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-   -   Rocker arm ejection question. (https://www.ft86club.com/forums/showthread.php?t=145620)

blsfrs 06-07-2021 02:28 PM

Rocker arm ejection question.
 
1 Attachment(s)
Is there a pattern to FA20's kicking out rocker arms? Mine recently ejected the intakes on cylinder #3. I wonder since #3 and #4 are at the end of the line with regards to oil pressure. Are they more prone to failure that cylinders 1 and 2. I'm looking for a smoking gun but haven't found one yet.

NoHaveMSG 06-07-2021 02:48 PM

I lost both intakes on #2. As far as I can tell I don't think oil pressure is the culprit. Our valve specs are a bit looser then I expected so the oil pressure against the lifter and pivot may have a small effect, but we are talking .005in lash it may be taking up out of the total static lash. I think it is a geometry issue as Subaru's fix for it was to lengthen the valve stem and deepen the pocket of the rocker. The updated engines do have issues still periodically with kicking out the rockers.

rixter145 06-07-2021 04:19 PM

That and Gravity, since our heads are mounted sideways, we are always going against gravity and thus the arm has a higher chance of falling out that way...

Retainers are the solution, as that's how most engines have it

blsfrs 06-07-2021 08:27 PM

If not cylinder related, is it more often intake than exhaust? And, BTW, there is another post where a loose retainer became a problem.

NoHaveMSG 06-08-2021 12:28 AM

Quote:

Originally Posted by blsfrs (Post 3439707)
If not cylinder related, is it more often intake than exhaust? And, BTW, there is another post where a loose retainer became a problem.

Seems to be the intake every time. I bet there is more angle on the intake valves.

makinen 06-08-2021 07:15 PM

Quote:

Originally Posted by blsfrs (Post 3439707)
If not cylinder related, is it more often intake than exhaust? And, BTW, there is another post where a loose retainer became a problem.

I've lost #1 intake and #3 exhaust at each time. Then I've made rocker retainer clips to prevent more ejection.

makinen 06-09-2021 08:23 PM

Quote:

Originally Posted by blsfrs (Post 3439707)
there is another post where a loose retainer became a problem.

Could you please give me that link?

blsfrs 06-10-2021 09:07 AM

It's in this forum somewhere in the past couple of weeks. I did a quick search but couldn't find it. It was in a thread related to something else. I'll look again when I have more time.

blsfrs 06-10-2021 09:56 AM

found it


BrahmaBull1990 (05-25-2021), Ultramaroon (05-26-2021)
The Following 2 Users Say Thank You to rixter145 For This Useful Post:


Hello from Mill Creek over here! I recently installed my Emtron gauge and finally got my oil pressure sensor working... I been pretty much cruising at around 180+ F with an oil cooler that opens at around that temp. I think I broke 200 F when I was hooning around but so far no problems...

Oil pressure was within 20-60 psi range. Will drive more and see how the data looks.

Have to mention that I am using 5w40 oil and with a rebuilt motor. Also am kinda scared to drive that right now since my stupid retainers that sit on the rocker arm sheered off (And I don't know how!)...
https://www.ft86club.com/forums/imag.../wol_error.gifThis image has been resized. Click this bar to view the full image. The original image is sized 4032x3024.https://i.imgur.com/TMsI7g1.jpg
Really need to get that retainer kit back in...
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rixter145 06-10-2021 02:05 PM

Oh that's me. I hope that's just a freak incident, will report back on what happened when I pull the cover apart... that's scheduled end of month

blsfrs 06-11-2021 08:46 AM

Oil pressure and lash
 
Quote:

Originally Posted by NoHaveMSG (Post 3439635)
I lost both intakes on #2. As far as I can tell I don't think oil pressure is the culprit. Our valve specs are a bit looser then I expected so the oil pressure against the lifter and pivot may have a small effect, but we are talking .005in lash it may be taking up out of the total static lash. I think it is a geometry issue as Subaru's fix for it was to lengthen the valve stem and deepen the pocket of the rocker. The updated engines do have issues still periodically with kicking out the rockers.

Element Tuning did my original build. I would have sent the engine back to them but they moved from Maryland to Florida and I wanted someone more local. I've been in touch with Phil concerning my problem and in our last communication the oil pressure vs lash question came up and he said: "If the lifter wasn't hydraulic the rockers would eject very quickly as there's nothing holding them in place securely. The oil pressure takes up the lash. That's why i made the comment about how he said the rockers are loose, as they are, but by how many thousandths. They pivots are in the oil pressure galley, then push up, exposing a relief port, and then there is also an oil port into the roller socket. The roller socket has barely a relief for oil to escape. On the cam's base circle you can wiggle the crap out of the rocker with only 5-8 thousandths (intake/exhaust) clearance but that's not loose, that's correctly lashed. I'm not saying you can't go tighter but you better have a good idea what your new valve seating recession will be after run it, what service interval you are trying to achieve, and what overall temperature you are lashing for as higher temps require looser clearances to deal with expansion." Seems logical.

NoHaveMSG 06-11-2021 11:30 AM

Quote:

Originally Posted by blsfrs (Post 3440744)
Element Tuning did my original build. I would have sent the engine back to them but they moved from Maryland to Florida and I wanted someone more local. I've been in touch with Phil concerning my problem and in our last communication the oil pressure vs lash question came up and he said: "If the lifter wasn't hydraulic the rockers would eject very quickly as there's nothing holding them in place securely. The oil pressure takes up the lash. That's why i made the comment about how he said the rockers are loose, as they are, but by how many thousandths. They pivots are in the oil pressure galley, then push up, exposing a relief port, and then there is also an oil port into the roller socket. The roller socket has barely a relief for oil to escape. On the cam's base circle you can wiggle the crap out of the rocker with only 5-8 thousandths (intake/exhaust) clearance but that's not loose, that's correctly lashed. I'm not saying you can't go tighter but you better have a good idea what your new valve seating recession will be after run it, what service interval you are trying to achieve, and what overall temperature you are lashing for as higher temps require looser clearances to deal with expansion." Seems logical.

To me, I would probably defer to Phil. Although it still doesn't seem to make much sense to me. Stock valve lash specs are .004-.006in intake, .008-.01in exhaust. That is pretty much in line with what a DOHC direct actuation setup runs. So I don't see the need for oil pressure to take up any additional lash unless there was something I am missing. I am aware that the rocker pivot sits in the oil galley. An early change to these engines actually had to do with the rocker pivots, I believe the oil hole in the passenger head was larger then the pivots in the driver side head. These were later updated to be the same size on both heads.

blsfrs 06-16-2021 10:24 PM

We're not the only ones
 
1 Attachment(s)
I found this on a Tundra forum. Corolla's have the same set up and issues.

makinen 06-17-2021 10:53 AM

Quote:

Originally Posted by blsfrs (Post 3442397)
I found this on a Tundra forum. Corolla's have the same set up and issues.

Yeah, we are not.
https://youtu.be/llD0B2Xc9Vg


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