74 corvette oil burning

[calimedeiros]

Ok so my 74 vette just keeps burning that oil I don't get any smoke from the pipe but its burning specially at 3000 rpm on the hwy around 1/2 liter per 300 miles pretty bad
Had the valve seals replaced but that didn't help at all
A few people have been telling my to do a leak down test which I'm doing myself
My question is if the leak down test turns out ok I was told valve guides are in order Is this something I can do myself ? Or is it pricey to get them done at a shop ?? Anyone with experience on this

 

[Case75]

Valve guides can be reamed oversize and new larger diameter valves installed but I've heard good and bad results with this process vs installing new valve guides. My '75 burns oil as well after having changed the valve seals; not as bad as you are experiencing though. I might consume a quart every 2000 miles. If your bottom end is good, you may want to look into getting new heads installed as you'll have to pull the heads to do the valve job anyway.

 

[buckhorn76]

what do the plugs look like ? are they fouling ? have you done a comp test ?

 

[calimedeiros]

Plugs are new I will be doing some testing to determine if I can pin point the problem

 

[buckhorn76]

even though the plugs are new they will tell a tale if there is oil on them. a dry and wet compression test will tell how well the rings are sealing. if your problem lies in the heads, greg is right about replacing them, the old 882 heads aren't worth fixing. in an older engine 40 - 50% of oil consumption is from worn valve guides and the rest is getting past the rings.

 

[Shayne]

one more thing. if you are getting your oil changed at a drivethru place. a lot have name brabd oil ,but the oil has a higher sulfer content causing it to burn/use more oil than normal.

 

[calimedeiros]

No I do my own oil changes.