400 big block dyno run

[33 IMP]

That is nothing... you think I'll be able to run 89 octane or should I just stick with 91?... you think I could get more compression with the thinner gasket but I want to try to run only 91 max I don't want to run additive that would get very annoying every time I fill up I would have to add additive

I haven't read the whole thread. What Pistons are in yours? (The factory pistons were so far down the hole stock, that there was little compression, but no quench at all, and even though the compression ratio was very low, it had poor knock resistance. To keep them from knocking the timing got pulled back. Perfect recipe for a dog. Major reason why stroking 400s is so popular. Lots of piston choices for a stroker.)
A stock stroke 400 CAN be a runner, depending on what pistons are used. Though IQ52 has recipes for making a low compression one RUN!

 

[Michael400]

I haven't read the whole thread. What Pistons are in yours? (The factory pistons were so far down the hole stock, that there was little compression, but no quench at all, and even though the compression ratio was very low, it had poor knock resistance. To keep them from knocking the timing got pulled back. Perfect recipe for a dog. Major reason why stroking 400s is so popular. Lots of piston choices for a stroker.)
A stock stroke 400 CAN be a runner, depending on what pistons are used. Though IQ52 has recipes for making a low compression one RUN!

The Pistons that I'm running in my charger 400 they're not stock they are Dome Pistons unfortunately in the 70s early '80s my dad bought them he's the only one that knows but he already passed away... I think I remember him saying they're Irish Iris Pistons I forgot what he said but I know they're not stock and when looking at the Pistons inside the block thay are not Way Down in the Hole as you can see in the pictures.

 

[Michael400]

A little bit better picture

 

[33 IMP]

A little bit better picture

View attachment 1282321

Those look like they may be Icon pistons. They look to have a similar dome to a 11.5 trw piston for a 440, but in theory would have less than a 440 due to a shorter stroke.
And the trw 440 piston is closer to 10.5 in most cases.
If I had to guess, just looking at the photos, I would guess 10 to one, but it could be anything from 9.5 to 12, depending on actual measurements of deck, heads, head gasket etc.

 

[Michael400]

Those look like they may be Icon pistons. They look to have a similar dome to a 11.5 trw piston for a 440, but in theory would have less than a 440 due to a shorter stroke.
And the trw 440 piston is closer to 10.5 in most cases.
If I had to guess, just looking at the photos, I would guess 10 to one, but it could be anything from 9.5 to 12, depending on actual measurements of deck, heads, head gasket etc.

I'll just run 91 just in case I don't want to ruin anything but it sure is not no dog this thing picks up pretty good even better once I change the gears

 

[rumblefish360]

Fact;

Low compression equals low octane or your just wasting dollars and making less power with higher octane. While the higher octane may allow you to run more advance, your not getting the true potential of the octane with what the engine is crippled with, low compression.

With those pistons in there, you need to take all the measurements required to find out the actual static compression ratio. From there, you can start building an effective package.

Break out the bridge and mic!

 

[Michael400]

Fact;

Low compression equals low octane or your just wasting dollars and making less power with higher octane. While the higher octane may allow you to run more advance, your not getting the true potential of the octane with what the engine is crippled with, low compression.

With those pistons in there, you need to take all the measurements required to find out the actual static compression ratio. From there, you can start building an effective package.

Break out the bridge and mic!

Damn so I got to take the whole engine apart again?

 

[33 IMP]

Damn so I got to take the whole engine apart again?

No, I think Rob thought it was still being assembled.
You just need to experiment with timing and fuel (octane) to find out what it likes,

 

[rumblefish360]

No, I think Rob thought it was still being assembled.
You just need to experiment with timing and fuel (octane) to find out what it likes,

Yes and thanks for clearing that up.
I also have a 400 that I’m interested in keeping the 3.38 stroke.

 

[Michael400]

No, I think Rob thought it was still being assembled.
You just need to experiment with timing and fuel (octane) to find out what it likes,

Oh okay now I get it well I know it does not like 39 or 40 total timing it just makes it run weird very slow... maybe 36 is Max with 91 right now it's 35... and it runs pretty good maybe I'll try 89 see how that feels

 

[rumblefish360]

Sorry to ask, what is the actual static compression ratio and the exact cam being used?

 

[Michael400]

Sorry to ask, what is the actual static compression ratio and the exact cam being used?

For my engine? The cam is 7194 Edelbrock cam Camshaft Specifications: - Duration @ .050 Intake: 238 degrees - Duration @ .050 Exhaust: 246 degrees - Lift @ Valve Intake: .480" - Lift @ Valve Exhaust: .495" - Lobe Separation: 110 Degrees - Intake Centerline: 105 Degrees... and the cool crank compression was 140 through 155.. that was the last time I checked it

 

[Michael400]

Yes and thanks for clearing that up.
I also have a 400 that I’m interested in keeping the 3.38 stroke.

What are your plans with it??

 

[rumblefish360]

Ported 6 pack, TF heads, solid cam, 1.6 rockers, etc… basic pump gas hot rod stuff in a ‘79 Magnum, 727/9-1/4 w/3.55’s. Nothing fancy. 2500-6500 performance arena.

 

[Michael400]

Ported 6 pack, TF heads, solid cam, 1.6 rockers, etc… basic pump gas hot rod stuff in a ‘79 Magnum, 727/9-1/4 w/3.55’s. Nothing fancy. 2500-6500 performance arena.

Damn man I need to keep up with you I was also thinking of trick flow heads

 

[rumblefish360]

Damn man I need to keep up with you I was also thinking of trick flow heads

Never keep up with the Jones. Ether pass them or go around them. LOL!
Yea, the TF’s offer the best bang for the buck OOTB.

 

[Michael400]

Never keep up with the Jones. Ether pass them or go around them. LOL!
Yea, the TF’s offer the best bang for the buck OOTB.

Are you going to use the stock Pistons? What kind of Cam? Are you going to be running a shift kit in that 727

 

[rumblefish360]

Are you going to use the stock Pistons? What kind of Cam? Are you going to be running a shift kit in that 727

Stock pistons? LMAO, negative!!!
Cam? Solid flat tappet.
Shift kit? Yes

 

[Robert Schaad]

Hi I'm Michael I'm new here and I'm currently working on a 73 Dodge Charger done some modifications took it to the dyno just want to see if these are good numbers what do you think it'll run on the quarter mile or 1/8 of a mile

400 big block 30 over
7194 Edelbrock cam Camshaft Specifications: - Duration @ .050 Intake: 238 degrees - Duration @ .050 Exhaust: 246 degrees - Lift @ Valve Intake: .480" - Lift @ Valve Exhaust: .495" - Lobe Separation: 110 Degrees - Intake Centerline: 105 Degrees

750 Edelbrock Performer Series Carburetor 1411
Edelbrock RPM intake manifold 7186
TTI headers 1-3/4
Two and a half inch exhaust with MagnaFlow mufflers
High top pistons don't know the actual compression last time I checked the crank pressure they were at 145 to 155
323 rear end gears
Accel ignition coil
NGK XR5 spark plugs
Stock cylinder head [346 not ported]
Timeing at 35
Firecore spark plugs wires
Mopar distributor stock version
Torque converter TCI stall 2400 - 2600
180 thermostat
Power steering AC installed but not working
Stock crank stock fan clutch stock 727 with a shifter Improvement kit
It made 286 hp and 330 tq
Rear tire 275 60 r15
View attachment 1267654

The 400 was a good motor. Most did not like it since it was the replacement for the 383 when emission controls changed. But a great engine builder at the time took the 400 and made it, 400/400/400 Which ment, 400 cubes, 400 HP and 400 TQ. There was a complete layout in one of the hot rod mags in the 70s. I have the article but will need to find it if you want to know about it.

 

[Robert Schaad]

The Pistons that I'm running in my charger 400 they're not stock they are Dome Pistons unfortunately in the 70s early '80s my dad bought them he's the only one that knows but he already passed away... I think I remember him saying they're Irish Iris Pistons I forgot what he said but I know they're not stock and when looking at the Pistons inside the block thay are not Way Down in the Hole as you can see in the pictures.

View attachment 1282313 View attachment 1282316

In the later 70s a mopar engine expert built a 400/400/400, which means, 400 cube, 400 HP, 400 tQ. The article was in a popular hot rod mag in those days. I have that mag and will dig it out if you want to know about it.