Iron head test starting on '78 440.

[DMR440]

Killer thread! Thank you for doing this. Many questions arise but I'm impressed the thing made 450HP with ported 516's. What was the intake/exhaust flow/CFM with those heads. For the average Joe like most of us here I'm guessing the 250CFM you had suggested (in another thread) in any head will make an easy 500HP on a budget with a good cam, intake, carb, headers etc while keeping the RPM at a realistic livable level. How much machining/balancing went into assembling each part? This has to be part of the whole combo for it to perform as well as it did with low comp and RPM?... still have a few more Q's on this... very impressed with your skills and expertise. Thanks for keepin it real

 

[IQ52]

516 head flow on the day of the dyno demonstration.

Lift.........Intake/exhaust

.100............85/62
.200..........160/132
.300..........210/182
.400..........237/203
.500..........250/216
.600..........261/229

Machining and balancing huh? That's a laugh! This was a stock engine we pulled out of the bone pile. It had been previously rebuilt .040" over and there was no ridge at the top of the cylinder, so we gave her the old flexhone with new rings and bearings and fired her up.

 

[IQ52]

We're going to do it, it goes into the Satellite tomorrow.

 

[70bigblockdodge]

First off kudos to you for exposing some myths and misinformation in this awesome thread. I usually hang out over on for c bodies only, they are very anti header over there, mostly because of limited headers offered for those cars, read:cheap ones, big on hp manifolds so it was very cool to see the near zero gain over the regular logs which are way easier to find and cheap! I love this thread because I reringed and bearinged a 77 440 in my bro-in-law challenger, stock pistons are down at.120 changed to forged crank due to 4-speed just for neutral balance. I pocket ported the bowls, profiled the guides a bit, opened pushrod pinch a little, gasket match, and a general smoothing core shift nothing crazy, and back cut valves all on 452's, I didn't cc them but if my compression is over 8 I would be shocked, has a eddy perf. rpm and 750 eddy carb and a used 509 cam with hp manifolds. We put a 2.94 rear in the car and after some tuning (it still needs more) car gave 13mpg Pittsburgh to Columbus Oh runs on 87 octane at 35btdc took it to Norwalk in sept ran it only got a disappointing best of 14.92 out of the car, now before you all laugh, always check your details, after returning home I started checking to see if there was anything obvious and found out that carb wasn't opening all the way about 3/4 on primary which is even less on secondary side, yes I just smacked myself again in the head, car runs even stronger now I think I have some secondary side jetting and I may go back in and change cam timing as I think I retarded it instead of advance, or at least put it at 108 ctr line that it is supposed to be at. Never made it back to track after throttle issue I'll try to post something in the spring. There is nothing wrong with 12:1 motors withsolid rollers at 500in and $750 forged pistons, but boy it is more fun to pull into the D.Q. with lopy cam and people thinking its fast, meanwhile its a smogger with 1977 cast pistons a free cam and lifters runs on junk gas gets mpg you can live with in a muscle car, and if some dummy would have payed more attention with the throttle cable might actually have a time they can be proud of. LOL.

 

[dieseldazzle]

Man what a great test!

 

[Doba76]

Huh, apparently it's international ask a question on a three year old thread day. Anyway, all parts being equal, would you expect similar gains for a 77 400? It's a low mile engine, so I'm hoping the compression ratio is still close to the 8.0:1 that it supposedly left the factory with. Unfortunately I'll be running a Torker on it as it's what I have right now, and it was free, but if I find it hurting the bottom end too much, I'll punt it for a dual plane.

*EDIT* Completely ignore me, just found the thread on the 400 slug. Great info!

 

[MOPOWER871]

There should be tests and information all over the internet of what horsepower difference you get with a compression ratio change only. If I'm being generous I'll say you get 4% increase with one more point of compression. For a 400 HP engine, if you raise the compression one point, from 9:1 to 10:1, you'll see 12-16 HP increase. It's the reason if I'm building a pump gas engine for someone else I keep the compression ratio into the really safe range, it just doesn't cost that much horsepower.

One of the more intense question will be answered during these tests, "How many times can you reuse a FelPro 8519 PT1 head gasket?" With all the head changes we plan, we'll have a stack of them on hand, but we're gonna reuse them until they are really worn out.

- - - Updated - - -



Sadly this is going to, at least in the beginning, test how much horsepower you can get with the factory iron heads in various states of porting. We've been throwing away 516 heads for years now simply because they aren't very good. But a lot of people want to run them just because they are going to get a smidgen of compression increase, bah! So we'll work them over and see what they will do. We've seen the difference on the flowbench, differences in valve seat angles, but we have no real test to see where it makes a power difference, if any. Some test results may not be revealed just so we can have some secrets.

WOW. that was great

 

[Garys1969RR]

Yes, it is International dig up a 3 year old thread day/week! I love it! Good way to pass the time on these long winter nights. I've unearthed a few myself recently! Ha!

 

[Garys1969RR]

Hi Doba, although the various things he did to the 440 made power gains, usually the biggest improvement comes from improving the cyl head port flow.You can have the best intake, carb, headers and cam, but if the heads won't flow the air needed, they will be a restriction in the whole system. So yes a 400 will see increased power output from the Hi Perf items. Start with good heads.

 

[IQ52]

Doesn't the MOPAR world just wish that those were stock 516 heads! No the very best stock 516 port we ever tested was:

.100............65/45
.200..........126/94
.300..........176/130
.400..........203/144
.500..........222/151
.600..........228/153
.700..........234/156

I'm not sure what people do to crack their heads. We have designed and built derby engines to run start to finish without water, the longest was thirty minutes. The valves turned blue, the camshaft bearings melted out of the engine and we reused the heads in a water engine. The heads had some serious valve guide issues but that was it.

This has bothered me for all these long years. I've never tested a stock 516 with this much flow. These are the best flows we ever got from a stock 906 head.

 

[PRHeads]

Today is comment on an old thread day??
Sure...... I can do that.....

I hardly ever do anything with 516 heads, so I had to go back a ways to find any info......

This was a nice unmolested head that didn’t have the seats pounded out to no man’s land.
Intake test only-
A- stock head, oe 2.08 valve and valve job
B- install 2.14 valve with back cut, 5 angle seat, mild bowl blend

Lift—— A/B
.100— 61/74
.200—128/142
.300—179/197
.400—202/227
.450—212/236
.500—217/240
.550—221/242
.600—225/244

The best untouched 906 I’ve tested wasn’t even a whole head...... it was like a piece of a head that had been cut in 1/2.
It was an F head, and was unusually good.
I don’t even know where the sheet went, but it went like 240 for the big number.
Not all F heads are good, but supposedly they’re considered the “good” ones. But I’ve seen them also only flow in the mid-220’s...... so they arent all magic.

 

[PRHeads]

On the small screen on my phone, the big spaces between the columns get all jumbled up and I can’t make heads or tails of how the numbers compare......... so I tightened up the columns for easier small screen viewing:

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.