350 spark plug removal
Melting Slicks
Joined: Jul 2006
Posts: 2,291
Likes: 493
From: Salmon Arm, BC
I agree with TimAT that those are good numbers.....even the lowest at 125 is probably because of the same crap on the plug is also on the valves, so that is going to compromise the valve seal. The bottom end to me seems OK....now it's time to look at ignition.
Thread Starter
Le Mans Master
Joined: Dec 2009
Posts: 6,397
Likes: 649
From: Saskatoon Saskatchewan
Race Director
Joined: Mar 2006
Posts: 14,112
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From: Florida
I would run a set of plugs one step hotter than those, some new wires, new pcv and use a 195° tstat and take some serious long drives with it. the heat and lube will do wonders.
A lot of problems on these engines are years of putzing around in them. Drive them and if the're screwed up, it will surface. Better now than later.
A lot of problems on these engines are years of putzing around in them. Drive them and if the're screwed up, it will surface. Better now than later.
Thread Starter
Le Mans Master
Joined: Dec 2009
Posts: 6,397
Likes: 649
From: Saskatoon Saskatchewan
We put in plugs one heat range hotter. I couldn't convince hubby to let me test the plug wires, he just wants to see how the engine runs with the new plugs.
In the time I've had it its only had very short drives around the city and I suspect it was the same with the previous owner as well. I'll try and work some longer drives in this summer, but I don't know where we would go, lol.
In the time I've had it its only had very short drives around the city and I suspect it was the same with the previous owner as well. I'll try and work some longer drives in this summer, but I don't know where we would go, lol.
Thread Starter
Le Mans Master
Joined: Dec 2009
Posts: 6,397
Likes: 649
From: Saskatoon Saskatchewan
Yes, I was expecting much worse because I'm a pessimist at heart. I figured the cylinder that first spark plug came out of would be at or near zero. The choke was comming off properly before the carb rebuild so I assume it should be fine.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
You don't need "new plug wires" to test the condition of one of them. Just pick another plug/wire that will do the job and "reconnect" the wire ends (at plugs and at distributor cap) to 'switch' between the problem plug and another [adjacent] plug. Then run the car for a while and check those two plugs. If the 'switched' plug is now the one that is gummed up, you need to replace the defective wire.
If the same plug is gummed up (and you have installed new plugs), it could be a defective valve seal, piston ring problem, or a damaged head gasket that is allowing some oil to leak directly into the cylinder.
If the same plug is gummed up (and you have installed new plugs), it could be a defective valve seal, piston ring problem, or a damaged head gasket that is allowing some oil to leak directly into the cylinder.
Last edited by 7T1vette; Jun 17, 2013 at 03:25 PM.
Thread Starter
Le Mans Master
Joined: Dec 2009
Posts: 6,397
Likes: 649
From: Saskatoon Saskatchewan
I figured I'd just pull the plug wires one by one and test the resistance of each one. Hubby says that's not reliable because the spark will jump a one inch gap so a wire can have very high resistance and work well, on the other hand it can have low resistance and be arcing and not spark at all. To me it doesn't make sense to put new plugs in and then wait until one or more is fouled to find out there's a bad plug wire(s) and then have to replace (some) plugs yet again.
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Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
You really can't check a "high-tension" wire out using an ohmmeter; you need something that utilizes high voltage to check them out properly.
If they are old wires, just change them out. Not worth the trouble and/or time to evaluate the old ones.
If they are old wires, just change them out. Not worth the trouble and/or time to evaluate the old ones.
Thread Starter
Le Mans Master
Joined: Dec 2009
Posts: 6,397
Likes: 649
From: Saskatoon Saskatchewan
Easy for a lot of Corvette owners to say, but when we've been waiting several months to come up with the money to do some over due dental work I need every penny counts.
Advanced
Joined: Apr 2013
Posts: 83
Likes: 0
From: Sequim Wa
I did mine last night. My knuckles are a bloody mess, literally. Forward two from above, and aft two from below. Some you can get with a ratcheting socket wrench, others I had to use an angling ratchet. You'll want to use your hands to start the plugs in their respective places when replacing. Makes sure also that you set the gap on the plug, should be .045.
Thread Starter
Le Mans Master
Joined: Dec 2009
Posts: 6,397
Likes: 649
From: Saskatoon Saskatchewan
I did mine last night. My knuckles are a bloody mess, literally. Forward two from above, and aft two from below. Some you can get with a ratcheting socket wrench, others I had to use an angling ratchet. You'll want to use your hands to start the plugs in their respective places when replacing. Makes sure also that you set the gap on the plug, should be .045.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Hate to say this, but I would be pulling the intake mani off there, and having a look see at the lifter valley, if it's clean as he oil should be, it is fairly common for some engine guys to hone the heads a tad off angle, to raise compression, but that opens up the bottom of the intake passages to the lifter valley oil mist....gets sucked right into the runner past the gasket.....you can see the bottom of the passage in the head, and if it's all oily wet, and not dry from GASOLINE, that's what happening, almost bet on it, look at the gaskets also, the bottoms are soaked in oil....
Thread Starter
Le Mans Master
Joined: Dec 2009
Posts: 6,397
Likes: 649
From: Saskatoon Saskatchewan
I think we'll see how it goes with the new plugs and if its still a problem we'll look at pulling apart the motor down the road when I may come into some money. Most of the plugs weren't anywhere near as bad as the pictured one, I'd expect they'd all look like that if what you're suggesting was the problem. The plugs that were in there were one heat range cooler than GM recommends as well. I was planning to install vortec heads and TPI on this motor before I ran out of cash but I don't want to do that if the bottom end of the motor isn't in good shape.
Last edited by Priya; Jun 18, 2013 at 12:44 PM.
Race Director
Joined: Jan 2000
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From: San Jose CA
There was a fair bit of swearing when my husband did it but watching him it was obvious many years of experience replacing plugs on all manner of vehicles helps a great deal. He did some with an angling ratchet, but most were done with a 5/8 long socket with a little wee "extension" that just consisted of a plug to go into the socket and a 9/16" head that he could put a wrench on. He did most of the plugs with this socket on the spark plug and turning the socket with a wrench. I could tell by watching him wrestling with them despite his well thought out approach that it would have made me absolutely nuts to do this. In fact in some situations with him having to pull off/on plug wires with his hand and arm in very unusual positions I don't think I'd have had the strength to do it all. On the passenger side the second plug from the back he had to bend the mounting bracket for the spark plug cable heat shield to get a socket straight on it and then bend it back to reinstall the heat shield.
There's a lot of up/down/left/right/stand on your head nonsense when it comes to pulling the spark plugs on these. Almost enough to make me go LS1... but not quite!
Melting Slicks
Joined: Sep 2010
Posts: 2,413
Likes: 59
From: Emerald Isle NC
We put in plugs one heat range hotter. I couldn't convince hubby to let me test the plug wires, he just wants to see how the engine runs with the new plugs.
In the time I've had it its only had very short drives around the city and I suspect it was the same with the previous owner as well. I'll try and work some longer drives in this summer, but I don't know where we would go, lol.
In the time I've had it its only had very short drives around the city and I suspect it was the same with the previous owner as well. I'll try and work some longer drives in this summer, but I don't know where we would go, lol.
Then go blow the soot outta that thing!!! Two or three times!!!
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