Mack Thermodyne?

[tkobes43]

I went to go look at my truck before. Its a 1959 model thermodyne. Did they have turbos? Cause this one does. I'm just trying to see if its an original engine. I will post pics later. Just wanna get some feedback first.

Thanks,

Tom

[bullhusk]

I think it was 205hp turbo-charged

[Rob]

Yup, 205 horses. Not fast by any means today and will practically run forever if not hot rodded. I have a couple of them that run like a top. A duplex, or triplex is a very good power combination behind this engine.

Rob

[HK Trucking]

T Bone, I see in your info that your 59 Mack is listed as a B61. This would indicate that the truck was originally equipped with a naturally aspirated Thermodyne engine. If it was originally equipped with a turbocharged Thermodyne it would be a B613.

Someone apparently dropped a turbo motor in there at some point. It could be a ENDT673A, ENDT673B, ENDT673C, a END711 with the factory retrofit turbo conversion, or a ENDT 675 Maxidyne. The only way to tell for sure is to read the engine model # stamped in the block just in front of the inj. pump, on the surface just behind the timing case cover.

.

[tkobes43]

How would I tell if it was a b613

[Freightrain]

Look at the right frame rail, above the rear spring hanger on front axle for the original VIN stamp. The door tag could have come from anything(switched, different door).

[theakerstwo]

T Bone, I see in your info that your 59 Mack is listed as a B61. This would indicate that the truck was originally equipped with a naturally aspirated Thermodyne engine. If it was originally equipped with a turbocharged Thermodyne it would be a B613.

Someone apparently dropped a turbo motor in there at some point. It could be a ENDT673A, ENDT673B, ENDT673C, a END711 with the factory retrofit turbo conversion, or a ENDT 675 Maxidyne. The only way to tell for sure is to read the engine model # stamped in the block just in front of the inj. pump, on the surface just behind the timing case cover.

.

Or some one may have made a ENDT673 from a END673. I have done alot of them years ago.There was a ENDT 673 and a ENDT673A which was total two different engines.

the A was a good engine and was same as a Maxidyne all but the governor.

[tkobes43]

here are some pictures. Hopefully these will help to see if its a thermodyne or not!

Thanks Guys.

[tkobes43]

Anyone know what it is by the pictures?

[jeffbyrne]

TBone, my guess by looking at that engine, if the engine is an unaltered engine. The large oil filter, a WBG, the oil cooler that I think I can just see in one pic, I would say it is an ENDT673 or 675, as opposed to an END673T. Not sure about an END711 Turboed.

Jeff.

[tkobes43]

So you think its a thermodyne engine? If it is ill be happy as a bull dog. Haha

Tom... tbone

[Freightrain]

If you look at the front of the injection pump area, there is a part number that will tell you what it is. It's on the casting of the accy drive at the front of the motor.

[jeffbyrne]

TBone, it could be a 237hp Maxidyne, an ENDT675, the original Maxidyne, you need to look at the engine #. The numbers on the fuel pump and turbo could tell also, providing you have a manual that tells you how to interprete the numbers. By numbers, I mean numbers stamped in to a plate riveted to the pump or turbo or stamped in to the body of the pump or turbo. Any numbers cast into the block or other components are common numbers to thousands of units produced.

These numbers are ok when your looking for a replacement item. I'm pretty sure an ENDT673 Thermodyne block is the same block as an ENDT675 Maxidyne, but an END673 or an END673T Thermodyne is a different block but it looks the same as a ENDT.

I do stand to be corrected.

Jeff.

P.S. The engine # is stamped, not cast. It comprises engine model/type followed by the serial# of your engine.

Engine numbers are typically, depending on age of engine,

END673P 477-60, END711-51-H96, END864-8-29, ENDT673C-2X-1234 and so on. Later engines were just T673C-2G-2345 or T675-3B-3401

[tkobes43]

If it is a Maxidyne id gladly trade a thermodyne for it!

Tom

Ill let you know in a few days wont be able to get to the truck for a little.

And information will be appreciated.

[theakerstwo]

Its a mack engine. The ENDT673 will have 18 head bolt studs which is 9/16 and a nut that a 7/8 shocket goes on it. It also does not have oil cooled pistons.

The ENDT673a b and c is same block as the maxidyne and will have 20 head bolt studs or cap screws. They are 5/8 in size and a 15/16 shocket. will fit on the nuts. It also has oil cooled pistons.The END and ENDT 673 with 18 head bolts was same block but different from the A,B,C

The early END 672 and 673 did not have a full flow oil filter but a partial flow by/pass 500 luberfiner.

The ENDT 673 a b c was same block and heads as the 674 675 676 but ever new model has a improved something as all engines.

Some guys say the first maxidyne had cap screw head bolts but i am sure i have seen them in the early years with studs and nuts.

[jeffbyrne]

TBone, If the engine is unaltered from original, I'm talking about appearance, then that Perry water filter dates it to about mid 60's at the earliest.

theakerstwo, I have never heard of an ENDT674, or an END674, please enlighten me.

I've found that the blocks without provision for piston cooling are not 'T' blocks. AFAIK there were only two Mack engines built turbocharged w/out piston cooling, they were the END673T and the END864T. All engines designated ENDT have piston cooling galleries in the block. It is the 'T' in the ENDT that indicates this. The 205hp Thermodyne, Mack's 1st turbocharged engine, is officially an END673T, just an END673 Turbocharged. Whereas an ENDT673 has a block designed for/to be, a turbocharged engine, i.e. amongst other features, piston coolers.

BIDSTBC

Jeff.

[tkobes43]

Alright guys. Do you think its most likely a maxi dyne or a thermodyne?

[fifth wheel]

If I had to guess, a Thermodyne. As posted eairler you need the stamped number on the pump drive gear boss. ( END*673** Thermodyne- END*675**, END*676* Maxidyne). From the outside they look similar, the block, crank, cam, rods, pistons, sleeves, pump, injectors, and more all different. From looking at the radiator tierod set up it is not a turbo chassis. What ever it is I would leave it in and use it.

FW

[theakerstwo]

TBone, If the engine is unaltered from original, I'm talking about appearance, then that Perry water filter dates it to about mid 60's at the earliest.

theakerstwo, I have never heard of an ENDT674, or an END674, please enlighten me.

I've found that the blocks without provision for piston cooling are not 'T' blocks. AFAIK there were only two Mack engines built turbocharged w/out piston cooling, they were the END673T and the END864T. All engines designated ENDT have piston cooling galleries in the block. It is the 'T' in the ENDT that indicates this. The 205hp Thermodyne, Mack's 1st turbocharged engine, is officially an END673T, just an END673 Turbocharged. Whereas an ENDT673 has a block designed for/to be, a turbocharged engine, i.e. amongst other features, piston coolers.

BIDSTBC

Jeff.

You are correct i have put the T in the wrong place as wrong on the endt674

[tkobes43]

Alright guys. Thanks alot for your information! One more question, What is that giant cylinder in picture 3? It goes right through my hood. lol

Thanks again,

Tom

[Rob]

Alright guys. Thanks alot for your information! One more question, What is that giant cylinder in picture 3? It goes right through my hood. lol

Thanks again,

Tom

It is the full flow oil filter.

Rob

[fifth wheel]

Come on, we will tell you what it is when you tell us the engine number.

FW

[Rob]

Come on, we will tell you what it is when you tell us the engine number.

FW

The topic is getting a little "long in the tooth".

Rob

[Mike]

I'm still trying to figure why Mack would have put a hole in a good hood just to install a oil tank.

mike

[tkobes43]

That's why I'm thinkin its not the original engine... but hey you never know... ill know the engine number in a few days I haven't been able to gdt to the truck for a few days.