Solid lash adjusters - EA82T

[Ibreakstuff]

So this popped up in another discussion, but I thought it might warrant its own thread..

I'm making some adjustable solid lash adjusters, by just machining some 4130 round bar and using some radius head/rocker screws and locking nuts to set/control the lash. The alternative would be modifying an off the shelf kit for another type of engine, but generally all other import motors use smaller HLA's (that I have found so far).

 

Pros to SLA's:

More accurate and consistent valve timing throughout the entire rpm range

Not adversely affected by higher spring loads or higher rpms

Less chance of spontaneous failure (thrown rocker, failed hla)

 

Cons to SLA's:

Initial setup will take hours and is very tedious, cam case removal/install x 100000

Periodic maintenance required checking/adjusting lash

Generally louder than properly working HLA's

 

 

 

I originally believed that our stock HLA's provided some additional lubrication to the rockers, but after disassembling an HLA they don't (radius heads holes are not drilled through). Not sure if this exclusive to the ea82t. All of my heads have an oiling bar which squirts oil directly on each cam lobe... So blocking the HLA oiling ports should be without consequence?. And it should even increase overall oil pressure, added bonus.

 

 

Any ideas, thoughts, comments?

Edited April 6, 2014 by Ibreakstuff

[ruparts]

hi,

  i think you are correct in the overall information, the oil supply that supplies the oil tube squiters would need to be retained.  the actual lifter passage would not be needed for this solid configuration, i know you know, but the installed height for your sla would need to be as original with the hla to maintain correct  rocker geometry.  seems  a lot of effort to do it,  but i don't see there will be a gain that is equally great,  some i guess,  but not a whopping dyno buster mod imo.  make sure your tip radius and size match oem hla's and  be sure to provide the little recess in the tips to retain oil in there for the rocker cup end.  i see no reason it can't work just as you outlined.  btw  in the old days, 50's to me, guys ran solid lifters on hyd cams as a performance mod, the hyd grind they say had more lift and duration than a comparable solid grind for the era, but idk , i was a kid then just learning all i could about hot rods.  post back as you proceed i'd be interested in your experiment and results.

[idosubaru]

gobs of work for little gain but go for it, you're skillled and got the time, tear it up!  you'll certainly learn a ton and see some good mechanical systems operations.

 

doubtful increase in reliability, the HLA set up has proved extremely reliable and robust on well maintained engines.  a quarter million miles is fairly standard without issue.  it's been proven over 3 decades and heavily valid statistical representation.  if one made a list of all reliability related repairs that had similar failure rates statistically speaking you'd have a lot of money and repairs to put into this vehicle.  there's a lot of things with much higher failure rates than Subaru valve trains.

 

at this age most of the issues are how the car has been maintained and treated since new.  the low value of ER/EA vehicles pushes them into the hands of people not prone to do great maintenance and repairs on them outside of Subaru groups like this (and even that we have to wonder, since some of us don't care to push limits either LOL)

[Gloyale]

Oil still needs to be able to flow around each tower and on to the next chamber.  If you block the HLA gallery........Oil will not get to the Relief valve, or the relief pipe (the pipe that drips oil on the rockers).

 

You would be effectively deadheading the pump too......since it would be blocked from the relief valves.\

 

So whatever you make.....just make sure it has the notch in the middle for oil to flow around and through the galleries.

Edited April 6, 2014 by Gloyale

[Ibreakstuff]

Yep it is more work than its worth, but I am more doing this for educational purposes. Actually my whole idea for building some ea82t motors was for learning and fun. These motors will mostly see rallyx/autox, so the SLA's can't hurt the performance. The smiles to cost ratio is all that matters.

 

And I agree lol, it is definitely a performance mod of my grandpa's racing era. He has to be smiling down on me for some things and rolling over that I am not building ford motors.

 

I have had few failed HLA's but mostly as you mentioned, from gunked up cars. They usually can be cleaned out tho and will start working again. One of my ea82t's ended up having a destroyed thrust bearing.. good times. The amount of metal I pumped out of the HLA's is crazy.

 

I tripled checked (actually 24x checked lol), the HLA's have no oiling abilities.. the hole in the radius head is not drilled (checked all of the HLA's from all of my gen2 heads I have here). No idea why it was machined to have holes, but not drilled through. The only oil from the HLA's would be weeping from the HLA sleeves. I plan to use a rubber o-ring with the SLA's too, to keep the oil contained and to aid in adjusting the lash by keeping the SLA body from spinning so freely.

 

Very true Gloyale. I am definitely not blocking the galley, just blocking the hole in each HLA sleeve. Oil still flows around the sleeves as normal. Oil "squirters" in the cam cases will still be retained.

 

We stopped by summit in Reno today, was eyeballing some pedestal rocker adjusters. These could possibly allow lash adjustment without removing the cam cases. But the rocker screws + locking nuts would probably be easier to fab. And drilling forged rocker arms doesn't sound like much fun.

 

I will post the results and pictures here when they are built.

Edited April 7, 2014 by Ibreakstuff

[Ibreakstuff]

This was my inspiration for this, included are the specs for setting the lash. Old 80's era WRC/GroupA RX tech documents for the ea82t..

 

 

Edited April 7, 2014 by Ibreakstuff

[scoobiedubie]

I am smelling a destroyed engine somewhere.

[Ibreakstuff]

I am smelling a destroyed engine somewhere.