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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

did upgrades and power is just ok

  • Thread starter Thread starter mercurycapri
  • Start date Start date Nov 5, 2006
M

mercurycapri

Member
May 30, 2006
211
2
18
washington
Nov 5, 2006
#1
  • Nov 5, 2006
  • #1
my 86 5.0 I did some mods to it and it doesn't seem to be any quicker than a stock mustang. unless I put it to the floor and push on the throttle hard onto the floor then it takes off pretty good. Here is what ive done
86 stock short block flat top pistons with 1978 rebuilt heads more for the extra compression ratio. Solid motor mounts BBk shorty headers 1 5/8 gutted H pipe 2 1/4 flowmaster cat back. Edelbrock performer intake and edelbrock 600 cfm carburetor. Electric cooling fan and eliminated the smog pump and AC unit. Stock manual trans and rear diff. Im just confused why the car isn't faster than a stock mustang the coil is good new tune up good fuel pressure and new fuel filter. Could the distributer be bad? Could I have not adjusted the carburetor right? Timing chain is brand new
 
M

mercurycapri

Member
May 30, 2006
211
2
18
washington
Nov 5, 2006
#2
  • Nov 5, 2006
  • #2
sorry its in my 86 capri I took the fuel injected stuff off
 

EMW150

Founding Member
May 22, 2000
2,020
1
46
Roaring Spring,PA
Nov 5, 2006
#3
  • Nov 5, 2006
  • #3
What is the total timing set at? Is it a stock cam?
 
M

mercurycapri

Member
May 30, 2006
211
2
18
washington
Nov 5, 2006
#4
  • Nov 5, 2006
  • #4
its stock camshaft and I put the timing at 11
 
F

fastranger347

New Member
Nov 4, 2006
59
1
0
york PA.
Nov 5, 2006
#5
  • Nov 5, 2006
  • #5
the heads are your problem,you picked a head that was created during a smog crises and gas crunch, they have no flow, no port size and only emmisions in mind no matter howmuch porting you do to those heads youll be better off with e7te castings (87 and up) if you wanto stick with a factory head
 
M

mercurycapri

Member
May 30, 2006
211
2
18
washington
Nov 5, 2006
#6
  • Nov 5, 2006
  • #6
I would have bought E7 but these where a killer deal and I needed my car to run. I was kinda low on cash at the time that's why I bought those but these heads should be heck allot better than the E6 that was on it. It was very quick when i first took it for a spin but seemed to slow down a bit or maybe im just used to it now
 

stangjunkie

New Member
Nov 15, 2004
381
0
0
Nov 5, 2006
#7
  • Nov 5, 2006
  • #7
mercurycapri said:
I would have bought E7 but these where a killer deal and I needed my car to run. I was kinda low on cash at the time that's why I bought those but these heads should be heck allot better than the E6 that was on it. It was very quick when i first took it for a spin but seemed to slow down a bit or maybe im just used to it now
Click to expand...


i have 3-4 pairs of stock heads from fox mustang if your intersted lemme know... they don't do me any good
 

rd

Founding Member
Jan 12, 2000
3,316
63
109
Ocean Springs MS
Nov 5, 2006
#8
  • Nov 5, 2006
  • #8
I went down that road exactly with my 79. Put a rebuilt shortblock in about 87, with stock replacement pistons, and ported 78 D80E heads. 464 lift Rhodes lifters and VVt270 cam. With a 4v upgrade, slightly losser converter in the C4 and even 4.10 gears I could never get it past 15.30's.

The porting helped, because when I swapped the stock 79 heads back on, it slowed down about 3 tenths.

Most likely, you have 9 to 1 or lower compression. I calculated it at 8.7 to 1. You have a stock deck height piston setup, and 69 or 70 cc head volume. This is the crux of the problem.

Next item, and it took 15 years to figure it out, even though I had a valvetrain ok to 6000 rpm plus, the stock tach is about 3-500 rpm high at around 6k. If the cam and springs are good, get a tach or shiftlight and start using the powerband. I got about 2 tenths this way.

With exactly the same shortblock in the 82, 400 lbs lighter, more converter, and Iron Gt 40 heads, its in the 12's.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,258
17,942
224
Massachusetts
Nov 5, 2006
#9
  • Nov 5, 2006
  • #9
'78 heads????


Why?? Your E6's are a better head than those.
 
D

Daggar

New Member
Jul 19, 2004
3,902
5
0
Nov 5, 2006
#10
  • Nov 5, 2006
  • #10
Save your nickels and dimes for a set of TFS heads. They'll mate to the 86 flat-tops and will give you lots of room to grow if you later decide to go with a different piston with valve reliefs.
 
M

mercurycapri

Member
May 30, 2006
211
2
18
washington
Nov 5, 2006
#11
  • Nov 5, 2006
  • #11
man I hate learning my mistakes I should have just bought the E7's I heard that the E6's were the worse heads for flow. I was thinking that I would have increased my compression ratio because of the smaller cc's since my pistons have no notches it should be pretty good ratio. Well I will ask stangjunkie about his heads I hate to dig into this motor again but a man got to have his power.
 
F

fastranger347

New Member
Nov 4, 2006
59
1
0
york PA.
Nov 5, 2006
#12
  • Nov 5, 2006
  • #12
what do you meen by """killer deal" and "shoulda bought" you can get e7's practicaly for free, usually less than 75$ around here, they came on every windsor style v8 built in and after 87(f150's,e150's,302's,351's etc) the only other mass production head that was on a pushrod v8 was the gt40 on the cobras and the gt40p that was on the explorers
 
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