New rebuild, strange loss of power
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- Posts: 151
- Joined: 2021 Mar 22, 15:58
- Location: Newington CT
- Vehicle Information: 1986 Mustang GT, Stock block, TFS 170 Heads , N41 cam, ported cobra intake, nitrous, T5 , 3.73s
Re: New rebuild, strange loss of power
If the stock air box has the silencer in it that could be costing some power. Mine never had it, iDK what it looks like or how small the opening is. Just an idea.
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- Posts: 17
- Joined: 2021 Feb 17, 14:14
- Location: Finland Ilmajoki
- Vehicle Information: SIGNATURE
Ford Mustang Cobra -94. Ported M112 ratio 2.375:1, 4.6 Dohc, ported c-heads, TR3650, 3.55 IRS, ZYA2
Coretuning/Moates/HPTuners/Innovate/Tunernerd Knock Monitor/
Re: New rebuild, strange loss of power
Trickflow 170 heads, with 1.6 roller rockers.
I made some years ago 5.0 from my cobra, original gt40 iron heads, lunati stage 1 cam, long headers 330 hp. I have similar calibration on this, this feels worse than stock with 3.73 gears
I made some years ago 5.0 from my cobra, original gt40 iron heads, lunati stage 1 cam, long headers 330 hp. I have similar calibration on this, this feels worse than stock with 3.73 gears
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- Posts: 321
- Joined: 2021 Feb 16, 15:53
- Location: Victoria, BC, Canada
- Vehicle Information: 1994 Flarside, XLT, 351w E4OD
SD48b, Quarter Horse, Burn2
Re: New rebuild, strange loss of power
Why plus 15 degrees?Pappacosworth wrote: ↑2021 Nov 04, 11:12Code: Select all
Intake Closing Point (degrees) ABDC @ 0.050 lift plus 15 degrees 54
Doesn't the cam card show 39, not 54?
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- Posts: 17
- Joined: 2021 Feb 17, 14:14
- Location: Finland Ilmajoki
- Vehicle Information: SIGNATURE
Ford Mustang Cobra -94. Ported M112 ratio 2.375:1, 4.6 Dohc, ported c-heads, TR3650, 3.55 IRS, ZYA2
Coretuning/Moates/HPTuners/Innovate/Tunernerd Knock Monitor/
Re: New rebuild, strange loss of power
https://uempistons.com/p-27-compression ... lator.html
I think in that point starts proper combustion?
I think in that point starts proper combustion?
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- Posts: 17
- Joined: 2021 Feb 17, 14:14
- Location: Finland Ilmajoki
- Vehicle Information: SIGNATURE
Ford Mustang Cobra -94. Ported M112 ratio 2.375:1, 4.6 Dohc, ported c-heads, TR3650, 3.55 IRS, ZYA2
Coretuning/Moates/HPTuners/Innovate/Tunernerd Knock Monitor/
Re: New rebuild, strange loss of power
Few things checked, no help. I measured exhaust backpressure both sides from o2 sensor bungs. Both sides show zero pressure, at idle needle swings from 0-0.2 bar, but 0 at half/open throttle.
Also timing works, I checked with stroboscope that advance moves according to rpm and is correct.
Also timing works, I checked with stroboscope that advance moves according to rpm and is correct.
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- Posts: 151
- Joined: 2021 Mar 22, 15:58
- Location: Newington CT
- Vehicle Information: 1986 Mustang GT, Stock block, TFS 170 Heads , N41 cam, ported cobra intake, nitrous, T5 , 3.73s
Re: New rebuild, strange loss of power
Say the engine is down 100hp and something major is wrong. I would think it would sound strange. Does it sound normal under load? sound normal idling? Stuck injector or injectors?
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- Posts: 5099
- Joined: 2021 Feb 15, 12:23
- Location: Metairie, LA
- Vehicle Information: Work Truck
'19 F-150 3.3L
Re: New rebuild, strange loss of power
Most of the time when an engine is big time down on power its fuel related. Make sure all the injectors are working and that fuel pressure isn't dropping.
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- Posts: 17
- Joined: 2021 Feb 17, 14:14
- Location: Finland Ilmajoki
- Vehicle Information: SIGNATURE
Ford Mustang Cobra -94. Ported M112 ratio 2.375:1, 4.6 Dohc, ported c-heads, TR3650, 3.55 IRS, ZYA2
Coretuning/Moates/HPTuners/Innovate/Tunernerd Knock Monitor/
Re: New rebuild, strange loss of power
Engine runs fine, lifters are audible but not sounding faulty. Exhaust is quieter than I expected. One cat and chamber muffler / side. H-pipe
O2 sensors show that both sides goes stoichio when cruising. Other side is wideband and driver side is switching fast. Afr doesn't go lean when accelerating to limiter.
I'll check next cam timing and lift again.
O2 sensors show that both sides goes stoichio when cruising. Other side is wideband and driver side is switching fast. Afr doesn't go lean when accelerating to limiter.
I'll check next cam timing and lift again.
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- Posts: 17
- Joined: 2021 Feb 17, 14:14
- Location: Finland Ilmajoki
- Vehicle Information: SIGNATURE
Ford Mustang Cobra -94. Ported M112 ratio 2.375:1, 4.6 Dohc, ported c-heads, TR3650, 3.55 IRS, ZYA2
Coretuning/Moates/HPTuners/Innovate/Tunernerd Knock Monitor/
Re: New rebuild, strange loss of power
Cam is 4 degrees retarded, I must adjust it again. I checked it many times when I was assembling it. Maybe it was settled properly only after run-in.