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That 440 235 HP Motor Home Engine

Auggie56

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Stopped by the machine shop I have used in the past. So I have some faith in what the man says. I told him what I have, and what I wanted when done. Pretty much a toy that sounds good, and not really a giant killer. He suggested that I replace the pistons with notched ones, and take thirty thousands off the cylinder heads, to increase compression. He suggested a cam, but I don't recall the spects he rattled off to me. Also suggested a high flow intake. He said some of the heads on these engines are respectable as far as flow goes. But he needs the numbers off them to tell me which ones I have. He's a Mopar man, and said the bottom end and rods in these engines are pretty good. Since I'm going with new pistons, and value in putting bigger one's in ? What do you guys think ? Any suggestions ?

Thanks
 
The man might be onto something.
In 2001 I built a nice street 440. The block was a 78 from a New Yorker. The cylinders had almost no taper so The machinist just honed the cylinders. I put in new rings and bearings. The heads were milled .050. The block was decked .010. This resulted in the compression rise to 9.2 from the advertised stock # of 8.2. I slipped in a Mopar 280/474 cam, an Edelbrock Performer RPM and a Holley 750. With 1 7/8" headers, the car idled nice with a decent rumble, got decent mileage and ran real strong. I figure it had to be at least as powerful as a stock 440 Magnum even with about a half point lower compression. The bigger cam, headers, better intake and carb probably added 30-40 HP over stock. I liked that engine but had to have MORE, so I built a .030 over 440 with new pistons and aluminum heads. That engine threw a rod at 846 miles!
 
What is the difference, decking or just milling the heads ?
 
I used a motor home 440 in my 71 satellite, I wouldn't do much to it. All I did was put new valve seals in it and a set of headers with eldlebrock 4bbl would run 14.70s in the 1/4 all day. While not fast by some standards it was a fun good sounding car like you described you wanted. I think I may have put a Mopar Performance. 0.484 lift cam also.
But unless you want to run premium gas and go faster than that I was happy with the low compression motor. Also a high flow intake usually kills low end torque which in my opinion takes away from the fun In street driving.
 
What is the difference, decking or just milling the heads ?

I'm not sure. In both cases you are increasing compression. Often times, a block is square decked to ensure that each piston is the same height in the bore at TDC. Thicker decks make for a better head gasket seal. I was following the advice of Mopar Muscle magazine.
 
What is the difference, decking or just milling the heads ?
auggie, decking and milling are simply machining operations done to achieve a certain dimension of design and to get a proper sealing surface, but extra material removal equals a increased compression ratio of choice, up to a point. I would recommend just a light cut on the decks to achieve a good sealing surface with the same height as well as the heads and you wont then have to have the intake and block runners machined also! Now for your mechanic of choice, changing the flat top pistons to notched pistons means simply that you have low comp/height pistons as a later model and or a truck engines had and they were if I remember correctly around 7.8 or8.2 c/r and didn't need valve reliefs because they were quite a ways down in the hole. pistons with valve reliefs and that come to the top of the deck at tdc will have all the compression you want for street. I would hold back on a lot of cam and would just use a old edelbrock dual plane. need to make sure what heads you have too as they will also effect compression. oh yeah, if you take much off the heads and deck you will need shorter push rods. there are many guys on here that can quote the comp ratios without doing research, I just can't remember any more like I used to. DO YOUR OWN RESEARCH! and good luck keep it simple, buy some bb mopar books.
,
 
F irst thoughts..If you atre changing pistons, Don't go to the expense of decking block and milling head, just use the right pistons to increase your compression ratio, taking the thickness of your head gaskets into consideration. Use a thicker style of gasket to compensate for any slight variations in stock deck and heads.......................................MO
 
Factory Chrysler decks are usually sloppy and higher than spec. It's not always a killer but they should be checked before a decision is made. Measure them right now before disassembly so you know what you have, check the 4 outer corner pistons. Then make an informed decision. I'd shoot for 9.5-1 actual unless you're not replacing piston's. If you use the original pistons you won't get to 8-1 without decking /milling.
Doug
 
Factory Chrysler decks are usually sloppy and higher than spec. It's not always a killer but they should be checked before a decision is made. Measure them right now before disassembly so you know what you have, check the 4 outer corner pistons. Then make an informed decision. I'd shoot for 9.5-1 actual unless you're not replacing piston's. If you use the original pistons you won't get to 8-1 without decking /milling.
Doug

Doug, I was thinking that using notched pistons, were for the higher cam lift, and the closeness of the valves, after plaining the heads.

- - - Updated - - -

Thanks for the input fellas.
 
I have a 1978 440 car engine. I don't remember the specifics now, but the top of the flat top piston was a bit down below the deck at TDC. I increased the comp. ratio to about 9.5 to 1 by useing closed chamber heads and a steel shim head gasket . the head surface was milled just enough to assure it was not warped................................MO
 
Doug, I was thinking that using notched pistons, were for the higher cam lift, and the closeness of the valves, after plaining the heads.

- - - Updated - - -

Thanks for the input fellas.
Pistons may have nothes for piston to valve. The major difference is because the compression height is greater. C/H is measured from the pin centerline to the piston top. compare these.
https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=440 mopar pistons
Make a plan. either stock piston low compression, or new pistons. shoot for 9.5-1 with iron head. Aluminum heads can go 10,5-1 or higher with a larger cam. Most .500" cams will clear the stock low compression piston with no notch.

Doug
 
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"closed chamber heads" Are they the ones without the wedged shaped chamber ?
 
"closed chamber heads" Are they the ones without the wedged shaped chamber ?

Close chamber heads will have the side of the combustion chamber across from the spark plug level with the deck surface.
Doug
 
All big block engines had WEDGE heads except the HEMI. The vast majority of them were open chamber style.
I've wondered why Chrysler went away from the closed chamber design back then. For 1966 and 67 they had the '516 and '915 casting heads with the closed chamber but went open chamber with every head after that. Closed chambers promote better combustion with more swirl effect, doing it withless risk of detonation due to quench.
 
All big block engines had WEDGE heads except the HEMI. The vast majority of them were open chamber style.
I've wondered why Chrysler went away from the closed chamber design back then. For 1966 and 67 they had the '516 and '915 casting heads with the closed chamber but went open chamber with every head after that. Closed chambers promote better combustion with more swirl effect, doing it withless risk of detonation due to quench.
IIRC it was an emmissions thing............................MO
 
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