440/6 Bird running lean?

[boss429kiwi]

Hi guys

My 440, 6 pack Bird seems to be running lean? Idling in the garage, you can only stay there for a few minutes, and the fumes are overwhelming and burns my eyes (in layman's terms). This is not a new problem, as it has always been this way. Besides this, it's runs very strong.

Should I just alter the fuel mixtures on the inboard carb, or should I look out for anything else?

The carbs were rebuilt a couple of years ago, and the engine was rebuilt by Ray Barton 12 years ago. It has very high compression 13-1 and has a "performance HEMI" cam (rather "lumpy"). Not sure why, but this is what the engine build sheets states.
It is also a 4 speed.

Or could my problem simply be the engine set up, running on pump gas (95-98 octane), and I do not have an issue?

Thanks
Gary

[Ghoste]

I would take that as being too rich.

[boss429kiwi]

I would take that as being too rich.

Unlike my 428CJ Mustang which runs rich, there is no sooty rear end

OK, now you have me thinking!

What's the best way to determine between rich and lean, besides taking it to a garage, where it would sit for a week! 

[JB400]

Without an air/fuel ratio gauge, pull the plugs.  You're looking for the right color on the plugs and also whether or not they are wet.

Here's a more detailed description:

http://www.dragstuff.com/techarticles/reading-spark-plugs.html

[500Jon]

Very rich condition on tickover normally means a POWER-VALVE failure!
Burning eyes is a good/bad sign of this.
Common fault with Holleys.

5J

[PettyMower]

My comment has nothing to do with your possible fuel / air mixture.....95-98 is not enough octane for 13-1 compression ratio.

[62 Max]

And if it were mine,the 13.1 comp would be gone in a heartbeat but that's just me.

[Ghoste]

I think octane is rated differently down under though.  Not sure in what or even for sure that it is. 

[500Jon]

Yep, you can run 13 to 1 on pump gas, but not for long!

It will eat the bearings for sure!!!
It will have constant detonation that is normally inaudible.
Been there, done that, its gonna end in tears.

High octane race fuel will be the only thing that can solve your problem.
Backing the timing out to less than 30 degrees will help.
The over-rich mixture on idle is hiding the detonation I believe?

What may happen is, Bore-wash, failed rings and piston-skirts and ultimately bearings.

'Golden rules for PUMP-GAS' is no more than 10 to 1 with iron heads and 11 to 1 with aluminium heads!

HNY from 5J

[PettyMower]

500Jon.....agreed!

I've had much success with 10.5 to 1 with 92-93 octane Pump gas.

Jay

[nascarxx29]

Wont hurt to check heat riser They do get stuck

[boss429kiwi]

Yep, you can run 13 to 1 on pump gas, but not for long!

It will eat the bearings for sure!!!
It will have constant detonation that is normally inaudible.
Been there, done that, its gonna end in tears.

High octane race fuel will be the only thing that can solve your problem.
Backing the timing out to less than 30 degrees will help.
The over-rich mixture on idle is hiding the detonation I believe?

What may happen is, Bore-wash, failed rings and piston-skirts and ultimately bearings.

'Golden rules for PUMP-GAS' is no more than 10 to 1 with iron heads and 11 to 1 with aluminium heads!

HNY from 5J

I hear what you are all saying.
In fact I question the 13-1 compression, as a local V8 specialist said it did not idle, drive and preform like 13-1, even though it states 13-1 forged piston on the build sheet.

It does not ping at all.
The engine build is now over 12 years old and has more than 6000 miles since.
I would have thought that if it was going to have long term octane issues etc, it would have gone "bang" by now?

The engine is numbers matching so going "bang" is a major concern for me.
I will have the engine stripped down and check in the near future, and change the compression if required.

I will remove the front carb and replace the power valve.

Cheers
Gary

[Tom Q]

Your car needs a proper tune up. Once that is done you will be good for years and years
To properly tune up your engine will require some one to read and comprehend the six pak tuning guide and apply the knowledge to your particular engine.
There are wayyyyy too many variables to fix it via the keyboard.

If you can wait another week or so I will send you via email the latest revision of the tuning guide as I am working the flow and grammar at the moment.

[500Jon]

Hi AeroFolks...

Every 440 engine from 1972 onwards has been somewhere around 8.5 to 1 compression.
Not since the mid sixties have people contemplated running higher that 12 to 1 with Five-Star pump-gas.
My FULL-RACE 440 engine ran 12.5 to 1 on High Octane race-fuel, it also ran on Super-unleaded 100 octane (just about).
We can still buy leaded 100 octane in the UK, but its not cheap as you would imagine...
To 'bleed-off' the high static compression, a real big cam is needed, over .600 lift and long duration too.

I didn't think you could buy 13 to 1 pistons any more, for iron heads?
I've got a shed full of dead high comp 440 pistons from the 70's and 80's lol!

New technology says the pistons should be FLAT-TOP and tight combustion chambers as per new style ali heads.
Old School pistons have huge raised domes to fill the Old School '906' iron heads, which harm 'flame-travel'...blah.blah.blah...

My thoughts are 'GET-RID', before you damage the bores and crankshaft, a little grief now will save in the long run.

Just my

[Hemi Runner]

I would take that as being too rich.

Unless it's due to lean misfire where unburnt mixture is sent out the exhaust. Ignition problems can also be the cause. This build is 12 years old, it's obviously not 13-1 CR or it would have went boom along time ago on pump fuel. As mentioned, plug read is the best way.

[boss429kiwi]

Ok, I have just re-read the engine built sheet and it's contradictory.

It says "install 13-1 pistons", but in the parts list it says "JE RB aluminium flat top piston 4.350, bore 3.750, stroke 6.76, 11.6-1, w/73cc.

So I guess it is 11.6-1!

Removed a plug and the plug is slightly sooty, so I guess it is running rich. Which I guess is partly due to pump gas.
I will adjust the mixture screws to see if it wants to be leaned out more.

Gary

[b5blue]

Gary read this through it has good info:
http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Board=QuestionAnswer&Number=5995396&Searchpage=1&Main=5995174&Words=+Warrant_Officer&topic=&Search=true
The outboards idle screws have tiny cork O rings that if not in good condition can raise hell setting idle mix correct. If running ethanol use a stabilizer, my bowls started crudding up pretty quickly when the car did not get driven much. (Down for repairs.)   

[500Jon]

Hi Boss,
Flat tops is GOOD!!!
What heads are you running there?
Very few iron heads are 73cc's anyways...
More like 80cc plus.

Lower pic is my old school 12.5's

[boss429kiwi]

Hi Boss,
Flat tops is GOOD!!!
What heads are you running there?
Very few iron heads are 73cc's anyways...
More like 80cc plus.

Lower pic is my old school 12.5's

Hi

The heads are stock and numbered correctly.

Thanks

[boss429kiwi]

Gary read this through it has good info:
http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Board=QuestionAnswer&Number=5995396&Searchpage=1&Main=5995174&Words=+Warrant_Officer&topic=&Search=true
The outboards idle screws have tiny cork O rings that if not in good condition can raise hell setting idle mix correct. If running ethanol use a stabilizer, my bowls started crudding up pretty quickly when the car did not get driven much. (Down for repairs.)   

That's great information.

Thanks