Wierd things happening when I attempted valve spring change

[Datsunboy]

Well guys, I have a BAD feeling about what happened today when I attempted to change my valve springs.

I applied pressure to cyl.2 and had already removed the rocker assembly. I heard air whooshing through the motor and coming out the exhaust. Lovely... time for a valve job huh? i figure thats the deal. Oddly though, compression was the same as the 1 cyl which was not passing air....

Now for the concerning part, cyl. 4 was passing air, but i could feel the air escaping through the pushrod holes!!!! Do I have a bad headgasket or are my rings shot?

Please help, its getting ripped apart tomorrow and i need to know what to keep headsup for. I have been burning oil on startup lately and assumed that the problem was valve seals.

Thanks guys, im really feeling sick about this..

Evan

 

[John Larkin]

You had air pressure applied to #2 but only felt air coming from #4's pushrod holes? Did anything happen when you had air on #6? If not, then there must be a pretty direct connection between #2 and #4 which would point to head gasket most likely. Being that the front cylinders tend to lean out, it shouldn't be too surprising if this were the case. Any concerns with the other bank of cylinders (1, 3, and 5)? As for the burning oil on startup, like you say, might as well do a valve job too and have the valve guides checked.

 

[Datsunboy]

John, the odd bank of cylinders was acting normally.

I had air applied to cyl number two, and was getting air coming out the exhaust (I suspect i need a valve job bad)

When I applied air to the number four cylinder, I was getting air out of at least the front four pushrod holes, I never did feel the back.

I am hoping for blown HG here. I just found it really wierd that, even though the cyl number two was leaking air through the exhaust valve, i had good compression. Seems wierd to me to have good compression with a bad seal, and possibly a smoked headgasket.

I have a spare pair of heads that will get ported before I do this, but im calling summit today to order the kit. I need to do them like now.

Thanks for the insight - Evan

 

[John Larkin]

One thing you could do is to hit the top of the valvestems and see if they will seat properly after the new springs are on. Maybe that one valve was bound up in mid-thrash. Strange things can happen.

 

[Datsunboy]

I never did change the seals/springs. I stopped mid project because I didnt know which way to go. I already tried tapping to seat them with no luck.

Ill be going out tonight to remove the top end of the car. PRAY for me that the cyl walls are clean, and the headgasket is blown.

one other wierd thing, there was air coming out the top, thought the air was coming from the intake manifold but in retrospect, it could have been coming through a blownout gasket.

My car did used to sneeze a puff of exhaust up that way when I started it too. Hmm things are seeming pretty clear here.

Thanks man - Evan