Iron head test starting on '78 440.

[wedgie]

Watching this thread with great interest.

 

[Ltlgto]

Interesting to see the results. Lots of great info!

I am hoping for the same type of increase in my 383. As far as I know it's a stock '65 383 except it is running headers, orange box ignition and 600 Eddy. I just ordered an RPM Performer intake and will be picking up a set of big valve 915's that are ported. Not sure of the current cam, but would like a mild street cam.

 

[IQ52]

Results are posted on forabodiesonly right now. After work I'll get them up here.

 

[Gpuller]

Jumped over to FABBO, impressive numbers for sure!

 

[IQ52]

So we'll try to put the next three pulls side-by-side. 1st we'll do the cam swap to the MP 509, 2nd we'll add an 850 cfm Mighty Demon carb, and because the fuel lines hit the ignition coil bolt towers on the M1 we'll make some room by adding a 2" Super Sucker carb spacer. 3rd we'll replace the stock 906 heads with some ported 516 heads. These heads will bump the compression to 7.85:1 and will flow about 250 cfm @ .500" lift. We'll not be getting the full .509" lift from the cam because we are still using the stock stamped steel rockers.

Here we go,

............................509....................850 w/spacer...............ported 516

RPM.....................TQ/HP......................TQ/HP.........................TQ/HP

2500..................360/171...................359/171
2600..................371/183...................373/184
2700..................384/197...................382/196
2800..................396/211...................392/209
2900..................407/225...................412/227
3000..................409/234...................431/246......................434/248
3100..................415/245...................441/261......................445/263
3200..................425/259...................442/269......................457/278
3300..................436/274...................450/283......................458/288
3400..................432/280...................449/290......................462/299
3500..................432/288...................449/290......................458/305
3600..................430/295...................436/299......................447/307
3700..................428/302...................435/306......................443/312
3800..................425/307...................430/311......................443/321
3900..................421/312...................434/322......................446/331
4000..................419/319...................438/333......................450/343
4100..................419/327...................445/347......................453/354
4200..................419/335...................444/355......................461/368
4300..................416/341...................443/362......................463/379
4400..................412/345...................434/363......................461/386
4500..................403/346...................432/370......................470/402
4600..................399/349...................429/376......................473/414
4700..................400/358...................427/382......................468/418
4800..................389/356...................419/383......................467/427
4900..................388/362...................415/387......................459/428
5000..................377/359...................405/386......................459/437
5100..................366/355...................391/379......................453/439
5200..................359/355...................383/379......................453/448
5300..................345/348...................374/377......................445/449
5400.................................................361/372......................428/440
5500...................................................................................421/441
5600...................................................................................407/434
5700...................................................................................397/431
5800...................................................................................391/431

What a piece of crap, we've only gained 227 HP @ 5500 RPM vs the first pull.

 

[XCELLR8]

Would these gains be possible with a smogger 400? The C/R is about the same.

 

[tallhair]

So we'll try to put the next three pulls side-by-side. 1st we'll do the cam swap to the MP 509, 2nd we'll add an 850 cfm Mighty Demon carb, and because the fuel lines hit the ignition coil bolt towers on the M1 we'll make some room by adding a 2" Super Sucker carb spacer. 3rd we'll replace the stock 906 heads with some ported 516 heads. These heads will bump the compression to 7.85:1 and will flow about 250 cfm @ .500" lift. We'll not be getting the full .509" lift from the cam because we are still using the stock stamped steel rockers.

Here we go,

............................509....................850 w/spacer...............ported 516

RPM.....................TQ/HP......................TQ/HP.........................TQ/HP

2500..................360/171...................359/171
2600..................371/183...................373/184
2700..................384/197...................382/196
2800..................396/211...................392/209
2900..................407/225...................412/227
3000..................409/234...................431/246......................434/248
3100..................415/245...................441/261......................445/263
3200..................425/259...................442/269......................457/278
3300..................436/274...................450/283......................458/288
3400..................432/280...................449/290......................462/299
3500..................432/288...................449/290......................458/305
3600..................430/295...................436/299......................447/307
3700..................428/302...................435/306......................443/312
3800..................425/307...................430/311......................443/321
3900..................421/312...................434/322......................446/331
4000..................419/319...................438/333......................450/343
4100..................419/327...................445/347......................453/354
4200..................419/335...................444/355......................461/368
4300..................416/341...................443/362......................463/379
4400..................412/345...................434/363......................461/386
4500..................403/346...................432/370......................470/402
4600..................399/349...................429/376......................473/414
4700..................400/358...................427/382......................468/418
4800..................389/356...................419/383......................467/427
4900..................388/362...................415/387......................459/428
5000..................377/359...................405/386......................459/437
5100..................366/355...................391/379......................453/439
5200..................359/355...................383/379......................453/448
5300..................345/348...................374/377......................445/449
5400.................................................361/372......................428/440
5500...................................................................................421/441
5600...................................................................................407/434
5700...................................................................................397/431
5800...................................................................................391/431

What a piece of crap, we've only gained 227 HP @ 5500 RPM vs the first pull.

That's pretty amazing and thanks for doing this IQ52 !

Question why does the last column of numbers not start until 3000 RPM? Also a request if possible and you don't mind .. if you have no more mods to make or gear to swap out it would be interesting to see a swap back to the HP manifolds and see what the power loss is if you haven't broken this set up down yet or if you have a more to try with this motor could you try the HP manifolds at the end?

 

[hunt2elk]

This is a great thread with tons of useful info, and at a great time because I am at the point of thinking about the motor for my Charger. IQ52 - what are your thoughts on the mp528 solid cam for a street car?

 

[Gpuller]

How would those ported 516's compare to say OTB Stealth? What would the differences in chamber volume be?
By the time a person rebuilds a set of 516's and had them ported would the Stealth be a better choice?

 

[XCELLR8]

How would those ported 516's compare to say OTB Stealth? What would the differences in chamber volume be?
By the time a person rebuilds a set of 516's and had them ported would the Stealth be a better choice?

^^X2

 

[HT413]

Thanks, Jim, for this test. I've been planning / budgeting for a motor to replace my low compression '72 413 and now instead of spending $5000-$8000 on a motor, I might just review my combo and make a few changes and get pretty close to my goals on the cheap.

- - - Updated - - -

Based on your testing, what do you think would be a nice optimized combination for one of these low compression engine? I realize you were trying to stay w the parts that were at hand or were loaned, but if you had a choice of your cam, intake, heads, etc, for this shortblock, what would they be? Obviously this kind of build would be a budget street setup with maybe some fun at the strip from time to time.

Thanks again.

- - - Updated - - -

Would a solid cam net any gains over a hydraulic at these rpms and performance levels?

 

[67Satty]

The thing I'm taking away from this is that, even with good-flowing ported heads and a cam with pretty big duration, the power still peaks at 5,400 rpm. So to me, there's no reason to wring these things up to 6,000 rpm before you shift. These torque monsters like to be short-shifted and kept in the mid-range IMHO.

I bet a switch to some Stealth or RPMs and a cam swap to a solid cam could get it to break 500 hp pretty easily.

 

[m79ded]

So we'll try to put the next three pulls side-by-side. 1st we'll do the cam swap to the MP 509, 2nd we'll add an 850 cfm Mighty Demon carb, and because the fuel lines hit the ignition coil bolt towers on the M1 we'll make some room by adding a 2" Super Sucker carb spacer. 3rd we'll replace the stock 906 heads with some ported 516 heads. These heads will bump the compression to 7.85:1 and will flow about 250 cfm @ .500" lift. We'll not be getting the full .509" lift from the cam because we are still using the stock stamped steel rockers.

Here we go,

............................509....................850 w/spacer...............ported 516

RPM.....................TQ/HP......................TQ/HP.........................TQ/HP

2500..................360/171...................359/171
2600..................371/183...................373/184
2700..................384/197...................382/196
2800..................396/211...................392/209
2900..................407/225...................412/227
3000..................409/234...................431/246......................434/248
3100..................415/245...................441/261......................445/263
3200..................425/259...................442/269......................457/278
3300..................436/274...................450/283......................458/288
3400..................432/280...................449/290......................462/299
3500..................432/288...................449/290......................458/305
3600..................430/295...................436/299......................447/307
3700..................428/302...................435/306......................443/312
3800..................425/307...................430/311......................443/321
3900..................421/312...................434/322......................446/331
4000..................419/319...................438/333......................450/343
4100..................419/327...................445/347......................453/354
4200..................419/335...................444/355......................461/368
4300..................416/341...................443/362......................463/379
4400..................412/345...................434/363......................461/386
4500..................403/346...................432/370......................470/402
4600..................399/349...................429/376......................473/414
4700..................400/358...................427/382......................468/418
4800..................389/356...................419/383......................467/427
4900..................388/362...................415/387......................459/428
5000..................377/359...................405/386......................459/437
5100..................366/355...................391/379......................453/439
5200..................359/355...................383/379......................453/448
5300..................345/348...................374/377......................445/449
5400.................................................361/372......................428/440
5500...................................................................................421/441
5600...................................................................................407/434
5700...................................................................................397/431
5800...................................................................................391/431

What a piece of crap, we've only gained 227 HP @ 5500 RPM vs the first pull.

Thanks very much for the info this is fantastic and a wealth of info.
Makes for an outstanding street engine

 

[IQ52]

Would these gains be possible with a smogger 400? The C/R is about the same.

You can expect gains with the 400, not to the extent you will get with the 440's longer stroke.

That's pretty amazing and thanks for doing this IQ52 !

Question why does the last column of numbers not start until 3000 RPM? Also a request if possible and you don't mind .. if you have no more mods to make or gear to swap out it would be interesting to see a swap back to the HP manifolds and see what the power loss is if you haven't broken this set up down yet or if you have a more to try with this motor could you try the HP manifolds at the end?

I didn't see any benefit in worrying the engine down there when we were going to wind it higher. The power would have been the same as the previous pull.

Lots of people want to see how the HP manifolds do in this situation. The engine will be on the dyno for a few more weeks, but elk season is coming up, I don't know how much time we will have for what.

This is a great thread with tons of useful info, and at a great time because I am at the point of thinking about the motor for my Charger. IQ52 - what are your thoughts on the mp528 solid cam for a street car?

If I already owned a 528 I might try it. I'm not going to buy one for that purpose.

The thing I'm taking away from this is that, even with good-flowing ported heads and a cam with pretty big duration, the power still peaks at 5,400 rpm. So to me, there's no reason to wring these things up to 6,000 rpm before you shift. These torque monsters like to be short-shifted and kept in the mid-range IMHO.

I bet a switch to some Stealth or RPMs and a cam swap to a solid cam could get it to break 500 hp pretty easily.

The cylinder heads are the power peak limit in this situation. The Stealth or RPM heads would need a good valve job, but after that they should give better results than the 516 heads.

Every engine is an experiment of one. We haven't tried much in the way of tuning and the dyno data says that this engine wants more carburetor still. If we drop the oil pressure, go to 1.6 adjustable rockers, another intake and 950 cfm carburetor there is more power available.

We were just using the junk we had laying around to have a dyno day for people to come by and get introduced to our shop.

 

[rumblefish360]

How would those ported 516's compare to say OTB Stealth? What would the differences in chamber volume be?
By the time a person rebuilds a set of 516's and had them ported would the Stealth be a better choice?

This is my take on iron vs. aluminum heads. The budget can rule the day. Even if you can afford new aluminum heads, is it worth the expense? Probably in most cases but before you jump on a set, realize your goal and needs to achieve it.

Can a set of bowl ported iron deliver enough air to do the job? What would the cost be.
How far can the iron be ported? Vs. the Aluminum head being entertained for the build as a OOTB head?

With these 2 factors in place, I see no reason a set of re worked iron heads could be used. The rebuilding should be cheaper! Vs the OOTB Aluminum heads that still need a machinist to check out at a added cost.

While the iron head certainly has limitations, if it can flow enough air to meet the need, why not? Of course, if your cam has a big lift where the aluminum head can out do the iron, well there's the perfect red flag to dump the iron head.

There is room to grow with the aftermarket head. Will you use it?

Get the head you need.

 

[tallhair]

Lots of people want to see how the HP manifolds do in this situation. The engine will be on the dyno for a few more weeks, but elk season is coming up, I don't know how much time we will have for what.

Thanks IQ52. I hope you are able to find the time for the HP manifolds before elk season kicks in but appreciate your efforts nonetheless.

 

[IQ52]

Thanks, Jim, for this test. I've been planning / budgeting for a motor to replace my low compression '72 413 and now instead of spending $5000-$8000 on a motor, I might just review my combo and make a few changes and get pretty close to my goals on the cheap.

- - - Updated - - -



Based on your testing, what do you think would be a nice optimized combination for one of these low compression engine? I realize you were trying to stay w the parts that were at hand or were loaned, but if you had a choice of your cam, intake, heads, etc, for this shortblock, what would they be? Obviously this kind of build would be a budget street setup with maybe some fun at the strip from time to time.

Thanks again.

- - - Updated - - -

Would a solid cam net any gains over a hydraulic at these rpms and performance levels?

Some solid cams would and some solid cams would not.

Have you noticed that I don't "recommend" a cam, intake, heads, compression and I don't design an engine combination here on the forum? I report what I have discovered at times.

The reason I don't make an engine design recommendation, is that people don't put the engines together the way I do, even if they use the same parts. If we take the same pile of parts and attempt to build an engine that performs exactly the same it ain't gonna happen. I am here to help out, and I believe I have with this thread. Use the information to extrapolate what may be best for your build. But simply and more direct, I design engines for those that have me build their engines. Mercenary yes, I'm not going to lie about it.

If I was building the engine in this thread for myself or a customer, it wouldn't have been built as it was. It was just to get us through our "dyno day" and I thought others would be interested to see from a quantitative stand point what you could accomplish with the parts changes we just had laying around. I bought the 509 camshaft because it came with lifters, I didn't want a 509, I wanted a set of lifters for the $50 I paid for the cam kit.

- - - Updated - - -

This is my take on iron vs. aluminum heads. The budget can rule the day. Even if you can afford new aluminum heads, is it worth the expense? Probably in most cases but before you jump on a set, realize your goal and needs to achieve it.

Can a set of bowl ported iron deliver enough air to do the job? What would the cost be.
How far can the iron be ported? Vs. the Aluminum head being entertained for the build as a OOTB head?

With these 2 factors in place, I see no reason a set of re worked iron heads could be used. The rebuilding should be cheaper! Vs the OOTB Aluminum heads that still need a machinist to check out at a added cost.

While the iron head certainly has limitations, if it can flow enough air to meet the need, why not? Of course, if your cam has a big lift where the aluminum head can out do the iron, well there's the perfect red flag to dump the iron head.

There is room to grow with the aftermarket head. Will you use it?

Get the head you need.

Good points. Remember all, this stupid low compression 440 made 387 HP with stock 906 heads. Do you know what a 387 HP punch in the back feels like? Its pretty wild.

 

[HT413]

Some solid cams would and some solid cams would not.

Have you noticed that I don't "recommend" a cam, intake, heads, compression and I don't design an engine combination here on the forum? I report what I have discovered at times.

The reason I don't make an engine design recommendation, is that people don't put the engines together the way I do, even if they use the same parts. If we take the same pile of parts and attempt to build an engine that performs exactly the same it ain't gonna happen. I am here to help out, and I believe I have with this thread. Use the information to extrapolate what may be best for your build. But simply and more direct, I design engines for those that have me build their engines. Mercenary yes, I'm not going to lie about it.

If I was building the engine in this thread for myself or a customer, it wouldn't have been built as it was. It was just to get us through our "dyno day" and I thought others would be interested to see from a quantitative stand point what you could accomplish with the parts changes we just had laying around. I bought the 509 camshaft because it came with lifters, I didn't want a 509, I wanted a set of lifters for the $50 I paid for the cam kit.

No worries, I figured it wouldnt hurt to ask. I dont give away my sevices either lol.

 

[AMX364]

What people forget on iron heads is the work for unleaded gas that must be done. If you remember to factor that in the budget then the costs get much closer.

 

[rumblefish360]

IQ52, I sure do.

With the point I was trying make and a direction I was trying to suggest to follow is there is no sense in spending lots-O-money on a part that you really may not or don't need when a OE part will do.