Valve lash on Extreme mileage heads

[CB7Man]

I have a head on my 4 door that has roughly 340,000.
I set all the valve lash to factory spec and it TICKS.
I tried useing the loosest specs...it was loud, I tried useing the tightest specs. Its Louder.

When I got the head some doof had the valve lash set to NONE.
Idled like a champ!
The engine wouldnt rev past 5K unless in neutral.
However the idle was whisper quiet and it was smooooooth.

Should I go for a tighter lash?
I mean it sounds like one rocker is waaaay out of adjustment. But I have checked them time and time again.

[19dabeast85]

I have a head on my 4 door that has roughly 340,000.
I set all the valve lash to factory spec and it TICKS.
I tried useing the loosest specs...it was loud, I tried useing the tightest specs. Its Louder.

When I got the head some doof had the valve lash set to NONE.
Idled like a champ!
The engine wouldnt rev past 5K unless in neutral.
However the idle was whisper quiet and it was smooooooth.

Should I go for a tighter lash?
I mean it sounds like one rocker is waaaay out of adjustment. But I have checked them time and time again.

Do you have an oil psi gauge? If so, what's your psi cold start, heat soaked idle, heat soaked 3k rpms?

With that many miles you probably need to run 10w40.

[visualpoet]

Also keep in mind that they all have some noise. I've yet to have someone open the hood on their cb7 and they didn't have some lifter tick. All you can do is tighten them down to within specs and learn to live with it. There's a lot of activity going on underneath the VC, and aluminum isn't known for it's sound insulating qualities. I'd worry more if you didn't hear anything.

[Fleetw00d]

Part of the reason there is clearance is to account for thermal growth of the valves relative to the head and rocker assembly. The valves are exposed to combustion temperatures (particularly the exhaust valves) and are not direcly cooled like the head, so the valves actually get a little longer and reduce the clearance. If you set them with no clearance when the engine is cold, they may not close completely when the engine is hot, leading to performance problems and potentially burning a valve. You should notice that there is probably less noise once the engine is completely to operating temperature vs. when is it just started. I wouldn't set them any closer than the minimum recommendation.

[old honda tek]

[QUOTE=fleetw00d;2651614]Part of the reason there is clearance is to account for thermal growth of the valves relative to the head and rocker assembly. The valves are exposed to combustion temperatures (particularly the exhaust valves) and are not direcly cooled like the head, so the valves actually get a little longer and reduce the clearance. If you set them with no clearance when the engine is cold, they may not close completely when the engine is hot, leading to performance problems and potentially burning a valve. You should notice that there is probably less noise once the engine is completely to operating temperature vs. when is it just started. I wouldn't set them any closer than the minimum recommendation.[ the reason they still make noise when they are adjusted properly is the rocker arms are worn out where they pivot on the shaft that is where the tiking is comming from .......

[19dabeast85]

the reason they still make noise when they are adjusted properly is the rocker arms are worn out where they pivot on the shaft that is where the tiking is comming from .......

If you know the rockers are worn then the answer to your question of how to stop the ticking is replace your rockers with a low mileage assembly.

[Losiracer2]

try looking for a low mileage head...parts wear out eventually...and 340k seems to me like you got your money's worth haha

[CB7Man]

I paid $50 for the head. Its actually quiet when the engine starts. Then it gets loud when its warm. I got a nice jdm F20 im building with alot less mileage.

[19dabeast85]

I paid $50 for the head. Its actually quiet when the engine starts. Then it gets loud when its warm. I got a nice jdm F20 im building with alot less mileage.

Switch to 5w40 or 10w40 and post back.

[CB7Man]

I use Rotella-T 15w-40. The engine is spotlessly clean inside.
It probally doesnt help it has a rod bearing clearance issue. {3K rod knock}

Ive decided to let it be. The engine has been ticking and knocking its way past 7,000 miles already. Pure gutless and it guzzles (20mpg) but Im getting to work.

Its amazing too, it still gets up to 100mph+ without flooring it.
I never floor it, anything over 3K just sounds like metal flying around.

[19dabeast85]

Yeah your engine must have some pretty serious wear issues....just don't take any long trips. The rod bearing wear is likely what caused the excessive valvetrain noise. Your best bet is to start looking for a low mileage replacement engine.

[D1sclaimer]

Yeah your engine must have some pretty serious wear issues....just don't take any long trips. The rod bearing wear is likely what caused the excessive valvetrain noise. Your best bet is to start looking for a low mileage replacement engine.

lol