Few engine questions

[Nima]

Hey everybody:
I have few general questions about engines:
1- If your vlave guides/sleeves are wide or loose, can you still perform engine compression test? If no, is there anyway to find out the condition of the block without pulling the engine out?
2- If timing chain slips, what will happen to engine? Let's say engine was in a good working condition before slipage.

The reason I am asking these questions is that my valve guide(s) in my current 350 engine are wide (I am sorry I don't know the terminology. I believe I have vaccume leak based on my vaccume gauge manual) and Now, I came cross a 1977 olds cutlass supreme with 350 engine which has slipped timing chain which I can buy for few hundred $$. Give me your tought please.

[cableguy0]

both engines are probably completely worn out and due for a rebuild. it takes a lot of miles before a timing chain will actually slip. the olds 350 is not the same engine as the chevy 350. parts usually wear at the same rate. if the top end is worn out in an old engine the bottom end is likely not far behind.

[QKENUF4U]

sounds like i would stay with the motor you have now cause the bad timing chaing will cause way more problems if it does actually "SLIP" (bent valves when the pistons come up and hit them etc.)
so what makes you think its just the valves guides thats causing whatever problem you have ?

[MrC1]

A slipped chain (if that's what really happened) is very uncommon and would probably take 150,000-200,000 miles of wear to get that much stretch in a chain. More likely, the engine had a plastic timing gear from the factory and due to heat cycles over the years, it fell apart.

Either way, it's very easy to bend valves and/or damage pistons if the timing chain isn't doing its job.

Worn valve guides or valve stem seals are typically diagnosed by small puffs of oil smoke when starting up from a light. If it smokes all the time, that's more likely worn/damaged piston rings.