How to get More Horsepower out of a 1967-68 440?

[17WithaCoronetRT]

hey guys, happy new year to all of you, i haven't been on here in awhile regrettably, got some new news on the coronet rt, so those of you who have been following the project, you all know we picked up a 71 440 in nevada... well we found out that its not worth the money to fix it compared to the luck we just struck up on. the machine shop run by a man named calvin told us that sleeving 2 cylinders would throw off the rest of the engine kinda, and just then he told my dad he had a .030 bored 67 440 with 915 heads that a man dropped off 2 years ago and never picked up, so he is willing to sell them as they are just taking up room, and the block does not work. since this isnt an original block to our car i wanted to see how much i can do within a budget of some sort, in ways of increasing horsepower and torque before we get it from the machine shop. and i was also wondering what we should get for the rest of the engine to increase horsepower. i know there is alot that can be done, but imm not looking for a drag car but a really strong car to drive around in while im in my late teens and 20s and then maybe ill cool it down a little and go with a stock 440, but im just lookin for ideas for now. if any of you can offer knowledge id greatly appreciate it guys! looking forward to the responses :headbang:

 

[kidmopar]

a good cam, intake and headers will help alot.. for torque use a dual plane intake, for more rpm and top end use a single plane, many camsmanufacturers can recommend a grind cam with all ur info such as weight, idle quality, street or strip use and compression ratio, 915 heads are really great, closed chamber design for more compression ratio and keep headers to no bigger than a 1 7/8 tube size for street use

 

[Red63440]

a good cam, intake and headers will help alot.. for torque use a dual plane intake, for more rpm and top end use a single plane, many camsmanufacturers can recommend a grind cam with all ur info such as weight, idle quality, street or strip use and compression ratio, 915 heads are really great, closed chamber design for more compression ratio and keep headers to no bigger than a 1 7/8 tube size for street use

+1...good info.

 

[17WithaCoronetRT]

i heard putting closed chamber 915 heads on a 440 creates a 13:1 compression ratio, is this true? and if so should i plan on buying a stronger crank that can handle that much pressure?

 

[Red63440]

i heard putting closed chamber 915 heads on a 440 creates a 13:1 compression ratio, is this true? and if so should i plan on buying a stronger crank that can handle that much pressure?

The compression ratio would depend on the block and pistons. If they are stock 67 pistons then you should end up with about 10.1 compression or a little less. The crank will be fine for that and more.

 

[moperformance]

Please don't take this the wrong way but your putting way too much faith in "hear say". The 67 440 did take "high test" but most of them came in large land barge type cars. Mine came out of an 67 2dr Imperial. Any way look up the specs for the different heads, closed chamber or open along with bore and stroke to get a feel for what the different combinations are possible. Plus why the 915 with it's "quench area"is a great choice depending on piston shape and placement in the bore. most mistakes are made by people putting together the wrong compinations and NOT checking piston to valve clearance.
Good luck on your find as the heads and the steel crank are worth the price of admission alone.

 

[17WithaCoronetRT]

the pistons that are being put in the block we are getting are flat head pistons and are meant for .030 bored cylinders, we trust the guy that we are going to and im sure he'll do all the testing we need before we start putting combinations of stuff together

 

[1stBxMopar]

Have your machinst square the block and set it up so that the piston is at zero deck height. Hopefully the flat top pistons you chose have flycuts to accomodate a larger selection of cams without piston to valve clearance issues. This along with the 915 closed chamber heads should give you the compression to make the hosepower your looking for. (Check my streetcar combination in the racers hangout section, the thread is 12 second combos)
Good Luck........

 

[HEMI-ITIS]

BOOST:toothy10:

 

[17WithaCoronetRT]

Hahaha I knew I'd get that response at some point, I do have a full 10 lb bottle of nos but it's for decoration, I'm not putting nos in my car

 

[HEMI-ITIS]

Nitrous is a power adder that requires you to refill the bottle all the time.Boost comes from a supercharger or turbo charger.There are centrifical superchargers that go on the front or the roots style that bolts right on the intake manifold:grin:

 

[Cranky]

A 440 with 0 deck pistons and no valve reliefs and a composition gasket (.040 thick) with 80cc heads (915's) will get you right at 11-1 compression....

 

[17WithaCoronetRT]

^^ thank you for that info, i just saw the 13:1 compression and just about freaked, i kinda didnt believe it haha, and HEMI-ITIS, whenever i saw boost written i almost always saw nitrous, haha, hmm if i do a supercharger or turbo itll probably be on a smaller cr later on in life, i wanna put this car close to original with little engine upgrades

 

[Meep-Meep]

How fast you want to go is directly proportional to how much money you want to spend. It's an old saying but very true. And if you don't spend the money wisely then the money you spend vs. any gains you get can really get away from you. Go see my green Belvedere build in the 12 sec combos and note the few aftermarket "trick" parts used. It really doesn't take a whole lot to get some really good performance out of a 440.