Differences Between Mack B-73, B-75 and B-77

[mackdaddy]

On ‎1‎/‎29‎/‎2019 at 7:20 PM, Superdog said:

did they have the twin turbo V8 in '63? I thought it came later,'66 or so.. Maybe this was a test truck for the engine??

The papers I have on the history of the Mack V8 shows the ENDT864 (note there is no double T?) was used from 1965 thru 1972 with 4 different versions of the ENDT for a total of 661 built. I assume they were all twin Turbo'd. Surprisingly they built over 7600 of the naturally aspirated 864's and they were offered along side the 865 and 866's for 3 plus years. I sent off a request to the museum to verify if they would have installed a few earlier than 1965 as you would assume a few were out there for testing. The late Bob Brown told me that when he was the northwest Mack service manager they shipped a few up to Alaska for trial runs and he thought it was an awful idea as they were constantly broke down as they worked out the bugs with them. It seems that was in the very early 60's in F models.

[AZB755V8]

13 hours ago, mackdaddy said:

The papers I have on the history of the Mack V8 shows the ENDT864 (note there is no double T?) was used from 1965 thru 1972 with 4 different versions of the ENDT for a total of 661 built. I assume they were all twin Turbo'd. Surprisingly they built over 7600 of the naturally aspirated 864's and they were offered along side the 865 and 866's for 3 plus years. I sent off a request to the museum to verify if they would have installed a few earlier than 1965 as you would assume a few were out there for testing. The late Bob Brown told me that when he was the northwest Mack service manager they shipped a few up to Alaska for trial runs and he thought it was an awful idea as they were constantly broke down as they worked out the bugs with them. It seems that was in the very early 60's in F models.

I heard the same thing about the 864 naturally aspirated, it was available in 1962. It was Mack's first BIG HP attempt. That was told to me by a Mack engineer the was involved with the E9. The Twin turbo 864 was available for sale starting in 1966 in F&R models. It is a shame, but truly there are very few of the 7600-8250 of those engines produced that are still running and less than 10 of the twin turbo's for sure. I have seen one or two TT in Mack fire trucks as well. There is only one engine that I know of more rare to see, a Big Al, but was never in a Mack.  

Edited February 7, 2019 by AZB755V8

[Rob]

Company I worked for in 1978 had an R model dump truck with the 864V8 with twin turbochargers. I worked on it a bit but it was repowered shortly after I started as it didn't run consistent and the engine sold to someone for parts. It never blew up, just was getting dragged back to the shop for something and then parts weren't supported very well with extended wait times. 

[Superdog]

12 hours ago, AZB755V8 said:

I heard the same thing about the 864 naturally aspirated, it was available in 1962. It was Mack's first BIG HP attempt. That was told to me by a Mack engineer the was involved with the E9. The Twin turbo 864 was available for sale starting in 1966 in F&R models. It is a shame, but truly there are very few of the 7600-8250 of those engines produced that are still running and less than 10 of the twin turbo's for sure. I have seen one or two TT in Mack fire trucks as well. There is only one engine that I know of more rare to see, a Big Al, but was never in a Mack.  

there were some Western F models built with Big Al engines,this one sold on Ebay a few years ago

 

 

 

 

 

72 FS A-C 475 4.bmp

72 FS A-C 475 3 (2).bmp

72 FS A-C 475 1.bmp

72 FS A-C 475 2.bmp

72 FS A-C 475.bmp

[41chevy]

16 minutes ago, Superdog said:

there were some Western F models built with Big Al engines,this one sold on Ebay a few years ago

 

The Autocar I bought in 2008 has a AC25000 . Benn looking for a crankshaft now for 10 years. Spun two rod bearing after I put 200 miles on it. SOB I bought it from staked and shimmed them.

Edited February 7, 2019 by 41chevy

[yarnall]

I had a discussion with someone about this who had some documents with Mack that had conflicting numbers.  There were 14 CF719’s built with the twin turbo 864’s made. I have number 12 and the other guy has number 9.  His documents show that for the fire service it was boosted to 350hp.  I bet there are more than 10 running examples left since I know of third surviving CF and Tom has one in his R719. As for non-turbo, my F715 is on it’s third or forth. The first blew up on the first trip. It went right back to Mack to be replaced. Mike. 

[Superdog]

21 minutes ago, yarnall said:

I had a discussion with someone about this who had some documents with Mack that had conflicting numbers.  There were 14 CF719’s built with the twin turbo 864’s made. I have number 12 and the other guy has number 9.  His documents show that for the fire service it was boosted to 350hp.  I bet there are more than 10 running examples left since I know of third surviving CF and Tom has one in his R719. As for non-turbo, my F715 is on it’s third or forth. The first blew up on the first trip. It went right back to Mack to be replaced. Mike. 

I've got 3 864's that are runners,(B815,R615,&F715)and 2 more I'm not sure of,(B615 & F715),plus a twin turbo in the barn for a R719 I have that was repowered by a 237

 

[AZB755V8]

11 hours ago, Superdog said:

there were some Western F models built with Big Al engines,this one sold on Ebay a few years ago

Should have said engine that I ever have seen or heard of in a Mack. That F model looks like it was at the end of the road. As for Big Al's, I have only heard one running the others were broke and parts were very hard to get.

[mackdaddy]

12 hours ago, yarnall said:

I had a discussion with someone about this who had some documents with Mack that had conflicting numbers.  There were 14 CF719’s built with the twin turbo 864’s made. I have number 12 and the other guy has number 9.  His documents show that for the fire service it was boosted to 350hp.  I bet there are more than 10 running examples left since I know of third surviving CF and Tom has one in his R719. As for non-turbo, my F715 is on it’s third or forth. The first blew up on the first trip. It went right back to Mack to be replaced. Mike. 

Mike, that would have been ENDTF @350hp and most likely the F is for firetruck. Then there was an ENDTI @255hp which is also what the standard naturally aspirated 864 was rated at. Also an ENDT864A at a whopping 355hp. It appears the standard EMDT864 was @325hp. 

[CaptainCrutch]

Another question in this same theme, does anybody know how many Bs were built with the CA-31 cab?

[Jamaican Bulldog]

Slightly off topic but do the B67 have shorter hoods than the B7 series? Also was the L cab only available on the B7 series?

[CaptainCrutch]

Yes, the L cab was only available on the B7 series, the front of the hood was wider which did something to allow a slightly modified L cab to be installed, most likely made the hood straighter which made something line up. The advantage being the L cabs have much more room.

Edited February 24, 2019 by CaptainCrutch

[Hobert62]

1 hour ago, Jamaican Bulldog said:

Slightly off topic but do the B67 have shorter hoods than the B7 series? Also was the L cab only available on the B7 series?

B67 has a 7" shorter front fenderd then the standard B61.  Idk the hood diffrence.   I'm guessing 7" also. 

Edited February 24, 2019 by Hobert62

[Jamaican Bulldog]

1 hour ago, CaptainCrutch said:

Yes, the L cab was only available on the B7 series, the front of the hood was wider which did something to allow a slightly modified L cab to be installed, most likely made the hood straighter which made something line up. The advantage being the L cabs have much more room.

I always wondered how come the less roomy B cab replaced the more roomy L cab.   I personally think the L cab looks better. I like it on the C model too.

[B815SX]

I’m Interested In The Twin Turbos If You Still Have Them You Can Call Me At 978-423-4213 Thanks

[theakerstwo]

On 2/6/2019 at 7:34 AM, mackdaddy said:

The papers I have on the history of the Mack V8 shows the ENDT864 (note there is no double T?) was used from 1965 thru 1972 with 4 different versions of the ENDT for a total of 661 built. I assume they were all twin Turbo'd. Surprisingly they built over 7600 of the naturally aspirated 864's and they were offered along side the 865 and 866's for 3 plus years. I sent off a request to the museum to verify if they would have installed a few earlier than 1965 as you would assume a few were out there for testing. The late Bob Brown told me that when he was the northwest Mack service manager they shipped a few up to Alaska for trial runs and he thought it was an awful idea as they were constantly broke down as they worked out the bugs with them. It seems that was in the very early 60's in F models.

I was working for the Tulsa mack dealer in 65 and it may have been 66 when the first twin turbo 864 came there new in a R700.It was there almost one year before a local purchased it.The owner of the dealer Perry Harper told us it was the first one from the factory sold west of the Miss, river.

[yarnall]

On 2/23/2019 at 7:42 PM, CaptainCrutch said:

Yes, the L cab was only available on the B7 series, the front of the hood was wider which did something to allow a slightly modified L cab to be installed, most likely made the hood straighter which made something line up. The advantage being the L cabs have much more room.

4 B85F’s were built for Chicago with the L model cab.    mike. 

Edited November 23, 2020 by yarnall

[AZB755V8]

6 hours ago, B815SX said:

I’m Interested In The Twin Turbos If You Still Have Them You Can Call Me At 978-423-4213 Thanks

Sorry, the turbo's are long gone. All of the B and LT parts I had recently sold as well. Down to just complete trucks now.

[doubleclutchinweasel]

Someone mentioned the Allis-Chalmers "Big Al" engines a few posts back...

https://www.donhummertrucking.com/blog/2015/04/17/big-al-is-king

 

Edited November 23, 2020 by doubleclutchinweasel

[Brian L Blaylock]