440 w 750 Eddy....Too Rich After Leaning Off 2 Steps ?????

[momack55]

Hi All,

After a dyno test, my 440 '70 Challenger is STILL running at 8.5:1 air/fuel ratio at WOT!!  Is this way too rich??  Do I lean off another two steps??

My set up is stock!  440 with 750 Eddy, leaned off two steps from stock, dual plane performer intake. Stock cast iron exhaust manifolds, 2 inch exhaust w two small sports mufflers. Timing at 7 btdc.  Motor originally out of a '72 Imperial

Help!!   Thanks ...Mozz 

[Strawdawg]

If it were me, I would first put  a larger exhaust on it, and then I would set the timing up some....both can make it run richer than it would otherwise

[momack55]

Thanks Strawdawg!!

I was thinking in that dirrection.  Leave the carb for the moment, install headers or extractors, 3" stainless exhaust, open sports mufflers same diameter.  Then step out the timing a little to suit!! 

Is that the way!!??

Mozz!! 

[HP_Cuda]

Exhaust and bump that timing up to 10 degrees!

[momack55]

Fanx HP_Cuda,

Is there anything else that could be done?  And if I run 98ron instead of 95ron??

Mozz!!   

[Strawdawg]

Thanks Strawdawg!!

I was thinking in that dirrection.  Leave the carb for the moment, install headers or extractors, 3" stainless exhaust, open sports mufflers same diameter.  Then step out the timing a little to suit!! 

Is that the way!!??

Mozz!! 

Unless you are planning to make more than 450-500 hp, 2.5" exhaust should be good.   Set total timing to about 34-36 degs with initial in the range of 14-16 degs

Steve

[HP_Cuda]

Although I agree with Strawdawg, I would go up to 10 and see the delta on your air/fuel mix and then head up to the sweet spot 14-16 timing.

Unless you have detonation, there is no need to use a higher octane. Right now you are just trying to lean it out a bit.

 

[momack55]

Hmmm It did Pingk a little at top rpm WOT!  So we didn't push for a third shot!

[Chryco Psycho]

The Performer 440 is a horrible intake with terrible fuel distribution , I would start with a swap to almost anything else even the stock intake first , disconnect the vacuum advance & bump the timong up to 16 * or more , I would be more worried about total timing around 36* , exhaust will help as well

[momack55]

What would you suggest for intakes Chryco??  I will go with anything that is an improvement!!

Mozz!

[hemiken]

Go for the performer RPM Edelbrock or look at the WEDGE intake that Mancini offers.

[Chryco Psycho]

Any intake , , I like the Holley Street Dominator , the Eddy RPM , CH4b , M1 dual plane , Toker 2, literally any intake will be an improvement !!
 If you look at the intake you will see the carb is way foraard from center leaving the primaries very close to the front 4 cylinders & far from the rear cylinders

[momack55]

Chryco,

I should have described a bit better.  It's a Eddy RPM Performer intake!!   1411 Eddy 750cfm.  440 source electronic dizzy!!

Mozz!!

[hemiken]

Hey Mozz,  That is the intake you want buddy. Just use it with the 440 source heads and you will be well on your way, make sure you pick the right camshaft is the ticket buddy

[DocMel]

I beleive the choices mentioned so far are great choices, but lets stick to the basics before you start getting new intakes, cams, heads, etc

I know you have a carb:  But I put FI on my 69 dated 440 with the stock intake, a poor design at best  Thats what I am running now

I know you are running a carb, but with my FI i can  adjust my air/fuel any mixture I want, with seperate settings for idle, WOT and cruising

So the intake isnt what is causing a possible rich condition.  Its your carb, period  Lest get back to the carb later

So lets look at your air/fuel:   You are at roughly 9;1     The so called overall perfect mixture for overall running is about 13.5:1   But lets just say 14:1 for general talk

Now understand, 14:1 is considered the perfect, or better called most efficient  mixture, but that doesn't relate to performance.  Usually you want a richer mixture for street performance, say 10:1 or 11:1  (again, lotsa opinions on this, but lets keep the post simple for now)

Id say you are maybe a just a little rich, BUT:  You have to be honest about what condition your  engine is in:  Is it in tune, good timing curve, ect.  Playing with mixture will really do no good until the other components are right

Just changing out the main jet sizes on an eddy wont get you where you need to be.  Its a balance of th emains and the intermediates.  You have to balance them out.  If you have squared away dyno shop that has techs that know their stuff, they can help you with that change.  But most dyno shops will only record, and MAYBE help you with timing, and thats it

Its the carb.  Stay away from timing, etc, until you get the  carb right  Get a mixture reading at idle, mid range and WOT.  Then start adjusting/replacing mixture components from there

Get help on the jets, intermediate jets, etc:   Call the eddy techline:  You will just chase your tail around this whole mixture thing until you hit the right combo.  Trust me, when you do, it will seriously wake up your engine

Once you get that carb right, then start changing out the intake, fiddle with timing