Old school 440 build

[Montclaire]

Hello, I’ll be building a 440 in the near future. This will be an “old school” build - no stroker kit or turbos, just a 440.

I’m starting with a seasoned 73 block, supposedly with 50k original miles on it. I’m fully expecting to find a cast crank inside which will be fine for what I need.

I have a vintage MP 509 cam kit and a pair of worked 915s that I got second hand. The heads are cut for bigger valves (can’t remember the sizes offhand) and I added a set of springs good for 510 lift from a set of 440 Source heads with comp cams hardware.

Intake is an A&A cross ram with 440 ports and I believe twin 500cfm carbs. Rear has 3.91s and I’m using a beefed push button 727. Converter is a 70s 360 piece that should stall around 2400-2600.

What I am wondering is this; this motor is rated stock with a 8.2 CR. The 915s should be good for a full compression point over the 452s. Should I just stop there and call it a day?

Most threads that I read these days recommend around 9.5 CR, and I’ll be dang close to that as-is. I used to be able to find 94 octane locally but I think 93 is the best they can do in 2020.

This is not a race car, it will be street driven occasionally to work on nice days and for an ice cream a couple times in the summer. I want a mean sounding big block that I can romp on from time to time and chirp the tires but won’t grenade itself or cost 10k to build.

Thoughts? You won’t talk me out of the cam so just accept it and move on. Thanks

 

[1968rt]

The 509 needs a little more compression or your bottom end will be soft.That cam will bleed off some compression due to overlap. Can you mill the block and or heads to up the compression?

 

[IQ52]

You will find that a 1973 440 with stock pistons and 915 heads will be about 7.9:1 compression. Why? I did about the same thing. I even used a 509 camshaft. Here is the saga...................
https://www.forbbodiesonly.com/moparforum/threads/iron-head-test-starting-on-78-440.58687/
https://www.forabodiesonly.com/mopar/threads/dyno-testing-a-stock-1972-440.249866/

 

[Montclaire]

The 509 needs a little more compression or your bottom end will be soft.That cam will bleed off some compression due to overlap. Can you mill the block and or heads to up the compression?

There’s a chance the heads are already milled, I have to measure them. I’d be nervous milling the block, too - weren’t there interference issues with these heads back in the day?

 

[Montclaire]

You will find that a 1973 440 with stock pistons and 915 heads will be about 7.9:1 compression. Why? I did about the same thing. I even used a 509 camshaft. Here is the saga...................
https://www.forabodiesonly.com/mopar/threads/dyno-testing-a-stock-1972-440.249866/

Thanks, will check it out

 

[IQ52]

The 509 needs a little more compression or your bottom end will be soft.That cam will bleed off some compression due to overlap. Can you mill the block and or heads to up the compression?

The overlap has nothing to do with it. It is because of the late intake valve closing. Overlap occurs during the intake valve opening.

 

[1968rt]

I think they go hand and hand!

The overlap has nothing to do with it. It is because of the late intake valve closing. Overlap occurs during the intake valve opening.

 

[beanhead]

Lots of '73s still had forged cranks; mine did. But you're right, a cast steel crank is fine too. If what you want is to 'sound mean' and be able to chirp the tires a little on the way to the ice-cream shop, build what you have. I don't think you're asking too much of a basic 440 in that regard.

I think they go hand and hand!

Well then you probably also think compression must be increased to use aluminum heads
I do agree with your first statement though, that the .509 and low compression typically doesn't amount to a very fun street driver...at least until the RPMs get wound up some.

 

[beanhead]

There’s a chance the heads are already milled, I have to measure them. I’d be nervous milling the block, too - weren’t there interference issues with these heads back in the day?

You can run into intake and valley pan fitment issues, which can be rectified by having the machinist mill the front and rear block rails, take some off the intake mounting side of the heads...but if your re-building anyway, the best plan is to just get better pistons. Unless you weren't planning on boring the block?
Dang 93/94 octane pump gas I'm jealous!

 

[69Bee]

There’s a chance the heads are already milled, I have to measure them. I’d be nervous milling the block, too - weren’t there interference issues with these heads back in the day?

Mopar had the pistons about 0.070"ish in the hole, and you will find after replacing the pistons, it to be about 0.100"ish down. Pistons are destroked for gas reasons on replacement pistons. Now, I am ONLY referring to OEM replacement Sealed Power pistons. Always check the compression height of the piston and do the math before ordering. Like Beanhead said, squaring the block will ensure the head deck is parallel to the crankshaft, and 90 degrees to each other. A good machine shop (like me) will always finish up by cutting the valley rails so they are straightened out, equal height, and if the intake seals to the end rails (not this case), remove an amount to account for head/block material removal so intake bolts line up.

 

[33 IMP]

Mopar had the pistons about 0.070"ish in the hole, and you will find after replacing the pistons, it to be about 0.100"ish down. Pistons are destroked for gas reasons on replacement pistons. Now, I am ONLY referring to OEM replacement Sealed Power pistons. Always check the compression height of the piston and do the math before ordering. Like Beanhead said, squaring the block will ensure the head deck is parallel to the crankshaft, and 90 degrees to each other. A good machine shop (like me) will always finish up by cutting the valley rails so they are straightened out, equal height, and if the intake seals to the end rails (not this case), remove an amount to account for head/block material removal so intake bolts line up.

Op says he is using A&A 440 style crossram, and they Do seal the intake to the china wall, like a chevy.

 

[Montclaire]

You will find that a 1973 440 with stock pistons and 915 heads will be about 7.9:1 compression. Why? I did about the same thing. I even used a 509 camshaft. Here is the saga...................
https://www.forabodiesonly.com/mopar/threads/dyno-testing-a-stock-1972-440.249866/

What a great thread. From what I saw it sounds like I am fine to use the stockers. Now, if the block needs more than just a hone job I’ll end up picking a better flat top piston but I think something like a Speedpro 2355 would be overkill, esp with the 915s.

 

[Jerry Hall]

Hello, I’ll be building a 440 in the near future. This will be an “old school” build - no stroker kit or turbos, just a 440.

I’m starting with a seasoned 73 block, supposedly with 50k original miles on it. I’m fully expecting to find a cast crank inside which will be fine for what I need.

I have a vintage MP 509 cam kit and a pair of worked 915s that I got second hand. The heads are cut for bigger valves (can’t remember the sizes offhand) and I added a set of springs good for 510 lift from a set of 440 Source heads with comp cams hardware.

Intake is an A&A cross ram with 440 ports and I believe twin 500cfm carbs. Rear has 3.91s and I’m using a beefed push button 727. Converter is a 70s 360 piece that should stall around 2400-2600.

What I am wondering is this; this motor is rated stock with a 8.2 CR. The 915s should be good for a full compression point over the 452s. Should I just stop there and call it a day?

Most threads that I read these days recommend around 9.5 CR, and I’ll be dang close to that as-is. I used to be able to find 94 octane locally but I think 93 is the best they can do in 2020.

This is not a race car, it will be street driven occasionally to work on nice days and for an ice cream a couple times in the summer. I want a mean sounding big block that I can romp on from time to time and chirp the tires but won’t grenade itself or cost 10k to build.

Thoughts? You won’t talk me out of the cam so just accept it and move on. Thanks

I like it as you described. My preference would be to move up to a steel crank. If you have to bore it any, you can move up in compression to the 9.5, 9.6 range. I do mine to 10.0 to 10.1 as was stock in 67 and I can tune to run on 93. True I don't like it so I mix my fuel and bump the timing up the few degrees I had retarded it for 93.

 

[khryslerkid]

And what pray tell might this 440 be going into

 

[PRHeads]

I wouldn’t really make any “plans” on how to proceed until it’s been inspected/measured....... and you know what you have, what’s good, and what needs replacing.
Then make the plan.

I will say this....... if I had to buy pistons..... I’d be building for quench.

 

[Remusa12]

I'm not a transmission expert but can you use a small block torque converter in a big block I thought the size would be off or something?

 

[493 Mike]

I'm not a transmission expert but can you use a small block torque converter in a big block I thought the size would be off or something?

Nope. Not if they're both 727 transmissions with the same spline count. I've done it too.
Mike

 

[BSB67]

I think they go hand and hand!

Not really.

 

[33 IMP]

You had better check that 360 converter for weights, to make sure it is compatible with the cast big block crank. They are both externally balanced, but maybe to a different value. If you have a forged crank, you will have to remove the weights from the 360 converter.

 

[BSB67]

......weren’t there interference issues with these heads back in the day?

No. There will be no interference issues with your set-up if you mill the block.