Misses when cold, goes away when warm...
#43
Moderator
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/moderator.png)
iTrader: (12)
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,884
Total Cats: 3,075
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Does anyone else get seasick watching that in full screen?
I was hoping to see the valve seats in clear detail. I guess the head will be coming off regardless of what you see at this point.
I was hoping to see the valve seats in clear detail. I guess the head will be coming off regardless of what you see at this point.
#44
Elite Member
![](/mt2011/images_td/ranks/supporter1.gif)
Thread Starter
iTrader: (2)
Join Date: Jun 2009
Location: Istanbul, Turkey
Posts: 3,222
Total Cats: 1,701
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
If I have to chuck all the Supertech valves, would it be stupid to install the stock valves back in the head?
They were OK when I pulled them to make room for the Supertechs.
(and, I would not just pop them in. The machine shop will go over them of course.)
Spending $300+ on valves - on top of all the other stuff - is a bit much at this time.
They were OK when I pulled them to make room for the Supertechs.
(and, I would not just pop them in. The machine shop will go over them of course.)
Spending $300+ on valves - on top of all the other stuff - is a bit much at this time.
#45
Elite Member
iTrader: (21)
Join Date: Jun 2007
Location: Rochester, NY
Posts: 6,623
Total Cats: 1,277
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I am still not sure what exactly is going on here. If you've gotta fart around with the valves, might as well do it with the Supertech over the stock ones, right?
Is the general consensus just that the lash is all messed up? I'm confused as to why it would misfire when cold but disappear when warm.
Have you pulled the head yet?
Is the general consensus just that the lash is all messed up? I'm confused as to why it would misfire when cold but disappear when warm.
Have you pulled the head yet?
#48
Elite Member
![](/mt2011/images_td/ranks/supporter1.gif)
Thread Starter
iTrader: (2)
Join Date: Jun 2009
Location: Istanbul, Turkey
Posts: 3,222
Total Cats: 1,701
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Snowstorm's over, weather report says 50F and sunny for tomorrow, and I will be able to pull the head finally.
Working outside sucks sometimes.
I will post all dirty details here as soon as the head is out.
I just hope my valves are not "tulipped"...
Working outside sucks sometimes.
I will post all dirty details here as soon as the head is out.
I just hope my valves are not "tulipped"...
#52
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I hated reading this thread.
Similar setup - wiseco's, eagles, arp, 99 head, +1mm supertechs. Cold miss. My brother rode with me and said it seemed down on power from the last time he rode with me (6+ months ago).
Ignored it while I got the car past (and passed) emissions. Car started puking oil out of the catch can and rear main a week later. Finally had a chance to poke it tonight.
Compression was 120, 150, 150, 150. Leakdown (via crappy HF gauge at 15psi) was 95%, 55%, 45%, 55%. Loosened the caps and retest - 25%, 26%, 24%, 27%. Well, at least it's not the rings.
Exhaust valve clearance is ***** on, .30mm all day long.
Intake - couldn't get the .04mm feeler between 6 buckets. The other two were .06 and .08. FML.
Looks like I need a new machine shop. Though I did promise myself if I ever had to pull this engine again, a V8 was going back in its place.
Similar setup - wiseco's, eagles, arp, 99 head, +1mm supertechs. Cold miss. My brother rode with me and said it seemed down on power from the last time he rode with me (6+ months ago).
Ignored it while I got the car past (and passed) emissions. Car started puking oil out of the catch can and rear main a week later. Finally had a chance to poke it tonight.
Compression was 120, 150, 150, 150. Leakdown (via crappy HF gauge at 15psi) was 95%, 55%, 45%, 55%. Loosened the caps and retest - 25%, 26%, 24%, 27%. Well, at least it's not the rings.
Exhaust valve clearance is ***** on, .30mm all day long.
Intake - couldn't get the .04mm feeler between 6 buckets. The other two were .06 and .08. FML.
Looks like I need a new machine shop. Though I did promise myself if I ever had to pull this engine again, a V8 was going back in its place.
#55
Elite Member
![](/mt2011/images_td/ranks/supporter1.gif)
Thread Starter
iTrader: (2)
Join Date: Jun 2009
Location: Istanbul, Turkey
Posts: 3,222
Total Cats: 1,701
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Gentlemen,
After buttoning the head up with my used original valves, I knew I would have to go in once again and make things right.
(I was really pressed for time then. I had to get the car back on the road ASAP)
Needless to say, I am not working with that machinist anymore.
(For the record, he cut the old valves razor thin - they are pretty much on borrowed time. And, I am seeing excessive EGT levels during fast cruise and under boost.)
I have put together a list of parts. I will take the head apart when I have everything in hand over here.
Please tell me what you think, it will be much appreciated.
I'm really hoping this will take care of my problems once and for all.
After buttoning the head up with my used original valves, I knew I would have to go in once again and make things right.
(I was really pressed for time then. I had to get the car back on the road ASAP)
Needless to say, I am not working with that machinist anymore.
(For the record, he cut the old valves razor thin - they are pretty much on borrowed time. And, I am seeing excessive EGT levels during fast cruise and under boost.)
I have put together a list of parts. I will take the head apart when I have everything in hand over here.
Please tell me what you think, it will be much appreciated.
- Supertech MAEVI-1206 - Exhaust valves Inconel (+1mm)
- Supertech MAIVN-1206- Intake valves (+1mm)
- Supertech SPR-2082-K - Inner valve spring kit (to move up to the "light double" setup)
- MiataRoadster MR-BVG-16 - Manganese-Bronze valve guides
- Fel-Pro HS 9717 PT-3 - Head Gasket Set
- Sealed Power 245-1250-56 - Exhaust Valve Seat Set
- Sealed Power 245-1437-74 - Intake Valve Seat Set
I'm really hoping this will take care of my problems once and for all.
#57
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I feel for you. I really do. I changed machine shops too and the '99 head on the Red car (with OEM valves but good machining) has been solid since.
I've recently gotten the Silver car back on the road -- street driving only. The motor (including the head) was done by that first machine shop. I live in fear -- but hydraulic lifters are much more forgiving. So far so good (3K miles).
I've recently gotten the Silver car back on the road -- street driving only. The motor (including the head) was done by that first machine shop. I live in fear -- but hydraulic lifters are much more forgiving. So far so good (3K miles).