Help!! My Intake Valves Keep Wearing Out! - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Race Prep Miata race-only chat.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 01-04-2015, 12:48 PM   #21
Junior Member
iTrader: (1)
 
Join Date: May 2013
Location: Sandia Park, NM
Posts: 386
Total Cats: 38
Default

Your MS rpm is correct to within an extremely small error. It needs to be in order to correctly time ignition events
leboeuf is offline   Reply With Quote
Old 01-04-2015, 01:50 PM   #22
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 5,140
Total Cats: 1,137
Default

If running light doubles and not critically money shifted (8500+), then it's the seats. No installed or cut correctly. I've posted this before but BP heads don't flow much regardless of what you do so there is no sense in getting agro with teensy drag style valve seats that destroy valves in 10 hrs. The seats themselves need to be the correct hardened type as well. We lost a head a few years ago that had the wrong seats installed, also ate it's valves in short order.

Test the valve springs if you like but we have not encountered any losses in spring rate in any of our ST valve spring sets. Every set that goes into or comes out of one of our engines in is checked.
emilio700 is offline   Reply With Quote
Old 01-04-2015, 03:20 PM   #23
Elite Member
Thread Starter
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 5,981
Total Cats: 576
Default

Quote:
Originally Posted by emilio700 View Post
If running light doubles and not critically money shifted (8500+), then it's the seats. No installed or cut correctly. I've posted this before but BP heads don't flow much regardless of what you do so there is no sense in getting agro with teensy drag style valve seats that destroy valves in 10 hrs. The seats themselves need to be the correct hardened type as well. We lost a head a few years ago that had the wrong seats installed, also ate it's valves in short order.
Great info. This particular head had been "ported" prior to my ownership, so there is a distinct possibility that there is something funky with the seats.

Last edited by hornetball; 01-04-2015 at 08:36 PM.
hornetball is offline   Reply With Quote
Old 01-04-2015, 05:02 PM   #24
Junior Member
 
guttedmiata's Avatar
 
Join Date: Sep 2012
Posts: 438
Total Cats: -3
Default

Quote:
Originally Posted by emilio700 View Post

Test the valve springs if you like but we have not encountered any losses in spring rate in any of our ST valve spring sets. Every set that goes into or comes out of one of our engines in is checked.
Not gonna get into a pissing match with a vendor, but my previous statement is from tested springs, not just theory. Might not be every set, but I will never put ST springs in my engine.
guttedmiata is offline   Reply With Quote
Old 01-04-2015, 06:08 PM   #25
Elite Member
iTrader: (2)
 
Mobius's Avatar
 
Join Date: May 2008
Location: Portland, Oregon
Posts: 3,119
Total Cats: 256
Default

My tach reads 2-300 RPM high at the hgh end as compared to what the ECU reports to the scanguage. I think it's a deliberate Mazda "feature."
Mobius is offline   Reply With Quote
Old 01-04-2015, 07:36 PM   #26
Senior Member
iTrader: (1)
 
Join Date: Jan 2011
Location: Chattanooga, Tn
Posts: 1,027
Total Cats: 155
Default

Its not metalurgically (did I make that up?) possible for a spring NOT to lose pressure once it's broken in. Valve springs are a wear item in a race motor and should be treated as such....valves shouldn't be wearing out before the springs do though.
TNTUBA is offline   Reply With Quote
Old 01-04-2015, 07:38 PM   #27
Senior Member
iTrader: (1)
 
Join Date: Jan 2011
Location: Chattanooga, Tn
Posts: 1,027
Total Cats: 155
Default

I have personally seen popular name brand valve springs lose as much as 20% of their seat pressure after 200 autox runs.
TNTUBA is offline   Reply With Quote
Old 01-04-2015, 08:29 PM   #28
Elite Member
Thread Starter
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 5,981
Total Cats: 576
Default

Hmmmm . . . . 200 runs x 1.5 minutes ~ 300 track minutes ~ 5 track hours.

Last edited by hornetball; 01-04-2015 at 10:33 PM.
hornetball is offline   Reply With Quote
Old 01-04-2015, 08:32 PM   #29
Senior Member
 
Join Date: May 2011
Posts: 530
Total Cats: 55
Default

good info in this thread. thanks for posting everyone. I don't have anything to add other than my tach is the exception to the rule and it reads dead nuts accurate up to about 7500 rpm... I wish I didn't know that and I wish i didn't have the MS logs to prove it.
EErockMiata is offline   Reply With Quote
Old 01-04-2015, 08:34 PM   #30
Elite Member
Thread Starter
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 5,981
Total Cats: 576
Default

Yeah . . . but you have one of them fancy NB cars . . . .

(Oooops, I guess Mobius does too).
hornetball is offline   Reply With Quote
Old 01-04-2015, 10:14 PM   #31
Senior Member
iTrader: (4)
 
Join Date: Nov 2012
Location: Colorado
Posts: 710
Total Cats: 45
Default

I think either of these guys could help you out with your valve issues


K Miata Home

NA/B 90-2005 - LFX products - V8 Roadsters
dcamp2 is offline   Reply With Quote
Old 01-04-2015, 10:31 PM   #32
Elite Member
Thread Starter
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 5,981
Total Cats: 576
Default

Quote:
Originally Posted by dcamp2 View Post
I think either of these guys could help you out with your valve issues

K Miata Home

NA/B 90-2005 - LFX products - V8 Roadsters


Inching closer . . . .
hornetball is offline   Reply With Quote
Old 01-05-2015, 01:19 PM   #33
Senior Member
iTrader: (14)
 
Join Date: Jan 2007
Location: Murfreesboro,TN
Posts: 1,240
Total Cats: 45
Default

Quote:
Originally Posted by hornetball View Post
Hmmmm . . . . 200 runs x 1.5 minutes ~ 300 track minutes ~ 5 track hours.
It would be curious to see the percentage of time spent at the upper RPM range in that time period.
Midtenn is offline   Reply With Quote
Old 01-05-2015, 04:34 PM   #34
Senior Member
iTrader: (1)
 
Join Date: Jan 2011
Location: Chattanooga, Tn
Posts: 1,027
Total Cats: 155
Default

I would say on National Level courses 75% of the time on course is spent above 5000. But that's just a WAG
TNTUBA is offline   Reply With Quote
Old 01-05-2015, 09:19 PM   #35
Senior Member
iTrader: (14)
 
Join Date: Jan 2007
Location: Murfreesboro,TN
Posts: 1,240
Total Cats: 45
Default

I would guess the same based on my experience in a CSP car.
Midtenn is offline   Reply With Quote
Old 01-05-2015, 10:48 PM   #36
Elite Member
Thread Starter
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 5,981
Total Cats: 576
Default

Head's pulled. I'm getting damn quick at it. Going to someone I trust tomorrow. My instructions will be simple . . . (valve face support) > ("flow")
hornetball is offline   Reply With Quote
Old 01-05-2015, 10:54 PM   #37
Elite Member
iTrader: (2)
 
Join Date: Jun 2009
Location: Istanbul, Turkey
Posts: 2,038
Total Cats: 427
Default

Please take some close up pics of the valves and seats.
We can post and compare our cases when I get a chance to pull my head.
(Will at least be a couple days before this snow storm goes away)
Godless Commie is offline   Reply With Quote
Old 01-05-2015, 11:21 PM   #38
Elite Member
Thread Starter
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 5,981
Total Cats: 576
Default

Quote:
Originally Posted by Godless Commie View Post
Please take some close up pics of the valves and seats.
We can post and compare our cases when I get a chance to pull my head.
(Will at least be a couple days before this snow storm goes away)
Here's what my last set of valves looked like (the ones that were removed in September):

Intake Valve (trashed):


Exhaust Valve (normal):


Closeup of that Intake Valve:


I expect this set to look similar. They are very recessed into the head.
Attached Thumbnails
Help!!  My Intake Valves Keep Wearing Out!-img_0506.jpg   Help!!  My Intake Valves Keep Wearing Out!-img_0508.jpg   Help!!  My Intake Valves Keep Wearing Out!-img_0509.jpg  
hornetball is offline   Reply With Quote
Old 01-05-2015, 11:57 PM   #39
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,037
Total Cats: 99
Default

I'm expecting to see my intake valves look the same. I'm hoping otherwise. My intake valves all tightened up, builder (trackspeed) recommended reshimming and checking it more often. And I hope its just normal wear. If it opens up another .001 in the first 2 auto-x's the heads coming off and I know that this will the problem. I dont know why no one here is using the manley valves they cost $10 more per set of 8 and use a higher quality stainless. You arent even close to the first one to see intake valves exactly like that, it was the plague of a certain west coast csp car. I think he adjusted his machinist adjusted his valve job to compensate or something.

Add me to the list of people hearing about other people's ST springs loosing seat pressure. Those super cheap BC springs in bogous svo's thread seem better and better.

Last edited by Leafy; 01-06-2015 at 07:42 AM.
Leafy is offline   Reply With Quote
Old 01-06-2015, 12:26 AM   #40
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,208
Total Cats: 1,226
Default

Quote:
Originally Posted by Leafy View Post
I dont know why no one here is using the manley valves they cost $10 more per set of 16 and use a higher quality stainless. You arent even close to the first one to see intake valves exactly like that, it was the plague of a certain west coast csp car. I think he adjusted his machinist adjusted his valve job to compensate or something.
Do you ever read your own posts? You bitch about the valves, talk about a CSP car having the same issue, and then admit that the machinist adjusted the width of the ******* valve seat to fix the issue.

Cognitive dissonance at its finest. Jesus ******* christ.
Savington is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 57 07-19-2017 04:11 PM
OTS Bilstein to motorsports ASN conversion stoves Suspension, Brakes, Drivetrain 5 04-21-2016 03:00 PM
Expected intake temps on the track? tazswing Race Prep 20 10-03-2015 11:04 AM
Moroso Air Oil Separator Catch Can Aroundcorner Miata parts for sale/trade 2 10-01-2015 03:20 PM
Going back to stock. Need some 1.6 parts. Trent WTB 2 10-01-2015 12:15 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 12:29 PM.