what to expect out of a 440???

[Meep-Meep]

I agree your compression numbers don't look too good and it's interesting the difference is bank to bank. Make each cylinder the same then proceed.

Looking at the cam duration (278) it's possible the intake valve closing point is not in complete agreement with your static compression ratio. What pistons did you put in it? If they are speced for a late model 440 you probably have 8:1 with comp head gaskets and open chamber heads. For an 8-8.5:1 engine I'd like to see 150-160 PSI on all cylinders. There may be more going on here but first make it right mechanically.

 

[68chargerguy]

Pistons are stock 73'. When I took the motor apart and took it to the machine shop was told the cylinders looked good and so it just got honed. Had the crank turned at that time also. This may not be anything but I'm going to mention it. This motor set for about 2 years after the rebuild. don't get me wrong, I primed the motor before I started up the first time about a month ago. Motor sounds great and has no smoke or leaks. Just wanted to add that into the equation if need be. I will drive it a little more and check the compression again after I put on a few more miles.

 

[Satellite65]

I don't think that the engine sitting has much to do with it so I wouldn't worry too much about it. The bank-to-bank cyl pressure variations may be because someone replaced or repaired one of the heads at some time in this engines life. The new/reconditioned head may have been resurfaced and the chambers are a bit smaller. Only CC'ing the heads would tell for certain. Another way to quickly check is to measure the deck thickness with a caliper. BB heads are supposed to be 1" thick at that point.

A 278* duration cam is kinda large for a low compression engine such as a '73 440, I'm actually surprised your cylinder pressures are as high as they are. If this engine is built the way you say it is and seems to run well otherwise, a decent torque converter and gearset are in order. That'll wake up the combination and let it run to it's potential. That motor's probably going to want headers too, if you don't already have them.

 

[Cranky]

65....look at the specs at .050 and not advertised duration.....also pay attention at when the intake opens etc. His engine should be at least 150 with that cam.

 

[Satellite65]

Yeah, I see that but I'm also going to take a wild guess and say his pistons are .140"-.150" down in the holes. These engines were 7.8:1 - 8.2:1 on a good day. This cam isn't exactly what I would call an RV cam. Something with an adv duration of 256* would be in order for a stock rebuild of a '73 440. It just doen't have the compression to support it but the right converter and gears (remember, he has a 2.76 rear!!!) would do wonders for this combo. I've been down the "low compression/big cam" road before.

 

[Cranky]

I've been down the "low compression/big cam" road before.

So have I and this cam isn't big by any means. A buddy and I played with a 72 318 Demon with 360 heads with a mild port job, .480 lift cam. Don't remember the specs off hand but with the 360 heads, we figured compression to be around a tick under 8-1, headers, Torker intake, lots of gear, stock converter...the thing run 13.50 @ 102. It's a slug off the line but wakes up at 3000. Thing is, the PSI is pretty even across the board with 115k miles on the bottom end. It also likes a lot of ignition timing. Something that low compression engines seem to need. A similar situation with another buddies 440 engine in a 67 'Net. Pistons down in the hole, 484/284 Purple shaft, headers, intake, 3.91's. Have now idea what it would ET because there was just no traction at all but it ran 104 MPH. It also liked a ton of ignition timing.

I'm looking at the intake event with 6 ATDC and closes at 30 ABDC....with a number like that and if it's installed according to the number, it should be packing the cylinders full but even with that, the engine has two much variation between cylinders to be worried about throwing gears etc at it right now.

 

[Mebsuta]

Your heads should be fine. There's not that much difference between 73 heads and 68-70 906 heads; just a flatter intake port. I have used all the open chamber castings and could not tell that much difference.

If you only have 50 miles on it, not sure how much I would worry about compression test just yet. Drive it around some more maybe. A 383 HP with a Roadrunner cam should have about 150 psi cranking compression. I know yours is a 440, but your pistons probably have a lower compression height and I would not expect really high cranking compression.

The closer I put my stuff back to factory, the better it ran.

 

[Satellite65]

So have I and this cam isn't big by any means. A buddy and I played with a 72 318 Demon with 360 heads with a mild port job, .480 lift cam. Don't remember the specs off hand but with the 360 heads, we figured compression to be around a tick under 8-1, headers, Torker intake, lots of gear, stock converter...the thing run 13.50 @ 102. It's a slug off the line but wakes up at 3000. Thing is, the PSI is pretty even across the board with 115k miles on the bottom end. It also likes a lot of ignition timing. Something that low compression engines seem to need. A similar situation with another buddies 440 engine in a 67 'Net. Pistons down in the hole, 484/284 Purple shaft, headers, intake, 3.91's. Have now idea what it would ET because there was just no traction at all but it ran 104 MPH. It also liked a ton of ignition timing.

I'm looking at the intake event with 6 ATDC and closes at 30 ABDC....with a number like that and if it's installed according to the number, it should be packing the cylinders full but even with that, the engine has two much variation between cylinders to be worried about throwing gears etc at it right now.

My previous engine build sounds exactly like the one in your buddy's '67. At first I ran it with a Torker, 3310, Hooker Supercomps, B&M Holeshot converter and 3.54 rear. It wasn't too bad but that 'verter was a slippy P.O.S. when cruising. I swapped it out to a stock unit and the performance dropped significantly. A friend suggested I ditch the big headers for stock manifolds, car got worse. One thing though, it always pulled like a freight train on the highway and yes, it liked a LOT of timing. So much I thought the balancer may have slipped.

Like I said, the combo can work with a little tweaking, I think the dead gears and stock converter are the big issues.

The closer I put my stuff back to factory, the better it ran.

That's what I was shooting for, it only made matters worse.

 

[Cranky]

Timing like 20 initial and 50 total? lol

 

[Satellite65]

Sumthin like dat!!!

Yeah, it was a lot, the engine just kept wanting more. Not really the ideal way to run a motor but hey, any port in a storm!!!

The new one should be a MUCH better street engine.

 

[Cranky]

Yeah, the first time I messed with a low compression 'performance' (ha) engine, it just kept wanting more and I thought maybe my timing light had gone stooopid but after a double check with another light and confirmed the balancer wasn't moving, I believed it. 50 total was when it quit going faster so we stopped there and checked the plugs one more time and decided it would work lol. That one was the 13.50 318 Demon. The 440 powered 'Net was pretty close to the same timing specs....

 

[Meep-Meep]

It's been my experience that rings seat in the first several mins of run time but that's assuming the bores are round and everything fits really well. As mentioned you could run it a bit more and re check your compression numbers.

The point of intake valve closing (in degrees) is when the pressure starts to build in the cylinder and that happens closer to the advertised number.

Of course lower gears will help your situation but it's not fixing the real problem.

 

[YY1]

Finally, someone that agrees a 284/484 is NOT "too much cam" for a lower than 10:1 motor. Cranky's setup sounds similar to my Bee, with the Torker, 3.55's, stock converter and LOTS of advance!!! I think my 70 383 was 9.5:1.

I once passed a guy in a nearly new GTA with my 150 speedo buried. That motor also ran on 91 octane and only got 93 on Friday nights.

Degree the cam and check your advance.....it's FREE.

That was one thing I paid real close attention to (degreeing) I remember I even got a video from DC (MP) that showed how to do it.

 

[Cranky]

Finally, someone that agrees a 284/484 is NOT "too much cam" for a lower than 10:1 motor. Cranky's setup sounds similar to my Bee, with the Torker, 3.55's, stock converter and LOTS of advance!!! I think my 70 383 was 9.5:1.

I once passed a guy in a nearly new GTA with my 150 speedo buried. That motor also ran on 91 octane and only got 93 on Friday nights.

Degree the cam and check your advance.....it's FREE.

That was one thing I paid real close attention to (degreeing) I remember I even got a video from DC (MP) that showed how to do it.

Low compression is not the optimum thing for the larger cams but they can be made to work and one of the things that helps is advancing the cam. Higher compression engines will generally not like as much cam advance as a lower compression engine and usually do not like as much timing advance either....and I degree all my cam installation no matter how stock or little the cam is.

 

[Satellite65]

Finally, someone that agrees a 284/484 is NOT "too much cam" for a lower than 10:1 motor. Cranky's setup sounds similar to my Bee, with the Torker, 3.55's, stock converter and LOTS of advance!!! I think my 70 383 was 9.5:1.

I once passed a guy in a nearly new GTA with my 150 speedo buried. That motor also ran on 91 octane and only got 93 on Friday nights.

Degree the cam and check your advance.....it's FREE.

That was one thing I paid real close attention to (degreeing) I remember I even got a video from DC (MP) that showed how to do it.

The 284/484 cam is not really a big cam, especially by todays standards but there's a big difference between 9.5:1 compression and 7.8:1, which is where a lot of these motors wind up. My 440 was 7.8 with .040" head gaskets and 8.2 with steel shims and I could definitely feel the difference.

Low compression is not the optimum thing for the larger cams but they can be made to work and one of the things that helps is advancing the cam. Higher compression engines will generally not like as much cam advance as a lower compression engine and usually do not like as much timing advance either....and I degree all my cam installation no matter how stock or little the cam is.

Advancing the cam works because the intake valve closes sooner in the cycle, building more cylinder pressure. Yeah, it'll bring the powerband down a few rpm's but the cam's not really going to run to it's full potential, like it would if it had the compression it wants to begin with.

 

[Phantomcobra]

At the beginning of this string when I saw he could barely squeek the tires the first thing that came to mind and I didn't see mentioned anywhere is if he has a posi-grip rear end. I do and can barely leave a scratch. But she'll definitely out run a Geo. Front end lifts up and she just goes.

 

[Stumper]

Gear change for sure, but even at that if you are still 73' stock that's not the high performance motor most people think of when they think 440. I think the stock 440 in
73' was used mainly in the big cars and was rated something like 280 hp (maybe less).

 

[74sundance]

440 Spec's 1969/1973

1973 CARB BORE STROKE COMP HP RPM'S TORQ RPM'S OIL PRESSURE
V8-440 4-bbl 4.32 x 3.75 8.2:1 220 @ 3600 350 @ 2400 45-65
V8-440 4-bbl 4.32 x 3.75 8.2:1 275 @ 4800 380 @ 3200 45-65

1969
V8-440 4-bbl 4.32 x 3.75 10.1:1 350 @ 4400 480 @ 2800 45-65
V8-440 4-bbl 4.32 x 3.75 10.1 375 @ 4600 480 @ 3200 45-65
V8-440 3x2-bbl4.32 x 3.75 10.5:1 390 @ 4700 490 @ 3200 45-65

 

[Stumper]

What a difference a few years makes eh?

 

[moparfanUSA]

I'm pretty much having the same issue as he is, before the rebuild I could smoke the tires and now no way. I have 3:55's in the rear. I had the motor done by a race shop, but had to repalce the cam he put in, the car just would not take off with it. The cam was degreed 4 degs advanced. With the new cam in it now it is at TDC. I have about 12-14 advanced timing in it right now. I am also running a 650cfm carb. not much power to brake the wheels loose, but seems to start to move after about 15MPH. I have not done a compression check on it yet. It's my next step.