help me make the best of this old pile of new parts

[eldubb440]

68 440 block .030 over

had it machined in 1988 or so (when I was young and dumb), and purchased the common forged flat tops (2266?)

over the years, I became aware of bogus compression ratios, and the "down in the hole" issue (appears to be .090-.010ish)..... so at some point, being the know-it-all that I am; I rounded up a set of 915 heads (big ex valves, hardened seats installed).

had the 915s cut, did the math, and came up with 9.6ish CR, IIRC



looking back, I probably should have done things differently, but my question is (now that I am old and dumb)........ will this POS run without dropping back and punting?

 

[eldubb440]

oh, here are the cam specs.........

BB HYD FLAT TAPPET CAM 224/228 -111ºLSA

LOBE LIFT .345"/.353"

Duration @ .050 .... 224 I 228 E

lift.........552 I 565 E with 1.6 rockers

Use: Mild street performance or hot HP restoration engines. Likes some head work & oversize valves.
Idle: Smooth to noticable
Vacuum: Medium level
Converter: Stock to mild stall
Rear gear: 3.55 +
Benefits: Hotter daily driver.

 

[eldubb440]

were 67 440s higher compression than 68 - 70?....... were the HP motors not rated at 375 Horse for all four years? were 67s even deeper in the hole? I have questions, dammit

do I have a mess on my hands? ........ come on, I can take it

 

[miller]

were 67 440s higher compression than 68 - 70?

That all depends on the combination of parts used in it, but I'll add a 67 model 440 is a damn good start!
Like any other motor, it can be built to walk and talk, or squat. Which one you want?
Get dangerous, and assume a steel crank. Can't image other. Rods and pistons...

btw...

 

[miller]

Oops. You said a 68 block. Still can be made to run.

 

[69 GTX]

I recall right 67 had the closed chamber heads with a smaller exhaust valve. I think they would work fine with your cam. Sounds like a good combo, put it together with a dual plane (eddy performer rpm) and you'll have a good street engine.

 

[eldubb440]

i guess im asking 2 questions here.... the second one, if 67's heads have the smaller combustion chamber (which they do); they must be a higher compression motor........ and if so, why weren't they rated higher horsepower than the 68-71s? or do the pistons start out even deeper in the hole to compensate?

 

[eldubb440]

I recall right 67 had the closed chamber heads with a smaller exhaust valve. I think they would work fine with your cam. Sounds like a good combo, put it together with a dual plane (eddy performer rpm) and you'll have a good street engine.

my heads have the larger valve installed along with some port work......i probably picked them up 15 years ago......they look nice, i hope nobody F'ed them up

also running an edelbrock ch4b......i like the period parts, and I believe that intake will work with my stock air cleaner for proper hood clearance

 

[69 GTX]

Maybe the difference in rating @ RPM or cam & intake.

 

[eldubb440]

and back to my first question...... after reading a lot of internet mumbo jumbo, is this thing gonna run on good pump gas?

should i swap out pistons for something closer to deck height? which would give me even more compression, but better quench? i just want a snappy dependable driver.... i prefer just to button it up as is and run it

 

[69 GTX]

I say yes. Just may have to watch the timing. For sure with 93, 91 probably, 89 maybe.

 

[eldubb440]

nobody else? if it runs like crap, there will be hell to pay!

 

[miller]

and back to my first question...... after reading a lot of internet mumbo jumbo, is this thing gonna run on good pump gas?

What your looking for, is an easy answer. Sorry...ain't got one! Good pump gas?

I would suggest you look over other builds, that would include most of your hard parts.
That means block, crank, heads, and so on. In a heartbeat, I'd use the 915 heads, as long as they have the big valves. But, I'd also go for some compression...one of the little items, that make an engine run. Don't say a lower compression motor won't run, and run good. But, it's the overall build, parts used, AND how their put together, that makes it all work.
How's that for mumbo-jumbo?

You have some good parts to start with...but, .090 in the hole? If that's what you want. (Mine are .002 in the hole, with other parts, give me 10.2-1 CR.)
The name of the game is choices. Only you can do that.

 

[eldubb440]

isn't the "down in the hole" thing a contributor to detonation?, this is my main concern...... i prefer to just run it as is, but I don't want to waste the effort either

I can always build another one at a later date

 

[miller]

No, not really. Pre-ignition, and detonation are usually caused by timing, not being set right for the engine. It 'can' be caused by heavy build-up of carbon, on top of the pistons, that create hot spots.
Sounds like that build (down in the hole) is for a lower compression motor, that will run on less octane.

Of course you can put it together 'as is', and run it for now. As long as the parts are still in fair shape.

 

[eldubb440]

No, not really. Pre-ignition, and detonation are usually caused by timing, not being set right for the engine. It 'can' be caused by heavy build-up of carbon, on top of the pistons, that create hot spots.
Sounds like that build (down in the hole) is for a lower compression motor, that will run on less octane.

Of course you can put it together 'as is', and run it for now. As long as the parts are still in fair shape.

parts never been run, just been around for a couple of decades, the idea back then was the 915s, cut .050 or so would give a nice little compression bump. As I said, it calculates out to about 9.6:1 with standard felpro head gaskets.......I'm just looking for any suggestions without getting into any new machine work..... gonna run it and see, I guess

 

[oldbee]

You knew you were going to try it when you first posted!! I just waited to see what kind of answers you'd get. Run the blasted thing!!! Lol

 

[eldubb440]

i was contemplating a piston swap........ but F it!

 

[oldbee]

I used to hear rumors that comp.ratio was always 1/2 point or so less than what they quoted. This was 68-70 and I don't know why that rumor got floated around.

 

[threewood]

Run a thicker headgasket to get compression in the 8.5:1 range and slap on a set of turbos!