5.7 Hemi carb jetting nightmare

Discussion of the 5.7L-6.1L-6.4L HEMIs.

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jojohemi
Posts: 2
Joined: Tue Jul 01, 2008 9:22 pm

5.7 Hemi carb jetting nightmare

Post by jojohemi » Tue Jul 01, 2008 9:51 pm

Hi Everyone!

I'm new here but it seems like there is a wealth of knowledge here so I thought I would see what advice if any I could get on this....here it goes

2006 5.7 Hemi 11,000 miles swapped into a 1974 Dodge Challenger
650 cfm holley
xv motorsports intake
msd Hemi 6 controller

car has no power or very little plugs are rich(black coal black) lean it out has even less power if you get plugs jetted down to where they should look it will run on primaries and totally fall on it's face going into secondaries.

richen it back up and it picks up power only to black up and foul out the plugs with only moving jet sizes a little at a time.
it goes from bad to almost ok....trust me I have run the gammit on this one.
I am a distributor for Procharger for 10 years and tune supercharged engines on a regular basis but this one does not make any sense.
I have changed the lifters in it to the older style without the MDS...and it has the MDS elimination kit.

I called XV but they blew me off with every questioned I asked

So if anyone has been thru this or had these problems please let me know or drop me a line (419)529-4446 I will gladly pay for a solution...heading for Good Guys in Columbus!

Thanks
Jason

mart
Posts: 536
Joined: Tue Mar 22, 2005 2:06 pm

Re: 5.7 Hemi carb jetting nightmare

Post by mart » Wed Jul 02, 2008 3:26 am

What have you go in the carb for a power valve??
Could it be blown? A blown-out, leaky, power valve
will give the symptoms you describe.

mart
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jojohemi
Posts: 2
Joined: Tue Jul 01, 2008 9:22 pm

Re: 5.7 Hemi carb jetting nightmare

Post by jojohemi » Wed Jul 02, 2008 7:29 am

Sorry 6.5 power valve it's not blown even took power valve out used block off jetted up still same outcome

65 jet primary
6.5 power valve primary
78 jet secondary

wondering if it's pulling enough vacuum checking that today.

Thanks

superjay
Posts: 2
Joined: Mon Aug 16, 2004 1:34 pm
Location: Isle of Palm So. Car.

Re: 5.7 Hemi carb jetting nightmare

Post by superjay » Tue Jan 13, 2009 2:44 pm

Have u tried a different carb on it?

392heminut
Posts: 488
Joined: Sat Nov 30, 2002 2:16 pm

Re: 5.7 Hemi carb jetting nightmare

Post by 392heminut » Wed Jan 14, 2009 8:15 am

I'm running a Holley 750 vac. sec. (3310) on my 5.7 with an MP intake and the Hemi-6 controller and the only problem I've had is a slight hesitation when floored from a dead stop. I just need to tweak the accelerator pump shot to fix that. Not sure at this time what jets I'm running, but I've had no problems with rich conditions at all.
Owner of the Poor Man's Hemi Cuda

superjay
Posts: 2
Joined: Mon Aug 16, 2004 1:34 pm
Location: Isle of Palm So. Car.

Re: 5.7 Hemi carb jetting nightmare

Post by superjay » Wed Jan 14, 2009 9:04 am

Yes, a 28, or 31 will most likely do it. To fine tune it, ya can try different acc. pump cams, on either the #1, or #2 position.

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