Mack Gas Engines ?!?!?

[B61TENDT711]

I haven't heard of Mack producing Gas engine's but i would like to learned anything about them . . .

I also have never seen any of them if you got Mack Gasser photo's please post them.

Specs: cubic inches number of cylinders Inlines V's ect i'd love to see and hear about them.

Mike

Edited October 31, 2009 by B61TENDT711

[B61TENDT711]

I did a few dozen google n yahoo and even ask searches i can not find anything dealing with or related to Mack Gas engines. . .

I was chatting with a friend and even he don't even remember seeing a mack powered by nothing other then a Diesel engine. ..

Was there no such things as a Mack Gasser ?

Mike

[ThaddeusW]

Yes there were a few gasoline engines made by Mack. The biggest is the strait six EN707. I think the 707 block is very closely related to the 673/711 block. But insted of an injection pump you had two distributors and a carburetor on the intake. None of the gassers were turbo.

There were smaller strait six and V8 flat head gassers. The EN404 is one. I am sure many others here can provide more info. Oh and Mack also used a Chrysler V8 big block in some of their trucks. Someone has an R400 powered by a ChryslerV8, all factory original.

[Allison]

I have a EN 707 gas engine in my 1957 B-model. Straight six .... monster.... reading this post makes me ask a question. Mine is dual ignition. Were all the 707's dual... Im also in the process of ordering new distributor caps, rotors, wires and plugs. As i ordered the plugs i used the specs right out of the manual and they actually turned out to be two different parts numbers... wonder why??? Actually in the manual if i remember corectly they referenced a # 18 for the right side and # 16 for the left side. And from what i have heard they are damn good motors....!!??

Allison

[B61TENDT711]

EN707 ?!?!? my 711 is 707CID so i basically have a High compression gas engine ? . . . that some one creatively Turbo charged

Mike

[ThaddeusW]

EN707 ?!?!? my 711 is 707CID so i basically have a High compression gas engine ? . . . that some one creatively Turbo charged

Mike

No, the 711 is a diesel engine. The 707 is a spark ignited gasoline engine. None of the gassers were turbo.

[Packer]

Go to oldmacksrus.com

Lots of info there!!

Tom did a GREAT job!!!!!!!!!!

Packer

[B61TENDT711]

I know the site I registered my 59' B61T there back in 01...

I never thought about looking for Mack info there...

Mike

[HK Trucking]

I have a EN 707 gas engine in my 1957 B-model. Straight six .... monster.... reading this post makes me ask a question. Mine is dual ignition. Were all the 707's dual... Im also in the process of ordering new distributor caps, rotors, wires and plugs. As i ordered the plugs i used the specs right out of the manual and they actually turned out to be two different parts numbers... wonder why??? Actually in the manual if i remember corectly they referenced a # 18 for the right side and # 16 for the left side. And from what i have heard they are damn good motors....!!??

Allison

I think the dual ignition is a fire truck thing. Sort of a redundant system to ensure that the engine doesn't quit due to an ignition problem while at a fire scene.

[HK Trucking]

Yes there were a few gasoline engines made by Mack. The biggest is the strait six EN707. I think the 707 block is very closely related to the 673/711 block. But insted of an injection pump you had two distributors and a carburetor on the intake. None of the gassers were turbo.

There were smaller strait six and V8 flat head gassers. The EN404 is one. I am sure many others here can provide more info. Oh and Mack also used a Chrysler V8 big block in some of their trucks. Someone has an R400 powered by a ChryslerV8, all factory original.

There were the EN330 & EN331 straight 6 flathead gas engines, one of those was actually a Continental engine, I can't remember which one.

Then there were the EN401 & EN402 straight 6 flathead gas engines.

The EN414 was actually a Chrysler 413 industrial overhead valve gas V8.

Then there were the EN540 & EN707 overhead valve straight 6 gas engines.

Mack never produced a flathead V8.

.

[HK Trucking]

EN707 ?!?!? my 711 is 707CID so i basically have a High compression gas engine ? . . . that some one creatively Turbo charged

Mike

711 diesels were all non turbo when new. The turbo upgrade was available dealer installed in the 60's as a way of reducing the chronic head gasket problems that the 711's were experiencing.

Rob has a turbo 711 in one of his B models.

I bought a turbo 711 from a junkyard back in the 80's and put it in a B613T that I had made into a single axle dump truck. That engine had a lot of power. Sounded nice too with that big Schwitzer turbo on it.

.

[B61TENDT711]

Yea they do have a uniquely unique sound them 711 turbos do...

My 711 diesel has a turbo charger on it the guy I bought it from had it added.

This why in my sig lines I always list is as a END+T 711 as the T was added after the fact.

When it was rebuilt 12years ago they dynod it at 315hp at the fly wheel.

Which I thought was a big jump from 211hp but then again its a turbo charged non turbo diesel so I guess cranking up the fuel n adding some boost I guess its possible.

All I know is the beast tow 100K n not bat n eye.

Mike

[Rob]

Yea they do have a uniquely unique sound them 711 turbos do...

My 711 diesel has a turbo charger on it the guy I bought it from had it added.

This why in my sig lines I always list is as a END+T 711 as the T was added after the fact.

When it was rebuilt 12years ago they dynod it at 315hp at the fly wheel.

Which I thought was a big jump from 211hp but then again its a turbo charged non turbo diesel so I guess cranking up the fuel n adding some boost I guess its possible.

All I know is the beast tow 100K n not bat n eye.

Mike

If you have 315hp with a 711 at the flywheel and the thing will hold head gaskets, you are doing better than five others (besides myself) could. I could just break 312hp, (calculated) before blowing the head gasket between #2, and #3 cylinder four times before giving up on the project. All clearances were well within spec.

I have two 711 engines that have factory conversion turbocharging kits installed. One is a 1964 B-61S, the other a 1962 B-67ST. The former uses a Garrett, the latter a Switzer that is huge.

I've don't have the B-67 running as of yet, nor home. The acquisition process was finished just this morning. It has been sitting in the same spot since August, 1999 without being started.

http://www.bigmacktrucks.com/index.php?showtopic=10771&st=0&p=40784&fromsearch=1entry40784

Rob

[B61TENDT711]

Like I said I'm not betting the farm on it truly making 315hp that is just what the shop technician told me.

I got 6.38 gears and my rev's threw the gears float between 2200rpm n 1600rpm.

Rap it up to 2100-2200rpm shift it drops back to 1550-1650rpm.

I'm never hard on the throttle tho ease on it then ease off it.

With them 6.38s n 12.00-24 tires it rolls 65mph@2000rpm.

Mike

[Granite]

I have a B85 with the 707. Duel Ignition as well.

And I have a B475. Has a 354 Chrysler Hemi.

I think only 50 where made.

[Greg Rider]

There were the EN330 & EN331 straight 6 flathead gas engines, one of those was actually a Continental engine, I can't remember which one.

My A30 has a flathead 330. I've seen it refered to as the EN331 in some books. My paperwork from Mack says it displaces 330 cubic inches. Rob,Larry,and B61 Fred have seen it and Rob even wondered if it was a Continental engine till I showed him the old Mack logo in the block. I think that the similarity in the engines is just the displacement. I have heard about Chrysler engines used as options including the 392 Hemi. I think 401 was the biggest flathead Mack engine.

[B61TENDT711]

any chance of the EN331 being a Reo engine ?

My 1953 studebacker M275 Has a Reo-331 I-6 gas and the intake/exhaust manifold assembly says on it "golden comet power"

Mike

[Speed]

My 1945 EH model has an EN354 flathead six;the parts clip I got has an EN354 too,but it's a Re-Con REO overhead valve six. At least it's tagged as a 354.

Speed

[B61TENDT711]

My Reo-331 isn't a flat head. . .it just seems like an awful lot of truck builders used the Reo Gas engines. . .

Mike

[Packer]

Some where in the dark places of my mind I remember someone telling me that

after the Second World War, many, many old vehicles were re-engined with surplus

engines.

When the old flatheads gave up, OHV engines were cheap and higher HP.

White, REO, etc, replaced the old Mack flathead.

I have a 1948 'EH' with a REO engine, and that's how it was explaned to me.

Packer

[B61TENDT711]

I bet them Gas engined Mack's are nicer to drive no splitting. . .just clutch n shift maybe even shift no clutch

Splitting the Thermodyne so you didn't split the Thermodyne stick your arms threw the steering wheel and start grabbing gear, hoping you never hit neutral on both sticks at the same

Mike

[Speed]

I bet them Gas engined Mack's are nicer to drive no splitting. . .just clutch n shift maybe even shift no clutch

Splitting the Thermodyne so you didn't split the Thermodyne stick your arms threw the steering wheel and start grabbing gear, hoping you never hit neutral on both sticks at the same

Mike

My truck has a 5 speed w/direct fifth and a 3 speed Brown Lipe 6031 with overdrive high. It shifts pretty much the same as the boxes on the diesel models,no syncronisers,etc.;the hard part of splitting on the gas jobs is the engines pick up and lose revs faster,so it's harder to match rpms. Other than that,same game.

Speed

[B61TENDT711]

Really ?

I figured with the Gasser you could just pick your range and bang gears 1-2-3-4-5. . .

Thats how i was taught to drive the IHC Gas engined truck's, pick your range and shift. . .

at least missed shifts on the gas engine don't = crank case full of coolant

Mike

[dockmen027]

In the late forty's and early fifties, my Father owned several Brockways with Continental gas engines, He was talked into buying a Reo Comet gas job and never liked it, removing the Reo engine, He replaced it with a Continental. Still unhappy with the Reo, which he had lemons painted on the hood, he sold out and went to work for somebody else.

[B61TENDT711]

Really ? . . .

The Reo gas engine in my Studebaker 2.5ton 6x6 runs great pulls like no other Gas engined big truck had ever seen, most of the gas powered trucks i've owned in the past where high revving slow moving Gutless dog's, and this beast totally changed my thinking on Gas engines and large trucks.

I'm used to driving F700 Ford's with 351 n 361 V8's or C60 n C70 GM's with 350 n 427 V8's . . .

I found the only Gasser's that performed well where the GMC Big Block V6's, the IHC 345's n 392's and this Amry surplus Studebaker with the REO-331 I6.

I haven't owned a Mack Gasser but i'm sure after running Mack turbo diesel's i wouldn't be impressed by them. . .

Mike