Ray
Regarding the very long length of the big six, I can't find an explanation other than that it was designed in an era (circa 1937) when they needed a lot of iron to guarantee strength and it was intended for an application where weight wasn’t much of an issue. Also a diesel version was introduced a year later so maybe they wanted to be very sure it would be strong enough.

The post war version had revised porting with a port for every valve. (Six intakes & six exhausts)

Here is a cutaway:



By ortegren1924

what a monster..that's the type of over engineering that get's you a reliability reputation

I see that four of the mains are considerably narrower than the others...

There's a scrapyard somewhere that's got a truck with one of these in use, I got some pics sent to me once. I think it's in California.

I tried to post this spread sheet I made yesterday but the posting process scrambled it. So here it is as a jpeg (I tried 4 times to make the size correct but couldn't get to go.. help!).

The figures are for the last and biggest version of each engine type and the years are “car only”; nearly all continued much longer in trucks and industrial power plants. Also, the book (see earlier post) lists block length, but the early engines included the bell housing at the back and had an extended nose due to the chain drive generator, so they measure really long.
Check the cylinder spacing on the “Big Six”…lots of metal there!


URL=http://img216.imageshack.us/my.php?image=fheadspecspreadbw6.jpg] [/URL]

See if I can get a look at it with the bracket added...

Oh yeah, that's better. Over six inches up... does the flywheel shroud come into that too?

I didn't know the 8cyl had an offset wristpin...

Thanks for making this readable Ray!

I think that Chrysler was measuring the overall length of the block casting so the flywheel shroud would add a lot and those early engines had more metal in front as well because the chain to the cam also drove the generator, which had a tension adjustment. The block extended out in front to keep oil on this assembly, and to make a mount on the front cross member. They had a different idea about space utilization back then. Some sporty two seaters had 12ft wheel bases.
The rods in the eight are offset at the bottom so that there is more bearing on the side facing the center of the engine than on the side facing away from it. This was done to get the bores a little farther apart with out redesigning the whole bottom end. Apparently this was done to the smaller six cylinder engines as well, but then they got a complete redesign in 1937 that eliminated this feature. I haven’t ever seen the bottom end of an eight to verify this and my 1948 Motor Manual doesn’t mention it, so I can’t swear they had this right up to 1950, but it seems like they did.

Here is a picture of a model 77 six:
(I wish I could make these things come up the right size; I don't know what I am doing wrong)

Not much, Leif...

When you click on the line on Imageshack, you're selecting a 'thumbnail'... scroll down the page and look for the first one below all the ads and stuff... it's labelled 'Hotlink for forums (1)'.

Now, this offset business... this is where the big end is offset compared to the rod, to space the journal away from the main bearing, right?

I doubt that there's much compromise in that, is there?

Just as you say; the rod isn't centered over the bearing; it's toward one side so that the cylinder above it can be moved to get more room for a larger bore. Obviously this isn't ideal but you are correct about it not being much of a compromise. I think the biggest down side was that it required assemblers to pay attention because 4 were off set one way and 4 the other direction. Reading about this again I think I said it backwards before… "The cylinder centers were judiciously moved, resulting in the narrow 3.5 in spacing being increased to 3.625in, the intermediate spacing being reduced to 3.8125in, and 0.125in being removed from the center spacing to make it 4.0.”


From:
http://www.sae.org/technical/books/R-365

I had a chance to get a 50' 8cyl...now I wish I had...I'l love to see that bottom end!

Here's a link to some pictures of a '49 straight 8. You can zoom in and see the offset.
http://images.google.com/imgres?imgurl=h...rysler%2Bstraig

I just seen one of them big sixes like in that picture
http://img512.imageshack.us/my.php?image=77sixpt8.jpg
Its sitting in a barn here in Arkansas. The dude put a V-8 in the truck. It is maybe a 54 Dodge with 3 back windows. One in the middle and a curved window on each back corner of the cab.

How big is the one you saw? 48" overall? Did it have two carbs & duel exhaust manifolds?

I dont know. It was the first one I ever saw in real life.
The owner invited me over for bar-b-q so I guess I will have to take him up on it.

Take a tape measure. See if overall length is 48". See if the head is 30" X 9" and has 33 studs. See if it has 12 ports. Chances are it's not that big. Try to locate casting #s and let us know what you find. Here's pictures of mine. Thanks

http://picasaweb.google.com/sixpics/52DodgeBigSix?authkey=BZdrDZ3_kiY#

btt

How'd you get the chicken to perch on the yardstick?

It's her yard stick. She just let me use it.


Thanks Tim!

Almost three months since anyone's posted anything on this forum... so I'll break the ice:



Reckon this truck featured one of these big sixes, right?

What a great shot of MOPAR classic trucks! In '59 my dad and I hauled our family's worldly possessions from Texas to California In a '52 Dodge 1/2 ton 3 speed pulling the biggest Y'ALL HAUL trailer we could get. Other than a few blow outs and vapor locks we had no trouble. We were way overloaded and could not do the same thing today. The trailer had no brakes. Stuff tied on the outside and my Cushman riding on the tongue. The small 221 had torque I can not imagine what the 413 could do. Beater

Does anyone know if the Imperial big six is the same engine as the truck big six? Did all the Big six's have a twelve port block?

Yeah, it's good...

I pulled three pics from a Powerpoint series of pics of this sort of thing I got with an e.mail yesterday. There were Fords, GMCs and Studebakers as well, maybe even something else.

e.mail me (raybell@racingphoenix.com) and I'll send it on... in the meantime, here's one of the others I did salvage, more Mopar inliners:

That car hauler is great. Made when design mattered. I fell out of an old Dodge four door when I was about six. Suicide doors earned the name. Once they are open on the highway it's hard to close them.

CC, I don't think all of them were 12 port. I know that intake and exhaust had different orders on some engines. There is more information here but the search feature is hard to use.

Good question...

I saw this suggested for the first time yesterday, but I'd like to know whether it's right or not.

Based on those specs, it looks very different.

While the Imperial 6 may have been used in some trucks the 413 truck engine is far too heavy to have been used in a car. I have some more truck specs I'll try to post.

This may help out., http://www.allpar.com/mopar/flat.html

It didn't...

It's clear that the writers of those pages knew less than perhaps they should have before they became authors of such a thing.

For instance, when putting a '59 six into a '48 model (one speaks of doing this and needing to change the flywheel), you have the issue of the number of flywheel attachment bolts to deal with.

Anyway, the page does say that the 265 inch version of the long block was the biggest six used in a Chrysler automobile. I think there was maybe something back in the late twenties that was bigger, but that was from the ZSB family of engines.

Long time no post on this topic but will give it a try anyway.

Got a line on the smaller 331cu" big six. But of course not much info on these floating around.

Mainly concerned over the weight of these monsters, as would be finally put to rest in a custom P15. Of course anything will fit anywhere given the will and $$.

But I need to ship this bad boy from the right coast out to SoCal, unless anybody has a lead on a more local complete unit.

Anyway, since you've had your hands on one, what do you think it might weigh? I've read anything from 1,500 lb to 500lb.

This pic was from this site sometime ago. 413 cu in?


regards,Rod

That's mine. I don't know how to link to threads on this site but here is the name of a thread with links to more MOPAR flathead info. Maybe you can cut and paste it or search it.
Chrysler Industrial & other big Mopar Flathead 6s

And this: '50s Dodge truck 2X1 manifold & duel exhaust.

My big six weighs closer to a ton than to 500 lbs. It was all my '89 GMC 3/4 ton wanted and much more than I'll ever put in my '53 1/2 ton again.

Ca'nt find the first one you mention, but here is the one where you haul it home.
Somewhere I have more pix of it, just have to search a bit harder.
Your picture link (Picasaweb)in the thread is now dead, so unless you post a new set,no-one can see them.

"50s Dodge truck 2X1 manifold & duel exhaust."

CLICK HERE

regards,Rod

OK, here's the other one.
LINK

Give us some dimensions Beater, how long is it from where the bellhousing mates up, to the front of the water pump flange, and how tall from the bottom of the oil pan to the top of the breathers.

Strictly a truck engine from what I can find.,
Larger trucks used another family of in-line flathead six cylinder engines. There was a 331 cubic inch and a mammoth 413 cubic inch lugger was available in the T series and up. There may have been another engine in the 370 CID range, but I am not sure about that. The 331 was highly regarded in trucking circles as a durable, hard working engine. The 413 was equipped with two single barrel carburetors and had a very large appetite for gasoline. It was noted for twisting the drive sprocket off the end of the camshaft.

Original is at Chrysler's Flathead Engine http://www.allpar.com/mopar/flat.html#ixzz2IiskQHYf
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For sure a heavy truck engine. From what I have found the 331 is just two clicks below the 413 and appears to have the same outside dimensions. The in between is 376.9. They all use the same size bearings. The 331 has a 3 3/4 bore and a 5" stroke. 280 ft lbs at 1600 rpms. It would be legal in the FX classes.

Some 413 specs:
Bore& Stroke 4 1/16 X 5 5/16
413 ci
171 hp @ 3,200 rmp
424 ft. lbs. @ 1,200 rpm
8.5 to 1 CR
12 ports
head 9" X 30: 33 studs
Overall length Dampener to trans 48"
Bell housing to timing cove surface 33 3/4"
Pan sump to top of carbs 34"

Why didn't Chrysler just use this two carb'd 413 rather than go through the time and trouble of designing the bent eight that they did use in their 300 series cars in the sixties?
Was an oil filter that important? Or, was it too hard to rig up power steering to the six? I mean they only picked up about 200 ft/lbs, and it cost them another valve cover to do so.
I guess thats why they never made it to # 1 or even #2 in sales-too many poor upper management decisions -- Walter P. must have been on vacation that day.

A car chassis would not keep the pan off the ground. Power steering is no problem it ran a two cylinder air compressor for brakes that mounts to the left front of the block. It weighs about 100 pounds. I need to get back to the car museum in Reno and take a better look at the White Flyer. It has a 500+" four cylinder! Some of our members volunteer there and Al Abrams is the guy who got the White running for the Pebble Beach Concourse.

White-Thomas what the heck?

Beater, I found a vehicle for your big 6,

I think this is a small 6 but just make bigger retractable skid plates.

I like it. The cheapest thing to run at Bonneville is a bike.

You can put a sidecar on it and you and jalopy can cruise around in the pits.

He's get sucked into the 6 S&S side drafts!

Not as l as long as I got the margarita maker in my lap. Here's where the pic came from. http://geekbobber.blogspot.com/2013/07/plymouth-monster.html

Maybe we could run it on margaritas. My engine is almost twice as big as the Plymouth so we could try for 600 mph. I wonder if they ever actually ran it and how fast it went.

SOOOooo...
...did it do 300?
200?
100?

Says 180 MPH over at: http://justacarguy.blogspot.com/2014/04/the-plymouth-lsr-land-speed-racer.html

It did 180 MPH in second gear and then threw a rod so the potential was there even if the courage wasn't ..

Go in any bar in the country where there are more than 2 motorcycles parked in front and eventually you will hear 200+ mph thrown around like they really understood what 200 mph is. 180 on that monster with a loose rod looking for the exit would be enough to make most question their commitment.