Hi Guys! New guy here and I have a few questions about a 1972 motorhome engine I have. Its was pulled from a 72 dodge swinger(which has been in the family for decades) and its a virgin with only 18,000 miles on it.

The motorhome is retired and this is eventually going to go into a 1951 dodge pickup, but I have some questions first.

It is one of the commercial engines by the way with a factory holley 4 barrel. the plan is to change the entire top end, but I want to learn a little about it first, so onto the questions.

How durable is the bottom end in these? Are these cast crank motors, or steel, and what about the rods and pistons?

From what I gather, Im best off with the 915 heads to be able to make a little compression, but does anybody actually know what the factory compression is on these things, as well as where it will end up with the 915 heads? Pump gas is a must.

Ive heard about reverse rotation cams being used. Any way to tell if thats what this is before pulling it apart?

Will any of the valvetrain in the current heads work? Im most concerned about the rockers. Do these weird heads use the same shaft rocker setup as the conventional heads, or do I have to replace all of that also?

Lastly....Ive heard it said that these wont bolt up to the later autos, but its actually bolted to a 727 auto now with the E brake on the tailshaft of the trans(factory trans also with 18k miles).

If there is any difference in the crank or anything, am I going to have issues getting any off the shelf converter to fit? Or is the converter in there "unique" to this package. If so, what needs to be done to ready it for any aftermarket off the shelf converter?

Thanks folks!

Hay Greg .. that is a 413 ....

and LOTS can be said ....... but it all can be boiled-down-to just keeping the shortblock ....and putting the smallest-chambered heads you can find on it. For a rat-rod/street-rod ... and set of shaved 516 heads would work grrr8!

I have one of these in a 70 model and if yours is like mine it will have a steel crank. Don't believe there is any such thing as reverse rotation cams in these. However some of them I believe have a reverse flow cooling system. They have strange looking heads, nothing like passenger car heads. If you have the original torqueflite that came with it I believe there will be some heavy duty hemi parts in it.

Roger

There WERE reverse rotation marine engines for applications where there were two engines in use. One powered the right prop and the other powered the left. If both spun the standard rotation, the ship would want to pull to the right ALL THE TIME!

If you want to hot rod that truck, strip the 413 to the short block.
If the truck is going to be a cruiser or just a run around toy the engine will work great as-is. That engine will have TONS of low end power but the heads aren't going to make big power up top.
If the truck is going to be at cars shows and such the current configuration of the engine will add a nice touch of "different" under the hood. It will be a nice change from all the other engines in the show field.

Unless you're going to race it, I say run it like it is.

To clairify Docs reply,
the 413 truck/MH motor with the gear drive does have a cam that rotates in reverse, but, it's not the same cam as the reverse rotation Chrysler Marine 413/426/440 motors. Both cams rotate backwards but only the marine motor runs backwards. RightHand is reverse, LH is std.
The reverse rotation marine motors were also used it single engine applications, not only in dual engine boats. The reason is when there is only the driver in the boat and their weight tips the boat to one side when under way, the motors rotational torque is used to level the boat back out.

Thanks fellas. This confirms most of what I've read so far.

As for the title....it was a typo. I meant to put 413, but apparently was typing faster than reading! Im unfamiliar with this particular "industrial" engine, but we definitely have mopar blood in the family and wouldnt have made that mistake under normal circumstances haha.

guess I'll have to dig in and see for sure whats in there for the cam setup. In all honesty...it'll be easier to mock up for building the motor mounts with the whole top end off, so I guess its time to dig in regaurdless.

Still curious about the valvetrain though. The rocker setup is my biggest concern. Ive found that most everything else is uncommon(longer pushrods for example) but it would be great to be able to at least use the rocker setup in this set of heads on another for the time being. Anybody know if its compatible?

also is there any machine work needed whatsoever on the front of the block to just swap to a regular timing chain?

We definitely intend to add some horsepower to this thing. The truck is heavy for sure, and it will be driven also, so no expectation to break records or anything, but a reliable driver that could run bottom 13's would be excellent for this heavier truck.

Thanks again!

If it has a chain no difference. If it has the timing gears the cam and dizzy rotate backwards just swap them out. the cam and the gears have to go together.

Thank you guys very much!

Lets say I find that this does turn out to be a reverse rotation setup......does this have any effect at all on the oil pump?

Forgive that newby question, but I wasnt sure if this was going to spin the distributor bacwards, and in turn the oil pump also....or if this is a non issue.

I should actually have more than enough room to use the oil pan thats on the thing. Clearance isnt much of an issue in this truck, hence the reason to keep the stock pan, pump and pickup if nothing funny is going to happen with the pump.

NO on the oil pump .... the distributor drive gear is diff. And if you use the stock pan ... best to add a bunchObaffles and a tray.

So the stock pan isnt anything to write home about I take it?

And just so I follow...A "normal" big block distributor with a standard rotation camshaft/timing setup wont create issue with the stock pump?

Thanks again!

No on the stock oil pan. Some were 4 quarts capacity. You would want an oil pan with at least 6quart capacity. I believe the Hemi and 6-pack motors used them. They should still be available. Cheap insurance and works well with Doc's recommendations for the windage tray and pan baffles.

If you are not planning on racing the 413, you may consider these pistons. You may be able to have a small valve relief cut in them to. This will give you more head options to. cast piston tho, but in different bore sizes


http://cgi.ebay.com/ebaymotors/Dodge-Chr...=item27b2b7eeba

I had a 73 Winny with a 440 with a TQ. It had timing gears and sounded like it had a roots blower on it when I revved it up. It was a great engine.

I can't believe the 'just get a 440' tirade hasn't started yet!

Somebody else said it, I also think the Industrial water pump/head setup would look kinda neat in an old truck. Could get the cam reground by Bullet, if they can do reverse-rot cam lobes.

Here's a bunch of links for more reading...

https://board.moparts.org/ubbthreads/favl...amp;postmarker=
https://board.moparts.org/ubbthreads/favl...amp;postmarker=
https://board.moparts.org/ubbthreads/favl...amp;postmarker=
https://board.moparts.org/ubbthreads/favl...amp;postmarker=
https://board.moparts.org/ubbthreads/favl...amp;postmarker=
https://board.moparts.org/ubbthreads/favl...amp;postmarker=
https://board.moparts.org/ubbthreads/favl...amp;postmarker=
https://board.moparts.org/ubbthreads/favl...amp;postmarker=

Thanks for the links. I'll be reading up when I get home tonight!

Truth be told...it sure would be nice if this one were a 440. However, the reason for going this route is because we know the history on this. The motorhome has been in the family forever with my grandfather, and its always been well maintained. Doesnt smoke, holds good oil pressure, and doesnt even have 19k on the clock.

Finding out that its a steel crank motor for sure is nice also....which basically means we have a good enough shortblock to start with and didnt have to spend any money on it!

Not sure what direction things will go "just yet" though. From what I gather...its a dished piston motor with rather low compression. Without knowing for sure how big the dish is right now, I have no clue what the final compression will be with a closed chamber head.

Id sure hope to be able to abduct bare minimum 9:1 compression out of it, if not closer to 10:1, but something tells me thats wishful thinking.

It might be necessary to either re-evaluate the goal for this particular shortblock.....or just say the heck with it and have the block checked to see if it can go .060 and order up some 426 wedge pistons and do it right. We shall see.

Strongly considering a set of those 440 source stealth heads also. They look like a good option for an under 500 horsepower deal for the price unless I really get lucky and find a set of prepped 915's at the right price.

Keep in mind, aluminum heads require a higher CR due to the greater conductivity of alum, they draw more heat out of the combustion chamber. Stealths would require a chamber even smaller than -516 or -915 to compensate.

IMHO, if you decide that you want to go the piston route, it's time to eval whether a different engine becomes a better idea. If you're gonna go with pistons, perhaps a stroker crank of the right size can bring your existing pistons up to quench specs? Either way, there's $1000 easily and a lot more work. And you lose some of the mystique of it being Grandpa's engine.

I'd probably find a good set of -516 heads, conventional water housing/pump, mild cam, small carb, and run it. No need to spend $thousand$ when you don't have to.

no doubt about that. Right now im just "daydreaming", but no big decisions will be made until the shortblock is bare and I can verify what Im working with.

No clue where the deck height is on this thing and if quench would be reasonable as is with the right gaskets, or if it really needs work, and/or different pistons. Also no clue what compression will even look like. Even with a closed chamber head...my gut tells me still on the low side....but I wont know til I get in there and find out.

Sort of just window shopping everything at the moment but probably wont get inside the engine for a couple weeks til Im on vacation.

Then again....I gotta yank the trans in the street/strip car to try out another converter I have that week also, and the mrs. wants me to spare a few of my time for her also, so who knows if we'll even get going on it then!