Lol yeah. We're all ripping seals. Uh huh.

I installed mine without the valves even in the head. Then I oil the valve and carefully slid it in.

I'm sure on @EO2K's professionally built head they ripped every single exhaust seal perfectly.

See above for his "ripped" seals.

This just in: Everyone installs Supertech valve seals incorrectly. Everyone installs OEM seals correctly.

We use ST seals, they're installed when the heads are rebuilt at our machine shop, I have not noticed any problems or had any motor customers complain about this (although "no complaints" doesn't mean "no issues"). I personally have not noticed any problems on the two built motors in my own cars, though.

If there are customers out there with my engines who have had issues, I want to hear about it. :party:

I didn't at first but just did. Maybe he'll join in. Good to hear from a vendor ^ though.

This is why we love you, thank you Andrew :likecat:

No problem man! Thought it might save some time for people searching for these. I think I am going to try a set of those as well, I kinda don't want to spend $120 on valve seals.

I ended up taking my cylinder head and block to Rob's Auto Machine in Hayward, CA. It was recommended to me by a fellow miata enthusiasts in Los Gatos. I also read some good reviews about them in many other forums. Rob Jr. even told me that they do/have done work for TSE, so if that's true, I would guess that the shop does pretty good work. I haven't picked up my block or head yet, but will be getting them this week I believe.

Where are you located? I'm in Salinas, CA. I'll most likely take you up on your offer to lend the valve train disassembly tools. I don't feel like leaving the Supertech seals in then making a mess and having to swap them out in the future anyways.

Agreed. $120 seems ludicrous for a set of seals. I guess if its the ONLY thing that works, then its the ONLY thing that works. But I'm not convinced of that just yet. We'll see how the 949 ones go.

Also Salinas. There are a couple local guys here on the forum, but I'm not sure either are super active. Drop me a PM when you are ready and we'll figure something out. I've got a valve spring compressor set and a set of seal pliers, plus an in/lb torque wrench for the cam caps if you need one.

I'm going to look around and see if some sort of magical install tool exists, but I doubt it. Every time I look it up, generic install recommendation seems to be to just use a small socket of piece of tube.

Out of curiosity, how is everyone installing these things?

I use a plastic straw.... Just big enough to fit over the valve stem.

1. Cut a piece of medium plastic straw about 1" and insert the straw through the seal (about 6mm ID).
2. Insert valve stem through guide
3. Slips straw/seal over valve stem
4. Pull straw out
5. Use deep socket (forget Dia... 12mm?) to push seal over guide OD until it "clicks". Don't push more.

As you'd expect on this site... lube it well.

Repeat....

Sounds stupid but the straw keeps a the seal from catching on the edge of the stem and prevents any tearing. Or so it seems....

I've not done ST seals until this engine but in previous engines I've not had any issues. My method and I'm sticking with it...

I just put some oil or grease on the seal and valve stem, carefully slip them over the valve stem, slide them onto the guide, and use a socket/hammer to tap them onto the guide all the way.

If they are right, then I broke all 16 seals they sold me, both times. And to the same degree of tearing, as they all dumped oil the same.

Don't shoot the messenger...

What did you expect them to say? We sell inferior seals that we source from Vietnam because why not??

Oh I understand, no shot at you. I think it's funny when a product sucks, and the company blames the user. If their seals really are so sensitive to installation then they should include instructions stating that.

I was going to pull my cams and then use this (Lisle Tools 36200 Valve Keeper Remover and Installer | eBay) tool.

They're like the opposite of an MSM diff!

Has anyone bought from a different brand as of yet with success?

Here in the UK, the Mazda dealer wants £162 for the full set of 16 valves, which is approximately $209!!!!

I am slightly nervous that Ford, or GM for example, may have had a 'cost down exercise' and changed supplier of their valves. So even though they measure the same on paper, they aren't genuine Mazda parts - which may be the difference.

Also, could someone please confirm that KL0110155 & KL0210155 are the correct part numbers for my '99 NB 1.8?

Whilst I'm here - double springs? I assume this is so you guys can have higher rev limiters? I am happy with a 7k limit so assume no benefit?

Thanks

Wilson

If you guys want to go down the cross-reference rabbit hole, i can tell you that from the part numbers given here, that 2.7 litre Suzuki V6s very likely use the same dimensions.

The machinist who is working on my cylinder head told me that it is done. However, I provided Supertech valve seals to him. I just ordered a set of the 949 seals, looks like I'll be disassembling the head to swap these in instead. @emilio700, I noticed you used to sell the Supertech valve seals on your site, but you no longer do. What is your experience with the Supertech seals? Did you have any leak on you and that's why you no longer sell those?

Possible different batches are slightly different sizes hence some people have a problem and some don't.

Here in the UK. 4 people running over 300whp had the problem along with one running over 400whp that I know of. This doesn't include myself.

When I removed them. They were generally bigger than the OEM. and this was less than 2000 miles. So it's possible they expanded slightly but not that much. All 16 were showing signs of leaking (This was also with running the correct inlet and exhaust seals)

Installing them wrong? I struggle to see how you would as it's quite an easy install. Just be sensible and gentle.


Even if It's down to different batches. It's a risk I wouldn't advise taking.

I had to install the OEM while the engine was in the car with the air compressor trick. A bitch of a job. But It solved my problem.

Or just look up replacements for the Miata on RockAuto. The vehicle cross reference application list is SUPER long.

I'm not saying they will fit or they are any good, but it is an extensive list.

I tried ringing Ford, Suzuki & Toyota.
-Toyota had what they called exhaust valves - listed as inlet valves on the link and were more expensive than Mazda.
-Ford didn't even recognise the part number
-Suzuki weren't open.

I have found a seller on eBay selling genuine Kia intake valves - £8 for all 8... I have bit the bullet and bought the full engine gasket set from Mazda - there's another $350 gone.

Now to decide whether to use the stock HG or buy Cometic.

If you look at the link I posted and take a minute you'll see all the cross-references/vehicles/dimensions/part numbers you need and can order whatever you want online. Valve stem seal cross-reference - post #37

Also, for whoever is so inclined, here's a paper (attached) on valve stem seals + design + materials + tips on installation etc.

I have another email into Supertech to get a definitive answer on diameter range their seals can handle. Will post when/if I get a reply.

EDIT: Well I got a reply but nothing of substance. I specifically asked what valve stem diameter the seals were designed to accommodate and the reply was "They're designed for 6mm stems".

Kind of funny especially when they list their exhaust stems @ 5.94 which is 0.025 [.001"] below the factory tolerance (5.965-5.980, 5.915 Min). Oh well.

https://cimg0.ibsrv.net/gimg/www.mia...49327e3516.jpg

Shits unnerving y0

Supertechs installed this winter. A couple hundred miles on them, and I could see the oil pissing out the exhaust manifold.
https://cimg4.ibsrv.net/gimg/www.mia...eee6360c84.jpg

I'm in the middle of replacing them with felpros. My impression is that it's way easier to feel the double click as the felpros seat.

Also, use this gimmick when you reinstall the keepers

1) seat the keepers so they're started on the valve stem.
https://cimg6.ibsrv.net/gimg/www.mia...5c11d22038.jpg

2) slip a Ziploc bag over the top of the keepers and under whatever you use to compress the spring. Push it. Push it real good. The plastic guides the keepers into place. Super easy.
https://cimg7.ibsrv.net/gimg/www.mia...6ebdaf3d55.jpg

Very nice post. Have a feeling I'll be doing this soon. Your oil out the exhaust flange just looks like a poorly sealed exhaust flange.

Yeah, I'm sure that's part of it. The picture doesn't do it justice. It's literally dripping out the bottom of the manifold.

poscat for the keeper bag trick. I'll be using that tomorrow

"What are all these black dribbles down the side of the block under the exhaust?"

Its oil, don't worry about it.

"Are you sure?"

Yeah.

I've been having this same conversation since my STs went tits up back in 2015 :giggle: I hope the felpros work out for you, we definitely need more datapoints on this one.

did anyone with leaky ST seals notice that once warmed up they didnt seem to leak? i was stuck at a readlight for a bit today and didnt notice any smoke when i took off. however if i let it sit for any time when cold it will smoke

Theoretically there should back pressure in your exhaust manifold when running. Harder to leak?

What about engine off at a red light

i dont know about engine off. It will do it when running and getting up to temp before i leave.

Exhaust manifold pressure is basically ambient at idle or even part throttle/off-boost.

--Ian

How far back does this problem go? Were ST seals ever any good? Reason being Mobius has some oil in his exhaust, but I put his CNC head on (with ST valve stem seals AFAIK) at least 2 years ago.

Supertech never admitted there was an issue. So I doubt well ever find out about any sort of manufacturer change that may have caused this.

Fingers crossed, but the Supertechs (that I thought were OEM, but apparently not) in my head (which got installed around the same time as Gordon's) seem to be holding up OK. No smoke or oil drilling down the head, at least.

--Ian

Are you running a cat?

I do not run a cat on the track, no.

--Ian

Not surprised at super tecks responds. I'm sure they are well aware if their seals are dodgy or not.Who would admit to that. But as far as the specific details of the seals themselves go They might be concerned that you will start havin your own ones mad which may end up better than thiers.

I've just installed the Miata Roadster ones from Bill.
COMP Cams Valve Stem Oil Seals - MiataRoadster - High-performance service...and parts for Mazda Miata Roadsters

not sure what the verdict is for those. Its only been a few weeks.....before I spotted this thread.

I have found this on rockauto. Viton seals from engine tech. No idea the quality but it might be something to try.

https://cimg6.ibsrv.net/gimg/www.mia...ebd5e0151a.png

@curly, my CNC head was ordered at around the same time as Mobius and they've leaked since the beginning.

Well shit.


(Much more recent CNC owner, getting installed [again] soon).

@dleavitt, are you smoking/leaking past the seals?

Short version: maybe.

Slightly longer version: Had my head installed by a competent shop back in January. After a few starts at the shop (still waiting for other parts) much smoke appeared. Shop suspected valve seals, but Emilio INSISTED that it was the rings in my 150k block. At the time I said to myself: "You know, Emilio is probably right. Besides, what are the odds of all of the valve seals being bad in a brand new head?"

While I waited for my block to be completed, this thread pops up with basically everyone saying Supertech seals are full of fail and AIDS. :facepalm:

Car is getting put back together as we speak, so we'll see what happens.

We should know soon enough, curly is putting the motor back together at our shop.

My Mahle one's don't seem to be leaking. I've just had the car idling though.

I swapped out new Supertech valve stem seals for some 949 racing valve stem seals. We will see if they leak or not.

https://c1.staticflickr.com/5/4287/3...2ec17295_b.jpg

https://c1.staticflickr.com/5/4220/3...be9ab827_b.jpg
https://c1.staticflickr.com/5/4249/3...2793361a_b.jpg

Cheater, you took the head off.

haha the head hadn't even been installed yet, which made it that much easier for me. Now I just have to keep my fingers crossed that these will not leak. Who knows maybe the Supertechs I had originally installed at the machine shop wouldn't have leaked either.

Much smoke = not valve seals.

Brand new CNC head on 150k old bottom end = much smoke

Any news on the Fel-Pro seals?
Anyone use them? Any leaks?

I'd been following this thread thinking to myself... maybe intake contamination. Then I see that many of you have the valve cover vented to a catch tank; separated from the intake. Then I'm thinking... probably worn guides... Now I'm seeing at least a couple of you are using new guides. If it is the valve stem seal then I wonder if there's a way to bench test it?

I remember that once I had an oil leak in a new build (it was near the rear main seal). Differential diagnosis was rear main seal vs input shaft seal on trans. (both using synthetic so hard to tell by smell) The folks at Jerico (trans manufacturer) told me to pressurize the trans case and look for seepage. It worked beautifully and the problem was found. Could this be applied to the stem seals? Could you apply a little positive pressure from above and demonstrate leakage?

Shame on you for wanting to use scientific methods! Hearsay, innuendo and accusations are the order of the day here.

Seriously, this is a great idea. What pressures does a stock engine generate in the valve cover area? How about a 10-12 PSI tracked car? What pressure point should the seals hold to under typical conditions?

I'm using the 949 "Same supplier as Mahle, Clevite, Fel-Pro, others" seals. I'll have had them installed for a couple weeks now, and I'll been driving the car through the end of the week and then pulling the exhaust manifold some time this weekend. So while this won't be a long term durability thing, and I'm driving the car N/A at the moment, my STs died on the way home from breaking in the engine when it was first installed so I'll be able to at least tell you if they lasted longer than my STs :giggle:

You are talking about adding positive pressure to the entire crankcase in order to test the crankcase-to-port-past-the-valve-guide sealing ability. Lots of places to loose pressure that are lower paths of resistance than the valve guide/stem seal.

Are you talking about intake valve stem seals or exhaust valve stem seals? N/A application the intake stem seals are **always exposed to vacuum from the intake port and the exhaust valve stems seals are **always exposed to backpressure from the exhaust port. Add boost and now you've got pressure and vacuum on the intake and even more backpressure on the exhaust side. It would be fairly easy to pressurize the ports with the valves closed, but I very much doubt that would be a good enough seal to accomplish any meaningful testing with the head on the block.

** Yes, I understand how the ram air effect works on the intakes and scavenging works on the exhaust, but if you think for one moment this tractor motor of a BP has perfectly tuned intake and exhaust systems, you've got another things coming.

I'm thinking that you could squirt a little oil over the valve stem and seal ( springs removed), then press a piece of 1/2" hose over the stem and simply blow into it.

We never had massive issues or premature failures with the ST seals. We just noticed some minor leakage after long term inspection. We noticed engines run about the same usage with OEM seals had less or zero leakage. We installed OEM seals and seals from a few other manufacturers in various engines starting about three years ago. Over that time we noticed which seals leaked the least or not at all. OEM Mazda seals are perfect, just silly expensive. The alternatives we offer work just as well and cost a fraction as much.

So the process to determine which seals would be an improvement began long ago. We wanted to have long term data before making the switch from the ST seal to seals we offer now.

I have had them in my car. They're what I used when my ST seals leaked. I want to say since 2015. I have several autox and drag strip runs on them, no leaks. I catch a whiff of oil sometimes on decel after heavy boost, but my 2871 churbo is blowing some oil, so I think that may be the cause. Not using any oil at all and no evidence of leakage last time I checked. I don't want to stick words in his mouth, but I think Pat is using them with success too.

My Mahle seals are holding up well, no issues thus far. I'm thinking my rings might be tired however. I put a catch can in my car and have yet to see any more blue smoke under boost.

Insanely glad I found this thread today as I was about to purchase a set of ST seals for my wife's Miata. I still need to diagnose why it's consuming so much oil naturally-aspirated but figured this would be a good place to start. I plan on ordering the Fel-Pro kit.

141k miles, '99.

We have had the same experience as Emilio. We were buying FelPro rebuild gasket kits for our new engine builds, but using ST Viton valve seals. After noticing leakage down the stems after 10-20 hours of race running, we started just using the FelPro seals in the kits instead. No problems since. We have had a couple of engines come back that were due for new valve springs, and the seals still seemed ok.

I had originally installed ST valve stem seals on my freshly built head, but took them out and put in the seals 949 racing sells which I think are the same as Fel Pro. I have about 750 miles on the engine and so far there is no leaks that I can see, also car does not smoke.