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When I asked about provisions for FUTURE DI I was not questioning why it isn't there now, only if it could easily be added if needed in the FUTURE without a major redesign of the heads. That is exactly what was done with the Coyote.

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13 hours ago, jpd80 said:

But going to say 4.125" bore would require the use of a siamesed block ...would that work OK under sustained loading in HD and MD?

Ford was underscoring the use of a big block with wider bore centers to get adequate cooling water in around the cylinders under sustained load. I wonder if GM is so confident in the LS' reliability  that it's prepared to push the design envelope, they now have years of experience with the design.

The new GM 6.6L has a 103.25mm (4.065") bore and a 98mm (3.85") stroke.  Bore centers are 4.40", same as all LS engines.  The iron 6.6L block does have siamesed bores, but features inter-bore cooling passages.  Siamesed bores do not represent a problem if the cooling system is designed right.  I have heard some say that the Small Block 400 had problems related to its use of siamesed bores, but that isn't true.  The 400's oil control issues were due to cylinder wall distortion caused by head bolt torque.  The head bolt holes were too close to the cylinder walls, and when the bolts were tightened the cylinder walls would bulge out slightly and interfere with ring sealing.  The problem is easily corrected by using a torque plate when boring and honing.  One advantage of siamesed bores is that it makes the block casting stronger and more stable.  The 6.6L must have done well in testing, not only is GM confident enough to use it in their medium duty trucks but Navistar and Isuzu will as well.

As for the 7.3L, the Ford engineer did comment about coolant flow around the cylinders.  I wonder exactly how much flow is between the cylinders, if in fact they are not siamesed as well.  The 7.3L's bore is 107.2mm (4.22"), and with a bore center of 4.6", the distance between the cylinders .38" (9.6mm).  The GM 6.6L has .335" (8.5mm), a slight difference.  What puzzles me a bit is why didn't Ford go to a 4.75" or even 4.90" (Lima) bore spacing since this engine is a 'clean sheet'.  GM went with 4.40 because the 6.6L is a variant of an existing engine family.   

 

  

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9 hours ago, 7Mary3 said:

The new GM 6.6L has a 103.25mm (4.065") bore and a 98mm (3.85") stroke.  Bore centers are 4.40", same as all LS engines.  The iron 6.6L block does have siamesed bores, but features inter-bore cooling passages.  Siamesed bores do not represent a problem if the cooling system is designed right.  I have heard some say that the Small Block 400 had problems related to its use of siamesed bores, but that isn't true.  The 400's oil control issues were due to cylinder wall distortion caused by head bolt torque.  The head bolt holes were too close to the cylinder walls, and when the bolts were tightened the cylinder walls would bulge out slightly and interfere with ring sealing.  The problem is easily corrected by using a torque plate when boring and honing.  One advantage of siamesed bores is that it makes the block casting stronger and more stable.  The 6.6L must have done well in testing, not only is GM confident enough to use it in their medium duty trucks but Navistar and Isuzu will as well.

Thanks for the detail on the new 6.6 V8, so I giuess that it's still standard deck height, 9.24"?

Quote

As for the 7.3L, the Ford engineer did comment about coolant flow around the cylinders.  I wonder exactly how much flow is between the cylinders, if in fact they are not siamesed as well.  The 7.3L's bore is 107.2mm (4.22"), and with a bore center of 4.6", the distance between the cylinders .38" (9.6mm).  The GM 6.6L has .335" (8.5mm), a slight difference.  What puzzles me a bit is why didn't Ford go to a 4.75" or even 4.90" (Lima) bore spacing since this engine is a 'clean sheet'.  GM went with 4.40 because the 6.6L is a variant of an existing engine family.   

The 1960s FE 427 engine series had a bore of 4.23" and a bore spacing of 4.63" . Someone previously remarked that Hot Rodders used to use the 3.98" crank out of the 428 in a 427 to make a 445, pretty close to the new 7.3. Relatively speaking, the new 7.3's bore spacing is wider than that of the 6.2 Boss (4.53").

In any regard, the 7.3 V8 definitely has a wider bore spacing than the GM 6.6 V8 and rvrn though the pistons are bigger,  that is still in slightly better proportion that the GM V8. Most cylinder walls are around 3mm or 1/8" so there's better than 3mm water gap on the 7.3 V8. I think it's all relative and probably moot if all the MD truck durability studies and trials have been done.

 

 

Edited by jpd80

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Just saw this in the 6.6 V8 video, 401 hp @ 5200 and 464 lb ft @ 4,000 and 10.8:1 compression

 hyper-eutectic pistons, powder metal rods, forged crank.

 

 

 

 

 

Edited by jpd80

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5 hours ago, jpd80 said:

 

Just saw this in the 6.6 V8 video, 401 hp @ 5200 and 464 lb ft @ 4,000 and 10.8:1 compression

 hyper-eutectic pistons, powder metal rods, forged crank.

 

 

So GM finally has an answer to Ford's V10 torque of 457 ft-lbs it's been rated at since 2005. Only the V10 does it 750 RPM earlier.

I don't think this 6.6 is going to be much competition for the new 7.3. On paper the 6.6 LS looks like a V10 that pulls 40 hp harder at the expense of low-end grunt. Yawn.

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7 hours ago, jpd80 said:

Thanks for the detail on the new 6.6 V8, so I giuess that it's still standard deck height, 9.24"?

The 1960s FE 427 engine series had a bore of 4.23" and a bore spacing of 4.63" . Someone previously remarked that Hot Rodders used to use the 3.98" crank out of the 428 in a 427 to make a 445, pretty close to the new 7.3. Relatively speaking, the new 7.3's bore spacing is wider than that of the 6.2 Boss (4.53").

In any regard, the 7.3 V8 definitely has a wider bore spacing than the GM 6.6 V8 and rvrn though the pistons are bigger,  that is still in slightly better proportion that the GM V8. Most cylinder walls are around 3mm or 1/8" so there's better than 3mm water gap on the 7.3 V8. I think it's all relative and probably moot if all the MD truck durability studies and trials have been done.

 

 

Also remember the FE 427 was replaced by the less-oversquare FE 428 in part because of difficulties with core shift in the 427 block.  Of course that was with mid-60's casting technology.  FWIW, it looks like the GM 6.6L has relatively thick cylinder walls judging from the cut-away views in the plant video.

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4 hours ago, 7Mary3 said:

Also remember the FE 427 was replaced by the less-oversquare FE 428 in part because of difficulties with core shift in the 427 block.  Of course that was with mid-60's casting technology.  FWIW, it looks like the GM 6.6L has relatively thick cylinder walls judging from the cut-away views in the plant video.

Yes, I've actually sonic tested a lot of blocks over the past 30 years, most are very solid on the sides but in between the cylinders is where they thin out, siamezing the bores and adding cross holes to improve circulation is brilliant and overcomes the need for those "steam holes" we used to see on the early Chev 400s with 4.125" bore.  The 7.3 will probably maintain separate cylinders and full water circulation thanks to the wider bore centers - I know the Ford engineer didn't actually confirm that but I get the feeling that's what he meant in the video...

5 hours ago, Sevensecondsuv said:

So GM finally has an answer to Ford's V10 torque of 457 ft-lbs it's been rated at since 2005. Only the V10 does it 750 RPM earlier.

I don't think this 6.6 is going to be much competition for the new 7.3. On paper the 6.6 LS looks like a V10 that pulls 40 hp harder at the expense of low-end grunt. Yawn.

It makes me wonder too, GM basically developed an iron block version of the Gen V 6.2 but with a slightly longer stroke and I get what they are doing.

It's pretty much what we were expected GM to do, beat the 6.8 V10's figures on paper and use the 10-speed auto to make up for any low torque deficit. Simple efficient robust extension of the existing LS architectural, it gets the job done for GM in a clever way across the board with HD and MD trucks.

Speaking of clever, how smart is Ford to keep the 6.2 V8 as a base engine with optional 10-speed and then take F Series to another level with the 7.3 V8, I think it's a spectacularly brilliant move and a secret that was well kept up until now, perhaps holding back the power details until GM showed theirs and maybe just add the figures from the tune that steals  GM's thunder?

 

 

 

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Looking at that video, I'll wager the 7.3L does have siamesed bores.  Noticed the machined slots between the bores?  Might not be enough material between the cylinders to cast the water passage, so they precisely machine a slot.  Doesn't have to be too deep.

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10 hours ago, Sevensecondsuv said:

So GM finally has an answer to Ford's V10 torque of 457 ft-lbs it's been rated at since 2005. Only the V10 does it 750 RPM earlier.

I don't think this 6.6 is going to be much competition for the new 7.3. On paper the 6.6 LS looks like a V10 that pulls 40 hp harder at the expense of low-end grunt. Yawn.

I think the 7.3L will beat it power-wise, but the 6.6L will be a tough and reliable engine.  GM spent MUCH less to bring this engine to market.  And I'll bet GM Performance will have hi-po crate versions out in the next catalog.  Wonder how the 6.6L would do with a blower on it............

BTW- the 6.6L will use an improved version of the current 6L90 6 speed transmission.  LS's like to rev., probably doesn't need 10 gears. 

 

Edited by 7Mary3

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and with that, I think that GM just blinked.

While the 6.6 V8 and 6L90 is a good combination, a re-work of the 6.0 Vortec line and no 10-speed auto smacks of cost cutting. The equivalent would be Ford increasing bore and stroke on the 6.2 Boss to make a 6.8 V8 or 7.0 V8 and calling it job done, you just know that ford would get panned for doing that but GM gets a pass on just reworking its small block....

I don't mean to be overly harsh on GM, they may have more planned in the works if the 6.6 is successful in increasing  sales of gasoline HDs.

Ford's  7.3 V8 and 10-speed auto fills the long term void created when the 6.8 V10 was withdrawn for Super Duty, It will be interesting to see what happens with regards to possible sales bleed away from the 6.7 Powerstroke to the 7.3 gas engine and whether propane or natural gas prep kits are offered...If the new Ford 7.3 lifts sales, will Ford have enough production capacity to keep up supply?

Edited by jpd80

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26 minutes ago, jpd80 said:

and with that, I think that GM just blinked.

While the 6.6 V8 and 6L90 is a good combination, a re-work of the 6.0 Vortec line and no 10-speed auto smacks of cost cutting. The equivalent would be Ford increasing bore and stroke on the 6.2 Boss to make a 6.8 V8 or 7.0 V8 and calling it job done, you just know that ford would get panned for doing that but GM gets a pass on just reworking its small block....

I don't mean to be overly harsh on GM, they may have more planned in the works if the 6.6 is successful in increasing  sales of gasoline HDs.

Ford's  7.3 V8 and 10-speed auto fills the long term void created when the 6.8 V10 was withdrawn for Super Duty, It will be interesting to see what happens with regards to possible sales bleed away from the 6.7 Powerstroke to the 7.3 gas engine and whether propane or natural gas prep kits are offered...

Jp-Bottom line unless they blow it on pricing this thing will be a home run in class 5,6 and 7.  No doubt there will be loyal Ford customers who in any case would have bought a Ford so yes, I would guess no net sales gain.  But for those who are buying Hinos, Internationals, Paccars, and the new 5500, 6500 GM's here is a chance for them to get  the power they need without the up front first cost premium that goes with the diesels  as well as the maintenance savings associated with higher oil change costs, as well all the BS associated with DEF issues.  

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Gaseous fuel upfits are almost a certainty for the 7.3L.  It might be one reason Ford stuck with port fuel injection, as it makes the conversion easier.  Direct injection CNG/LNG systems are being introduced though.

 

 

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Heads look good. - Heart shaped chambers - Generous valve diameters.  - Interesting deviation from the old FE in that the head incorporates a portion of the intake as opposed to the extended intake on the FE.

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Heads look borrowed from an LS.  Combustion chamber, large valves, spark plug position, long intake ports/head extending over valve lifters......

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On 1/30/2019 at 10:11 AM, MY93SHO said:

the

All very interesting info and discussion on the new 7.3 V8 and the GM 6.6 V8.

The design looks like a bulked up 351 W with added technology of variable valve timing at much wider bore centers with GM LS heart shaped combustion chamber.

Mary you are right about machined slots between cylinders!  We did that on current Chrysler FCA 3.6 liter V6. 

Great way to have stronger block and H2O where you really need it!

Ford FE and original Chevy 2.8 V6 had narrow cylinder heads that had cooling issues because of lack of water passages in critical places. I’m sure ford would not make that mistake again in new engine. Actually ford went backwards when the Lincoln Y block was discontinued. 4.63” bore centers, and they tooled the FE andMEL!

also, expect a smaller version of the new ford 7.3 to eventually replace the 6.2 doc V8 some time in the future.

edselford

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1 hour ago, edselford said:

Ford FE and original Chevy 2.8 V6 had narrow cylinder heads that had cooling issues because of lack of water passages in critical places. I’m sure ford would not make that mistake again in new engine. Actually ford went backwards when the Lincoln Y block was discontinued. 4.63” bore centers, and they tooled the FE andMEL!

edselford

The 317 'Cargo King' and later 332 versions of the Lincoln Y-Block were excellent truck engines.  Very durable, good cooling, and a very tall block, they probably were better than the 'FT' truck engines that followed, and could have been developed further.  Ford found themselves at a disadvantage in the mid-70's, even the FT 391 was easily out-performed by the Chevy 427 and Dodge 413 in medium duty trucks.  Ford responded with a special '475' version of the Super Duty V-8 for medium duty trucks, it had power and durability but very poor fuel economy.  The fix didn't come until 1979 when Ford released the 370 and 429 'truck' versions of the Lima.  Interesting that the 429 Lima eventually outperformed the 534 Super Duty!  

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Ford could of easily expand the 6.2 V8 to 7.3 liters.

There are many reasons they did not. I think they needed a gas engine for the F450/550/650 that made the most sense ie lowest cost, lowest frictional losses, best low end torque and best fuel economy for intended duty cycle.

If someone wants a V8 at about 7.0 liters, for mustang, it would probably be a dual overhead cam version of the 6.2. The question always is can the financial results justify the investment and resources given the SC 5.2 V8 availability.

Also, both GM LS gen 1 through 5 and the new ford 7.3. Engineblock archetectures look allot like the old Buick 364/401 V8 engine block!

edselford

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On 2/11/2019 at 12:49 PM, 7Mary3 said:

The 317 'Cargo King' and later 332 versions of the Lincoln Y-Block were excellent truck engines.  Very durable, good cooling, and a very tall block, they probably were better than the 'FT' truck engines that followed, and could have been developed further.  Ford found themselves at a disadvantage in the mid-70's, even the FT 391 was easily out-performed by the Chevy 427 and Dodge 413 in medium duty trucks.  Ford responded with a special '475' version of the Super Duty V-8 for medium duty trucks, it had power and durability but very poor fuel economy.  The fix didn't come until 1979 when Ford released the 370 and 429 'truck' versions of the Lima.  Interesting that the 429 Lima eventually outperformed the 534 Super Duty!  

I don’t know if I agree with you on all of this. The 330 HD , 361 and 391 were fabulously successful in C, F and LN trucks. 

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On 2/11/2019 at 12:49 PM, 7Mary3 said:

The 317 'Cargo King' and later 332 versions of the Lincoln Y-Block were excellent truck engines.  Very durable, good cooling, and a very tall block, they probably were better than the 'FT' truck engines that followed, and could have been developed further.  Ford found themselves at a disadvantage in the mid-70's, even the FT 391 was easily out-performed by the Chevy 427 and Dodge 413 in medium duty trucks.  Ford responded with a special '475' version of the Super Duty V-8 for medium duty trucks, it had power and durability but very poor fuel economy.  The fix didn't come until 1979 when Ford released the 370 and 429 'truck' versions of the Lima.  Interesting that the 429 Lima eventually outperformed the 534 Super Duty!  

Just curious-never heard that before about 429 vs. 534-or are you talking about fuel economy only?  And when the 429 came out in 800 series wasn't the Super Duty series out of production?

Also what WAS a 475?  I was of the belief it was NOT a Super Duty off shoot but an FE variant??

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Medium Ford Super Duty V8 came as 401, 477 and 534...

Edited by jpd80

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I wouldn't say the FT's were bad, it's just that they were down on power compared to the competition at the time (mid-70's).  We had a lot of F-series with 361 XD's (that basically meant 4 bbl. carb.), and a Chevy 366 would absolutely walk a 361.  So would a medium duty Dodge with the 360-3 or 361-3.  The 370 Lima was much better as well with a 4 bbl..  The FT's did tend to run not if worked hard.  I remember having a lot of radiators on those trucks rodded out, any blockage made things worse.  Didn't have to do too many major repairs to FT's, but I remember one 361XD we had that burned a bunch of valves.     

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18 minutes ago, Bob Rosadini said:

Just curious-never heard that before about 429 vs. 534-or are you talking about fuel economy only?  And when the 429 came out in 800 series wasn't the Super Duty series out of production?

Also what WAS a 475?  I was of the belief it was NOT a Super Duty off shoot but an FE variant??

The '475' was a 477 used in medium duty F-800's and F-880's (yes, F-880) from 1974 to 1979.  It was supposed to be 'lighter duty' version of the 477 for medium duty trucks, but I think it was exactly the same engine.  Ford needed the 475 to compete with the Chevy 427, and that came from Ford truck engineer James Wagner (get a copy of his book 'Ford Trucks Since 1905' if you don't have one already, he covers this).  The 475 was dropped from the F series after 1979, but the 534 was actually built until 1981 for the C series.  I remember talking to another Ford Truck engineer once about the 534 and he told me that the 429 made more usable power and used a lot less gas doing it by the late 70's!  Maybe not a totally fair comparison, the old Super Duty didn't do well after they installed all the emission controls are retarded the timing.  The more modern Lima ran cleaner.  The Super Duty had a 'plank' head, like a Chevy 409 or MEL engine, not efficient.  Surprisingly. Ford did design a nice new intake manifold for all the Super Duty engines around 1977.  It was a one-piece design with smooth runners, the original Super Duty intake was a horrible 3 piece affair that had 3 90 degree turns from carb. to port!          

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9 hours ago, 7Mary3 said:

The '475' was a 477 used in medium duty F-800's and F-880's (yes, F-880) from 1974 to 1979.  It was supposed to be 'lighter duty' version of the 477 for medium duty trucks, but I think it was exactly the same engine.  Ford needed the 475 to compete with the Chevy 427, and that came from Ford truck engineer James Wagner (get a copy of his book 'Ford Trucks Since 1905' if you don't have one already, he covers this).  The 475 was dropped from the F series after 1979, but the 534 was actually built until 1981 for the C series.  I remember talking to another Ford Truck engineer once about the 534 and he told me that the 429 made more usable power and used a lot less gas doing it by the late 70's!  Maybe not a totally fair comparison, the old Super Duty didn't do well after they installed all the emission controls are retarded the timing.  The more modern Lima ran cleaner.  The Super Duty had a 'plank' head, like a Chevy 409 or MEL engine, not efficient.  Surprisingly. Ford did design a nice new intake manifold for all the Super Duty engines around 1977.  It was a one-piece design with smooth runners, the original Super Duty intake was a horrible 3 piece affair that had 3 90 degree turns from carb. to port!          

Thx-after I did my post I did a search.  found a lot of BS but also one post that said exact same block as 477.  Biggest difference was it did not carry the 100,000 mile warranty that the SD did.  And I do have Wagner's book but could not find any specifics on 475 -other than its availability in specific service.

One interesting thing I remember.  Boston Globe paper had a fleet of F-800's. I was on I-495 one night passing one, looked over and entire muffler was glowing red! No clue what motor they had in them-this was about '78-80.

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On 2/9/2019 at 4:38 PM, jpd80 said:

Yes, I've actually sonic tested a lot of blocks over the past 30 years,  ...

I am always AMAZED at how far casting technology has come in the past 30+ years !  UNBELIEVABLE !!  Look that those exhaust manifolds.  Cast stainless (?) and they look almost as good as tube headers.  (IIRC, the first time Ford put tube headers on a production car was the Escort GT EFI.)

Composite intake and who need aftermarket manifolds !  I'm sure the cylinder heads could use a bit of "port matching" bit certainly no "hogging out" !

 

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