TNTUBA

iTrader: (1)

I will absolutely NEVER purchase another product from Supertech.

At this point, I could be given a lifetime supply of their parts.....and I would throw them in the garbage.

That is all.

mx5-kiwi

in terms of completing the circle of info in this thread do you care to say why after this time you now say this?

Presuming something has happened recently to stoke the discontent...

d k

iTrader: (4)

How come no one has mentioned valve seat width?

It should be at least .060"

ST coating the entire valve again relatively soon.

emilio700

iTrader: (3)

Several of the early replies were warning about valve seat width.

patsmx5

iTrader: (16)

I mentioned valve seat width in almost every post I've made in this thread.

FWIW I'm running supertech valves with very high RPMs, and < 1 thousandth valve lash change from when I set the head up before installing it on the car 3 years ago. Machine work (including seat width) is also a factor, not just the valves. That said I'm not a huge fan of supertech parts, some are better than others but I'll agree there are absolutely better parts available.

aidandj

iTrader: (5)

We're yours from back when they were coated?

Savington

iTrader: (31)

Three years on your car and three years on Eric Anderson's car could not possibly be less equitable.

patsmx5

iTrader: (16)

Nope, not coated.
Eric hasn't managed to get 3 years on a cylinder head with the racing he does. I have 3 years, about 20k miles on this head, and many many many more hours of use WITHOUT a failure. And it sees high RPM/ high power too. For a street car, mine sees a lot of abuse.

aidandj

iTrader: (5)

I mean the nitride hardening that was discussed a few posts back.

patsmx5

iTrader: (16)

I bought these valves in early 2013 from 949 Racing. Stock size supertechs on intake, +1mm inconel on exhaust. This is the valves I have:

https://www.miataturbo.net/attachmen...ine=1373995754

TNTUBA

iTrader: (1)

What you do with that car is childs play compared to the level of abuse this valvetrain sees.

I put this car through more abuse in one Pro Solo weekend than you could put your car through in a year.....and this current setup lasted 13 races.

If you don't understand that trying to compare your situation to mine is like compairing an apple to a suspension bridge.....then you are beyind the scope of this conversation.

patsmx5

iTrader: (16)

lol

I said mine is a street car, and have said that so many times on this forum. Some people who track there cars just love to point out that racing the car at the limit on a track is harder than street driving. No kidding! I never knew...

TNTUBA

iTrader: (1)

Then stop trying to compare it to one.

I don't think anyone who brought evidence to this thread asked about street cars......did they?

patsmx5

iTrader: (16)

The OP of this thread said he tracked and drove his car on the street and posted the race hours and street miles when it failed. Post 2 said he did the same thing and also listed time raced and street miles driven, and got same results which are supertech valves failing. I drive my car on the street and put some track time (drag strip as you very well know) on it and have not had any failures after 3 years/20k miles. Of course mine is not a race car, but it's making lots of power and revs as high as anything else here. If you believe my experience is not relevant that is fine. I'm happy not having failures.

I nor anybody else here thinks that street cars and race cars are the same, so you don't need to try to prove that they are different.

Have you measured valve lash before/after and been able to measure a difference with the new coatings you are running?

d k

iTrader: (4)

Does anyone have any data on FULLY nitrited (ST) valves having failures?

Since Supertech is starting to coat the seating area as well, could this be the fix?

TNTUBA

iTrader: (1)

I have edited this and softened it up several times in the interest of civility


You are the one that attempted to compare your car to mine...not the other way around. No, your experience is in no way comparable to mine nor is it relevant to me. Your "Mine has lasted 3 years and Erics hasn't" is an attempt at making yourself look superior.....which isn't the case. That is like saying my motor lasted 20 thousand miles.....that NASCAR motor only lasted 500. What's the point?

I log valve lash before and after every race...along with wet and dry compression and leak down. I have all the data in a 3 ring binder along with every other maintenance item for the car. I have one of these binders for every year the car has been raced.

I pulled this last motor apart after a 1.5 thousandths decrease in valve lash.

The valve seat pressure has been increaed every year AS HAS THE SEAT WIDTH. Every time the head has been rebuilt it has received fresh guides and had the seats cut on a Serdi machine. You know.....the best valve job machine on the planet. The intake seats were recently cut to .063" buy a machinest who works on heads that make orders of maginitdue more power and are ran by teams that rely on performance and relaibilty to make their living.
I'm not sure what contest you are trying to win or who you are trying to impress....but you are doing it wrong.

TNTUBA

iTrader: (1)

I absolutely think this will go a long way towards fixing the issues.

It will not cure bad machine work, low spring pressure, money shifts or other issues. But I absolutely think it is a step in the right direction and I am very happy to hear they are making this change.

patsmx5

iTrader: (16)

Yes to being civil, there's not reason not to be. There is no doubt we have two completely different cars, hell I'm pretty sure we've done this same BS conversation about our cars being different already, haven't we? Maybe that was me and Sav. Eric, your car is better and more abused than mine in every way, because yours is a very fast race car, and mine is a street car. But mine is a street car. A street car.

I hope that clarifies my position and doesn't offend those with race cars significantly faster/more powerful race cars than my street car.

I thought my point was obvious, but I'll say it again. I have driven 3 years/20k street miles and raced my car (at a drag strip 20-25 times/year making 10-20 passes at each event) for 3 years with less than 1 thousandth change in valve lash from when I built the head 3 years ago and solid compression across the board. I think anyone knows a street car and race car are not the same.

I would of clarify the engine makes more than 300whp , and revs to over 8,500 at every event it's raced at. Fuel cut is usually at 8,800 but shifted at 8,500-8,600. For a STREET CAR this is a pretty aggressive build and maintains very high reliability for a STREET CAR.

Leafy

iTrader: (1)

For what its worth I've gotten more life out of the supertechs in the TSE motor than Eric's been getting while spinning to 8.5k and doing the same racing. Of course with less power, but most of last season I was using a lot more rev limiter. Mine are onto their 2nd time of needing to be reshimmed in 3 years which tells me they probably look like his. This is one of the reasons I decided to ditch the BP platform.

bbundy

point of reference my flyin miata super tech 1mm oversized valves have been in use since bought in 2006. Head was rebuilt FM ported casting replaced with one ported from replika after ARP torque specs cracked it after needing the bottom end rebuilt, valves were re-used. I then burned exhaust valves twice running it on the track and melted a piston and did some knock damage to the head once. Im on the third rebuild of the bottom end, still reused the intake valves. 2013 I blew the freeze plug out of the front of the head and thought it might have been damaged too much during the melted piston event had it checked out real good and couldn't find any evidence of catastrophic damage so I re built it again and added Inconel exhaust valves, shim under bucket lifters, and went from super tech single to medium double springs still reused the intake valves. 2016 I broke an intake camshaft and replaced it. I still have not seen intake valve seat wear like others are seeing.

Current config is 2.0l stroker motor. bp4w head. with bp5a intake. makes ~330hp setup for the track ~400 setup for everything else. II holds all the TT2 lap records on northwest tracks. It does pretty good set up for SSM autocross as well and is nationally competitive. rev limit is set to 8600 rpm and it sees that on many autocross courses.

I think there is something to the supertech intake valves of much older vintage being better. mine are in 10 years of abuse now.