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EA81 hydro. lifter compression/valve noise after rebuild

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Background:

I recently did a rebuild on my engine. While I was at it I mistakenly loosened all my valve adjusting nuts and screws when I disassembled.

 

Procedure:

I used the Factory Service Manual to get them re-adjusted as follows (and I did it in the 2 steps as directed). I also checked the adjustments twice and one of the valves again last night to ensure they're 1.5turns out from Subaru's 'zero point'.

-"Loosen the valve locking nuts and screw in the adjustment screw 4-turns", since mine were already moved around I just screwed them in until they were nearly bottomed out because i had no reference as to what point i should screw them in 4 turns in from.

-"wait 15min. and unscrew adjustment screw until valve stops moving and rod just barely has freeplay" I backed them out from borrom waiting for the rod to become spin-able in the rocker seat and the valve spring to become uncompressed.

-"loosened the screw 1.5 turns further before locking into place" At this stage the valve to rocker arm clearance was like 1/2" at TDC but I wasn't overly concerned since the lifters had probably completely depressurized while the engine was being worked on but when looking at my parts engine the threads showing on the adjustment screw are far fewer (parts engine has maybe 1-2 visible threads while my rebuilt engine has 5-6).

 

Currently:

I started the engine up and its making a lot of valve noise. I've only run it for a couple minutes at a time, hopefully haven't done any damage. How long should it take for the lifters to pressurize or with that many threads showing have I just adjusted them completely incorrectly? Was I supposed to pre-fill the lifters before installing, the FSM didn't mention that? 

 

-I've got 25psi oil pressure at idle and it climbs as engine speed increases.

-Timing is set to 9-10deg on a weber carb.

-Car starts up great and sounds good aside from valve noise.

 

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Really don't have much to offer as far as "do this" goes. Only had the files I sent you due to swapping heads on one of my BRATs and figured I needed to do a valve adjustment. Asked for and received the files I sent you.

 

Thinking though, that I would let it idle for a bit, then repeat the procedure. Possibly do a "repeat as needed" thing to quite the one(s) that still want to sound off.

Thinking I had to do that due to one still wanting to rattle a bit. Been a few years, so really not sure on that.

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Really don't have much to offer as far as "do this" goes. Only had the files I sent you due to swapping heads on one of my BRATs and figured I needed to do a valve adjustment. Asked for and received the files I sent you.

 

Thinking though, that I would let it idle for a bit, then repeat the procedure. Possibly do a "repeat as needed" thing to quite the one(s) that still want to sound off.

Thinking I had to do that due to one still wanting to rattle a bit. Been a few years, so really not sure on that.

 

Yeah, I've been reading a bit about hydro lifters in general. It seems common for other engines to need to idle at around 2k for a while to ensure oil is pumped into them and get rid of noise. I just don't wanna do damage after the rebuild. Hoping someone here has some direct experience before I start hoping for the best...

 

I still think its odd that the adjustment on my rebuilt engine vs. parts engine is so much different (# of threads on rocker screw wise).

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Are you adjusting them all at once or using the sequence called out in the manual? If you are adjusting them all at once that would explain the noise.

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Are you adjusting them all at once or using the sequence called out in the manual? If you are adjusting them all at once that would explain the noise.

 

I did it in the 2 stages they describe in the FSM and double checked before installing the engine. I might just start it up and get the rpm's up high enough to raise the oil pressure and see if that fills the lifters but it seems risky.

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if they are anything like EA82 lifters, new, old and reco - they can need some drivng to operating temperature and then some to go quiet. An engine fitter I know would not want customers to know just how much or how hard he has to drive them to get some rebuilds hydros bled up ! I just make sure a compression test is good first, then just low speed cruising around the suburbs until it goes quiet. Never failed on EA82s - just nerve wracking until it does :)

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if they are anything like EA82 lifters, new, old and reco - they can need some drivng to operating temperature and then some to go quiet. An engine fitter I know would not want customers to know just how much or how hard he has to drive them to get some rebuilds hydros bled up ! I just make sure a compression test is good first, then just low speed cruising around the suburbs until it goes quiet. Never failed on EA82s - just nerve wracking until it does :)

 

They look much different than the EA82 lifters from what I've seen but they're still a hydraulic lifter pressurized by the oil system in the engine. If I don't think of anything else to try, I suppose I'll just cruise around the neighborhood a bit this weekend and see what happens, nerve wracking indeed! I do love that the most likely fix for this issues is just to drive it (possible hard) until it fixes itself... that's my kind of repair procedure.

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There is a very good chance they are too loose if you are hearing tons of noise. Try a drive around the block and see if that fixes it. If not you will have to turn the motor over by hand until the valve you are trying to adjust is closed and do as follows.

 

-Back out until you get play in the pushrod

-Tighten until you just start to feel resistance turning the pushrod between your fingers

-tighten 1/4 of a turn more and lock down the adjuster making sure you are not tightening it more

- go around and repeat that for each valve and you should be good

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There is a very good chance they are too loose if you are hearing tons of noise. Try a drive around the block and see if that fixes it. If not you will have to turn the motor over by hand until the valve you are trying to adjust is closed and do as follows.

 

-Back out until you get play in the pushrod

-Tighten until you just start to feel resistance turning the pushrod between your fingers

-tighten 1/4 of a turn more and lock down the adjuster making sure you are not tightening it more

- go around and repeat that for each valve and you should be good

 

 

I drove it around the neighborhood a bit this weekend and its still noisy, maybe slightly less but the valves are definitely still tapping.

 

The FSM states to do the exact opposite of what you're telling me (it states to loose 1 1/4 from 'zero point' or where the rods would just become spinable), not sure if you've done this with success but it seems wrong when compared to the FSM.

 

On the other hand, it would cut down the noise I'm guessing. I'm also confused as to why it matter all that much since they should self adjust, seems like you should be able to just get them kinda close and the hydraulic pressure should more or less adjust it.

 

Is driving the car with the valves miss-adjusted doing any damage?

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to your ears and reputation with the neighbours

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Make sure the fsm is telling you to do it for a hydro lifter motor and not a solid lifter motor. My guess is you are reading the procedure for the solid lifter motor. Those require a tiny bit of clearance where hydro motors do not. If you adjust a hydro lifter motor like a solid it will make a r.ton of noise. Last I heard the fsm does not go over hydro lifter adjustment because there should not be a need to in most instances. The method I described is exactly how to adjust hydro lifters on a small block Chevy or ford but there should be no reason at all why it would not work on a Subaru since the hydro lifter is acting the same in both instances.

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Make sure the fsm is telling you to do it for a hydro lifter motor and not a solid lifter motor. My guess is you are reading the procedure for the solid lifter motor. Those require a tiny bit of clearance where hydro motors do not. If you adjust a hydro lifter motor like a solid it will make a r.ton of noise. Last I heard the fsm does not go over hydro lifter adjustment because there should not be a need to in most instances. The method I described is exactly how to adjust hydro lifters on a small block Chevy or ford but there should be no reason at all why it would not work on a Subaru since the hydro lifter is acting the same in both instances.

 

 

I'm the one what sent him the files he used to adjust the valve lash for the Hydro engine. Info is straight out of the FSM files.

He disturbed the Factory settings, and now has to "play around" with the adjustments.

 

If you replace heads, have them milled, what have you,,, you need to adjust the hydro lifters.

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I'm the one what sent him the files he used to adjust the valve lash for the Hydro engine. Info is straight out of the FSM files.

He disturbed the Factory settings, and now has to "play around" with the adjustments.

 

If you replace heads, have them milled, what have you,,, you need to adjust the hydro lifters.

Well if thats what the FSM says then go by that but it doesn't make sense to me.  A hydro lifter is a hydro lifter whether its in a EA81 subaru or a 400 hp small block chevy.  They both operate on the same principle where there is a small spring inside and the oil pressure itself works to pump it up.  If he is loosening the adjuster 1 1/4 turns from where the pushrod is just starting to be tight that says to me that it will make a ton of noise.  

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I've taken the last 2 weekends off form working on the Brat. I definitely followed the FSM, double checked my adjustments and its still much noisier than before the rebuild. I'm beginning to think I need to just run it until the oil becomes less viscous and/or the oil pump builds more pressure in order to fill the lifters. The procedure of backing off the adjustment screws 1.5 turns after the lifters/rocker arms hit 'zero point' seems really loose to me. When I look at my parts engine there are far fewer threads showing. If anyone has an ea81 hrydro lifter engine with the adjustment screws visible at the moment, feel free to chime in with the visible thread count.

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You don't "back them off" you tighten them an additional 1.5 turns to put some load on the lifter by pushing the plunger down in to it's bore. This is the hydraulic adjustment cushion of oil that keeps them quiet.

 

Not according to Subaru.

They want you to tighten them until the lifter bleeds down to its fully collasped position and then back them off.

 

Seems like a screwy procedure to me too,

 

I think something was lost in translation.

They have you loosen the adjuster until there is "free play" and then loosen more.

This does not make sense to me.The lifter plunger spring will take up any free play until the lifter is fully expanded.

I think that when they say "freeplay" they really mean the pushrod is free to spin(no valve spring pressure on the pushrod).

 

The way I see it,the only way to get freeplay is to have the lifter fully expanded.

Obviously,you do not want to loosen any furthur than this.

I think this is exactly what happened.

The difference in the amount of threads showing above the adjusters between the 2 motors is a big clue

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Not according to Subaru.

They want you to tighten them until the lifter bleeds down to its fully collasped position and then back them off.

 

Seems like a screwy procedure to me too,

 

I think something was lost in translation.

They have you loosen the adjuster until there is "free play" and then loosen more.

This does not make sense to me.The lifter plunger spring will take up any free play until the lifter is fully expanded.

I think that when they say "freeplay" they really mean the pushrod is free to spin(no valve spring pressure on the pushrod).

 

The way I see it,the only way to get freeplay is to have the lifter fully expanded.

Obviously,you do not want to loosen any furthur than this.

I think this is exactly what happened.

The difference in the amount of threads showing above the adjusters between the 2 motors is a big clue

 

The procedure as it is written definitely seems screwy to me too.

 

I totally get that you want to compress the lifters to get them to a bled and compressed state, sort of a baseline. It also makes sense to me that Subaru would instruct readers to then loosen the screw until the rocker allows the valve to fully close and the lifer is able spin in its seat (zero point). After this I really don't know what to do...

 

I might just leave it at the 'zero' point unless someone has any better advice. At that point the number of threads showing looks much more similar to my parts engine. I really want to get this figured out so I can confidently get back to cruising this sweet ride.

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Do not leave it at 'zero' point, it will still be noisy. I made a similar mistake 20 years ago on my Brat and called an old Subaru mechanic I knew and was told to treat it like a small block chev. Do the sequence like the book says for order but for adjustment back them off till loose then take them down to 'zero' then tighten 3/4 of a turn and lock. I did this to mine and it ran for 15 years like that.

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+1 That's what I was trying to say above ;)  The (Chevrolet) procedure ^^^^ has worked fine for me more than once on Hydro EA81s.  YMMV

Edited by Crazyeights

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Which is what I said a few posts ago lol. A hydro lifter acts the same and doesn't kno it's in a 74 hp Subaru or a 400 hp small block Chevy. Get it to zero and give it 1/4-1/2 turn more and lock it down and you will be golden

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I really appreciate the advice! The procedure written in the FSM just didn't seem correct but I was kind of waiting to find someone who had first hand/better knowledge. I'll make the adjustment and hopefully all will be well.

 

thanks!

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