Mazda MX-6 Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
113 Posts
Discussion Starter #1
I had all new lifters and now a few of them compress completely by hand. I do have dual valve springs with an aftermarket cam regrind that gives more lift and duration. I imagine factory lifters are typically a weak point in a built valve train. It is possible that they were bad from the factory but they didnt compress by hand when i installed them. Would factory lifters from the b2200 head possibly be an upgrade? Anybody know if the lifters are any different between the dual valve spring 8v head in the b2200 vs the n/a 12v head on a 1g mx6? Its probably not safe to run the engine much with a couple bad lifters what do you guys think?
 

·
Registered
Joined
·
257 Posts
I too am interested in the answer to this question. I’ve got dual valve springs and a lifter that sounds like a bunch of tiny dwarves are having the time of their lives in my valvetrain.
 

·
Registered
Joined
·
13 Posts
I looked at lifters on rock auto for both the 8v B2200 and 12v mx6 engines and the part numbers were the same for all brands. I don’t know if that tells you anything but I’m assuming they’re the same.
 

·
Registered
Joined
·
113 Posts
Discussion Starter #4
Yeah same part number so must be the same. Not many options for these parts. Itd be ideal to keep them hydraulic and not convert to a solid lifter set up, but i also dont want to keep throwing lifters at it. Just for kicks though if i were to convert to a solid lifter i imagine id have to come up with the proper lash and safely lock them in place. The hla's compress so much before the oil pressure is supposed to push the valve and that distance is in turn your theoretical clearance between lifter and valve. If that makes sense. Im just going to replace them and see how long they last for now.
 

·
Registered
Joined
·
90 Posts
If you have a reground cam you will need lifter (HLA) spacers as the reground cam has had material removed from it making it a lesser diameter than stock.

If the HLAs can be compressed by hand it isn't primed with oil usually due to blockage in the oil port which on these motors is the smallest oil orifice in the motor and easily blocked. Had it happen to 4 HLAs at once with just a little gasket maker material, one other main cause of this is if the cam bearing surfaces are worn you wont get good oil pressure at the top causing HLA's to chatter badly because they can't get enough oil to pump up. Sounds horrible too. :wink2:
 

·
Registered
Joined
·
521 Posts
They're a fairly standard lifter used in a lot of different applications. Mazda used them in all of their 4cyl sohc engines, and i believe Mitsubishi and some Nissans as well! Sadly there's not much out there for direct drop in that's an upgrade over stock.

Best to make sure they're primed properly, sometimes they sludge up on the inside. Also as mentioned above depending on the cam profile you may need to add washers to shim the gap.
 

·
Registered
Joined
·
2,321 Posts
It's not a question of servicing the HLA's or shimming them properly, the problem is that on a 12V head with dual valve springs they seem to collapse (fail), this could be a turbo charge issue, rpm's climb faster and the HLA's don't have time to charge properly. I don't think it's because it's a 12V head, the 4 extra valves would add resistance to the cam but shouldn't affect the contact between rocker arm and valve. (Unless the 8valve head has more available oil to charge the HLA's).

I wouldn't worry about driving with collapsed HLA's, you just get less lift at the valves but the same duration. This would only be a problem running very high boost, in a case where both intake valves open completely and the exhaust valve doesn't and can't clear the cylinder then combustion pressure could build up.

I will be an ass and say this: If the HLA's collapse while running a ground cam and dual valve springs them it's kinda the opposite of an upgrade and would result in less valve travel than the factory cam profile.
 

·
Registered
Joined
·
521 Posts
I have been digging into converting to adjusting screws, and it's not as involved as you'd imagine...other than the cam needing to be changed to a solid lifter profile (have not done much research into the cam yet). However the rocker arms can be ground down, and oil supply holes can be redrilled. The rest involves an press in SS insert, adjusting screws, and nuts.

Nissan guys have done this without issue. If the insert is pressed into the rocker arm, and then the adjuster is locked in place with the nut...the insert will not move as the adjuster and nut have locked everything in place. Worse thing will be setting lash, running the car to settle the valve train...then setting lash again lol.

I'll be doing this over the winter if I find the motivation... I've got many spare rocker arms, a variety of adjusting screws, and maybe some time (winter sucks).
 

·
Registered
Joined
·
521 Posts
Found a spare rocker arm. It will need a lot more taken off where the adjuster has to go, most adjuster arms are about 12-14mm thick and I think this is around 18mm...it will also have the insert flange thickness lol. Luckily the hla oil casting shows there is PLENTY of height to play with for adjuster length.
 

Attachments

·
Registered
Joined
·
521 Posts
Pics before I cut it apart lol, this is a Mitsubishi rocker arm that I'm comparing it to. Sadly the M8x1.0 Mitsubishi thread pitch fails to yield any off the shelf inserts that would fit, so I'm off to the yard this week sometime to find an M8x1.25 adjuster set from maybe a Honda? I can't find their pitch online.
 

Attachments

·
Registered
Joined
·
113 Posts
Discussion Starter #12
That looks great! Could you just thread the hole you have in the rocker arm for your lifter? Lets say, to the same thread pitch and size as the mitsubishi lifter? I like the look of this i think youre on to a good hla to solid lifter conversion. For those who want to do the work anyway lol
 

·
Registered
Joined
·
521 Posts
The hla bore is basically smack on 12mm ID, while the adjuster is 8mm OD. A press fit insert would work well, and keep the adjuster concentric...also keep labor down (vs cutting threads into all 12 arms for some threaded adapter)...at least that's how my brain is taking this lol.

Only major issue I see is the dual valve springs seem to be adding a lot of upwards force on the rocker arms, I think my oil viscosity isn't heavy enough, and I also regret not adding a shim to the oil pump during assembly. Mazda says to check hla lash gap, should be between 0.15-0.05mm...and the oil supply gallery has a grub inspection plug to check oil feed...so checking those 2 today in hopes to find the reason for premature wear.

The wear I have found is on the bottom of the rocker shafts, the bottom of the rocker arms, valve tips and hla contact points....so I am a bit worried needless to say!!

Cam caps looks great tho lol fml
 
1 - 13 of 13 Posts
Top