mackattack2

hi,

I was mislead on the model number of the truck that I recently purchased. It's not a LJT like the paperwork states or the photo of the data plate the seller showed me, but its a smaller 125LS per the dataplate actually attached to the truck. Does that make any difference with your recommendations above?

Thanks.

Steve

Here is a great PDF with all the models and engine specs from oldmacksrus:

http://www.oldmacksrus.com/Adobe_Pdf's...0%20Engines.pdf

The ENDT/LT 673 @205 HP had a torque rating of 560/590 ft-lbs from 1400-1600 RPM.

hi,

Great info. Are all the diesels listed there straight 6 cylinder configurations? And, from a dependability standpoint, is any engine there particularly better or worse than any of the others? I'm still trying to decide which diesel to upgrade to from my mutilated EN 707B gasser. Are there any engines that are definitely known to be a direct drop-in replacement without changing motor mounts etc?

Thanks.

Steve

MackAttack:

I thought that the Lanova diesel was available in the LJT. If it was - isn't it about the same physical size as the 673?

. . . .

I would suggest, before you do anything, you should find out what the LJT had for engine options and front axle choices from the factory. Then you can figure out what will really work well for you. It may be as simple as beefing up the front springs and plugging in one of the Mack diesels.

Good Luck with your project -

Paul Van Scott

Hi Paul Van Scott and Fred,

Thank you for your comments. I'm still trying to find some documentation to know what engine options were available for that truck. I have full air brakes, not hydraulic or air over hydraulic. And the windsheild wipers are missing completely so I'll just need to find or design an electric setup for them.

I have no intention of trying to make the thing pump water. In fact, I might take out the entire pump assembly. That would probably save a couple thousand pounds and open up a lot of useable room inside the cab. I could leave the control panel intact and if done carefully, no one would ever know the difference. And after I'm gone, if someone after me decides they want it to pump water again, they can put the pump back.

I'm not clear, is the 237 the same as an E-7 engine? And is the Maxidyne engine the same as the Mack 300 hp engine referred to in previous posts? Do the 673 and 711 and 237 physically all have the same external engine block dimensions? What kind of fuel economy or mpg can I expect with each respective engine, including the 673, in a lightly loaded truck? If a Chevy 350 gets 12 mpg, should I expect only 6 mpg with a 672 cu in engine?

My truck has a 5 speed, will that be a direct bolt up to any of these mack engines? Do the engines referenced above all use a no 2 bellhousing? I'm not really interested in the allison trans.

Fred, when you said "a 673 would be a almost direct bolt in for the 707" does that mean the engines use the same engine mounts? If so, that would sure make things easy. To me, the 707 looks unnecessarily massive, and that's with its manifolds and starter missing. Paul Van Scott, what engine and trans did you end up using for your B67 project?

Sorry for all the questions guys, but I'm trying to give myself a crash course education on Mack trucks.

Thank you for your help and a thank you to anyone I forgot to mention in this post.

Steve

Hey Steve, give me a call at work M-F 8-5 1-800-999-8972

I can help you on an "L" fire truck

I also sent you an e-mail

Hi Charlie,

I sent you a long email this morning, did you get it?

Thanks.

Steve

hi,

I just recently acquired a Mack 125LS firetruck. It's been sitting rusting away in a field for the past 16 years. I had a more detailed post about it a few days ago before the web site was hacked.

Where can I obtain shop service manuals and parts manuals on this or any L series of truck? I've tried "Walter Miller" but they said they don't have any for the L series of truck.

Your help in getting me started in the restoration of this truck is appreciated. Does mack carry parts for older trucks like this or must all parts come from third-party rebuilders and or cannibalizing other trucks?

I'll post a picture of the truck as soon as the new web site allows it.

Thank you.

Steve

Or if you want to keep it a little closer to purebred, ex-Postal Service Macks are going for less than $5000. They give you a 300 horse Mack engine, Allison automatic, and a bunch of other good stuff to swap into your classic Mack.

hi GearheadGrrrl,

That's definitely something I will look into. But any idea where I would find an ex-Postal Service Mack? I've watched for old Macks on eBay for years, and I've never seen one there. Any idea physically externally how big a 300 horse mack engine is compared to a 707 cu in gas Mack engine?

Thanks for the suggestion.

Steve

I have a good 673 Mack diesel, normally aspirated, with new fuel injectors and fuel pump tune-up. I also have a good direct drive (10 speed) transmission to put behind it.

I am using a 711 and a triplex transmission in my truck, so I will not be needing these parts.

If I got $1,500.00 for the engine & transmission I would be happy, and you would be well on your way to converting to diesel power.

The engine came out of a running truck, recently. It was changed for more power, as the truck is being used on the road to pull fairly heavy loads. The duplex came out of my own truck, and was operating fine when removed.

You are welcome to pick up the parts, or we can arrange delivery at a reasonable cost.

Contact me through this website if interested.

Thanks,

Paul Van Scott

Hi Paul Van Scott,

I'm still new to macks. Pardon my ignorance, but is a 673 Mack diesel 673 cu in or how big is it? Something from a modern cement truck, for example, would be too big to fit in the narrow L cab type engine compartment. What year and about how many miles are on it? Does it have the starter, alternator, flywheel, etc? Does the trans have the bellhousing, clutch, etc? What would be needed to install it in my truck?

And anything you can add to help educate me is appreciated. As a shade-tree mechanic my only experience has been with light and medium duty gas-engined GM trucks.

Thanks.

Steve

How about a Cummins 'B' series (Dodge) with an automatic transmission?

Get an older model with manual fuel, rather than electronic, and don't look back!

The older engines are 180-200 hp and fuel consumption is 10+.

That's what's going in my 'EG'. Done my home work (and own a 2004 Dodge) and for most playing around,

this might work!

Packer

hi Packer,

Thanks for the reply. Can you tell me any more details about this engine? What years were they used in Dodge trucks? How is a 'B' series any different from any other series? Is it turbo-charged? What year did they start to use the electronic fuel injection? (I definitely don't want electronically controlled anything) Were they also available with a manual trans? Will the newer NP 6 speed bolt up to them? How would I recognize the proper engine if I saw one say at a wreking yard?

Thank you for your opinion, it is appreciated.

Steve

Hi

I'm new here and new to macks, but not new to truck restorations. It has been a hobby of mine for years. Recently I purchased my first Mack truck. It's a mack LJT sedan cab fire truck. I would like to upgrade the engine and trans to something more up-to-date and dependable. As for the engine it has now, a big 707 cu in gas engine, I think it's too far gone to try to do anything with. The truck's been sitting in a field with no spark plugs and the manifolds and starter in the back of the truck for 16 years. This brings me to my question. What engine/transmission combinations do you recommend?

I do eventually intend to drive this truck, not just to local parades but cross-country too. I would like to upgrade the engine/transmission to a later mechanical diesel drivetrain. My first priority is dependability. I want an engine that wil last hundreds of thousands of miles between rebuilds. My second is economy. I'm not looking for the biggest engine I can stuff under the hood, but something very economical I can drive on a regular basis. Someone told me (a non-mack person) I should consider a cummins 5.9 as they are used in everything from Dodge 1 ton trucks to school buses to Ford F800's. But I've still got a lot more research to do before I decide on anything. What are your engine/transmission combination suggestions? For a transmission I want a manual, with really low low gears and very high overdrive with lots of powerband overlap so there is no possibility of lugging the engine between shifts. From what I've read, I don't want a twin-stick trans, but I do want at least 6 speeds or more. What are your suggestions and opinions on what I should be looking into? I won't be racing to any fires, but I might be occasionally pulling an airstream trailer.

And if you have any suggestions on where I can purchase parts manuals and shop manuals for this old truck, it would be appreciated.

Thank you.

Steve

hi,

I'm Steve. I'm new here and just registered a few days ago. I had posts going in three sections - the engine/trans section, the cab and bodywork section, and the fire apparatus section. Today I find my posts and their answers were all deleted, and my account has been cancelled. Did I do something wrong? I just reregistered again, but I guess I'll wait to hear from the admin before I post anything else.

Thanks.

Steve