A unusual R model Mack

I'll throw my. 02 in. Most likely that's a Chrysler Hemi. Believe it or not, in 67/68 Mack and Chrysler had a relationship between the two companies and built a bunch of these R models with gassers.

I only know this from attending an antique truck show one day and saw an R model wrecker with one in it and had to do a double take. The owner then explained the story of the Chrysler/Mack marriage.

 

That's either a Mack EN540 or a EN707, it is a mack built engine with dual ignition and a single carb on the top. I think it would be an EN540 because of the size of it, that is 540 cu ins.

I've got something like it (En707) hooked to a generator on a skid to pull it up on a trailer and drop off at drill sites, it is a pretty good and dependable engine but man parts are getting hard to find. Mine has LPG conversion because gasoline is a PIA to deal with.

I agree with the terminal block, that would be great to troubleshoot but the oil filter isn't a spinner, it is a cartage filter on that engine.

Edit - that would make one great little RV for truck shows.

 

The outfit my old man worked for the first 35 years he was in trucking and construction ran strictly Mack's, as I recall a lot of their older mixers had gas Mack motors, mostly B models, Then he glider kitted a lot of those up to R models during the time he was running their shop.

 

Never heard of the 540. 711 and 707 yes. @MACK E-6

On a side note the 300 maxidyne put down 1425tq at 1050 rpm way back in the days of the 1693 3408 early a model's........out of a 10.9L. It took yellow and red almost a 3rd more displacement to get those numbers and lots more rpms not to twist blocks apart.

 

Really cool, thanks for sharing! Never knew Mack made a gas job. That redundant ignition is pretty slick!

 

Isn't gas more easily flammable than diesel, though? Why the switch?!?