Hi,
I just spent ages writting a long reply to your post on inlet valves & the forum refused to accept it :mad So I'll try again :)
This may/may not be relevant but is worth thinking about. I bought my bike new & carefully broke it in & all was fine. After a year (about 20 000 miles) I noticed the performance was down so pulled the head to find out why. There was very little carbon on the pistons & chambers but the inlet valves had a huge build up of softish, oily black crud on the rear of the heads. Even worse, the inlet tracts were almost clogged up with the same stuff. None of my mates Trumpets showed this problem & the only difference was that mine was new & had all the emissions stuff for the US market. The engine breather, like a SB PCV system, was routed into the air cleaner, so I blanked off the hole in the cleaner housing & carefully routed the pipe to an environmentally friendly area (the atmosphere). I've never had the problem since in the last 20 years. Without fail every bike I work on with the breather routed to the air cleaner has the same problem, excluding ones with an oil separator/filter/whatdyacallit fitted in the breather pipe. There's a lot of people who have changed perfectly good guides, valves & oil seals thinking that the problem is due to oil getting down the inlet guides. Worn valves, guides or seals can cause the same problem, as on the intake stroke the manifold vacuum can cause oil to be sucked down a worn guide & lots of people have assumed the problem is that, when in fact it's due to the engine breather throwing small amounts of oil into the air cleaner. This oil gets sucked into the engine, hits the hot metal of the intake ports or valves & burns on, leaving the black clag. When I had the problem I didn't notice any appreciable drop in oil level. Not sure of the science involved(!) but something coming out of the breather & getting re-routed directly into the intake without some sort of baffle or filter can cause it.
As I said, it may not be relevant, but is worth thinking about before spending out on a new valve job. I did a few checks on mine by routing the breather into an old can & a miniscule amount of oil was in the can after a few long rides, including heavy traffic, cruising & a long run at WOT (interrupted by a friendly traffic cop!). My conclusion was that either very small amounts of oil over a long time caused the build up, something else coming out was doing it, or the vacuum in the filter housing was actually sucking oil vapour/mist out of the crankcase & directing it into the engine.
:cheers:

 

I happen to drop my heads off at the porter today and asked him about it. He said big blocks are natorious (sp) for sucking oil up from the intake valley through the intake gaskets. He reccomened gasksinch and fel pro gaskets to fix the problem.

My pvc does not go into the air cleaner, it goes into the same inviro safe area your does :chevy

Thanks for the reply