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-   -   516 heads on a 440 (http://www.moparchat.com/forums/showthread.php?t=86952)

custom880 11-16-2004 07:04 PM

516 heads on a 440
 
I have a low compression 1978 440 that i want to use in a Belvedere. I dont want to throw a ton of money at the motor. I am thinking of using a set of 516 closed chambered heads to bring the compression up a bit. Does anybody know how much the closed chambered will help the compression? I believe the motor gets somewhere around 8:1 right now. The pistons are way down in the cylinders when you bring it up to TDC. The 516's will have the bigger exhaust valves installed. Any ideas?

MoPaul 11-16-2004 08:12 PM

http://users.erols.com/srweiss/calccr.htm
This may be a good reference for your calculations and help you select the right head. My '76 440 pistons were sitting .153 in the hole when stock, so yours should be around there. Hope this helps.

lenweiler 11-16-2004 10:37 PM

Even with a larger ex. valve, you'd be giving up more performance than gained with the higher compression with the '516 head. Besides, they are pre-unleaded.

custom880 11-17-2004 08:41 AM

Quote:

Originally Posted by lenweiler
Even with a larger ex. valve, you'd be giving up more performance than gained with the higher compression with the '516 head. Besides, they are pre-unleaded.

I am not to worried about the performance. I am going to turn the car around quickly. The engine came out of a 1978 Motorhome. The Belvedere has a six in it right now. I could easily put a 383 in with 906 heads, but the 440 I got for almost nothing, and the 383 I would have to build. Besides around here the word 440 generates lots more interest than 383. People are nuts about 440's and I can get more money for the car with the bigger motor even if it's not that much of a power plant. The 516 heads are goig to be redone so I will have hardened seats put in.

DartGT66 11-17-2004 08:45 AM

Before even thinking about it, measure the chambers of the 516's. there is a good chance that they aren't that much smaller than your current open chamber heads. Like said above, they have a different port design and will flow worse than the later heads with similar port work level. The factory ratings of CR's are a big joke, normally they aren't very close. In a typical late 440, the pistons are about .018" below the deck at TDC, with typical open chamber heads and a factory steel shim gasket your CR will be around 7.5:1. The last set of 516's I measured had 84cc chambers, bolting them on would raise the CR to 7.8:1. At those lower CR levels you have to make a big difference in teh chamber size to really make an effect on the CR. The way to go is to get new higher compression height pistons.

Rug_Trucker 01-28-2005 11:58 PM

Last time I talked to a machinest they said don't worry about the harded seats. Evidently the new unleaded gas isn't hard on the seats as the original stuff. I see you are in Port Charlotte! I just moved back here from 9 years ago. Was in Tennessee. I brought my collection of Mopar parts with me. I overloaded the Penske rental truck with all that iron. :evil: I bet those 516 heads give a great seat of the pants low to midrange ZOOM!

custom880 01-29-2005 09:12 AM

Quote:

Originally Posted by Rug_Trucker
Last time I talked to a machinest they said don't worry about the harded seats. Evidently the new unleaded gas isn't hard on the seats as the original stuff. I see you are in Port Charlotte! I just moved back here from 9 years ago. Was in Tennessee. I brought my collection of Mopar parts with me. I overloaded the Penske rental truck with all that iron. :evil: I bet those 516 heads give a great seat of the pants low to midrange ZOOM!

Yes I have heard the same thing. I have a set of 516's on a 400 that I have in my 63 880 right now. It takes forever for the seats to wear out. The 516's are great for low end. They bust the back tires of my 880 loose easily.They are great for low end and they did jerk the compression up noticeably, but they fall flat on their face just past mid range. They really do flatten out. The 440 is a motor that I dont want to put a lot into. It has medium miles on it and to really do it right would cost a couple of thousand. I dont want to put that into it for this car. The car will be more cost effective if I can sell it with the big motor without throwing serious money into it. Anything other than a 440 will not grab enough money. I do have a set of 452 heads that are in great shape. Since the slugs are so far down in the chambers I could use the 452 heads and throw a monster cam in it and not worry about clearence.

Rug I see that you are in Bonita Springs. Glad to see you in Florida. We need Mopar guys down here bad. There is a pretty good show that comes to the Shell Facory in North Ft. Myers once a month. Maybe you can hit it up sometime. Would like to meet you.
Bob

Rug_Trucker 01-29-2005 12:01 PM

here is my phone number 239 596 2802 would love to check out the show! I need to sell some 440's too. Maybe I can meet some other Mopar guys there.

Seeya! Walter :shades:


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