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Exhaust Valve Spring Retainer

- - - - - 1.6 cylinder head exhaust valve valve spring retainer

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#1
luvin_the_rings

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Hi guys, 

 

Was assembling my new head on the 1.6 for the start of the new season, and the intake valves went in no problem.  However it seems all the new exhaust valve springs that I ordered from Mazda have slightly smaller ID on the Ground flats of the spring.  On the top of the valve stem, This means that the spring retainer doesn't sit all the way down inside the spring.  I am using a combination of new spring retainers and used spring retainers from before, but using all new valve springs. Both new and used retainers both don't fit with the new valve springs. Mazda said they are out of stock of exhaust valve spring retainers, so I was only able to get 2 out of 8. 

 

It seems the new exhaust valve springs from Mazda are wound with wire which has a different, slightly squarish cross section.  The old valve springs are made with wire which is much more round in cross section.  I think this difference in manufacturing or design is the reason for them not fitting on the valve spring retainers.  

 

I am aware that the springs are slightly tapered for harmonics, I am trying to install the springs with the tighter wound coils on the bottom.  The tighter wound side has a larger ID of the spring coil.  This is correct right? 

 

The Part Number I ordered for the Exhaust valve spring is B61P-12-125.  

Part Number for the Intake Valve Spring: BJ01-12-113

 

Part number i ordered for the valve spring retainer is:  B6BF-12-113 these are the one's that don't fit, but I can see there is an alternate PN for this B660-12-113.  

 

I can also see there is another part listed right after this on the Mazda website: BJ01-12-113, is this the one for the intake side? Are they different? 

 

Has anybody had to modify the upper spring retainers (upper spring seats, according to Mazda to get them to fit on exhaust valve springs recently purchased by Mazda? 

 

Sincerely, 

 

-Z

 

 

 

 

 



#2
luvin_the_rings

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Looks like I'm going to have to resort to turning down the retainers by like 1mm.

#3
Steve Scheifler

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There have been several combinations over the years, including an oddball set on the “factory” crate engines assembled in Canada with aftermarket parts that never cane on a car new. I’ve probably got what you need, as would any engine builder doing many1.6s by the book.

You really don’t want to machine anything, even if the rules allowed. How big of a hurry are you in? If you mail me a miss-matched pair I can probably come up with either springs to fit the retainer or vice-versa. You are welcome to a set. If I send springs I’ll even take few minutes to check free-length and rate so you have a reasonably matched set. Or send me all your springs and I’ll go through them. I’ve got a little spare time and glad to help.

Edit: I see you bought springs, which also probably are not what was ever delivered in a 1.6 car, those ran out decades ago. If you like, measure the relevant dimensions as best you can and I’ll see if I have a set of retainers to match.
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#4
luvin_the_rings

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Steve, 

 

Thanks so much for the offer!  I will definitely take you up on that.  This will be the second time you came through for my team and I.  Can we chat on the phone?  I believe I still have your number from the last time we talked 1.6 dyno sessions on DynaPak.  At least 3 years ago.  

 

To clearly summarize my issue after calling Mazda: 

 

Mazda sells 3 different valve springs

  1. OEM Production Intake Valve Spring: BJ01-12-125
  2. OEM Production Exhaust Valve Spring: B61P-12-125
    • This part number above does not fit with any spring retainers I have from my existing engine. It also does not fit the corresponding new spring retainers that I ordered for the exhaust side.  This problem was probably the reason why the general aftermarket spring kit was used on the crate engines years ago.  See next point. 
  3. Aftermarket General Valve Spring used on 1.6 crate engines years ago: B6BF-12-125
    • This valve spring was used on intake and exhaust side of the 1.6 crate engines sold by Mazda for Spec Miata.  Somebody with more SM history than I can detail what years these crate engines were sold.  The spring kit used in these engines used the exact same valve springs for intake and exhaust.  This valve spring set is the most desirable by 1.6 SM engine builders. I'm guessing that the exhaust spring is a little lighter and makes a bit more power. Maybe Steve can clarify why. 
    • Also, these aren't listed on the "Valve System" page on MazdaMotorsport online store, I had to call and specifically ask for these by name. James was the one who I talked to. 
    • James from MM tells me that there is nothing that notes that a special retainer is needed for these springs, and either OEM retainer will work. Good thing because Mazda has discontinued all valve spring retainers. 

Mazda also sells different Valve Spring Retainers (aka Seat, Valve Upper) for Intake and Exhaust side.  

  1. OEM Exhaust Retainer - B660-12-113   (Now Superseded by B6BF-12-113) Both DISCONTINUED
  2. OEM Intake Retainer - BJ01-12-113 DISCONTINUED

 From what I can gather, I am likely dealing with a cylinder head off of a 1.6 Crate Engine sold by Mazda years ago for SM.  I can tell this because both intake and exhaust valve springs are identical dimensions.  And my other spare engine out of a low mileage daily driver has different springs from exhaust to intake. EUREKA! 

 

My problem has rooted from the fact that I am trying to Valve Spring #2 with Retainers #1 that are from a Mazda Crate Engine cylinder head.  

 

This still does not explain why by Brand New OEM exhaust valve spring B61P-12-125 does not fit the Brand New OEM Valve Spring Retainer B6BF-12-113 (I was able to source the very last 2 pieces from Mazda in October, lucky me and they don't fit).  But chances are they will indeed fit the general crate engine spring #3.  Especially considering the identical PN Prefix for the Crate Engine Spring and Retainer "B6BF"

 

So what I need to do is exchange my exhaust valve springs #2 for the Mazda Aftermarket springs sold in the 1.6 SM crate engines #3.  And use my existing retainers. That should fix it. 

But I definitely cannot use my brand new Exhaust Valve Spring #2 for this engine since I do not have any valve spring retainers which fit.  I do have another production engine which might have retainers that will fit this spring.  

 

In summary: If you want to replace valve springs, make sure you order the springs out of the crate engines B6BF-12-125, and re-use your existing retainers.  Both Intake and Exhaust retainers will work with this spring. However if you order production springs, B61P-12-125 you will need to make sure your cylinder head originally came with those springs (can be identified by looking at the wire used to create the coil spring.  The coils will be slightly squarish when looking at the cross section, and the free length and spring rate should match the FSM).  Finally, make sure you re-use or hold on to those spring retainers, as they are discontinued. 

 

Thanks, and I hope this helps people from making the same mistake I did. 

 

By the way, check your spring specs according to FSM, you may not even need new valve springs.  And springs, being made of steel, will have an endurance knee and may never need to be replaced if they are used correctly. (not overheated often or damaged from engine failure)

 

Sincerely, 

 

Z Kuretski



#5
RWP80000

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First let me clear up some misinformation as to the availability of the 1.6L valve spring retainers as I have just today received orders from Mazda for these parts in January of 2020 and they came from the Ontario Parts Distribution location. Both the 1.6L Engine PN BJ01-12-113 Intake valve spring "upper seat" and B6BF-12-113 Exhaust valve spring "upper" seat are available and being shipped.

 

The problem with the valve spring retainer or "upper spring seat" not fitting the spring is because the wrong retainer is being used with the wrong spring.  the BJ01-12-113 retainer is the only retainer that will fit the 1.6L Intake valve spring (PN BJ01-12-125 -yellow paint color code).  The reason for the interference is that the "BJ01" intake spring  has a smaller inside diameter due to the rectangular cross-section spring wire that is effectively 0.163 inches in diameter as compared to the 0.139 inch diameter wire of the Exhaust valve spring (PN B61P-12-125 -pink paint color code).

 

If you look closely at the Parts catalog and the exploded parts view, there is a reference to Illustration #1 and Illustration #2 ( or just (No 1) and  (No 2). In the parts list, the Part Numbers have a note below the number referencing this No1 or No 2 call out.  No1 is for the Intake valve and No 2 is for the Exhaust valve applications.  For the correct intake/exhaust valve spring part number identification you need to pay attention to the call out reverence numbers 114A and 114B which is used in the parts list to identify which spring is used where.

 

The correct spring retainer for the Intake valves (BJ01-12-113) has a 0.680 diameter spring locating shoulder on the underside of the retainer to allow in fit inside of the smaller ID inlet valve spring.  This is compared to the 0.718 inch diameter locating shoulder that is on the underside of the exhaust valve spring retainer.  The correct intake valve spring retainer is easily identified as it has a "coined" circumferential depression on the top outer edge of the retainer.

 

Rich Powers



#6
Steve Scheifler

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Rich, good to know that retainers are available. There was some confusion about the springs Z got but we chatted a few times and compared notes to sort that out. After pulling apart an old head he realized they had enough of what I call the flat-top rabbit-cut retainers to go with the springs he wanted to use and the head is probably back together by now.
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