1974 440 HP Has No Power

[Mike DC]

 

Blowing 105 psi is the classic 7.8:1 cast slugs.

Put an 8-71 on top.  Problem solved.   

[Nacho-RT74]

From the front driver side here is what we got
DS           PS
105         113
100         110
105         110
105.        115   

So the Driver side pressures are what I consider a lot lower than the passenger side.

Just thinking out loud, I could consider the diff maybe just about a "WONDERFULL" Machinist job from factory when decking the block after the casting getting one side lower than the other. Not really uncommon.

[c00nhunterjoe]

 

Blowing 105 psi is the classic 7.8:1 cast slugs.

Put an 8-71 on top.  Problem solved.   

Not really. The dynamic compression ratio of the said engine is probably in the 6s depending on the cam profile.its got the wrong cam, wrong heads, wrong pistons and wrong rods and wrong exhaust for an 8-71. A 125 shot of nitrous would live for years on that engine with a stock rotating assembly and be a far better choice then a blower.

[John_Kunkel]

https://help.summitracing.com/app/answers/detail/a_id/4988/~/supercharging-basics-%E2%80%93-engine-preparation

[Mike DC]

   

Not really. The dynamic compression ratio of the said engine is probably in the 6s depending on the cam profile.its got the wrong cam, wrong heads, wrong pistons and wrong rods and wrong exhaust for an 8-71. A 125 shot of nitrous would live for years on that engine with a stock rotating assembly and be a far better choice then a blower.

I was just making a joke about the CR being so low.   

[Kern Dog]

I got the joke, Mike!   

[c00nhunterjoe]

 

Not really. The dynamic compression ratio of the said engine is probably in the 6s depending on the cam profile.its got the wrong cam, wrong heads, wrong pistons and wrong rods and wrong exhaust for an 8-71. A 125 shot of nitrous would live for years on that engine with a stock rotating assembly and be a far better choice then a blower.

I was just making a joke about the CR being so low.  

I got the joke too, but some people are probably ordering an 8-71 because of it and more are ordering spray... in all honesty, a 6-71 would be better suited anyway.

[Mike DC]

 

I got the joke, Mike!  

I got the joke too, but some people are . . .

Glad it wasn't a total miss.    
   

in all honesty, a 6-71 would be better suited anyway.

Yeah the 6-71 would be better for low/mid-range driveability.  

But, as a solution to an inadequate CR, the 8-71 idea sounds even more ridiculous than a 6-71.  Critical factor in my decision.    
 

[mel t]

Passenger side plugs still installed during the test on the driver's side?
How much compression in your 389 using the same gauge?

[Kern Dog]

I started doing the following when I did compression tests:

Remove all spark plugs.
prop the throttle open.
Attach a battery charger to the battery to maintain voltage.
cross the terminals on the relay to spin the engine 5 times.
Record the highest point where the gauge needle swings.

These are the numbers when I had almost 11 to 1 compression and a Mopar 292/509 cam. The left side had 1.6 rockers, the right were stock 1.5s.

[c00nhunterjoe]

If you need to hook up a battery charger and setup an in depth prep to run a basic compression test- we have issues. I see this all the time. Just pull the plugs and record the numbers. If you have that many other problems that you need to prep for the test...  well. I dont know.

[mel t]

Text Book; Engine Compression Test -- for EFI, but still useful info.
A well-sealed cylinder should make 50% of its total compression in the first stroke -- use a remote starter button, record 1st, and 4th strokes.
The minimum spec for most gas engines is 100psi. If you're really at 100psi, you have problems. Verify your gauge is correct, and the test is consistent -- ALL plugs removed, cylinders dry, battery charged.

1.   Charge the battery if the battery is not fully charged.

2.   X Disable the ignition system. X

3.  X Disable the fuel injection system. X

4.   Remove ALL spark plugs.

5.   X Turn the ignition to the ON position. X

6.   Depress the accelerator pedal to position the throttle plate wide open.

7.   Start with the compression gage at zero and crank the engine through 4 compression strokes, 4 puffs.

8.   Measure the compression for each cylinder. Record the readings.

9.   If a cylinder has low compression, inject approximately 15 ml (1 tablespoon) of engine oil into the combustion chamber through the spark plug hole. Measure the compression again and record the reading.

10.   The minimum compression in any 1 cylinder should not be less than 70 percent of the highest cylinder. No cylinder should read less than 690 kPa (100 psi). For example, if the highest pressure in any 1 cylinder is 1 035 kPa (150 psi), the lowest allowable pressure for any other cylinder would be 725 kPa (105 psi). (1 035 x 70% = 725) (150 x 70% = 105).

•   Normal — Compression builds up quickly and evenly to the specified compression for each cylinder.

•   Piston Rings Leaking — Compression is low on the first stroke. Compression builds up with the following strokes, but does not reach normal. Compression improves considerably when you add oil.

•   Valves Leaking — Compression is low on the first stroke. Compression usually does not build up on the following strokes. Compression does not improve much when you add oil.

•   If 2 adjacent cylinders have lower than normal compression, and injecting oil into the cylinders does not increase the compression, the cause may be a head gasket leaking between the cylinders.

[tonyskala]

Ok, so here is what happened.

We could not get this thing to go into 3rd and reverse was really slow to engage.

So I took it to Transmatic in Oakland CA and left it. ( This guy has done lots of work for me on Mustangs, my Pontiacs, and my camareo) he has treated me right every time and sold me some parts extremely cheap that he had for the GTO.

So he called me and told me the linkage and adjustments we did were fine but the transmission seemed to have a bad clutch in it and rather than replace the bad ones he would prefer to rebuilt it and put in a slick shift kit into it.

So when he opened it he sent me some pictures of the clutch plates and 1 had completely delaminated and other rings had warped and 1 had even broke. So he told me for 1000 he would rebuild the whole thing. So it is getting a rebuilt transmission. And I suspect t will drive a hell of a lot better.

Then when we get it back we will adjust the timing like suggested. Get it to run correct. then from there we will decide on the engine.

[c00nhunterjoe]

upgrade the sprag while its apart.

[FJ571440B]

Being a '74, and if it's all stock, you'll never make real power with that wrist pin where it is at on the piston. I believe that is how they dropped the compression ratio, by raising the wrist pin bringing the piston down. Please correct me if wrong

[Kern Dog]

While low compression certainly hurts, it isn't  a death sentence. You can make po :2thumbs:wer with a low compression engine. Ask Jim LaRoy if you can find him!

[ACUDANUT]

Don't forget the zinc in your oil. Maybe too late 

[tonyskala]

Thanks for all the advice...

So we have car back did more fiddling and tuning and it is now much better than we got it. I am able to drive it around with out much issue.

We got all the gauges to work except oil pressure. We kept throwing a belt but swapped it out for a new shorter one and I can now take it on the freeway at 80 and it powers on. No tach in it but I suspect we are at 4 grand at 80mph. We moved the timing up like suggested and it sort of starts right up and after it warms up it starts and stops with out any issue. No choke on it. It has a mild flat spot on it accelerating out of a stop but it moves like a proper 6 cylinder mustang.

What I am saying is it still lacks power. I dont think this thing was ever for a muscle car. It has to be a motor home engine. But It is drivable and sounds mean and gas milage is up to around 15 miles a gallon. So it is tolerable. I am not sure we will get it much better than it is now with what is in the car.

In light of it working I am moving is a slightly different direction right now.

As I stated we got a Holley Sniper EFI and we will install that in the next 2 weeks. I got a new fuel tank with the baffles, All the plumbing and pumps. When we get that in we will tune it to make it run well and hopefully it will just be better on start up and get better gas milage.

Then I got a QA1 level 1 suspension kit with the shocks. I got a Pirate jack disk brake conversion kit, and all new tie rods, pitman arm, and idl arm and a new 1-1/8 sway bar.

I plan to get a new steeering column as well as this one has been slightly hacked with a grinder for a hazard switch and there is a kew slot in it that is not for anything.

Since all that is steering and suspension related I was thinking (EFI Aside) we will do all that at once. and get it to stop wobbeling and pulling so much. Then with the EFI It will keep my happy until Thanksgiving.

Now I am still looking into this engine. I will at some point rebuild it or have it replaced. I just am not sure. There is a 440 I found in the LA area and the guy was asking 4k. He sent me over some of the build specs and it doesnt look like it is terrible. It has never been run and the builder who built it has on the sheet it an estimation of 425 to 450 hp. So I then called around here for a shop to rebuild mine and got quotes as high as 7k down to 2,300. I asked simply for a short block build and told them the top end would be provided. So if I rebuilt mine I am guessing with the purchase of the top end kit I would be into it for 4500 to 5000. So the one already done looks promising.

But that is going to be a few months down the road. Right now. Steering , suspension and EFI are on the list.

Thanks for all the suggestions. I really appreciated all of it.  I will probably have more questions on the suspension as I have never worked with these torsion bars.

[tonyskala]

So I have been enjoying the car for a couple of weeks. The car is much much better but it would not win many, if any speed contests. I just cruise around at moderate  speed and people think it is a beast because I will not get on it.

Anyway driving around a week ago I heard a really loud bang and then some serious pulling from driver side front wheel. Brake idiot light came on. Had it towed home and have not looked at it yet as I bought a pirate jack 4 wheel disk brake kit and was planning to change them over anyway.

Been researching how to do the conversion and in the process determined that it would be a good idea to change out all the suspension components and bushings.

Like I said I got the Pirate Jack 4 wheel disk brake kit, new QA1 upper control arms, new QA1 front and rear shocks, new new dynamic strut bars, new lower ball joints, new inner and outer tie rod ends, new lower control rod shafts with greasable fittings an Addco 1-1/8 front sway bar and all the bushings to replace this stuff.

Because I did not have a good press I was also going to get the QA1 lower control arms, but it turns out they are not compatible with b body sway bars. You have to buy the QA1 K member and then you can use an a body sway bar. Well that k member and lower control arm set up would cost about 1800 and it turns out it pushes your motor back about 3 inches which means the drive shaft would need to be shortened.

So I am opting to just rebuild the lower control arms. I winded up getting the boxing plates to strengthen the lower control arms. Plan to start the work this weekend. This work should make it drive and stop like a brand new car.

My only real concern is pressing out the old bushings on the lower control arms and working with these torsion bars and breaking them free to remove the lower control arms.

[Kern Dog]

The loud noise surely was from something coming apart in the drum assembly. I had a spring pop off and jam against the shoe. SCREEEeeeeech!
I had a set of disc brakes pulled from a 75 Dart ready to go on, so I parked the car and did the swap the next weekend.
Good luck with the car!

[tonyskala]

So this thing had a ton of grease and dirt under it. It took me 4 hours to degrease and pressure wash the damn thing, And there is still a ton of dirt and grease on it.

Anyway I got it all apart. The driver side brake shoe pads ( both of them ) separated from the Brake Shoes. I got it all of and I have 2 issues so far.

1 I can not seem to get the rubberized coating I sprayed on to dry. It has been like two days and it is still tacky.

2. I can not get these bushings out of the lower control arms. I knew it would be a issue but man I banged on those things for like an hour. I stopped mid way and welded in the stiffening plates because I was banging on this thing so long I thought I was bending them.

I cant believe how poor of a design these things are. Dodge did not want these things coming out. I welded in washers and will try tomorrow to press them out. I have to go to harbor freight to get  press first. My hands are beat to hell. I have caught them on so many burs.

So I do have a question. I have new QA1 Upper control Arms. DO I tighten them up in the resting position down unlaoded position or should I load it like 1/4 of the way up and then tighten them up? Do I assemble the bottom contol arm and then load it with the torson bar and then tighten the  top

[Kern Dog]

Control arms and strut rods get tightened with the car on it's tires.

[Challenger340]

My understanding is the OP's trans calved....
was a substitute T/Convertor with slightly higher stall speed considered/installed, while the Trans was out being rebuilt ?  as was suggested earlier on Page #2 to allow the low-comp engine a 'run' into it's Torque Band
(ie: Saturday Night Special T/Convertor ?)

Just say'in.....
if the purpose of this Site and thread is to assist enthusiasts with their mopar efforts.... by relating practical tried/true and proven through experience tips/tricks and advice ?
Then what's the point providing the benefit of that experience trying to help with 'issues' if the advice gets ignored..... and the OP continues relating the exact SAME problem being NO POWER ?

Forgive me for saying so.... but this thread seems a complete waste of time if you are/were trying to correct the chief complaint being NO POWER ?

Here you were told on page #2
one of the best additions we found on those very low compression engines on the Auto Cars, albeit, ups the $ and labor investment was the addition of a Saturday Night Special type Torque Convertor. Something that gives an honest 2200-2400 stall is great even with 3.23 cogs.  
The extra Torque Multiplication down low just gives the low-pop engines a much needed bit of a 'run' into their power range where they can begin building cylinder pressure.

Yet, while the Trans was OUT and being rebuilt..... it seems NO T/Convertor was substituted for a very few hundred Dollars....
and yet....
the OP is contemplating an EFI setup for Thousand + Dollars to make even LESS power than a Carb(yes EFI makes LESS power especially on the low-pop engines)..... and the Engine is still slower than molasses ?

Just seems for every ONE step you try to take forward..... you take THREE steps backwards making the Engine even slower ?

[c00nhunterjoe]

   yup. 100%. I would personally go a little looser then that. Everyone is scared to death of converters. I would stick something that flashes closer to 3k in it. Hell, my stock silverado comes with a 3k from the factory. There is so much misconception that the flash number is where the converter will sit all the time.

[INTMD8]

Agreed on the converter. 

I've never heard of a Silverado with stock 3k converter however