! BTW, transmissions are essentially identical. E4OD for Darth and 4R100 for the Excursion.

I calculated that with his 3.73 gear vs my 3.55, his 17" wheels and larger tires, he still has a slight gearing advantage.

[Steve83]

I didn't see any "history" of the engine in that thread. And no specific reason for its termination.

Inline six cylinder engines remained very common until regulatory pressures on crash-worthiness and fuel/emissions rules begin to force other solutions...

When? When were I6s "very common"? And when did this regulatory pressure appear?Shorter engines generally are better designs for crash protection...Generally? What about the 4.9L specifically? Since it was only ever used in trucks, is the assertion being made that the 4.9L makes trucks LESS crashworthy than the 7.3L, 7.5L, 5.0L(W), 5.8L(W), 4.2L, 4.6L...? Are there any published stats available to confirm or refute that? In all the crash-test stats I've seen for these (old) trucks, there was never any distinction among the results for the various engines. And I've specifically seen that the V engines are MUCH closer to the firewall than the I6; but neither protrudes so close to the front bumper that it actually contacts the obstacle in a collision. So that discussion is moot....V-engines are generally lighter than equivalent inline engines.What does "equivalent" mean in that context? Torque? Hp? Displacement? We know that the 5.0L(W) V8 is NOT lighter than the 4.9L I6 (which is actually closer to 5.0L displacement). The torque & hp are relatively close. So which "equivalent" engine is supposed to be lighter than the 4.9L? Or does that claim have nothing to do with the 4.9L?...I-6 configuration is fading from the scene.When? AFAIK, BMW & GM continued designing, developing, & using I6s LONG after Ford dropped the 4.9L. So the only one that I'm aware of "fading" was the 4.9L.

As to the crossflow head... The claim that it changed the power curve was challenged in that thread. The claim that the U-flow cooked the injectors is wrong because the cooling fan was only used for the first ~1.5 years of EFI. For the next ~decade, the 4.9L was built without the fan (which I believe CAUSED more problems than it solved), and the injectors don't fail any faster than those on any other engine. Mine certainly haven't (after about a million miles); nor have any of the other 4.9Ls I've worked on regularly (which is nearly a dozen). I haven't heard of any other 4.9L owners complaining about failing injectors, either. Only sticking valves due to gasahol.

[Gary Lewis]

Funny thing, the 460 is damn near as long as the 300, there is 5 1/4" from the end of the waterpump shaft to the radiator core on Darth and barely room to get your hand behind the heads. If crash worthiness was a criteria, maybe that was part of the reason for killing the 460 and replacing everything except the 4.2L V6 with mod motors. V10 isn't short either. I would suspect emission requirements played a far greater role than crash tests.

As for moving the power band up, my son's V10 Excursion with 3.73 gears, needed to drop clear down to 2nd coming across the Blue Ridge Mountains towing his 1986 F150 5.0L 4WD on a trailer, I can take a similar load with Darth and never drop below 3rd with 3.55 gears. Mod motors need rpm to develop torque, even a very low compression 460 has more low end grunt than that V10! BTW, transmissions are essentially identical. E4OD for Darth and 4R100 for the Excursion.

I calculated that with his 3.73 gear vs my 3.55, his 17" wheels and larger tires, he still has a slight gearing advantage.

Here's a table that Keith posted on FORDification that helps us understand the issues. As Bill is pointing out, the 300 isn't as long as the 460. And, it shows that the 300 isn't as tall as the big blocks.

But, I wonder if it has to do with the way the 300 sits upright?

[Steve83]

Here's a table...the 300 isn't as long as the 460. And, it shows that the 300 isn't as tall as the big blocks.

Those numbers are HIGHLY suspicious (dubious) to me... The 4.9L uses the same ~4" pistons as the other smallblocks. 6 of them are 24" long, without any cylinder wall between them. Even if that wall is only 1/2" (which I think is VERY conservative), that only leaves 3.5" for the front & back of the block, and the timing gears & cover, and the balancer & belt(s).

[Gary Lewis]

Here's a table...the 300 isn't as long as the 460. And, it shows that the 300 isn't as tall as the big blocks.

Those numbers are HIGHLY suspicious (dubious) to me... The 4.9L uses the same ~4" pistons as the other smallblocks. 6 of them are 24" long, without any cylinder wall between them. Even if that wall is only 1/2" (which I think is VERY conservative), that only leaves 3.5" for the front & back of the block, and the timing gears & cover, and the balancer & belt(s).

I'll see if there's any info in the facts books. And, I'll measure my 400 that's on the stand in the shop to see if it corroborates the table.

[Steve83]

I'll see if there's any info in the facts books. And, I'll measure my 400 that's on the stand in the shop to see if it corroborates the table.

It looks like the 4.6L SOHC dimensions are right, based on the one I'm about to pull from my CV. The '96 5.8L on the stand is 33Hx29.5Wx29.5L (including throttle cable cover, oil pan, alt., PS pump, serp. pulley, but NOT flexplate or fan). But the 300ci/4.9L oil pan is 29.5L, so there's no way the whole engine (which would add the harmonic balancer) is only 30. And I have a hard time believing the smaller I6 is wider than the big one. But neither I6 width in that chart makes sense to me, even without the belt-driven accessories.

[NotEnoughTrucks]

Here's a table that Keith posted on FORDification that helps us understand the issues. As Bill is pointing out, the 300 isn't as long as the 460. And, it shows that the 300 isn't as tall as the big blocks.

But, I wonder if it has to do with the way the 300 sits upright?

All speculation as far as I could have anything to contribute, but the "crash worthiness" vs. dimensions seem to follow the width of the engine more than the length. The difference according to the chart is 1 inch length. This may be a small, but measurable effect on the crush distance during a front end impact.

We all know the bellhousing of the six is identical to a Windsor V8, so the profile presented in a longitudinal installation would be identical. The inline 6 provides only 1 cylinder head profile where the V8 provides 2. This becomes measurable as the width of the engine. I suppose one could view all this as the inline 6 as being easier to push through the firewall in a crash as opposed to the V8.

One could speculate all day on what this could have meant all those years ago when the boardroom decided to axe the inline 6. Possibly, you could also draw a conclusion that a transverse engine offered more protection than a longitudinal engine installation. Rear engine vs. front engine, who knows?

I will wonder if somehow production costs ruled the day? There may have been a nickle to be saved somewhere in the decision chain.

[Gary Lewis]

All speculation as far as I could have anything to contribute, but the "crash worthiness" vs. dimensions seem to follow the width of the engine more than the length. The difference according to the chart is 1 inch length. This may be a small, but measurable effect on the crush distance during a front end impact.

We all know the bellhousing of the six is identical to a Windsor V8, so the profile presented in a longitudinal installation would be identical. The inline 6 provides only 1 cylinder head profile where the V8 provides 2. This becomes measurable as the width of the engine. I suppose one could view all this as the inline 6 as being easier to push through the firewall in a crash as opposed to the V8.

One could speculate all day on what this could have meant all those years ago when the boardroom decided to axe the inline 6. Possibly, you could also draw a conclusion that a transverse engine offered more protection than a longitudinal engine installation. Rear engine vs. front engine, who knows?

I will wonder if somehow production costs ruled the day? There may have been a nickle to be saved somewhere in the decision chain.

Well, I just got a new Ford publication today called Ford Truck Body Builders Layout Book 1985. And it has a lot of interesting info in it - including engine dimensions. I'll get them scanned some day, soon I hope, but will have to farm that out for two reasons. First, I'm going to start powder coating parts for Dad's truck as well as for a friend almost immediately since the grandtwins left today and I must get something done. Second, the pages are something like 11" x 15", and my scanner isn't big enough.

Until then you'll have to take my word for these dimensions. And, heed the notes as these are the outside-to-outside dimensions.

And compare those dimensions with these, which are also said to be outside-to-outside. I don't know the source of these, but I do know the source of the ones above. So, once I get the pages scanned and up on the website I'll have to go to Keith Dickson, of FORDification where I got the table below, and suggest they aren't spot-on.

And here's a teaser of one of the pages from the book: