I have a freind with a GSR motor with Full JDM Type R internals, The problem that he is running into is that while coasting downhill the car is blowing blue smoke out the back. The motor was built last summer and have about 20k on it now. He thinks that the PCV system might be plumbed wrong, Could that have reason to be causing it? I thinking that it would be the rings didn't seat properly in the engine break in. Any insight would be nice thanks. He has not ran a compression test or leak down test yet.

 

The PCV idea could be correct. If he's pulling serious vacume (which he should with high comp.) on a decel, and his pcv is plumed to somewhere that doesn't have a good baffel, then hels gonna end up sucking oil into the intake mani through to the combustion chamber, at this point it would burn & fly out the exhaust.

tell him to try this as a test, disconnect any vacume source to his pcv system. Leave it to vent to the open atmosphere. Drive it around for a while & see if this still happens, it might take a little bit to burn off whats layin around in the exhaust but if thats the case then this would work.

 

Well i talked to him, right now the pcv valve sees no vaccum. I pretty sure it will be the rings. He said that it was been smoking since he first started it up. Im gonna make a weekend of it later and help him tear it down, and put new rings in it. Quick question: Could i use just a bottle brush hone instead of a 3 stone hone??? The guy at the machine shop that put together the bottom is a 70yr old guy that is next to impossible to talk too.

 

If it were the rings, it would be blowing smoke under throttle, not vacuum. I would definitely have a compression and leakdown test run before you pull everything apart. My bet is on the valve seals and/or guides.

 

Well today he was running the motor and after 4 mins it started to smoke. He said it will smoke on Accell, decell, and coasting.

 

now thats a different story, if it's doing it all the time then it's probly valve stem seals or rings.

 

If it's just the seals and it's smoking quite a bit there's a chance(trying to be optimistic) one or more is torn/broken.

However, if the seals have more than 5yrs./50k miles on them I would trying using some sort of seal conditioner just in case. No guarantees of course but it's a cheap, safe(if it's not designed to "swell" the seals) way to see if the problem is with the seals having become hard/brittle with age.

Most, if not all, "high mileage" oils are designed to condition seals so you could try that, though I haven't used one personally.
I use Bardahls which nowadays says stop leak (in addition to seal conditioner) on the bottle but it's designed to condition the seals, not plug leaks. A traditional stop leak designed to plug leaks or fill cracks I would stay away from if you can.

 

everything on the head is new, with exception to the valve guides. It was rebuilt with the bottom end (20k on)