questions on specs for 440 engine

[shrek]

Hey folks, as some of you know I have my 73 RR still in resto mode and am working on doing some add on stuff to the 440 that I have. The casting #'s on the block are 2536430, I have taken a set of heads from a 383 I have and put them on because I may have had an overheating issue and wasn't quite sure if the 440 heads were ok. The 383 heads were redone a couple of years ago. The 440 supposably came out of a 69 charger and was refreshed and sitting since 1982 with less than a 1000 miles on it. Can somebody tell me what the compression ratio is on this? I have just put in a .510 chet Herbert cam that was recommended. I am learning in progress on this and this site is an awesome place to learn. Thanks for your patience if I seem to be asking dumb questions. I guess my main question is, What do I have? Thanks

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I have also put on from summit, adjustable timing chain and gear and advanced it 2 deg. except cam all else is stock

 

[62 Dart Convertible]

Are the 383 heads the same (i.e. also open chamber) like the 440 heads should be if they are '69? What are the casting no's? Are the pistons flat tops and how far down the hole are they at tdc? With this, CR can be approximated. The only way to know CR accurately is by measuring ccs and calculating.

Did you degree in the cam with a degree wheel? Highly recommended and not overly difficult.

 

[Meep-Meep]

X2 what Frank said ^^^^ There were at least three piston choices for the 440 so depending what you have installed it can be 7.8:1 to about 10.5:1 with the open chamber head. The 69 engine should be about 9:1 in reality, but again, too many variables to make an accurate statement.

 

[66Satellite47]

The previous responses are right on. To get the REAL compression, you need to measure everything, chamber volume (can vary quite a bit even with the same casting # and any machine work done before), deck height (how far down the hole or above), net dome (any dome minus any valve notches), head gasket thickness. As Frank said you have to do the math. Another thing to measure & be sure of when changing cams is to check piston to valve clearance, especially if changing installed cam timing. Not sure what your cam is like, .510 with moderate duration should be OK.

 

[The Horvaths]

With it together, you can measure cranking compression. That will give you an idea of what ballpark you're in. Simply get a compression tester (cheap) and pull the plugs. Running a compression test also gives you a baseline with which to monitor engine health. Write each cylinder's pressure down and save it for future reference.
BTW: tolerances can add up to where getting a degree wheel and "degreeing" the cam, without trusting things to be where they should be, is a very good idea.

 

[Super Rob]

X2 what Frank said ^^^^ There were at least three piston choices for the 440 so depending what you have installed it can be 7.8:1 to about 10.5:1 with the open chamber head. The 69 engine should be about 9:1 in reality, but again, too many variables to make an accurate statement.

Could you please list the part #s for the three piston choices? Thanks!

 

[shrek]

Casting #'s on heads are 2843806-6, same casting # that are on the 440 heads. Port holes all look to be the same size. I do have a degree wheel, but a friend suggested to advance it 2 deg. on the adjustable timing gear. Pistons are flat top. I assume they are stock. did not check to see how far down the pistons are at tdc. Thanks

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Everything seems to be nice and smooth rotating engine over by hand.

 

[The Horvaths]

Degree wheels tell the reality of the situation. It is perhaps wiser to measure than to blindly trust. Tolerances can add up!