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

bone stock 5.0... adding 1.7s require sping upgrade???

  • Thread starter Thread starter Foxfan88
  • Start date Start date Nov 28, 2005

Foxfan88

My Grandpa has great wood.
Sep 13, 2004
2,487
4
0
Miami, Ok
Nov 28, 2005
#1
  • Nov 28, 2005
  • #1
i had some people tell me that i would need to. but it wouldnt raise the lift that much. then my friend had the rockers that i have now, he put them on it stock motor and said it ran good.....
so??
 
M

Mike92GT

Founding Member
Jan 23, 2002
583
0
0
Florida
Nov 28, 2005
#2
  • Nov 28, 2005
  • #2
I had 1.72 rockers on mine for a long time when I still had stock heads, and I never had any problems. However the stock valve springs are known for being weak, and there is the possibility that the increased lift can cause valve float at high RPM, especially if your springs have high milage
 

2000xp8

SN Certified Technician
Aug 8, 2003
8,016
1,613
194
NJ
Nov 28, 2005
#3
  • Nov 28, 2005
  • #3
No, you shoudln't need springs, but make sure you have a shim kit available at the time of install.
 

Foxfan88

My Grandpa has great wood.
Sep 13, 2004
2,487
4
0
Miami, Ok
Nov 28, 2005
#4
  • Nov 28, 2005
  • #4
this may sound gay but what is the shim kit for??
 

Curse

Member
Apr 8, 2004
791
2
16
El Paso, TX
Nov 28, 2005
#5
  • Nov 28, 2005
  • #5
I actually shied away from 1.7 rockers because a lot of people told me I would need a spring change. It was not worth it to me.
 

soontobefastfox

Member
Nov 15, 2005
275
0
16
Troy, Michigan
Nov 29, 2005
#6
  • Nov 29, 2005
  • #6
I wouldn't do it, you'll actually lose power.

http://www.fordmuscle.com/archives/2001/10/rockerarms/
 
Y

yelladawg351

New Member
Nov 27, 2005
22
0
0
Nov 29, 2005
#7
  • Nov 29, 2005
  • #7
From my understanding looking at tech issues on 5.0 Mustangs the stock E7TE heads can handle .500 lift pressure from a cam. A stock 5.0 cam is around .444 lift @ .050. Just keep your RPM's around 5200 and 5700 to prevent valve float. I believe it would put a stock cam around .456 lift. Look around this forum to find the formula for caculating the added rocker lift to a cam. Crane makes a good set for that comes(1.7 ratio) with shims, but you might not need them on your stock head but just read the instr. Yelladawg.
 

Modular2v

Founding Member
Jun 30, 2002
3,222
23
99
oklahoma
Nov 29, 2005
#8
  • Nov 29, 2005
  • #8
the stock springs can handle 500 lift....im running a 498/499 lift cam
 

tmoss

Gettin Wired
Founding Member
Jun 28, 2001
7,153
32
128
Saint Louis, MO
Nov 30, 2005
#9
  • Nov 30, 2005
  • #9
Fresh stock springs or 150,000+ mile springs - BIG difference!
 

Euphoric306

New Member
Apr 5, 2004
905
0
0
Nov 30, 2005
#10
  • Nov 30, 2005
  • #10
plus you're running the b cam right? id definitely wait it out foxfan and get all new springs, hardened pushrods, rocker arms, shimkits, and just upgrade your heads all at once. or wait on the head upgrade and get a cheap intake, wait till you get some gt-40's or other budget performance heads, dont go throwing a bunch of good parts into worn out unported e7's
 

04sleeper

Founding Member
Jun 22, 2002
2,674
14
89
Dallas, TX
Nov 30, 2005
#11
  • Nov 30, 2005
  • #11
tmoss said:
Fresh stock springs or 150,000+ mile springs - BIG difference!
Click to expand...


I have seen 70,000 mile springs turn to mush in just a few weeks with 1.72's
 

QDRHRSE

New Member
Dec 31, 2002
1,590
0
0
Palmdale, CA
Nov 30, 2005
#12
  • Nov 30, 2005
  • #12


Unless your stock springs are pretty new you will have a problem. TMoss put it best.
 

88gt

Founding Member
Aug 2, 1999
794
0
0
Drillers cabin
Nov 30, 2005
#13
  • Nov 30, 2005
  • #13
If I recall, he's already done this....he's asking after the fact...


 

Euphoric306

New Member
Apr 5, 2004
905
0
0
Nov 30, 2005
#14
  • Nov 30, 2005
  • #14
88gt said:
If I recall, he's already done this....he's asking after the fact...


Click to expand...

again
 

troyGT03

New Member
Feb 22, 2004
278
0
0
too close to memphis,tn
Nov 30, 2005
#15
  • Nov 30, 2005
  • #15
i didnt see e-cam in his sig. tmoss said it right on springs. but good low mileage motor, 1.7s wouldnt do anything but lower the valve float rpm if the spings are not up to par. good healthy low mileage motor no prob. i just did it on mine. 67k and never beaten on.
 

18mustangs

New Member
Jun 8, 2005
533
1
0
Virginia Beach, VA
Dec 2, 2005
#16
  • Dec 2, 2005
  • #16
Dont' take the chance, just get the new springs if you're planning on running 1.7s. I hear that valves crashing into pistons is a significant emotional event that you could do without.
Tim
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,216
17,899
224
Massachusetts
Dec 2, 2005
#17
  • Dec 2, 2005
  • #17
I would change them. Trick FLow makes a nice kit for the stock E7's for about $150
 
8

89'5.0

New Member
Dec 2, 2005
13
0
0
Dec 2, 2005
#18
  • Dec 2, 2005
  • #18
If you have the capability i would change the cam to a f-303 and upgrade and use the ford motorsports spring upgrade. This combo works outstanding. Though if you can't do a cam swap and want to use the 1.7 i would change the springs just for the sake of valve float.
 
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