Questions tagged [ls1]
13 questions
9
votes
1 answer
Do I risk damaging the valve seat if I lap this valve without removing carbon build-up?
This valve is from my LS1 (Exhaust #3). It's suffered from a lot of carbon build-up due to a history of fueling/spark problems.
I've tried cooking it in ethylene glycol. I've tried using abrasion with a drill-mounted brass wheel brush, and it hasn't…
Zaid
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9
votes
1 answer
Why is this valvetrain pitch-black?
I'm in the middle of an LS1 teardown.
Last weekend I removed the valve covers to and found it hard to see anything, as the pictures below will evidence.
While I wait for an opportunity to resume the teardown this weekend, I wonder what could be…
Zaid
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6
votes
1 answer
This valve is pitted - what options do I have?
This is that infamous Exhaust Valve #3 after cleanup. The cylinder had a history of fuel/spark-related misfires.
As the images show, the lip of the valve is pitted.
Here is the back of the valve.
I haven't cleaned the seat up yet but it doesn't…
Zaid
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6
votes
1 answer
Is this cylinder head junk?
There's a chunk of aluminum missing from the surface of my LS1 cylinder head. In the picture below it is located on the edge of the rusty looking cooling jacket port.
Is this something to be concerned about? Is it repairable?
Zaid
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6
votes
1 answer
LS1 - ticking slapping noise w video
So I'm trying to identify what may be the cause of this ticking noise.
I listened to all the LS1 ticking and knocking videos on YouTube but none are similar to mine.
It sort of sounds like when you hold a metal pen between two fingers and you tap…
Vincent Vega
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6
votes
1 answer
Is there any benefit in performing a 4/7 swap on an LS engine?
Based on some resources, I was able generate a list of all theoretical firing orders for an LS engine with a cross-plane crankshaft. Here they are (L,R denote which bank each cylinder in the firing order belongs to):
1-5-4-2-6-8-7-3…
Zaid
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5
votes
2 answers
Do I have a bad ignition coil? Measurements inside
I'm troubleshooting what I believe is an engine misfire on my LS1 Chevy and want to rule out if I have bad ignition coils.
In order to do this I took out the ignition coils and measured the resistances across every possible combination of the four…
Zaid
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4
votes
0 answers
Light abrasion on the valve stems - is the outlook gloomy?
Background
I'm rebuilding my LS1 Chevy. The cylinder heads came back from the machine shop fresh with a 5-angle valve job and mechanically-lapped valve faces and seats.
What concerns me is the presence of some light chatter marks on the valve stems.…
Zaid
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4
votes
1 answer
Should I be concerned about eccentric valve rotation?
Yup, it's that infamous Exhaust Valve #3 again (that "6" is a misnomer). It's now back from the machine shop, with a freshly-cut valve face as part of a 5-angle valve job.
Now that the valve and cylinder head are nicely cleaned up, the valve is…
Zaid
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3
votes
4 answers
Lapping valves by hand - does the compound have to be cleaned off?
I'm hand-lapping valves on the LS1.
This is probably a silly question, but I just wanted to confirm that I have to wipe off the lapping compound prior to the hydro test.
Zaid
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3
votes
3 answers
Is ATF effective for cleaning carbonized heads and pistons?
LS1 teardown underway, and it's not looking pretty
I know I can use carb cleaner, but was intrigued by a suggestion online to use automatic transmission fluid (ATF), especially since I have a leftover bottle of the stuff.
I fully intend to try it…
Zaid
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3
votes
3 answers
What are possible causes for belt tensioner "chatter" at idle?
Moving from one set of issues to another on my LS1 Chevy.
With the gear in 'D', A/C on and the handbrake pulled, I popped the hood and noticed for the first time that the main belt tensioner is "chattering" (video link below):
LS1 Belt Tensioner…
Zaid
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1
vote
1 answer
LS1 pops, doesn't start
I've been working at an LS1 conversion into a 1983 Jaguar XJ6 for a good while now. It has a standalone loom from 12volt Customs (which they said they tested before shipping), controlling everything related to the engine ignition, including the fuel…
William Waffle
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