Doing a little dyno testing on a low compression 440.

[heyoldguy]

Yep, put a 1972 440 on the dyno today to test out a few ideas, you know, like headers, camshafts, intakes, carburetors and heads. The first pull had it set up like this, '72 440 with .040" overbore for 448 ci, cast crank, cast pistons .160" down in the bore for 7.45:1 compression ratio, 906 heads, 1972 cast iron intake manifold, 1967 600 cfm Carter 4bbl, Summit Racing SUM-6400 camshaft 214/224 @ .050 .444"/466" lift 112 LS 106 ICL, 1964 stock cast iron exhaust manifolds. Results,

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

2500.............414...............197
2600.............402...............199
2700.............403...............207
2800.............402...............215
2900.............399...............220
3000.............403...............230
3100.............397...............235
3200.............399...............243
3300.............399...............251
3400.............391...............253
3500.............385...............257
3600.............380...............261
3700.............371...............262
3800.............365...............264
3900.............358...............266
4000.............350...............266
4100.............348...............271
4200.............336...............268
4300.............332...............272
4400.............323...............271
4500.............313...............268
4600.............304...............266
4700.............295...............264
4800.............283...............259
4900.............267...............249
5000.............260...............248
5100.............249...............241
5200.............231...............229
5300.............225...............227
5400.............214...............220
5500.............204...............214

The second pull today was with the HP exhaust manifolds, nothing much to report other than they lost 1 lb-ft of torque and gained 4 horsepower. Don't waste your money unless you are doing a restoration.

So, if you want to hang on, we'll take you through some bolt-on's we did today that took us to 463 lb-ft and 440 HP while NEVER taking the compression ratio beyond 7.8:1. We went to headers, bigger carb, aluminum intake, camshaft, even bigger carb and then ported 516 factory iron heads. 

[Brutalowner]

This is gonna be great info! Be curious what a RV 440 makes with a repo Magnum cam, current Eddy dual plane, 800cfm Eddy carb thru 452's and 1-7/8" headers....

[heyoldguy]

Guess I should state that we wanted at least 1hp/ci. So we did a little tuning just to finish off the day and got to 473 lb-ft and 449 HP. It was still making 431 HP at 5800 rpm where we shut it off.

[moparguy01]

I'm very interested in this as my 78 new yorker has a low compression 400 that needs some help. I'm sure it would respond similarly.

[myk]

Curious to see how my '78 440 would do on that dyno...

[heyoldguy]

Let's put the dyno headers on and see if there is any improvement, shall we?

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

2500..............427................203
2600..............422................209
2700..............416................214
2800..............419................223
2900..............419................231
3000..............419................239
3100..............417................246
3200..............417................254
3300..............414................260
3400..............406................263
3500..............400................266
3600..............393................269
3700..............386................272
3800..............376................272
3900..............376................279
4000..............368................280
4100..............365................285
4200..............357................285
4300..............348................285
4400..............342................287
4500..............328................281
4600..............318................278
4700..............311................278
4800..............298................272  +22 HP
4900..............278................259
5000..............271................257
5100..............263................255
5200..............247................244
5300..............234................237
5400..............224................230
5500..............213................223

At least the horsepower went up across the entire RPM range. It gained 11 HP peak to peak with a maximum gain of 22 HP at any one rpm.

[Cooter]

I'm a bit confused...you state you "NEVER" touched the 7.8:1 compression, but bolting on 516 closed chamber heads doesn't bump compression?
Still, fairly good nunbers for cast crank, low comp engine.

[heyoldguy]

I'm a bit confused...you state you "NEVER" touched the 7.8:1 compression, but bolting on 516 closed chamber heads doesn't bump compression?
Still, fairly good nunbers for cast crank, low comp engine.

With the combustion chamber work on the 516 heads they only bump the compression to, well, maybe I mis-spoke a little, I just rechecked and we are at 7.85:1 compression. With the 906 heads we started at 7.45:1 compression. I believe I said, "never taking the compression ratio BEYOND 7.8:1"

[tan top]

: intresting stuff   , thanks for sharing the info 

[Scaregrabber]

Great info, keep it coming.

Sheldon

[Musicman]

 

[Brass]

This is great!  There are a lot of low comp motors out there. 

[heyoldguy]

So then, for pull #4 all we did was change to an 750 cfm Edelbrock Performer carburetor. Pull #5 was a swap to an Mopar M1 single plane intake keeping the 750 Edelbrock.

RPM...........#4 TQ/HP...................#5 TQ/HP

2500............432/206......................416/198
3000............424/242......................415/237
3500............406/270......................418/279
4000............376/286......................395/301
4300............363/297......................381/312
4500............338/290......................363/311
5000............274/261......................298/283
5200.............................................265/263
5500............207/217

For pull #6 we change the cam and break 350 HP. Remember, we'll still be at 7.45:1 compression.

[heyoldguy]

Lets get the last three pulls out of the way.

#1 cam swap to the MP 509.

#2 add an 850 cfm Mighty Demon and a 2" Super Sucker carb spacer, used the spacer because the fuel lines hit the coil tower bosses on the manifold.

#3 swap the stock 906 heads for some ported 516 heads that flow 250 cfm at .500" lift. These heads flow approximately 20 cfm more than the 906 heads through out the entire lift range and will raise the compression ratio to 7.85:1.  oof, better get out the race gas!

....................509...............850 carb & spacer.......ported 516 heads

Lift...............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.................441/262..................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.................441/294..................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.......................................361/373..................428/440
5500....................................................................421/441
5600....................................................................407/434
5700....................................................................397/431
5800....................................................................391/431

Well there you are, vs the very first pull we could only gain 177 HP peak to peak, and just a 227 HP increase @ 5500 rpm. Junk
                                                                                                                                                                          junk
Still UNDER 8:1 compression. Ka-ching, did I just hear the price of low mileage motorhome engines just go up?                              junk
                                                                                                                                                                                      junk                       

[HPP]

Great info. I can't count how many times we see someone wanting to know what they can do with their low mileage, doesn't need a rebuild, '78 440.

[heyoldguy]

Yep, and that was just one afternoon changing parts in a big hurry. We'll be trying other things.

[firefighter3931]

Those are some descent results and what i would expect from a 250cfm cylinder head and that combination of parts. I don't see it being very street friendly though with that 509 cam and sub 8:1 static compression. The M1 with a 2in spacer won't clear a stock hood so it would be hood scoop time. 

That combo would need deep gears and a loose converter to be somewhat streetable. 

Good info and thanks for posting Jim 



Ron

[heyoldguy]

Now I want to put it into my 72 Satellite with the stock converter and the 2.76 gears and see how it works.

[Cooter]

So the prices of cast crank junk will stay the same if the cost duplicate what you've done here is like FI Vs carbs...
All depends on how much it takes to get a low comp motor to perform like a high comp motor that Chrysler already took the hit on...
Would be very interested in a cost per hp gained on a build like this. Or a total for the build...
Afterall, those FAST guys look like stock cars and run rediculous times, but enough money and anything can be forced to perform...

[firefighter3931]

Now I want to put it into my 72 Satellite with the stock converter and the 2.76 gears and see how it works.

I'd like to see that too 

My guess is that tuning this with a stock converter would be real fun...in gear the converter would pull the engine down bigtime. You'd have to crank up the idle speed and the idle circuit would become a non player. 

This one would start and run with the distributor locked out....no problem  I'd be willing to bet that it made peak power at well over 40* of timing   

Be interesting to see how it performs at the track....


Ron

[Budnicks]

  Thanks Jim all great informative posts, keep them coming... 

Let's put the dyno headers on and see if there is any improvement, shall we?

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

2500..............427................203
2600..............422................209
2700..............416................214
2800..............419................223
2900..............419................231
3000..............419................239
3100..............417................246
3200..............417................254
3300..............414................260
3400..............406................263
3500..............400................266
3600..............393................269
3700..............386................272
3800..............376................272
3900..............376................279
4000..............368................280
4100..............365................285
4200..............357................285
4300..............348................285
4400..............342................287
4500..............328................281
4600..............318................278
4700..............311................278
4800..............298................272  +22 HP
4900..............278................259
5000..............271................257
5100..............263................255
5200..............247................244
5300..............234................237
5400..............224................230
5500..............213................223

At least the horsepower went up across the entire RPM range. It gained 11 HP peak to peak with a maximum gain of 22 HP at any one rpm.

So then, for pull #4 all we did was change to an 750 cfm Edelbrock Performer carburetor. Pull #5 was a swap to an Mopar M1 single plane intake keeping the 750 Edelbrock.

RPM...........#4 TQ/HP...................#5 TQ/HP

2500............432/206......................416/198
3000............424/242......................415/237
3500............406/270......................418/279
4000............376/286......................395/301
4300............363/297......................381/312
4500............338/290......................363/311
5000............274/261......................298/283
5200.............................................265/263
5500............207/217

For pull #6 we change the cam and break 350 HP. Remember, we'll still be at 7.45:1 compression.

Lets get the last three pulls out of the way.

#1 cam swap to the MP 509.

#2 add an 850 cfm Mighty Demon and a 2" Super Sucker carb spacer, used the spacer because the fuel lines hit the coil tower bosses on the manifold.

#3 swap the stock 906 heads for some ported 516 heads that flow 250 cfm at .500" lift. These heads flow approximately 20 cfm more than the 906 heads through out the entire lift range and will raise the compression ratio to 7.85:1.  oof, better get out the race gas!

....................509...............850 carb & spacer.......ported 516 heads

Lift...............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.................441/262..................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.................441/294..................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.......................................361/373..................428/440
5500....................................................................421/441
5600....................................................................407/434
5700....................................................................397/431
5800....................................................................391/431

Well there you are, vs the very first pull we could only gain 177 HP peak to peak, and just a 227 HP increase @ 5500 rpm. Junk
                                                                                                                                                                         junk
Still UNDER 8:1 compression. Ka-ching, did I just hear the price of low mileage motorhome engines just go up?                              junk
                                                                                                                                                                                     junk                        

Now I want to put it into my 72 Satellite with the stock converter and the 2.76 gears and see how it works.

[heyoldguy]

So the prices of cast crank junk will stay the same if the cost duplicate what you've done here is like FI Vs carbs...
All depends on how much it takes to get a low comp motor to perform like a high comp motor that Chrysler already took the hit on...
Would be very interested in a cost per hp gained on a build like this. Or a total for the build...
Afterall, those FAST guys look like stock cars and run rediculous times, but enough money and anything can be forced to perform...

Cost? Lots of people wondering the same thing. I figure anybody with a computer can spend 20 minutes on the Summit Racing website and figure the whole thing out. If that's too much work............well.......

[XH29N0G]

Thanks for posting this.  I appreciate reading the discussion and results of your testing, and also liked the suspense.   

[Homerr]

Wow, cool info!   

[BigBlockSam]