3408 swap

[Macktruckman]

Has anyone ever seen or tried to put a 3408 in an R686? The biggest limiting factor with the R600 is the short hood right?  A 3408 should be considerably shorter than a 3406 right?  They are a 60 degree V instead of a 90 like the E9 so should be narrower than the big mack? Im just thinking for giggles. My EM6 needs some block work or just replaced and my first obvious choice would be an E7 given the many similarities with the E6 but I’m just curious about other options. And not so common options. Don’t crucify me for putting a cat in a dog as I haven’t done it. Lol. Just interesting conversation at this point 
Josh

Edited March 19 by Macktruckman

[tjc transport]

well, since you used to be able to buy a Mack with cat engine, it is not total sacrilege.

the problem i see with the 3408 engine is availability.

[fjh]

1 hour ago, tjc transport said:

well, since you used to be able to buy a Mack with cat engine, it is not total sacrilege.

the problem i see with the 3408 engine is availability.

Yup its as scarce as e9 if not worse! AND not as good ! They also had crank issues in my mind caused of the 60 degree throws ! If you ever seen these cranks you'll see what I mean! We pulled a few v12 Detroit's out of logging trucks here ! Retrofitted E9 ! it ran circles around the Detroit power and fuel wise and the 3408  fuel wise  it had the power but the fuel economy was in the toilet! The fuel savings with the V8 payed for the retro fit in less than 3 years!

Caterpillar Cat CT 3408B Crankshaft New Replaces: 1W5009 1W5 (dieselcranks.com)

[67RModel]

My guess is a 3408 is about 1,000 pounds heavier than an E6. 

[fjh]

Agree ! that too! 🙄wouldn't even consider this My self! Wasn't one of Cats better Ideas!  

[mechohaulic]

being on the outside looking in ; a large number of questions would be asked :: 1- is this a work truck or show truck? 2- what items are currently available for change over ?? 3- how far does the $$$$bank account support such a venture. ??? and few more questions of similar nature.  an R-700 would be truck  of choice; air bag assist under front axle/ frame or heavier axle  would help weight concerns. what's a couple more bucks ! one heck of a fabricating/ body shop would help also. those who can make a B model "rat rod" could surely plant a V-8 cat in an R-600!!!

[BOBWhite]

Where and why on earth would you want one? Sure there is the cool factor, but I think the E9 beats it out in any V8 coolness comparison 😉

For 20k to 60k you could buy several E7s and weld them together if you really want a monster engine!

[Back In Black Pulling]

til you mount air compressor n power steering pump on back same length as 3406 or c15  

[Mark T]

This wouldn't seem like a cost effective swap ( to say the least ) the E7 with a mechanical pump is your easiest path to a bigger horsepower swap, and I'm not sure that's gonna go without a hitch. Those 3408s are big, the 60 degree part really doesn't mean much as far as it's external dimensions.  They're big .

[Macktruckman]

I was curious about the length factor and I didn’t know that the compressor and pumps add length. That is information I was curious about. And the weight factor would hinder. I assumed that the reason it was a 60 degree was to make it narrow enough to fit where an E9 would not. Im asking questions. Curiosity and conversation. My plan right now is a mechanical E7 but it’s fun to learn about different things from all you guys. The conversation and the learning is really why I asked. I don’t see truck 3408’s but the industrial ones are around and I see one now and then. They seem to be rated around 400. Im positive that industrial injector pumps are different from automotive pumps and id guess having a pump built for a 3408 is not cheap. Lol. The replies are great it is how I learn. 
Josh

[mechohaulic]

are you talking a show truck or this plan for a work truck or as you say ;; it's all about the learning conversation.

[Mark T]

3408 was a good horsepower engine. Where they were used weight and size weren't a huge deciding factor. They weren't the best for pumping out huge torque (think like when shifting a loaded truck) The crank shaft had two rods on each throw and they didn't share the same centerline.  Not a ideal setup for automotive use.  They did much better sitting at one steady rpm making horsepower.  You could get one ein a truck and they were impressive, but expensive and somewhat fragile if the horsepower was bumped up.  E9 was a much better design for use in trucks. A true 90 degree V8   not a 60 degree tricked into thinking it was a 90.  🤔  cram an MP10 in there (lol) that'd be different.

[Macktruckman]

This particular truck is my move tractor. It moves my excavator and dozer. And it pulls an end dump some.  So it does work but its local and while at times it weighs up to 100k thats not the norm and it doesn’t see many miles per year at all. Ive been studying differences between the E6 and E7 and externally they are plenty similar enough that thats not a difficult swap. And probably where this is headed but i haven’t found a good core to build yet. I just happened across a couple 3408 industrial engines and made me curious because id love an E9 but have the wrong truck for that and probably the wrong finances for either. Lol. I was just curious. I wondered if a 3408 would fit where an E9 wouldn’t. I love that V8 sound. Lol. And yes I definitely would love more power. I have some pretty serious grades here and the E6 doesn’t like long hills. Lol. 
josh

 

[Macktruckman]

I dont know what else would fit besides E6 and E7. Saw pictures of a C-12 in one. Im sure some version of the old Detroit 2 stroke would fit but i have no interest in a Detroit. Lol. I figured someone on here has seen or done something unconventional. Lol
josh

[mrsmackpaul]

Length I reckon will be the issue

Here is a pic of a R700 a bloke in Australia owns and he put a 3408 in it

Bonnet is severely modified to make it fit

And remember it started outas a R 700

With the 375 as made

 

Much later, same truck with a 3408

 

 

Paul

[terry]

Wow I guess some modifications! Pretty impressive.   Terry

[Mark T]

That's the same truck in both pictures ?  Holy cow.

[Macktruckman]

Well there ain’t no stuffing one in a R600 then!  Lol

[mechohaulic]

had to look twice !! not just a different paint job.  R-700 turned into a superliner !! real nice job. 

49 minutes ago, Macktruckman said:

Well there ain’t no stuffing one in a R600 then!  Lol

as a work truck looks doubtful  as a rat rod or an R-600 having a dog house in cab .????  don't have all specs on a 3406 = 6 vs 8 have any positives ?? weight/ HP / size ??3406 more then likely to long ?

[mrsmackpaul]

Mechohaulic, it's a Superliner with a long long sniffer

Does it make it a Superdooperliner then

The owner contacted me some time ago after watching me rebuild my old bucket of bolts on youtube 

He explained a lot of details, both the owner and the truck are retired now

The 375 endt 866 went kahput and the E9 was still under development so a substitute was found

A huge tropical radiator was shoved in and the chassis extended  to accommodate all the mods

The owners  words "a lot of fellows are aghast at the extra length, I personally don’t give a f**k" 

Anyway, it's not my story to tell, it sure is a different looking truck and has served the owner well for many decade's 

Paul

[Macktruckman]

Yeah im sure the 3406 is too long. I have a big cam here and I’ve tape measured around on it and it’s definitely too long. Only real option im seeing then is the mack E6-E7 of course and then possibly a C-12 which i dont have and don’t want to mess with the electronics and something like a 671 or 6v92 and being im the driver im not listening to that. Lol. Im still keeping an eye out for a mechanical E7 or vmac i cant put my robert bosch pump on. Sounds like the 3408 is too big to fit but from what I read the 3408 is wayyy heavy as well. 
josh