390 Lacking Power

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DGrant09
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Re: 390 Lacking Power

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This is the first I have heard of about Dialing or Degreeing a cam but I have only done 6 or so stock timing sets in the past. From what I have read this morning at Crane Cams, I should have been doing this all along.. :o
In looking for a tool kit is there anything I need to check for before picking a kit up?? Will one kit work for multiple cams or are they engine / brand specific??
Thanks.. Off to check the compression..
09", F350, Cabelas, 6.4L
72", F250, CS, 390, 2 WD
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Re: 390 Lacking Power

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The compression check showed 160 to 171, within 10% on all. However the spark plugs have a heavy coat of carbon on them, running too rich I imagine. I'll wait on the mixture settings until the timing is good. Off to find a cam degree kit..
09", F350, Cabelas, 6.4L
72", F250, CS, 390, 2 WD
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Re: 390 Lacking Power

Post by Dragon »

Wet black carbon or dry looking carbon. What is the center insulator color? Black, Brown, Grey, White or ash.

My insulators are pure clean white telling me no oil in the cylinders, the electrodes are fine black. White tells me I am too lean in cruise mode. Black tells me the full throttle with Secondaries and power valve helping make the engine slightly rich. 10,000 miles on my plugs and they look the same.
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Re: 390 Lacking Power

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The plugs had a dry black coating. I have or was fighting this Holley carb trying to find a good setting and I believe I missed on this one.. The mixture screws are about ready to fall out I have it leaned out so far. Once I am sure about the timing I'll dive back into the carb adjustments. My luck in finding a dial kit for the cam has struck out. I may have to order a kit..
09", F350, Cabelas, 6.4L
72", F250, CS, 390, 2 WD
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Re: 390 Lacking Power

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DGrant09 wrote:The plugs had a dry black coating. I have or was fighting this Holley carb trying to find a good setting and I believe I missed on this one.. The mixture screws are about ready to fall out I have it leaned out so far. Once I am sure about the timing I'll dive back into the carb adjustments. My luck in finding a dial kit for the cam has struck out. I may have to order a kit..
Try 1 1/4 to 1 1/2 turns out from the bottom. That is a good starting point. Also try a new set of plugs too. JMHO
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Re: 390 Lacking Power

Post by Dragon »

Even if the carb is totally the wrong size the idle will still be set the same amount give or take a tiny amount. If the plugs are black it says they are getting too much fuel. If your idle screws are all the way out that says you have a vacuum leak. Even racing cams don't get set more than 2 turns out on the most radical race motors.
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Re: 390 Lacking Power

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DGrant09 wrote:The plugs had a dry black coating. I have or was fighting this Holley carb trying to find a good setting and I believe I missed on this one.. The mixture screws are about ready to fall out I have it leaned out so far. Once I am sure about the timing I'll dive back into the carb adjustments. My luck in finding a dial kit for the cam has struck out. I may have to order a kit..
If it's idleing at the recommended rpm, I'd get your timing straightened out first like you said. The plugs may be black because you're getting an incomplete or cold burn from the timing being too retarded. If you've got the factory 5 degree retard set and you are running it at 6 btdc, then I believe that means it is actually at 1 degree btdc (someone please correct me if that's not quite right!), which obviously isn't near enough advance. I think that is your culprit, and if not at least you can rule it out after you get it all right!
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Re: 390 Lacking Power

Post by Dragon »

You could easily run a FE at 1 degree and it would be in better shape than he is talking about. When FEs got the retarded cam timing they did not get sick. They just did not pull as well as a 69 to 73 engine. But it was barely different. For the plugs to be black if the engine is that retarded it probably would not run. It would be almost impossible to get that incomplete a burn and keep running if retarded. Experience from a timing ring slip.

Black plugs says too much fuel and that could really make a engine sick. Imagine driving with the choke halfway on for 2000 miles the engine would eat gas like crazy have no power and fuel foul the plugs making the engine lose more power.

Take a look here.
http://www.fordmuscle.com/forums/all-fo ... d-cam.html
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convincor
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Re: 390 Lacking Power

Post by convincor »

As Dragon mentioned idle screws out that far suggests a vacume leak.
Is this a aftermarket intake?
What intake gaskets you using??
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Re: 390 Lacking Power

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convincor wrote:As Dragon mentioned idle screws out that far suggests a vacume leak.
Is this a aftermarket intake?
What intake gaskets you using??
The intake is from a 64 T Bird (I think). 80 lbs of pure steel!! The carb is a Holley 600cfm. The gasket set came with the engine kit from EPWI, probably Fel-Pro. As much as I do not like to, I'll use some carb cleaner around the intake, vacuum lines, and carb base to check for vacuum leaks.. I have checked these in the past year, but I have never check the one going to the transmission.. I'll get on this next while I am searching for a cam degree kit..
09", F350, Cabelas, 6.4L
72", F250, CS, 390, 2 WD
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Re: 390 Lacking Power

Post by Dragon »

Don't worry about the cam degree kit yet. You have to tear the motor part way down to use them. Remove the timing cover and check where the gear is set to.
Old Fords Rule
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71 F250 with Shell Car 390 NP435 Dana 60 3.73s, PS, PB, 750 EC VS Holley Accel Points Eliminator.
98 Volvo S70 2.4T Auto
71 Service manuals Volumes 1,2,3 and 4 So ask away. :)
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Re: 390 Lacking Power

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If I could figure out how to upload pictures I would show the plugs here.. :?
I see the image key above but how does it work??
09", F350, Cabelas, 6.4L
72", F250, CS, 390, 2 WD
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Re: 390 Lacking Power

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It takes to steps after you select the file with the "Choose File" function you click "add file" Then the window switches and you hit "place inline" for every file. It is not the easiest to do because it puts the code where ever it wants.
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71 F250 with Shell Car 390 NP435 Dana 60 3.73s, PS, PB, 750 EC VS Holley Accel Points Eliminator.
98 Volvo S70 2.4T Auto
71 Service manuals Volumes 1,2,3 and 4 So ask away. :)
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Re: 390 Lacking Power

Post by FORD428CJ »

If you had a vac leak....You would be lean and one of the plugs might reflect that! Like I said...Do all the basics first before you rip and tear everything out!. One step at a time..... :thup:
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Re: 390 Lacking Power

Post by DuckRyder »

Yes do the basics first.

If you are having trouble leaning a Holley out make sure that the idle isn't set so high that the idle transfer ports are uncovered in the primaries. If they are, you can lower the idle speed or open the secondary throttle plates slightly in order to obtain the same idle speed with less primary opening.
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