rocker assembly questions - 2F (8 Viewers)

[jfnall]

after much reading, I've given in to ask the question... looking for compatibility info of a rocker arm assembly for 2F engines.

Question:
Can a later model 2F rocker assembly be used on an earlier 2F engine? example: an 85 rocker assembly to a '76 2F head?

my concern would be - do the rocker arm ratios change between the years and change the timing? and are the pedestals different?

thanks for you replies.

 

[Dizzy]

Yes, they are different. The later slots for oiling is one thing I can remember off-hand. The pedestals are different. I've been curious about the same thing. The valve components are the same, aside from the stem seals. Are they, and the pushrods in the same place? Answering your question will help me with my mini-warehouse mega project.

 

[FJ40Jim]

Yes, they can be interchanged. No difference in rocker ratio. The only catch is the pushrods change, because the adjuster "ball" gets smaller and the pushrods cup gets smaller in 198x?.

Pic shows 1976 rocker & pushrod and early 80s parts.

 

[jfnall]

thank you Jim. exactly what i needed. do you sell parts? I'm needing to buy a complete rocker assembly late 2F if you have one available. I've got replace the one that is temporarily "loaned" to me until I can find the guy a replacement.

what is a solution for replacing worn rocker arm and bushings and shaft? anything available aftermarket? haven't had any luck finding new.

J

 

[FJ40Jim]

The later rocker arms (on the right in pic) are cast steel, without a bronze bushing. They are lighter, stronger, quieter. Best of all, they finally got the metallurgy right, so even without a bushing inside, they don't seem to wear.

Get a used later model rocker assembly and pushrods, install on early 2F, enjoy the quieter & more accurate valve train.

I don't have a good one for sale ATM, but post in the classifieds. Somebody's gonna have the all steel rockers & pushrods in a late 2F with cracked head.

 

[Dizzy]

I have a rocker shaft that was installed without respect for the shaft dimples that time the shaft's oiler holes on the rocker arms to the studs on the head. I'm thinking that it ended up becoming an FJ60 2FE project, and I was the parts recipient.

Something to look out for, both in purchase as well as installation.

 

[Herbou]

after much reading, I've given in to ask the question... looking for compatibility info of a rocker arm assembly for 2F engines.

Question:
Can a later model 2F rocker assembly be used on an earlier 2F engine? example: an 85 rocker assembly to a '76 2F head?

my concern would be - do the rocker arm ratios change between the years and change the timing? and are the pedestals different?

thanks for you replies.

Hi Jeff, did you end up installing the later model rocker arm assembly? I am at the point of doing the same and need some guidance.

 

[jfnall]

Hi Jeff, did you end up installing the later model rocker arm assembly? I am at the point of doing the same and need some guidance.

not yet. engine builder jacked up the whole thing. engine started eating itself so it’s all back apart again. i do think it works fine though.

 

[Beehanger]

not yet. engine builder jacked up the whole thing. engine started eating itself so it’s all back apart again. i do think it works fine though.

Having issues with my engine. Trying to trakc down the prblem. Im 27 and pretty new, been at this for 3 years.

I think the engine builder, after all this, did something wrong with the head. Likely guides/seats or something that is causing lower compressiona nd valve lash to jump all over the place upon adjusmtnet,

So im very curious: What do you mean by the engine started eating itself? how could you tell?
How did you fix the problem>

Would be very helpful to speak to someone else who has had a bad machinist,
Dan

 

[charliemeyer007]

You got some serious issues if valve lash is moving around. I don't I have ever seen that happen. Worn out valve guides so bad you can keep oil in the engine might do that. Valve seats falling out usually means piston contact - you would hear that.

Best cheap engine investigation. Dry then wet compression test. A leak down test. Video inspection of the combustion chamber. Vacuum gauge reading. Oil pressure reading. Reading the spark plugs. Listening to run - connecting rod knock, bad tappet, main bearing.

 

[Beehanger]

Valve lash was off about .05 mm in either direction. (See photos, the column labeled w is lash with the feeler gauge barely making contact with both surfaces)
Spark plugs looked fine.
Compression looked as follows (see photos)

 

[rkymtnflyfisher]

You got some serious issues if valve lash is moving around. I don't I have ever seen that happen.

I can attest.

After disassembly I found my camshaft was wrecked, lifters and all. Which led to another whole project.

 

[rkymtnflyfisher]

valve lash to jump all over the place upon adjusmtnet,

Remove that lifer inspection cover and pull a lifter or 2 one at a time, inspect the bottom of them, then look at the cam.

 

[Beehanger]

Remove that lifer inspection cover and pull a lifter or 2 one at a time, inspect the bottom of them, then look at the cam.

They used new lifters. Are you referring to the side pan inspection thing?

 

[Beehanger]

They used new lifters. Are you referring to the side pan inspection thing?

This inspection cover?

 

[rkymtnflyfisher]

This inspection cover?

View attachment 3927811

Yes.


My entire rebuild was started by trying to adjust the valves. I'd set them, run it, then they were all off, rinse, repeat, over and over again. I found multiple issues with my engine, but the lifters and camshaft were notable.

Is yours a recent rebuild?

 

[Beehanger]

Yes.


My entire rebuild was started by trying to adjust the valves. I'd set them, run it, then they were all off, rinse, repeat, over and over again. I found multiple issues with my engine, but the lifters and camshaft were notable.

Is yours a recent rebuild?

Yes. Been having headaches with compression and valve lash not being consistent.

It’s clanky as hell. Replacing the rockers tonight with a new assembly and seeing if this helps. My old assembly had a crack in support #1
an intake leak as well that was there thanks to a bad header.
800 miles into break in. May have been compromised due to bad air and fuel ratio, potentially.

I was expecting valve lash to stabilize on its own, but now you have me wondering….


What were your compression numbers?

Is .05 mm jumps out of alignment after driving just 100 miles significant?

Thanks
Dan

 

[Beehanger]

Push rods seem to match up better with the wider knob on the new assembly… I know with the 40 series there’s two sizes to the pushrods. Maybe the same here.

My 60 had head work done in 05’ so maybe they mismatched the “new” rocker they put in with the existing lifters

Things are Slightly more promising, but I still expect the issue is somewhat internal, I’ve gotten all the information I can collect that @charliemeyer007 talked about, the question is how badly off are things.

I’ll likely drive it since it has been drivable. Short of a major engine problem it doesn’t justify pulling everything if it turns out to already be half broken anyway. Drive it until it breaks mentality….

@rkymtnflyfisher how much was your lash fluctuation and what was compression like?

What else turned out to be wrong ?
Thank you for your info,
Dan

 

[charliemeyer007]

If you hear clanking then running it is likely doing damage. That will lead to more costly repairs or ruin it so bad it becomes scrap metal. Know any local car people you can ask to listen to it.

 

[rkymtnflyfisher]

@rkymtnflyfisher how much was your lash fluctuation and what was compression like?

Enough play in it that I knew it was wrong. When you set it to the proper clearance it should stay there, not another 5-10 thousands off every time you test it.

My compression issues were due to broken piston rings.