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

Engine Is My Cam Broken?

  • Thread starter Thread starter 93silverlx50
  • Start date Start date Sep 10, 2017

93silverlx50

Member
Jun 12, 2017
66
5
18
Sep 10, 2017
#1
  • Sep 10, 2017
  • #1
So I've got a crappy running car that I've got a long thread on. I will skip to the question. So could my Cam be cracked in 2?

I pulled off my upper and lower intakes and valve covers. I was adjusting my rockers that were loose and when I hand cranked the motor, I found that the rockers on cylinders 3,4,7 and 8 were not moving. I watched the lifters and saw zero movement there too. I pulled a lifter from #3 and swapped it with #5. That lifter rises and falls in #5 when I hand crank the motor the good one from #5 doesn't move in the #3 cylinder position. I thought my lifters were bad until I swapped them. Then without a lifter in #3, I put a pushrod where it would go and slowly hand rotated the motor. I didn't see any movement or any noise from the pushrod which I think in theory should ride and fall with the cam, is that correct? So could my Cam be snapped? Before I started taking the motor apart, it ran like it was only running on abou t half it's cylinders.

On a side note, I also found my block has a pretty crack through the valley. How terrible is that?
 

Steel1

Mustang Master
Aug 18, 2017
1,419
639
143
Connecticut
Sep 10, 2017
#2
  • Sep 10, 2017
  • #2
Cam lobes could be worn down. Given the cracked block engine has to be torn apart anyway so I guess you'll find out. Feel bad for you, that sucks.
 
Reactions: imp

93silverlx50

Member
Jun 12, 2017
66
5
18
Sep 10, 2017
#3
  • Sep 10, 2017
  • #3
Anyone run a car with a crack through the lifter valley? How bad is it really? What are the possibilities if I buttoned it back up and ran the car like that? (I have to clue how long it's been cracked)
 

Dan02gt

mazing how much gas smell came from that tiny hole
20+ Year Stangneter
Mar 2, 2003
909
415
113
Greenville, NC
Sep 10, 2017
#4
  • Sep 10, 2017
  • #4
I've never heard of a cam breaking in half but I guess it's possible. The fact that the valve train in the back half of the motor is not moving would definitely make me think that in your case it is broken. Add that to the crack and my advice would be to invest in a short block.
 

Adieu

Easy there, this ain't a dating site.
20+ Year Stangneter
Mar 7, 2002
9,531
5,187
224
Sep 10, 2017
#5
  • Sep 10, 2017
  • #5
93silverlx50 said:
Anyone run a car with a crack through the lifter valley? How bad is it really? What are the possibilities if I buttoned it back up and ran the car like that? (I have to clue how long it's been cracked)
Click to expand...
It will only get worse. Time to start shopping for a replacement.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,218
17,902
224
Massachusetts
Sep 11, 2017
#6
  • Sep 11, 2017
  • #6
How much power were you running? Your crack is the typical spot most 5.0s tend to split at. Usually it happens in the 450-500HP range, and High RpM is usually the catalyst that starts it.
 

vristang

15 Year Member
Mar 31, 2005
4,933
101
124
Seattle
Sep 11, 2017
#7
  • Sep 11, 2017
  • #7
check that you don't have any stuck valves?
Time to tear that thing apart... salvage what you can, block is done.
 

93silverlx50

Member
Jun 12, 2017
66
5
18
Sep 11, 2017
#8
  • Sep 11, 2017
  • #8
Mustang5L5 said:
How much power were you running? Your crack is the typical spot most 5.0s tend to split at. Usually it happens in the 450-500HP range, and High RpM is usually the catalyst that starts it.
Click to expand...
I dunno. Maybe 400 to 450. 306 block with TF Heads (ported), S Trim at about 14ish lbs of boost.
 

93silverlx50

Member
Jun 12, 2017
66
5
18
Sep 11, 2017
#9
  • Sep 11, 2017
  • #9
vristang said:
check that you don't have any stuck valves?
Time to tear that thing apart... salvage what you can, block is done.
Click to expand...
This sucks... lol.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,218
17,902
224
Massachusetts
Sep 12, 2017
#10
  • Sep 12, 2017
  • #10
93silverlx50 said:
I dunno. Maybe 400 to 450. 306 block with TF Heads (ported), S Trim at about 14ish lbs of boost.
Click to expand...

Yup, that would split a block.
 

mikestang63

SN Certified Technician
Aug 27, 2012
11,606
8,859
214
In the garage
Sep 13, 2017
#11
  • Sep 13, 2017
  • #11
That's a nice planter you have there SIr.

 
Reactions: a91what, All Stock93 and RaggedGT

Trojan Horse

Founding Member
Jan 7, 2001
1,168
0
36
MO
Sep 16, 2017
#12
  • Sep 16, 2017
  • #12
It's time to invest in a Boss 302 or another aftermarket block if you plan on running forced induction at 14 psi.
The block you have as others have said is toast and if you continue running it you will only damage more parts when it completely fails, as it will probably sooner rather than later. Sorry about your bad luck.
 
You must log in or register to reply here.

Similar threads

H
Ongoing Battle With Hydraulic Lifters
  • hailer06
  • Jun 8, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
7
Views
201
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jun 9, 2026
Noobz347
T
408w pushrods
  • Towegage
  • Sep 19, 2025
  • Fox Engine Swaparoo
Replies
5
Views
264
Fox Engine Swaparoo Sep 19, 2025
Noobz347
T
Oil burning on my recently buil 302
  • The blk67
  • May 15, 2026
  • Fox 5.0 Mustang Tech
Replies
3
Views
131
Fox 5.0 Mustang Tech May 15, 2026
Noobz347
J
MEED HELP!! 86 mustang
  • Jacob0121
  • Jan 23, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
6
Views
311
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Apr 25, 2026
CAMTWO1070
9
Forced Induction Prepping for supercharger on non-stock build
  • 91fox427
  • Nov 25, 2025
  • Fox 5.0 Mustang Tech
Replies
7
Views
384
Fox 5.0 Mustang Tech Jan 5, 2026
Qtrhrse23
Q
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?