UPDATE :: Return of the Pushrod | Ford's New 7.3L Engine is Actually an OHV V8

UPDATE :: Return of the Pushrod | Ford's New 7.3L Engine is Actually an OHV V8

7.3L_OHV_V8_003.jpg


I'm not sure how to even begin this. Recently I posted what I thought was a well thought-out speculation on what exactly this new 7.3L Gas Engine from Ford could be. To me, the most logical this was an update of the venerable 6.8L V10 for the HD Truck, Commercial, and Motorhome markets. After a lengthy discussion with a behind the scenes source it would appear that I was wrong. Very WRONG.


According to my sources on the inside the new 7.3L is actually the first in a new series of V8 engines that will feature pushrod valve actuation instead of the OHC configuration we've become accustomed to. I know, it sounds insane. I'm having a hard time coming to grips with it myself. However, I trust the source of the info and I have heard rumors of pushrod experimentation inside the Blue Oval for a couple of years; I just had dismissed them.


7.3L_OHV_V8_001.jpg

It's been a long time since we had a cylinder head like this installed on a new factory Ford engine.


So at this time it appears that this engine will first land in the F-Series for 2020. Word has it that the 6.8L V10 was going to need some major work to meet ever tightening emissions and Ford wanted a less expensive and easier to package engine. Like I mentioned in the previous article, the modular V10 is an enormous engine. However, the 4V V8 Modulars don't trail very far behind with their excessive girth. Certainly, one thing that has always be an advantage of the cam-in-block engines was their ability to squeeze more cubic inches into a smaller package.


We were told that cost and packaging were Ford's major concerns when designing this engine. I would say that they'll tick both of those boxes by going from a SOHC V10 to a Pushrod V8. I suspect the overall package size to be somewhere between the other OHC engines on the market. There's no word hey on the combustion chamber design or valve layout, but I wouldn't be surprised to see Ford use a form of the modified-hemi design they used in the Boss 429 and the current 6.2L V8. It allows for the use of supersized valves and can produce massive airflow. I expect the heads will be aluminum.


7.3L_OHV_V8_006.jpg

Wedge, Semi-Hemi, Canted Valves, Pent Roof, 2V,3V, 4V, Etc.? The head design is yet to be revealed.


As for the block, word is that it will be traditional grey iron or possibly Compacted Graphite Iron("CGI"). The 6.2L and the 6.8L both use standard iron block, which have the benefit of being fairly cheap while still being very tough. Also, with the introduction of the FRPP Boss 302 and 351 engine blocks Ford showed that they know how to cast a modern, strong, and economical iron pushrod block. Conversely, Ford's use of CGI has been growing over the past several years. Both the 6.7L Powerstroke and the 2.7L EcoBoost feature CGI blocks. It's not out of the realm of possibility for Ford to cast this new 7.3L block in strong, light-weight, CGI.


7.3L_OHV_V8_004.jpg

Being a truck engine, there's a very good chance the block will be an iron alloy of some type.


Clearly, the competition for this engine will be the GM LS/LT engines and Mopar's HEMIs. Currently, the two engines this 7.3L mill will face down in the 3/4-1 Ton truck market is the 320HP/380TQ L96 6.0L V8 and the 410HP/429TQ 6.4L HEMI V8. Ford's current 6.4L Boss/Hurricane V8 generates 385HP/430TQ and the 6.8L 3V V10 churns out 320HP/460TQ. However, with this new engine packing in 7.3L of displacement I would expect it out muscle everything mentioned above.


7.3L_OHV_V8_002.jpg

Remember, the Hellcat started life as a truck engine too.

The next question has to be, will there be a performance version of this engine? Well, the HEMI started out as a truck engine in the Ram 2500, now in Demon form the HEMI cranks out 808HP. So is it possible that we may see a Hi-Po version of the 7.3 plopped between the frame rails of a future Raptor or Mustang variant? I'd have to say 'yes', the possibility is definitely there. I haven't heard any concrete info on that development yet, but hopefully Ford has learned their lesson from the 6.2L V8. Don't let this new V8 languish in one basic form.


One other thing I asked about, because it has to come to mind when you're talking about an engine that displaces 7.3L, is whether or not this thing is a Big-Block or Small-Block? None of the people I talked to had an answer for that one. I would suspect it is a Small-Block, especially if packaging was a concern. GM seems to be able to stretch the LSX block out to 8.4L, so it would make sense that Ford wouldn't need a Big-Block to get to 7.3L. However, there is the possibility that Ford may split the baby and wind up somewhere in between. There's certainly precedence for that outcome. Anyone remember the Cleveland V8s?


7.3L_OHV_V8_007.jpg

Tumble-Port, Swirl-Port, or Drain Pipe Sized; Ford has lots of options for port deign.

Finally, I know the big questions are still left to be answered, but I will leave you with one last bit of speculation. The last time we saw a 7.3L engine in a Ford -F-Series truck it was the 2003 Powerstroke Diesel. That engine in its most powerful form made 275HP and 525TQ. I expect that when the 2020 model hits the new gasoline 7.3 V8 will make as much torque as the old 7.3L PSD. Horsepower estimates are tough to call accurately in trucks because they tend to be de-rated a bit from their passenger car counterparts, but I'm thinking we'll see at least a 150HP more than the venerable 7.3 Powerstroke. That would put the engine around 425HP and 525TQ. It's very possible that those numbers could be a bit on the low side, but I think that's a fair guess. I highly doubt that Ford will offer a gas engine that makes more HP than the top-of-the-line 6.7L Powerstroke (currently 450HP), but they seem to be dropping a few surprises on me recently. Only time will tell. Keep an on SVTP, we'll let you know as soon as we get more info.


7.3L_OHV_V8_005.jpg

FRPP was pretty proud of their Z-Cylinder Heads when introduced. Perhaps some of those lessons will carry over to the new 7.3L V8.
-SID297
 
Wow. Really surprised about it being OHV.

You think they could copy the Hemi/LT1 method of being "fuel efficient" by shutting down cylinders to improve MPG?
 
Wow. Really surprised about it being OHV.

You think they could copy the Hemi/LT1 method of being "fuel efficient" by shutting down cylinders to improve MPG?

I imagine it will be designed with something like that, or the provisions to add it later.
 
I don’t get it. I could see that as a crate motor from ford performance but in a truck? Remember what a gas guzzling non towing turd the V10 was.


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Interesting article.

But take the gas engine out of its peak torque area or even close to it and its a dog. My dad's could barely get 10mpg empty.

From the article. VVVVVVVV

2008 V10 (362 hp – 457 ft/lbs): produces about 80% of its peak torque (peak 457 ft/lbs, 80% of which is 366 ft/lbs) between 1000 and 4750RPM.

If he barely gets 10MPG empty he either has a lead foot, does most of his driving in town, or has an F-450/550. I've consistently knocked down 13MPG empty in a 2009 F-350 with 4.30 gears.
 

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