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I was looking at a 1971 Lt1 today for possible purchase. It was in good condition except for 2 things. It was missing the smog pump setup, and there was a hose from the back of the passenger-side valve cover that was just hanging there. From pictures, it looks like it should plug into the carb or something close. Any thoughts. Thanks.
The hose is supposed to connect to a fitting on the bottom of the air cleaner. It supplies filtered air to the crank case which is suctioned by the PCV valve on the other valve cover. If it is not connected, it is drawing dirty air into the engine.
Agree with R.J. above on the fresh air intake for the PCV.
The missing smog pump is a very common state. Unless you're going to have it judged for originality, it's A-OK to go without it. (Without it, HP is increased just a small bit due to removing the drive belt.) You can find them on eBay and used parts classifieds if you're really wanting to replace it.
A pic of the top of the engine may reveal some other feedback about missing or changed items.
Hello,
While it's true that the LT-! engine will run well without the AIR system it is then adding to the polluted air that is a wide spread problem throughout the U.S. and the world.
Remember that for 1970 the LT-! was rated at 370 hp WITH the AIR system. The drop in hp in1971 was mainly due to the decrease in the engines compression ratio.
The hose on the passenger's side valve cover is part of the Positive Crankcase Ventilation system. That hose should be connected to the base of the air cleaner.
The PCV valve is located in the front of the driver's side valve cover.
Regards.....
A 1971 LT-1 with the AIR system and PCV systems in place.
That would also mean buying new exhaust manifolds. Thanks, guys, for your help. I still haven't decided whether to purchase it yet. I still have a 1969 350 350hp 4-speed coupe to look at. The LT1 is a convertible.
That would also mean buying new exhaust manifolds. Thanks, guys, for your help. I still haven't decided whether to purchase it yet. I still have a 1969 350 350hp 4-speed coupe to look at. The LT1 is a convertible.
Posting pictures may provide you with more information from this group
That would also mean buying new exhaust manifolds. Thanks, guys, for your help. I still haven't decided whether to purchase it yet. I still have a 1969 350 350hp 4-speed coupe to look at. The LT1 is a convertible.
Shouldn't require that. Just use pipe plugs in the manifold's AIR tube holes - very commonly done.
As others have posted unless you’re worried about NCRS judging the last thing I would voluntarily do is source and install a complete smog system. I have a 72 LT-1 that the prior owner installed a complete date coded system on and it makes a lot of simple maintenance jobs much more difficult. I previously had a 69 L46 without and it was a lot easier to work on.
1971 Lt1 question
