Widening ring gaps???
TECH Apprentice
Joined: May 2006
Posts: 311
Likes: 3
From: Omaha,Ne
It was pump gas, 93. It let go on the highway in 4th gear at about 4000 rpm. Unfortunately, I had my laptop connected and sitting next to me, but forgot to turn the data logging back on, but I have more than 2 dozen logs of runs showing no knock.
I had the rear steam vents on the heads blocked off as I was using a FAST 90 intake, so I'm sure that cylinder got hot.
Are the thickness of the ring lands different on the 5.3l and 4.8l motors than the 5.7 ls1?
I had the rear steam vents on the heads blocked off as I was using a FAST 90 intake, so I'm sure that cylinder got hot.
Are the thickness of the ring lands different on the 5.3l and 4.8l motors than the 5.7 ls1?
It was pump gas, 93. It let go on the highway in 4th gear at about 4000 rpm. Unfortunately, I had my laptop connected and sitting next to me, but forgot to turn the data logging back on, but I have more than 2 dozen logs of runs showing no knock.
I had the rear steam vents on the heads blocked off as I was using a FAST 90 intake, so I'm sure that cylinder got hot.
Are the thickness of the ring lands different on the 5.3l and 4.8l motors than the 5.7 ls1?
I had the rear steam vents on the heads blocked off as I was using a FAST 90 intake, so I'm sure that cylinder got hot.
Are the thickness of the ring lands different on the 5.3l and 4.8l motors than the 5.7 ls1?
Well, pump gas is all I have available, but in an attempt to keep it cool, I'm going to vent all four corners back to the radiator, go with a cooler t-stat, and go with Evans waterless coolant.
I could also go with methanol/water injection as well to help keep the pistons cooler.
I could also go with methanol/water injection as well to help keep the pistons cooler.
9 Second Truck Club
iTrader: (17)
Joined: Sep 2006
Posts: 3,672
Likes: 9
From: Colorado Springs, Co/ Central, Ca
It was pump gas, 93. It let go on the highway in 4th gear at about 4000 rpm. Unfortunately, I had my laptop connected and sitting next to me, but forgot to turn the data logging back on, but I have more than 2 dozen logs of runs showing no knock.
I had the rear steam vents on the heads blocked off as I was using a FAST 90 intake, so I'm sure that cylinder got hot.
Are the thickness of the ring lands different on the 5.3l and 4.8l motors than the 5.7 ls1?
I had the rear steam vents on the heads blocked off as I was using a FAST 90 intake, so I'm sure that cylinder got hot.
Are the thickness of the ring lands different on the 5.3l and 4.8l motors than the 5.7 ls1?
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Verdad Gallardo Same thickness, the 1.2mm rings have a tad thicker land due to the thinner ring. You can NEVER trust pump gas. Just because it says 91 or 93 doesn't mean it's not 87 or worse. Whenever pushing a stock engine you are taking a gamble with pump gas. E85 is offers sooo many benifites. Sucks it's 4hrs away from me.
quick question, I had to use 2nd ring with .04" gap in one of the cylinders, will it cause any real problems (besides higher oil consumption)?
Last edited by Vetal; Dec 10, 2013 at 01:39 AM.
Meant .04", not .004 
Ran 8s as well, not making near the power some of these other guys are though. JY 2001 5.3, 24lbs E85 fuel. Gapped .024 .028. Had some blow-by Nothing horrible.
Bottom line is you have no idea what the rings are at unless u check. It is a gamble. My 160k motor had a top ring gaps as small as .018. (i believe someone was into the motor at one point as well)
Its pretty simple and easy to pull one and check for peace of mind IMO. Then again while your there might as well Gap them. Just dont over gap.
.006 x bore is pretty standard boost ring gap. So .022 should be good for a 5.3, which seems to be around what most high mileage motors are.
Bottom line is you have no idea what the rings are at unless u check. It is a gamble. My 160k motor had a top ring gaps as small as .018. (i believe someone was into the motor at one point as well)
Its pretty simple and easy to pull one and check for peace of mind IMO. Then again while your there might as well Gap them. Just dont over gap.
.006 x bore is pretty standard boost ring gap. So .022 should be good for a 5.3, which seems to be around what most high mileage motors are.
Last edited by Forcefed86; Dec 10, 2013 at 11:49 AM.
9 Second Truck Club
iTrader: (17)
Joined: Sep 2006
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From: Colorado Springs, Co/ Central, Ca
Before you go there with the gasoline statements, I used to work for Sunoco as a formulation chemist and would do spot checks testing as well at pumps. It's big big penalties if you don't meet the minimum requirements of octane ratings at the pumps. It's why most refineries actually formulate the gas almost a full point higher in most cases to avoid issues at the pumps.
On a side note I just pulled apart a 140k lq4 that had .024" ring gap, and a 34k mile 6.2L L92 that had .014" gap....
I guess it must depend on where you are because I have seen otherwise. All it takes is one bad tank and you're done on a 14 psi boost pump gas deal. I run pump/meth in my truck and have never blown an engine due to the gas because Im really in tune with things, but several times I could have. I have had tanks of fuel that I can hear ping on 12 psi and otheres that will take 16psi....
On a side note I just pulled apart a 140k lq4 that had .024" ring gap, and a 34k mile 6.2L L92 that had .014" gap....
On a side note I just pulled apart a 140k lq4 that had .024" ring gap, and a 34k mile 6.2L L92 that had .014" gap....
Haynes manual even says up to .04" is OK, so I guess for mild engine refresh I should be OK. Hell, I found out today that #1 piston head TWO top rings instead of top+2nd. Still worked just the same as other cylinders somehow