Rebuliding 440 - need advice

[JRL]

Hi,

need a little advice here on what direction to go.

The original 440 six pack has taken a beating, with a bad combination of going too rich with a loose distributor - getting serious exhaust tempratures.

I was planning to build me a 505 stroker, stock appearing on another block, but when I recently started cleaning it up, it was craced between 2 of the sylinders...
Rb blocks are hard to come by where I live so I'm thinking real hard on what to do.

I'm considering putting a pair of heavily ported 906 heads and a custom solid roller intended for the 505 on the stock motor I already have - to keep cost down. The problem with the 906 heads are 88 cc chambers which seemed like a good idea when I bought them for the stroker combo...

9 - something compression ratio, stock short block, 300 cfm heads, 600 lift cam.

So what do you guys think, bad idea?
Does this combination have a chance to work at all?

 

[Cranky]

Ran a set of heavily ported 906's years ago on a 440 but used pop up pistons also but knowing more specifics of your engine will help. Also, if you're getting 300 cfm from 906's, the flow bench is being generous or the port walls are pretty thin. IMO, 9-1 compression and a big cam is going to mean you will have pretty low cylinder pressures (depending on cam) in the lower rpm ranges so it might be a good idea to work with the cam grinder to give you something that will bring that up a little or at least get some advice on what to do with a decent stick for it. I ran a 660 lift roller but my compression was around 11-1. Just be careful with engine temps as max ported stock heads are prone to cracking.

 

[JRL]

Thanks for the reply

heads are cnc ported with 2.14 and 1.81 valves.
the shop claim they will flow 313/223 cfm @ .600
Looking at the work they have done, I'm not convinced, so I've been digging out the worst parts of the runners myself, trying to smoothen the runners as best I can.
Cam is a solid roller .609 lift 248/256@ .050, 110 lobe sep. 106 cl.

Six pack intake and carbs.

been thinking of advancing the cam to build a bit more pressure.

 

[IQ52]

Build it with what you have, it'll run good.

"digging out" sounds a little bit scary with those heads but way over 300 cfm with a 906 is possible without cracking in service. Our 906 heads were over 340 cfm when Comp Cams forgot to turn the water on to the dyno and the engine overheated to the point where the paint was burning off the cylinder heads. No cracking but the exhaust valves welded themselves to the bronze guides and pulled the guides loose in the heads. Tore it apart, fixed it, and the next day with water in it, it made 730 HP. Shoulda done better but it was running with 15 bent valves.

Anyway.........we have run a roller bigger than that (256/260) in a 451 at 9.5:1 compression and it ran just fine with 452 heads flowing 295 cfm. Tested it with a 6-pack and the thing made like 600 HP and 600 LB-FT of torque. With a M1 single plane and a 950 4150 carb it made 621 HP and 588 LB-FT.

So I say, run what you got and don't bust the wallet.

 

[Meep-Meep]

If you have a cracked block getting another one will be first on your list.

 

[JRL]

Thanks for the replies,

It was a second block that was cracked. Now I'm thinking of using the matching numbers block and rotating assembly with some of the parts intended for the stroker.

Doing this my consern is as stated above if this would be a decent working combination. If it were, would cap walk be another issue I should keep in mind?

I have alu. caps and girdle but really don't want to start messing with this block. I might just use the girdle on the stock main caps.

 

[IQ52]

If you are going to build a stroker in the future, you can run your present short block around a long time with the stock main caps and bolts. If you are worried and have the money, install main studs and have the block align bored. I didn't even put studs in the 451 stroker until we went over 700 HP. How often do you plan on driving around using the full 600 or whatever horsepower? The people that are breaking the blocks are constantly abusing them.

 

[JRL]

Ok, think I'll give it a try.

Any thougths about promax blocks beeing a good idea on this motor, or are the stock carbs good enough?