Rocker arm ejection question.

[churchx]

makinen: interesting video. Except cause for for rocker arm bearing failure over rev was mentioned. Can we blame part for failing then?

[blsfrs]

Does this happen with our FA20s?

[ML]

https://www.ft86club.com/forums/show....php?p=3361654

[makinen]

Originally Posted by churchx

makinen: interesting video. Except cause for for rocker arm bearing failure over rev was mentioned. Can we blame part for failing then?

Over-revving and valve float could be occurred first. But our rocker arms are floating design, therefore it is inevitable to be ejected when not enough force acts on valve stems.

If rocker arms have rigid shafts through them like e46 m3 or similar designs, we don't have to worry about time bomb.

When I experienced the ejections I was in normal RPM range. The time I actually did over-revving (over the stock red line) was several crankings before.

[blsfrs]

Here's what we need.

[blsfrs]

#3, where I lost my intake rockers showed signs of something being sucked in to the engine. There was some damage to the piston, cylinder wall, and valve seats. About a month before this started, I installed an oil catch can. I could have possibly introduced a small metal fragment then. Still 3-4 weeks from getting my engine back.

[NoHaveMSG]

Received a package from Australia. Now waiting on some 1217H. And time, could really use a few more hours in the day.




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[blsfrs]

I read a couple of articles talking about oem iron valve guides with stainless steel valve causing galling. Mine had the oem guides but no evidence of problems there. Being rebuild with bronze alloy guides.

[NoHaveMSG]

Originally Posted by blsfrs

I read a couple of articles talking about oem iron valve guides with stainless steel valve causing galling. Mine had the oem guides but no evidence of problems there. Being rebuild with bronze alloy guides.

I hadn't heard that before. I could see improper reaming creating galling. Or improper heat treat on the SS part would also do it.

[blsfrs]

From Enginebuildersmag.com "
Valve guides can be generally classified into two groups: cast iron and manganese bronze, which covers a wide range of applications.
Cast iron guides are used mostly by OEMs due to its wear characteristics that result in longevity for high mileage applications. Cast iron is used with chrome valve stem applications as well. Cast iron cannot be used with stainless steel because of its tendency to gall.
That’s why high performance applications do not warrant the use of cast guides due to the fact the material can’t handle the high loads associated with higher spring pressures. Under high stress, cast iron guides tend to crack and fracture, which can result in engine failure altogether. Cast iron is inexpensive and works best with daily drivers and high mileage applications.

For any kind of performance application, the choice is manganese bronze. The way to pronounce this correctly is MAN-GA-NESE. I often hear this as magnesium, which is not correct. Manganese bronze is ideal for performance because it is more compatible with titanium and stainless steel.


https://www.calverst.com/technical-i...als-and-usage/


Just for reference.

[NoHaveMSG]

Originally Posted by blsfrs

From Enginebuildersmag.com "
Valve guides can be generally classified into two groups: cast iron and manganese bronze, which covers a wide range of applications.
Cast iron guides are used mostly by OEMs due to its wear characteristics that result in longevity for high mileage applications. Cast iron is used with chrome valve stem applications as well. Cast iron cannot be used with stainless steel because of its tendency to gall.
That’s why high performance applications do not warrant the use of cast guides due to the fact the material can’t handle the high loads associated with higher spring pressures. Under high stress, cast iron guides tend to crack and fracture, which can result in engine failure altogether. Cast iron is inexpensive and works best with daily drivers and high mileage applications.

For any kind of performance application, the choice is manganese bronze. The way to pronounce this correctly is MAN-GA-NESE. I often hear this as magnesium, which is not correct. Manganese bronze is ideal for performance because it is more compatible with titanium and stainless steel.


https://www.calverst.com/technical-i...als-and-usage/


Just for reference.

Granted 99% of my engine building experience comes from motorcycles/atv's, I know of at least one instance where I used SS valves with OEM iron guides. It was a heavily modified air cooled engine. It was in the raw, no coating on the stem. Never had any issues

We liked to use copper beryllium seats with either bronze or copper guides depending on application for built engines.

[Trdfrssx]

Originally Posted by NoHaveMSG

Received a package from Australia. Now waiting on some 1217H. And time, could really use a few more hours in the day.




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Are those from denstoj? How long did it take to ship?

[NoHaveMSG]

Originally Posted by Trdfrssx

Are those from denstoj? How long did it take to ship?

Yes they are. Had them in about a week.


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[Trdfrssx]

Originally Posted by NoHaveMSG

Yes they are. Had them in about a week.


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Nice! Looks like the price just went down a couple hundred dollars, might have to order a set.