Command Decision Made:

[Rob]

Well, as some or most of you know I have this here 12V-71T engine sitting on my shop floor without a home. Tonight I took the first steps at getting it ready for installation into a truck.

I will start the story from the beginning:

First off, this engine had been part of my workload, (standby power generation) at the federal job for the past 21 years. This engine, along with several others, has always had good maintenance practices, (by myself) with the oil changed bi-annually, or every 200 running hours. Along with oil changes, coolant is changed also. In February 2005, the decision was made to replace this engine due to age and importance to air traffic control operations in this area, and a contract was let out for replacement/upgrade. This replacement was performed in early July, 2006. I elected to retain this engine for my personal use for future installation into a truck, circumventing the disposal process, (legally).

As this is an industrial engine rated for standby power generation and set to operate at one of two speeds, 0 rpm, or 1800rpm, I would need a new governor assembly, governor housing for the front blower, flywheel housing, flywheel etc. to facilitate fitment into a truck chassis. I discovered it much less expensive to purchase a complete engine with a limiting speed governor, and an S.A.E. #1 flywheel housing with all ancillary items as opposed to purchasing separate parts individually. With ebay to the rescue, I purchased a good running 8V-71 engine from an IH firetruck, (supposedly) and worked with several members of this board to get it to my shop. Now that I had most things that would be needed, I did not have a chassis to support the endeavor, so off to the next chapter.

In mid September 2006, a good friend and fellow member of this board calls me and states that a guy wants to sell an RL-700 series Mack tractor as he is keeping the engine for another project. This is just the ticket that I'm looking for. Upon reaching an agreement for the balance, and agreeing to pulling the engine at my shop we set out to Paducah, KY to retrieve the tractor. It is a little "rougher" than I was lead to believe, but still a nice unit. We proceed to drive this tractor almost 400 miles to my shop on a "wing and a prayer" as this truck had not even seen asphalt for 12 years! Best part of the deal was the seller had filled both tanks plum full, then discovered the clutch was so bad he couldn't pull a trailer, so he parked and forgot all about it. Anyways, after driving this truck without license, inspection, and only 1/2 the lights working, with intermittent/no windshield wipers in the rain, we arrived at my shop in the wee hours of the morning. Casually looking into the tanks to approximate usage, we discover the fuel is very, very red! This by itself is an instant $500.00 fine before they, (cops) even start to screw with you.

The truck was thought to be "different" in the fact that it has a 1693TA Caterpillar engine as built from the factory. I knew this had to be a limited production truck as I had never seen, or heard of one prior. My wife, (whom is an accountant at Caterpillar corporate) looked into some of the "files" from the era that the engine was built via serial number and production date stamping(s). What she discovered was that Caterpillar only filled orders for four 1693TA engines for Mack Trucks Inc. A call to the Mack museum, (Mr. Snowy Doe, r.i.p.) confirmed this to be a rare truck alright with only three being produced. I quickly renegotiated to acquire the balance of the truck complete!

This RL series truck was only considered for the installation of the Detroit engine and now that was out of the question. I looked around and eventually purchased an R-795 truck that is my current avatar. This is a "common" truck with nothing really special about it. After rebuilding the governor assembly, and fuel injectors, it really runs well. I had decided to keep the ENDT-865B engine as it was so again the Detroit project had no plans, or home.

Another year passes by and another deal I couldn't resist on a nice "Western" RL series tractor comes along, so I purchase it also. This is of course to do something with, but what, I don't know. At this point I"m starting the hear the "sweet voice" of my soul mate whom is not very pleased with my latest acquisition, (maybe I should take up fishing, golf, etc...??) ask

"What do you need more of that Mack Junk for?" Now this left me in the middle of the floor "babbling -n- shit" without a single intelligeble word to say; I take solace in that she knew I was MAD, and left my "Paradise".

This second RL series tractor is really nothing out of the ordinary, but does have an ENDT-866 engine with some mechanical problems. Neither the prior owner, nor myself have gotten into it for a proper diagnosis as of yet. Being an aluminum straight frame rail truck, I don't know if the Detroit would fit into the chassis satisfactorily or not, so this was not evaluated. The tractor being a lightweight, just may be a nice "daily driver". I do have a spare engine like it in the shop.

I have therefore arrived at the subject of this long winded post. Tonight I had both Detroit engines picked up by a "well qualified" mechanic to begin the conversion of the 12V-71T engine to automotive use. He is also going to install the 8V-71 engine onto the alternator to be sold at a later date. The R-795 is the participant and even though it runs quite well, is the best candidate to experiment with on this installation. I needed to do this quick before I had a chance to think! Currently the engine is set to 585hp at 1800 rpm and I have larger injectors if needed. Also have an RTO-12513 transmission that has not been installed since complete, professional, overhaul to go behind it. Should prove to be an interested project or "fun truck".

It was very hot today with matching humidity. I sat at the computer "cooling down" and thought I would type a bit to let you know what I'm up to in the "off time". I don't really get to work with my own stuff too often and am trying to change that. Still strange to consider working with something other than Mack.

If the story is interesting, great! If boring, my apologies are rendered.

Rob

[storkmack]

Boring? I think not! The thought of a Buzzin' Dozen in a Mack will give me sweet dreams tonight. Good Luck Rob, and keep us posted. Thanks, Brad

[skip]

Boring? I think not! The thought of a Buzzin' Dozen in a Mack will give me sweet dreams tonight. Good Luck Rob, and keep us posted. Thanks, Brad

How are ya mate? There is a bloke out here in Australia who is rumoured to be importing an LTL with a V12 Halls-scott. Do you know if this was a genuine fitment? I dont know too much about the early ones, but Im lead to believe it is original. Cheers mate, Skip

[Rob]

How are ya mate? There is a bloke out here in Australia who is rumoured to be importing an LTL with a V12 Halls-scott. Do you know if this was a genuine fitment? I dont know too much about the early ones, but Im lead to believe it is original. Cheers mate, Skip

G' Day Mate! I would not be any type of authority on the Hall-Scott engines at all. Never laid eyes on one that is in a truck but have seen them in boats, and static displays.

The LTL truck you mention: Is this a "Louisville" Ford type truck? I don't think the HS engines were around when they came out, but am not really sure.

Rob

[Bollweevil]

I don't think that these are dull ramblings at all. I think someone should only be limited by their imagination. Otherwise we wouldn't have light bulbs, airplanes, automobiles, or even an ice cold soda. I just can't leave Life, Liberty and the pursuit of happiness out of this either. When I was young, there were a lot of things I just couldn't do, because of my responsibility to my family. And neither could you. Well guess what. Now you can. I have stepped over someone else's toys, now they can walk around mine. Since I am already standing on this stump, when you do find yourself down under. Stay away from the Croc's. And if you can make it happen by any means take at least a short trip on a road train. It couldn't be any worse than pulling doubles through Mo. or Ill. And insist on driving, just don't look back. Hey man, you couldn't ride a bike either till the first time.

[Lmackattack]

G' Day Mate! I would not be any type of authority on the Hall-Scott engines at all. Never laid eyes on one that is in a truck but have seen them in boats, and static displays.

The LTL truck you mention: Is this a "Louisville" Ford type truck? I don't think the HS engines were around when they came out, but am not really sure.

Rob

Rob, I think Skip is talking about the lightweight LT mack models "LTL"

Sounds like your having fun with the trucks. Cant wait to see how it turns out. I would love to get a E9 V8 under the hood of the RS but fuel costs would have me worried. not to mention having to change the trans and driveshafts to get it all in properly. Whats the TQ rating on the DDV12s?

Trent

[Rob]

Rob, I think Skip is talking about the lightweight LT mack models "LTL"

Sounds like your having fun with the trucks. Cant wait to see how it turns out. I would love to get a E9 V8 under the hood of the RS but fuel costs would have me worried. not to mention having to change the trans and driveshafts to get it all in properly. Whats the TQ rating on the DDV12s?

Trent

You are probably correct there Trent. There were a few LT's produced that did have the H-S

engines as I recall. Must be fatigue as I did not even think of them. I know better.

There would be quite some value in an original LTL w/H-S power I'm sure.

Supposedly, there is about 1600 or some ft. pounds of torque in my engine set up the way it is currently @ 1650rpm. I may have the governor adjusted little different to up that a little but don't have near a transmission that would take full load.

I will probably find something that will handle all I can give it but since this will only be a "play truck", it is not that large of concern right now. Shop floor space is becoming a premium and I need to move some stuff to make room.

Rob

[Lmackattack]

1600 seams low for such a large engine However I guess it was big power for its day. I guess it makes it up with the HP?

I have only driven a few DD 2 stokers and they never felt like they had much power. just alot of noise and alot of gears needed to make the noise LOL

[Rob]

1600 seams low for such a large engine However I guess it was big power for its day. I guess it makes it up with the HP?

I have only driven a few DD 2 stokers and they never felt like they had much power. just alot of noise and alot of gears needed to make the noise LOL

It is only 852 c.i.d. so not much smaller than an NTC Cummins. Don't really know what the Cummins engines of that era were rated for as I've never been around them much. I do know the Cummins, and Cat engines were not nearly as smooth running as this thing is. This engine probably would not vibrate a glass of water off the top of the blower housings.

Rob

[brutus998]

Rob this is an awesome project. Fred Sanders had a Superliner Conversion with a 12v 71 under the hood that he pulled the sled with. They ditched the detroit last year for a 998 mack.

You ever thought of putting an Allison behind the 12v? You would be impressed. There is a guy around where I live who fit(crammed) a 12v71 into a GMC General with an Allison Automoatic. I hear he dragraces it against pick-ups and whips on them. I just know there is always a lot of shifting involved with the old detroits. My great uncle has a 68 Kenworth with an 8v 92 Silver Series with a 5 speed auto and it will move up the road!

Good luck

Tom

[Rob]

Rob this is an awesome project. Fred Sanders had a Superliner Conversion with a 12v 71 under the hood that he pulled the sled with. They ditched the detroit last year for a 998 mack.

You ever thought of putting an Allison behind the 12v? You would be impressed. There is a guy around where I live who fit(crammed) a 12v71 into a GMC General with an Allison Automoatic. I hear he dragraces it against pick-ups and whips on them. I just know there is always a lot of shifting involved with the old detroits. My great uncle has a 68 Kenworth with an 8v 92 Silver Series with a 5 speed auto and it will move up the road!

Good luck

Tom

Hi Tom, the answer to your question is YES! In fact I have an Allison HT series transmission from an old Oshkosh airport crash truck. I've kinda slated that for my daughters' B-61 in the future though. She demands an automatic transmission, air conditioning, power windows, locks, cruise, etc...(keep this quiet). It is a divorced type transmission. I'm pretty sure it would handle the torque as it was powered by my D343 from the Oshkosh.

I'm going to try my RTO-12513 and see if it does alright. I don't plan to be hard on it and certainly won't work it as it was designed so hopefully it won't destroy itself.

Rob

[ciw65]

Hi Tom, the answer to your question is YES! In fact I have an Allison HT series transmission from an old Oshkosh airport crash truck. I've kinda slated that for my daughters' B-61 in the future though. She demands an automatic transmission, air conditioning, power windows, locks, cruise, etc...(keep this quiet). It is a divorced type transmission. I'm pretty sure it would handle the torque as it was powered by my D343 from the Oshkosh.

I'm going to try my RTO-12513 and see if it does alright. I don't plan to be hard on it and certainly won't work it as it was designed so hopefully it won't destroy itself.

Rob

Rob, those 125 series eaton boxes were pretty strong. I had an RTO 12515 in my White behind 400 cummins that put out around 1150 ft/lbs stock, but as mine was "tickled" up a little would have been closer to 420 and 1250 ft/lbs, which is max rating for that series box. I used to pull 35 tonne containers around with it and never had a wimper out of the box. The ol' detroit 2 strokes weren't big on torque so quite a lot of the 8V92TTA's at 475 only put out about 950 ft/lbs. We had a saying at one place I worked, "constant noise, variable power". If you're not gonna pull heavy loads and make the engine make full power, the 12513 should survive just fine. There used to be an old W model running from Melbourne to Sydney about 10 years ago that was imported from the States back in the late 70's. It was looonng wheelbase by our standards, 42 inch bunk, 4 tanks, and a 12V71T up the front. Sweet sound it made too. Very unique. I think it was only putting out around 600 hp tho.

P.S. When you get here to Australia, I am pretty sure I can get you a trip in a road train, just be aware that alcohol is the alternative currency. Lol.

[Rob]

Well the latest is the 12 is no longer attached to the alternator and an 8V-71 resides mounted in it's place. The V8 did present some problems from a couple of stuck injectors due to sitting, but with dissassembly, and lubrication, they freed right up. The rack was run and now all is well. The V8 was purchased from ebay for the flywheel housing, limiting speed governor, and ancillary drives necessary for on road usage, and was a known good engine. I was rather surprised that it only had N55 injectors installed, as I was told it was 340 hp.

I now need to run electrical to all of the sensors that were transferred from the 12 and get voltage to the exciter via the regulator. I will then load bank the set to evaluate how many kilowatt she will output with this smaller engine installed. I have a resistive bank that can readily absorb 400kw. The 12 is currently sitting on the floor by it's lonesome. More on that chapter later.

Rob

[vanscottbuilders]

Rob -

I've meant to say something to you for some time -

Jimmy spent about twenty years and close to a million miles

behind a DD 12V-71 with twin turbochargers in a W-900 Kenworth.

I can give you his e-mail, and his phone # if you want. I'm sure he'd

talk your ear off about the various characteristics of the engine in heavy use,

and the common problems he encountered along with the solutions he used.

The project seems to progressing through the "design & planning" stage nicely.

Paul Van Scott