Engine Cam idle and timing questions - big cam, little knowledge

Dan02gt

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Mar 2, 2003
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Back ordered until at least August.
Doesn’t surprise me. I work in IT and with the chip shortage the amount of stuff we can’t get is unbelievable.
 
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jrichker

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Mar 10, 2000
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Oh I absolutely use the surging idle checklist. It’s a permanent tab on my internet browser.

I guess maybe I didn’t know I could continue to post in that thread to ask additional questions. So that’s my bad.

the reason I asked a question and made a new post was specifically because my X-cam in my car and not knowing how choppy is “should” or “shouldn’t” be.

but the whole reason the car runs at all now is in credit to the checklist!
I am glad to hear that you got it running, I don't have much input from Stangnet about the X cam. Check the lobe separation data against the figures for the stock cam The less lobe separation,, the more lumpy the cam will be at idle.

See https://performanceparts.ford.com/download/pdfs/FordRacingCamshaftSpecs.pdf for some input directly from Ford.
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Justin87

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Aug 7, 2017
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Doesn’t surprise me. I work in IT and with the chip shortage the amount of stuff we can’t get is unbelievable.
I’ve never even heard of this thing quarter horse thing until this thread so now I am super interested in one!
 

Middleagecrisis

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Aug 23, 2020
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Two questions for you regarding the idle quality:
1. Did you remove the spout before setting your initial timing?
2. Is your MAF Meter calibrated for your injector size? A Pro-M should have the injector calibrated size etched onto the nameplate.
If yes to both above, I'd advance my initial timing to 14-16 degrees first off and see how it runs, it might want more. I'm running 14 initial on my stock '93 GT, on 89 octane and an AOD with stock converter. You've got way more aggressive cam timing, so the motor's going to want a lot of initial timing. I would back down the fuel pressure (unplug the vacuum line) until the motor cleans up at idle. These things don't cost you anything, and you can put them back to whatever you had if your not happy with the results. Do the timing first, then play with the fuel pressure. Plenty of people have run similar combinations with the stock computer, so I think your troubles are fixable without buying a stand alone tuner.
 
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Dan02gt

10 Year Member
Mar 2, 2003
738
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Greenville, NC
I’ve never even heard of this thing quarter horse thing until this thread so now I am super interested in one!
For the cost it's supper sweet. Being able to monitor the computer and make changes in real time is awesome. You can even run it in a mode that has the car basically running off your laptop. The thing that really sealed the deal for me was the fact that you can start out with the stock A9L tune and tweak it to your liking instead of starting from scratch like other systems. I had Decipha at efidyontuning do a custom tune based on A9L2 for me. Downside is you still have a old computer and wiring.
 
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Justin87

Active Member
Aug 7, 2017
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Two questions for you regarding the idle quality:
1. Did you remove the spout before setting your initial timing?
2. Is your MAF Meter calibrated for your injector size? A Pro-M should have the injector calibrated size etched onto the nameplate.
If yes to both above, I'd advance my initial timing to 14-16 degrees first off and see how it runs, it might want more. I'm running 14 initial on my stock '93 GT, on 89 octane and an AOD with stock converter. You've got way more aggressive cam timing, so the motor's going to want a lot of initial timing. I would back down the fuel pressure (unplug the vacuum line) until the motor cleans up at idle. These things don't cost you anything, and you can put them back to whatever you had if your not happy with the results. Do the timing first, then play with the fuel pressure. Plenty of people have run similar combinations with the stock computer, so I think your troubles are fixable without buying a stand alone tuner.

Hello! Thanks for the input!

Yes, when setting the timing I did remove the spout connector and I have backed the fuel pressure off.

My MAF sensor is calibrated for the 30# injectors. I purchased both the injectors and MAF directly from Pro-M.

I do plan on bumping the timing up (it’s currently around 12) part of the initial problem was me just figuring that my car so so extremely out of time I couldn’t keep it alive.
 

Justin87

Active Member
Aug 7, 2017
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Just wanted to hop back on this thread and mention that the car is running great! No missing, stalling or bucking. Even idled her down a little from where she was previously at rechecked the timing.

sounds awesome gets a lot of looks and requests for burnouts . Just driving around town, nothing crazy so far with it being a brand new engine.

Thanks to all gave advice!
 
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