1978 440 Performance...

[The Dartman]

I just sent off the block and crank to the machine shop the other day, and I am doing a little bench racing in the meantime.

This cast crank 440 was supposed to have around 70,000 miles, and was from a delivery truck that the A frames rotted out on. The cylinders have very little ridge, and the rods and mains looked very good, with no crank damage at all. This appears to be an ideal candidate for a budget build to start the process of switching my car over from small block to big block.

I will be doing some mild port work on a set of closed chamber 516 heads, as well as getting the exhaust valve machine out for a 1.74 valve, before the valve job. I believe the closed chamber heads and low compression block will give me a target compression of at least 9 to 1. I was thinking of throwing in a simple MP 509 cam instead of my usual Racer Brown selection, just to save a little cash and partly becuase I will be running stock non adjustable rockers. The intake I will run will be a Edlebrock Victor, or a Mopar M1 single plane capped off with a 750 Holley Double pumper. Exhaust will exit through 2 inch fenderwell headers with no mufflers (striaght dumps). The transmission will have a 3800 stall converter, and the rear gear is 4.30 with a 28.5X13 tire. This will be in a BB adjusted weight of 3100 pounds, without the portly driver.

I have another forged crank 1966 motor that will be built in the future to hit my goal of 10.90's, but this motor will have lower expectations.

Any guesses as to what this car will run? What are the stock HP and torque specs for a 1978 440? My 318 runs high 12's, and this should be able to easily beat that.

Dartman

[MoparMarcIdaho]

Good luck with that cam-look up purple shafted,there has been problems with those as of late. 78 was the last year for a 440 If I remember correctly and they were pretty turned down,200 some odd horse is all but the closed chambers should help that.A single plane and large runner headers will help it breath.With the right cam and carb you should be able to achieve 400 horse-mabeye more.

[jelsr]

The low HP rating is mostly due to the rating method. The old (SAE) rating was (supposedly) a blueprinted unit w/o accessories. The later method (Net) is a randomly picked unit from the assy line and is tested with all accessories. The 516's will not breathe as well as the 452's that were on it and do not have the chilled seats for todays fuel. Haven't done the math, but a set of pistons (stock) for a late 60's unit will give you the compression you desire with the open chamber heads for about the same $$ you will spend on the 516's and will run much better. FYI, the pistons in the '78 are probably about 1/8" (.125") below deck. The late 60's pistons can be as little as .001" (6-pak) The difference is wrist pin location (compression distance) You can also do a little adjustment with the head gaskets, steel at .020, comp at .039. Just showing another way from point A to point B. Good luck!

[DartGT66]

You will not be nowhere near 9:1 with the stock pistons without an enormous amount of milling. If you think about a typical '73 and after 440, they have the pistons about 0.17" in the hole at TDC. If you calculate the CR with a steel shim gasket and typical open chamber heads, you'll get a CR of about 7.6:1. Lets assume that the 516 heads chambers are 6cc's smaller than open chambers. Have to measure for true results, but this shouldn't be that far from truth; think about open chamber vs closed chamber Edelbrocks, they have 4cc difference. With 6cc difference, your CR would raise to 7.9:1.

The only sensible way to raise CR in these engines is to change pistons. The 516 heads are worse performance wise than the later open chamber heads, you will gain less with the CR increase than what you will loose with less flow. This is true both in stock & ported form compared to similarily prepped early & late heads. Getting to about 9:1 CR you would have to remove 23 cc's from teh 516 heads or 29cc's from teh 452 heads that originally should have come with your 440. this means milling about 0.13" from the 516's and about 0.11" frim the 452's! An other alternative may be milling the block, about 9.2cc's for .040" milled there. Anyway, that's really too much milling to be sensible and will provide problems that must be fixed elsewhere (intake fit, lifter preload, head bolt attachment). Changing the pistons will most likely be less expensive and a better alternative otherwise too.

If you don't get the CR up to at least 9:1, the biggest MP cam I would use is the 280/.474" grind. Bigger than that will make the low rpm sluggish, to make it work even somehow you need ahigh stall converteer and short gear ratio.

Victor intake is propably too much even for 9:1 CR and the 292 cam. You will be way happier with a performer RPM or a Holley street dominator. But of course if you are aiming for the future, get the intake you will need then.

[bbaspense]

I ran 13.90 @ 98 with a bone stock 1978 440 and tranny/converter in a 3800 lb Aspen with a 3.91 gear.

My buddy has a Challenger that has gone as fast as 12.05 @ 109 with a stock piston 400 with a 509 cam, closed chamber heads, single plane intake with a AFB carb.. he used a 3500 stall, 4.56 gear and 29 inch tire. It weighed 3100 lbs..

My stock piston 400 has gone 12.80 @ 107 in my aspen.. with a 484/292 cam..

There is lot of potential with the 440

[DartGT66]

That's true. We run 12.36/112 mph with a 3600 lbs car, 11" TCI converter, 3.91 gears and a stock short block "smog" 440. The unpaired open chamber heads were mildly homeported and milled .060", headers, torker2 intake and a Holley 3310 carb + MP 280 cam. We later switched to MP 292 cam and M1 single plane intake and a 10" TCI, but it run just the same. Even tried playing with different rockers (stock ones, 1.5 & a.6 ratio rollers) with practically no effect.

[The Dartman]

I have been crunching numbers on the CR myself. I have found several sources that reference the 915 heads as being a 78.5 cc head, which the 516 head is similiar enough once the exhaust valve has been enlarged.

Based upon the .125 "in the hole" mentioned above, I came up with a CR of 8.95:1 with a steel head gasket. Using the .170 in the hole, plus a steel head gasket arrives at a CR of 8.26:1.

My CR calculations are based upon this compression ration calculator: http://www.4racecars.com/calculators...alculator.html

Although these numbers are slightly less than I was hoping for, I find they are perfectly acceptable for my goals. Heck, I can even use pump gas for the first time in 15 years! Well, with lead additives or course....

My biggest goal is to get the car switched over to big block power, including the motor and mid plates, transmission, fenderwell headers, etc. The swap parts alone are going to be very costly, so a budget build that may be mismatched with the future in mind is okay as well. I would say that this motor should be able to easily beat the 12.82@105 our of the 318, and that is also another goal. The 318 has been together for 12 years without a rebuild, and is due to let go any day now.

Thanks for the replies...

Dartman

[MoparMarcIdaho]

I had no idea that the compression was that low in the later 440s.I have a 73,what do those have?It seems strong enough in the old wagon and I am sure it will love frying the tires in a Road Runner instead.The chances of having the crank drilled for a stick arnt good though.

[jelsr]

Mopar BB's are not real sensitive about CR. The '63 Maxi's were available in 2 versions, 11.0X1 and 13.5X1, with 415 and 425 HP ratings. Not a big difference for 2.5 pts. The '64 was offered at 12.5X1 with the same 425 HP??
Marc, don't let the undrilled crank set you back, there is a bearing available that sits in the torque converter nose drilling or in the flywheel itself. (memory) You simply shorten the input shaft accordingly. This is a bearing, not a bushing. I'm sure someone on this board can give you a part number.

[madmax4073]

I had no idea that the compression was that low in the later 440s.I have a 73,what do those have?

The 73 440 has a c/r of 8.75:1. It used 82 cc heads and had 280 hp.

[DartGT66]

The factory ratings are a joke. The cc's and deck heights they claim are blueprint specs, the reality is somewhere else.Me living in the otherside of hte world, propably do not have as much material as most of you to check or to choose from, but I have yet to measure an under 90cc open chamber head that hasn't been milled. As far as I have measured, they are all equal. There may or may not be differencies in the pistons, but so far I have only seen three different ones in 440's. Check, measure and calculate, it's teh only way.

[madmax4073]

I realize the factory specs aren't exact, I was just quoting the specs as a referance, thats what they are for. Theres no way of knowing what any engine is up to, let alone a 30 or 40 year old one with an unknown history, without some checking.

[Brian Mills]

Well I had the heads off of my 1978 440 2 summers ago, big dishes in the top of the pistons, and they get nowhere near the deck at TDC. I'll go along with the CR in the low 7.2- 7.5 neighborhood. As I recall, HP is 185 and tourque is 360 lbs/ft, I forget the R.P.M.'s.

[bbaspense]

The nice thing is that you can shove in a 500 plus lift cam with no clearance issues with stock pistons..

[The Dartman]

The pistons from my 78 440 have no dish at all, and are a flat top style. My motor had never been disassembled, and was completely stock out of a delivery truck. This is not the truck/motor home style block with the extra steam passages, nor did it have truck heads (it has 452's). Could there be multiple versions of the 440 in 1978?

Dartman

[MoparMarcIdaho]

Yes I would think that the type 3 and other motor home versions were still being done then-John or someone else will know more than I do.

[Brian Mills]

Yes, now that you mention it, both of mine say 440-3 on the valve cover sticker. My motorhome I expected this, my spare one is from a cube van. Both have 452 heads.

[MoparMarcIdaho]

All the type 3s Ive been around had 5/8s spark plugs also.

[DartGT66]

I have had "motor home" heads (213 casting) with standard plugs, and non motor home heads with the small plugs with cone sealing.

[Brian Mills]

I know these ones use spark plugs with tapered seats.