Notices
Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by: KPower

Found something new I can break.

Thread Tools
 
Search this Thread
 
Old Jul 1, 2016 | 01:43 PM
  #1  
bbundy's Avatar
Thread Starter
Elite Member
 
Joined: Jul 2005
Posts: 2,502
Total Cats: 146
From: Anacortes, WA
Default Found something new I can break.

Intake cam. I think a cam cap broke first.

Attached Thumbnails Found something new I can break.-20160625_184044.jpg   Found something new I can break.-80-175775d1467394976_found_something_new_i_can_break_20160625_184044_b7c6fa0e1513d70fa0bfb2d21f9.jpg  
Old Jul 1, 2016 | 01:49 PM
  #2  
18psi's Avatar
VladiTuned
iTrader: (76)
 
Joined: Apr 2008
Posts: 35,821
Total Cats: 3,482
Default

wowza
Old Jul 1, 2016 | 01:56 PM
  #3  
psyber_0ptix's Avatar
Elite Member
iTrader: (4)
 
Joined: Mar 2012
Posts: 4,648
Total Cats: 544
From: Northern VA
Default

Time for someone to build billet cam cap replacements.
Old Jul 1, 2016 | 02:00 PM
  #4  
bbundy's Avatar
Thread Starter
Elite Member
 
Joined: Jul 2005
Posts: 2,502
Total Cats: 146
From: Anacortes, WA
Default

Interesting wear on the tops of the lifters. Only appears on #4 lifters. It's like pitting.

Attached Thumbnails Found something new I can break.-20160630_180036.jpg   Found something new I can break.-80-175779d1467395957_found_something_new_i_can_break_20160630_180036_527c79479481c9d4aa0d92246bf.jpg  
Old Jul 1, 2016 | 02:01 PM
  #5  
18psi's Avatar
VladiTuned
iTrader: (76)
 
Joined: Apr 2008
Posts: 35,821
Total Cats: 3,482
Default

was the car overrevved?
Old Jul 1, 2016 | 02:03 PM
  #6  
bbundy's Avatar
Thread Starter
Elite Member
 
Joined: Jul 2005
Posts: 2,502
Total Cats: 146
From: Anacortes, WA
Default

Originally Posted by psyber_0ptix
Time for someone to build billet cam cap replacements.
I just bought all new bolts. journals all look good.
Old Jul 1, 2016 | 02:04 PM
  #7  
bbundy's Avatar
Thread Starter
Elite Member
 
Joined: Jul 2005
Posts: 2,502
Total Cats: 146
From: Anacortes, WA
Default

Originally Posted by 18psi
was the car overrevved?
It broke as the car was pulling through a finish at near the rev limit I have set. 8600 rpm.
Old Jul 1, 2016 | 02:07 PM
  #8  
18psi's Avatar
VladiTuned
iTrader: (76)
 
Joined: Apr 2008
Posts: 35,821
Total Cats: 3,482
Default

I have a theory why it broke
Old Jul 1, 2016 | 02:17 PM
  #9  
psyber_0ptix's Avatar
Elite Member
iTrader: (4)
 
Joined: Mar 2012
Posts: 4,648
Total Cats: 544
From: Northern VA
Default

boop

Originally Posted by 18psi
I have a hypothesis as to why it broke
Old Jul 1, 2016 | 07:01 PM
  #10  
bbundy's Avatar
Thread Starter
Elite Member
 
Joined: Jul 2005
Posts: 2,502
Total Cats: 146
From: Anacortes, WA
Default

Im using Carrillo A-beam rods as well. small bolts. probably living dangerously.
Old Jul 1, 2016 | 07:57 PM
  #11  
EO2K's Avatar
Elite Member
iTrader: (37)
 
Joined: Apr 2010
Posts: 10,477
Total Cats: 1,924
From: Very NorCal
Default

Cripes Bob. Did you pull the head yet? What do the #4 valves look like?
Old Jul 1, 2016 | 08:17 PM
  #12  
thumpetto007's Avatar
Elite Member
iTrader: (15)
 
Joined: Sep 2010
Posts: 2,041
Total Cats: -117
Default

holy ****. 8600rpm?

I can't even imagine the drivetrain vibration and noise at that rpm. It is almost unbearable in my (street) car at 7200rpm.
Old Jul 1, 2016 | 11:32 PM
  #13  
bbundy's Avatar
Thread Starter
Elite Member
 
Joined: Jul 2005
Posts: 2,502
Total Cats: 146
From: Anacortes, WA
Default

Originally Posted by EO2K
Cripes Bob. Did you pull the head yet? What do the #4 valves look like?
Valves and cam journals and everything look perfect didnt pull it. I put a new cam and cam cap bolts in and it runs great again. The only lifter buckets that showed odd wear were the two on the #4 intake. they are on back order though. They were Supertech shim under bucket lifters quite a bit lighter weight than stock. springs are also Supertech the medium doubles.

the intake valves are also Supertech and I think they are ones made before supertech changed there manufacturing process because I have never expeianced seat wear with them that other people have.

I suspect one of the cam cap bolts on the back cam journal broke first and with the end of the cam not being suported it had some bending moment and the reverse bending cycles eventually killed it.
Old Jul 2, 2016 | 12:31 PM
  #14  
Stealth97's Avatar
Elite Member
iTrader: (5)
 
Joined: Oct 2007
Posts: 2,156
Total Cats: 67
From: Canton, Ga
Default

I hope this never happens to me with my unobtanium cams...
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
FAB
Fab9 Tuning - Miata Performance Parts
3
Jun 17, 2016 01:48 PM
gdoehl
Miata parts for sale/trade
2
Jun 9, 2016 07:44 AM
Darbymx5
AEM
5
Jun 7, 2016 03:11 PM
Darbymx5
Engine Performance
4
Jun 3, 2016 05:32 PM
Padlock
Miata parts for sale/trade
1
Jun 3, 2016 11:43 AM




All times are GMT -4. The time now is 04:18 AM.