Ford Engines - please help educate me (2.7l vs. 3.0)
09-09-2021, 10:32 PM
#131
sorry but I can't - I have no pics or bits from my time working in industry. But know that there are alot of engine design ideas and setups that make the test phase. for example there was a ecoboost v8 at one time. yes twin turbo, small displacement V8. If I recall the displacement was something around 4.2L so like a 3.5 v6 with 2 more cylinders tacked on. but obviously it never got past testing and this was years ago. There was a 4 cylinder powerstroke literally a powerstroke cut in half - ford didn't pursue it - GM did with the duramax though. The GM duramax diesel started life as a 4 cylinder single turbo setup. anyway there are a number of thing made that never see a vehicle.
A lot of people think this but no that's not quite true. while it would help to allow cleaning of the valves the reason for the dual injection engines is because a gasoline direct injection engine - like a direct injection diesel - will create soot powder under certain conditions because the fuel sprayed in under light load - will burn too slow on the edges of the cylinder and instead gassing out - will make ***** of ash. It's bad enough that EU starting wanting all GTDI motors to have the same particulate trap filters Diesels have. MPFI at lower RPM or Lower Load will mix better while compressing leading to a cleaner overall burn. So the new engine - with light load demand runs on MPFI alone - as it perks up - the strategy moves to both injectors and at hard load full demand it will use both injectors but lean on DI for most of the fuel delivery.
This leads to the cleaner exhaust over all and happens to also lead to a smoother running engine.
A lot of people think this but no that's not quite true. while it would help to allow cleaning of the valves the reason for the dual injection engines is because a gasoline direct injection engine - like a direct injection diesel - will create soot powder under certain conditions because the fuel sprayed in under light load - will burn too slow on the edges of the cylinder and instead gassing out - will make ***** of ash. It's bad enough that EU starting wanting all GTDI motors to have the same particulate trap filters Diesels have. MPFI at lower RPM or Lower Load will mix better while compressing leading to a cleaner overall burn. So the new engine - with light load demand runs on MPFI alone - as it perks up - the strategy moves to both injectors and at hard load full demand it will use both injectors but lean on DI for most of the fuel delivery.
This leads to the cleaner exhaust over all and happens to also lead to a smoother running engine.
09-09-2021, 10:41 PM
#132
Senior Member
because early DI engines using oils formulas with quite a lot of volatile off gassing end up leaving sticky residue in the intake tube - something that is just as much a problem on MPFI engines hence the prevalence of catch cans starting in the 90's.
But since crankcase vent back is mandatory - and since DI didn't let you put cleaner down the tract - the early di engines under light load would build up residue that would burn and leave ash/soot behind - happened worse when the engines weren't run under higher loads with higher flow rates.
Move forward to 2012 area and requirements like DEXOS 2 and oil starting having lower volatility - leaving less residue Another piece of that coke/soot is dirty air - it's not mentioned nearly enough but dirty allows the accumulation to grow very quickly. So driving around at light throttle - with bad oil and dirty air incoming - is a 3 way whammy.
Since 2014 or so there are fewer and fewer instances of DI engines with value coke issues. but you know how the internet is.
But since crankcase vent back is mandatory - and since DI didn't let you put cleaner down the tract - the early di engines under light load would build up residue that would burn and leave ash/soot behind - happened worse when the engines weren't run under higher loads with higher flow rates.
Move forward to 2012 area and requirements like DEXOS 2 and oil starting having lower volatility - leaving less residue Another piece of that coke/soot is dirty air - it's not mentioned nearly enough but dirty allows the accumulation to grow very quickly. So driving around at light throttle - with bad oil and dirty air incoming - is a 3 way whammy.
Since 2014 or so there are fewer and fewer instances of DI engines with value coke issues. but you know how the internet is.
The following 2 users liked this post by Napalm:
blksn8k (09-10-2021),
Twin snail putput (09-11-2021)
09-10-2021, 08:19 AM
#133
Beeps and Boops
The three holes along the bottom are for the direct injectors, the three holes higher up are the port injectors. The whole system is nestled in under the intake manifold and takes up no extra space. The 2.7 and 3.0's exterior dimensions are identical.
I would bet the 3.0 gets dual injection very soon, especially if it ends up in the Bronco Raptor/Warthog thing.
09-10-2021, 08:44 AM
#134
Senior Member
Thanks for that pic! I was thinking more of the need for the extra fuel lines, regulator, etc.
That said, I'm guessing it's just a cost issue. Saving a few bucks per vehicle seems to mean more than building a good vehicle these days.
That said, I'm guessing it's just a cost issue. Saving a few bucks per vehicle seems to mean more than building a good vehicle these days.
09-10-2021, 02:37 PM
#135
Senior Member
as far as I know - the engines with DI and MPFI - use smaller injectors for the multi port than engines of old. So it's not like they have gobs of extra fuel support to support crazy power mods.
but yes there is more than there used to be.
but yes there is more than there used to be.
09-10-2021, 03:52 PM
#136
Senior Member
If you only have DI, it's a much more costly upgrade. In some platforms, it's not even a possible upgrade as larger DI pumps are still fairly uncommon.
The following users liked this post:
Laminar (09-10-2021)
09-11-2021, 07:36 PM
#137
Senior Member
Dual DI and port injection is the most costly and the best. Port injection reverts to true true clean intake technology. Was found to be an easy way to get more fuel in the combustion chamber than DI alone. Two smaller systems do a better job than one larger if either design.
Meanwhile oil formulations are progressing for minimizing ash accumulation on the backside of intake valves. This exact problem was an issue for port injection 35 years ago driving the current requirements for gasoline detergents.
09-11-2021, 11:03 PM
#138
Senior Member
You seem to be playing both sides at the same time.
Dual DI and port injection is the most costly and the best. Port injection reverts to true true clean intake technology. Was found to be an easy way to get more fuel in the combustion chamber than DI alone. Two smaller systems do a better job than one larger if either design.
Meanwhile oil formulations are progressing for minimizing ash accumulation on the backside of intake valves. This exact problem was an issue for port injection 35 years ago driving the current requirements for gasoline detergents.
Dual DI and port injection is the most costly and the best. Port injection reverts to true true clean intake technology. Was found to be an easy way to get more fuel in the combustion chamber than DI alone. Two smaller systems do a better job than one larger if either design.
Meanwhile oil formulations are progressing for minimizing ash accumulation on the backside of intake valves. This exact problem was an issue for port injection 35 years ago driving the current requirements for gasoline detergents.
All that I can say is that I'm glad to have dual injection and think it's the best of the current options. If I had the ultimate say though, I think every vehicle should go back to straight port injection. The small fuel savings from DI is not enough of a benefit in my opinion.
09-12-2021, 12:53 AM
#139
Senior Member
The difference?
Well, the 2.7 is the CAFE engine, intended to help the fuel economy average.
It’s a teeny 165ci engine.
They are in no way the best engine for a F150 unless you never tow/haul or work it hard.
Of course - if the hardest thing you do with a truck is to climb your driveway it’ll probably last as
well as the more expensive engines.
Well, the 2.7 is the CAFE engine, intended to help the fuel economy average.
It’s a teeny 165ci engine.
They are in no way the best engine for a F150 unless you never tow/haul or work it hard.
Of course - if the hardest thing you do with a truck is to climb your driveway it’ll probably last as
well as the more expensive engines.
The following users liked this post:
N4HHE (09-12-2021)
09-12-2021, 11:06 AM
#140
The 2.7 EB is so good, it has more HP and Torque than the straight 6 found in the 4.9 , standard equip for the 1980 F350! There can be no doubt it will haul more last longer and have few problems than those old mills! I'm sure we'll see 10,000s of 2.7 still on the road in 40 years! The 1980 F350 "got the job done", but imagine how great it would have been, had it had a 2.7 EB!!
Last edited by pawprint; 09-12-2021 at 11:11 AM.
The following users liked this post:
bigtim3727 (02-23-2022)