Jelmoer

Dear members,

I have a problem with my 69 cutlas 350.
it is running on 7 cylinders.
I found the problem my number 1 intake valve is leaking.
​​​​​​It look likes he's not in the center.
The heads where done 2 years ago(hardened seats because of propane).
that was with the previous owner.
I have number 5 heads and I saw when I take of the valve covers that there are dampers only on the exhaust valves.
i do not have rotators.

My technical book says that they had to be mounted on both without rotators.
When the are mountend only on the exhaust valve is that a big problem?
Or do I need to place them on the intake valves also?
I found pictures of 350s that have 16 dampers and some have none.

See pictures what I mean.

My damper on exhaust valve.



My service manual

Service manual on Internet

My Leaking valve


My service manual

joe_padavano

The use of dampers or not depends on the specific valve springs you are using, but factory springs used dampers on all 16 valves. Lack of a damper won't cause the problem you are having, however, but it does say something about the quality of the work done to your heads.

Olds64

Since the heads are already disassembled you could have a machinist cut new valve seats and faces. I wouldn't take the heads back to the same machine shop though.

Jelmoer

Thank you(both)

For now only 1 head is off.
All other cylinders had good compression only the number 1 none.
when I put some air in the sparkplug hole it came out off the intake.

After removing the valve covers I saw the missing dampers.
But i dont no what happened to the rest.
I asked the machineshop and there where no other dampers the first time he had the heads.
Or somebody in the USA delete them or they had never be on.
See no old marks.
very strange.

Because I live in Europe I cannot just go to a shop and buy some parts.

The car ran good when I bought it.
The leak at the intake valve will be repaired.

My all-time question is can i just run the car without the dampers or does this engine need them.

Dont understand the function because never see it on European engines.(anti valve spring bounce at high rpm?)
i drive the car just for fun/cruise and maybe 1000/2000 miles a year.
Is it a big difference with them on all cylinders?

Do i have to buy new springs and dampers.
Do i buy only 8 dampers and put them on without removing the other head?
Or just leave it like this?



The camshaft is the original and I guess the valve springs are the stock ones.

I do not have the tools to measure the spring tension.

Wich parts on Rockauto would be the best/will fit?
Only the SBI have a damper. But at the info it is for the exhaust valve.(that is what my engine already has)
Or can i use the Melling vs720 without damper.
Cant find dampers without the outer spring.
Stock length should be 1.96"

joe_padavano

The dampers are simply designed to damp out harmonics in the main spring, especially at higher RPMs.

BillK

It probably wont hurt anything to run without them. I don't even know if you can buy the dampers separately, I have never seen them. The spring on the left in your picture looks a lot newer than the one on the right.

Jelmoer

Thank you,

Here are some pictures of the heads after cleaning and hardened seats.
i got them yesterday from the previous owner whejn i asked him about the missing dampers.
The springs had never been on these heads when he had the car
The springs looked a much better then they do now.
The surface rust you see now is because the person I bought it from build the engine with a friend but passed away.
I think after the machineshop it wasn't oiled and stand for more then a year in te corner.
Later he decided to finish the engine and sell the whole car because he didn't have enough room/space for it

It's just strange that the intake vakve leaks and was maybe 500 miles(2 yrs) since it left the machineshop.
i thought maybe because the springs was missing.it didn't close/get seated
so he did something else wrong.
But now i know the second spring is a damper and will not help the valve closing when the engine is off or at idle.
See what happens on higher rpms.
then I can always buy 16 new springs including the damper inside.

Altered 1978 350 Olds

In the first pictures is that surface rust on your intake valves or just dirt from the combustion process?

Jelmoer

It's surface rust and only on the number 2 intake valve spring.
it looks a lot worse on the first picture.
Don't know the age of the springs.
Some looks newer then the rest.

Altered 1978 350 Olds

I meant the intake valves on the picture (3rd from the top) of the combustion chaimbers, is that just dirt or are these valves rusted and pitted.

Jelmoer

Oops

I'm not sure but it looks like both.
when the head comes back i will try to clean it.
the car ran the last year on propane and that is most of the time a cleaner fuel.
i didn't got pictures when they heads were cleaned a couple of years ago.

But just looked with a boroscoop and i think its a residue from burning a little oil.(the other head)
and because of the leaking intake valve there was a bad mixture.