RS Aizawa ITB 1.6 - valve stem seals - improvements while in the head ?

So my white car, which, I promise I will do a walk around one day soon, has developed what is probably a valve stem leak (or, rings, but not likely)

When giving it the full monty between 6K and 8K, it smokes grey-blue when I lift off until it drops under 5K or so. All that vacuum. I've put in some seal conditioner and it has reduced to the smoke but not solved it permanently.

I've done an ATF soak (24h) of the piston rings in situ while hand cranking her. The rings I suspect to be perfectly fine. There's barely any blowby on cold idle either. I checked by blocking all but one breather. (NOTE: they weren't, it was probably the oil control rings that were gone, which I fixed separately through multi-day ring soaks)

This is one of those cars where, I really want to retain the character of the 1.6 and especially the 1.6 RSA ITBs / value therein - the car is an absolute blast on this intake setup and so that's the one thing I won't change, so I've no interest in going 1.8. It'd destroy the intrinsic value and nature of the car.

So... what to do ? Let's OVERTHINK this! :-)

Sourcing Seals. - I'd either get the OEM Mazda ones or a set of supermiata viton ones. Or are there better available than those ?

Since I'll be going into the head there's an opportunity to improve things. 8K rpm is probably not ideal with HLAs I'm eager to take it from HLA to SUB. It works fine now but I'd like to let it go a little higher and get there a little faster.

Sourcing SUBs - Probably want to get the mazdaspeed SUB lifters and then source / machine the lashcaps in europe (good supply of 6mm ones here) - has anyone got better suggestions ?

But there's opportunity to do more.

Valve springs and Retainers - to go past 8K and get there faster - All the google searches I do for valve springs kind of.. well, they're not really informative. and they're really old.

I see supertech have lovely kits. I have my doubts about supertech ones (actually, I have my doubts about supertech anything..) - are they OK ? But I'd love to lose more weight in the head - Supertech's TI retainers look unique and interesting. Thinking to combine those and some volvo or 'race engine' ones I can perhaps find from the EU mx5 tuning wasteland.. or from Japan ? But from who ?

Or should I forget about messing with the springs/retainers and just do the SUB conversion after replacing the seals ?

Not trying to save money, just want to get the best out of my 1.6 and do it the 'best' way and let it safely go over 8K. Arguably I should get everything from Japan (Maruha and the rest) but I'd rather get the unique things from there. Lashcaps aren't unique. etc.

All criticism welcome and insights gratefully received.

I think you are spot on in everything. I would (will) use OEM Mazda seals, but I know from a good friend that Supermiata ones are also decent, he has had no issue with them so far.

SUB's, take a look at Hyundai/Kia part no 22226 2B401 (or any number after B for that matter); they are identical to the Mazdaspeed ones, but easier to source in Europe and slightly cheaper.

Regarding valve springs, I would also upgrade since you are in there. I have the following data points:

OEM Mazda (NA8) [BP05-12-125] - 275lb/in
OEM Mazda VVT In - 235lb/in
OEM Mazda VVT Ex [BP2Y-12-125A] - 194lb/in
Sealed Power VS-949 - 283lb/in
Sealed Power VS-855 - 349lb/in
Brian Crower BC1600-1 (orange dots) - 237lb/in
Piper Cams VSSVTR2 - 276lb/in
PAC S90015 - 216lb/in

I have no data on the NA6 springs though. Please note that some of the above are not meant for B6/BP engines, but are close enough in dimensions. Let me know if you need more data, I have a spreadsheet with dimensions, block heights, seat pressures vs seat height etc.

So, here's the deal. I understand what you want to do, end goal, but I think you're leaving a lot on the table and I don't know the specs of your engine as it currently sits. If what I write below is redundant to what you already have, please forgive me.

If you want to spin the engine to 8k, springs will be needed. If you plan for the engine to live at those revs, you are probably going to need to consider more than upgrading the valvetrain.

In regards to valve stem seals (VSS), my first thought is OEM. Why not vinton? I had heard some brands were not lasting. It has been a few years, so double check that. Maybe it's installation, maybe a manufacturing defect, but OEM or OEM-quality hold up pretty well.

Valve springs (VS), retainers, seats, keepers, etc., yes Supertech are very good and for us here in the US, easy to get our hands on. Super rare JDM (y0!) stuff is neat, but I don't like paying a premium for similar stuff that would be very hard or impossible to replace if things went pear-shaped. If you plan to just take the revs up, a single spring is fine, if you plan on staying at 8k for extended periods, dual-springs should be considered. Also, factor in the possibility of whether or not you will playing with camshafts. Lift plays a big part in how much cam you can play with and the OEM valve springs don't have a lot of head room.

If you are planning on VSS and valve train upgrades, plan on pulling the head. Don't waste your time on trying to do this with the head still in the car. Why? Because that is where you are leaving a lot on the table for these types of performance upgrades:

Shave the head. I'm not talking about a re-surfacing, I'm talking about a compression bump. .025-.035" (.6-.9 mm), maybe more if you have the support. This is probably the easiest HP upgrade for the expense.

Replace the valve guides. You could go through all this work replacing the valve train and seals only to find out your valve guides are too loose. You will have the same issues you have now in short order, or little to no change.

Port the head - mild or wild, depending on your budget improving the air flow through porting, gasket matching, deshrouding, etc is a solid upgrade.

Valve seats - don't know how well your engine has lived, but without removing the head, there are many things you won't correct. New valve seats, machining the valve heads, can not only help sealing, but improve airflow. You *could* consider going to oversized valves in this route too.

Head studs - I'm a big proponent of switching from TTY head bolts to studs. Better clamping, reusable, better resistance to lifting, etc. It's a pretty inexpensive upgrade for durability and other power-adding options down the road.

At some point, you need to also consider for all this added zing (revs), what can your stock connecting rods handle? The loads on the rods reciprocating that fast are enormous.

The biggest question though, is where you want to stop is up to you, all this above are diminishing returns.

Quote:

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Originally Posted by kung fu jesus

what's on the table

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I've read what you wrote a few times KFJ :)

I absolutely agree with the head off thing - there's a lot that can be done and... I'm if it all goes to plan I'll have the budget to do go overkill with a forged bottom end.

Valve guides are probably buggered and should be replaced since that's path the oil takes past the VSS.

State of the engine it has probably been given a mild shave but internals are stock bar the cams, which are RSA's regrinds. I'd like to try to stick with those but I know I should go higher lift/duration for ultimate performance.

124HP at the wheels. this graph shows the difference with (green) or without (red) the 50mm intake spacers, both with the ITG filter on top of the 50mm trumpets. Also this has a ceramic coated Maxim Works header.

https://trull.org/alex/media/pics/ca...0mmspacers.jpg

My instinct tells me to stick with single valve springs. FM have a kit with ti retainers that's single spring and they claim it's good for 9K RPM. https://www.flyinmiata.com/default/v...tml#additional - is this just the ST kit relabeled ? :D

also I understand the NB valve keepers/collets are lighter weight than the NA ones ?

The bottom end thoughts are a lot simpler than the top end strangely..

Pretty much set on Carillo H beams, and sorely tempted by the nutty 80.5mm Mahle/Maruha pistons (3mm between cylinders), but I think some 79.5MM wossners (leaving 5mm between cylinders) would be better for block longevity/stronks. These are my paper calculations. I haven't measured an actual block.

I don't know if 1.8 VT components are lighter. I do know the 1.6 stuff has more specific orientations and placement. I also don't know if the FM stuff is ST, but it wouldn't surprise me.

Cams get tricky because I don't know the current specs on the regrinds and there is a fine line between drive-ability and performance if you start getting aggressive.

On the bottom, look into King racing main bearings or similar. I would be considering uprated con rod and main cap hardware (ARP) for "cheap" insurance.

I don't like a 3mm spacing on a 1.6, it's too fragile at that point for as high as you want to spin it. I wouldn't expect it to last long.

You should get solid numbers, like leakdown and compression before you start doing any of these repairs and upgrades. It's really useful data and helps you see where you have come from.

FWIW, my rebuilt 1.6 was built to survive track and street in pretty warm climates. After the rebuild and break in, I saw 210 PSI across the cylinders. Stock is about 190-195. The head was a mild port with gasket matching. I used a new OEM 1.8 BP oil pump shimmed because I had the long nose crank.

If you are going high RPMs, you are going to want to consider a blueprinted oil pump from Boundary. Those OEM pump gears aren't fond of those speeds for long.

LNC here too and already on a fluidampr. My oil pressure is quite good on this car but agree it's worth going boundary. The sender kind of gives up signaling properly at WOT over 7K but as soon as I come off the throttle at high rpm it shows the true pressure which remains good.

I had the same issue.

I've started buying all the bits to make a go of this..

Kind of doing a '1.5' job. I think the compression on this engine is good so I'd rather not touch the cylinders unless I have to.

So '1.5' means .. Not going to take the head off. Not going to change from the RSA regrinds cams.

Will be going lightweight everywhere I can change though :D

SUB & Solid lifters, Light Cam Gears, New valve springs add Ti retainers, and obviously... new seals.

We'll see!

Aftermarket springs on a budget: https://bofiracing.co.uk/valves/upgr...da-mx-5-na-nb/

Using the Volvo springs was initially discovered by someone on that mean turbo site years ago and is a tried and true option on a budget.

Valve stem seals are done. Along with the supertech spring kit. Installing the collets was interesting. FM tools are really good.

I measured up the cams that were in the car and they appear to be absolutely stock measurement. So several friends one of whom will probably end up tuning the car, have suggested 272 duration 9mm option.

Currently awaiting a delivery estimate from TODA on said cams.

And for your bizarre random facts book, here's a keeper (heh)

Also I can confirm now that the NB keepers/collets weigh approximately .06 grams more than NA ones....

0.69G - NA keeper
0.75G - NB keeper

I weighed four at a time to get this number. heh.

I always use a small, slightly magnetic flat screwdriver with a dab of grease to do collets. Once I feel the shoulder slip into the relief on the valve stem, I go to the next. The grease helps hold the collets to the screwdriver blade, and adhere them to the valve stem until you release the compressor. Valvetrain work is rhythmic.

Quote:

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Originally Posted by kung fu jesus

I always use a small, slightly magnetic flat screwdriver with a dab of grease to do collets. Once I feel the shoulder slip into the relief on the valve stem, I go to the next. The grease helps hold the collets to the screwdriver blade, and adhere them to the valve stem until you release the compressor. Valvetrain work is rhythmic.

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Aye. I was really enjoying it once I got into it. I ended up using a some thin tipped tweezers and grease. I didn't have a screwdriver with quite the right level of magnetism (it was too stronk).

Same. Valvetrain work can be very zen and enjoyable. It’s rewarding fitting all the precision components together.

I would love to experience this someday as well. But i think i would like to work on an engine with someone that knows what they are doing :).

Quote:

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Originally Posted by Willywongka

I would love to experience this someday as well. But i think i would like to work on an engine with someone that knows what they are doing :).

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I watched so many instructional youtube vids I wrote my own process on what to do as an aid to mind. I'd been prepping to do this work one way or another (psychologically or making queries with suppliers) since I wrote the original post.

I was going to ask someone else to do this for me but I realised it didn't make sense - I had the tools, I had the time, and leaving the car in a profit-making garage for up to a month wasn't something I wanted to do since I they'd just want to put it all back together ASAP but I wanted to research the parts I wanted and take my time.