How hot before heads warp - L83 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

gofast321 · 10-13-2023, 08:50 AM

I have an L83 with about 60k miles on it. I just completed a DOD delete. After I put the engine back together I attempted to get the cooling system to purge but I couldn't. I ran it a few times in the driveway and on my street reaching temps up to about 240-250 before shutting it off. Each time it was run for about 15 minutes.

After looking a little closer I realized I installed the head gaskets backwards like an idiot. So the coolant wasn't able to circulate and the heads weren't getting any coolant. I'm going to tear it back down this weekend to replace the head gaskets but my question is, should I be concerned that I warped the heads?

Thanks for the help.

Chad

**Jason Banks** · 10-13-2023, 09:29 AM

A friend of mine had problems with his electric fans on LS3 and was regularly hitting 230-235 and had not problems. I can't imagine 240-250 would hurt you too bad.

gofast321 · 10-13-2023, 11:07 AM

Thanks Jason. I appreciate the feedback.

LS short box · 10-13-2023, 04:39 PM

If you have a real good metal scale (machinist ruler) and a feeler gauge you can check the heads yourself. Or a machine shop can easily check.
Either way make sure they are super clean on the block side.

Joyridin · 10-14-2023, 08:32 AM

I am not sure if you have studs or head bolts, but if you are using factory style head bolts, be sure to buy a new set.

I doubt you hurt the heads, but I would do what LS short box states above and have them checked anyhow.

gofast321 · 10-14-2023, 03:29 PM

Thanks for all the information guys. I appreciate the help. But I chickened out, I'm going to send the heads to a machine shop close to my house on Monday just to be sure. His prices were pretty good and he can turn them around in a week so I thought it was worth the time and money just for the peace of mind.

I'm grabbing all new head bolts, gaskets, etc in the meantime.

Chad

LS short box · 10-14-2023, 04:37 PM

Just a note. Make sure before you bolt the heads back on to get all the coolant out of the bolt holes in the block.

gofast321 · 10-20-2023, 03:55 PM

Just got the heads back from the machine shop. No cracks or major issues. They did deck them down .004. Ultimately they probably would have been ok to just install but now I know for sure. Going to install them this weekend.

Accelo · 10-25-2023, 12:07 AM

I am going to reiterate what LS Short Box mentioned.
"Get all the coolant out of the bolt holes in the block. "
Many a bock has been ruined because this rule was not followed.
They hydro-lock and crack the block.

gofast321 · 10-25-2023, 10:36 AM

Good note guys. Yeah I spent a lot of time using the air compressor to blow all of the water out of those bolt holes and then I let them sit an extra day to fully dry.

I got the engine all back together last night and got is started. Everything seems to be working as it should and cooling is now working. Thanks everyone for the info and suggestions.

My take away from this project... Take your time and don't rush.

10-13-2023, 08:50 AM	#1
gofast321 Registered User Join Date: Sep 2010 Location: Pittsburgh, PA Posts: 38	How hot before heads warp - L83 I have an L83 with about 60k miles on it. I just completed a DOD delete. After I put the engine back together I attempted to get the cooling system to purge but I couldn't. I ran it a few times in the driveway and on my street reaching temps up to about 240-250 before shutting it off. Each time it was run for about 15 minutes. After looking a little closer I realized I installed the head gaskets backwards like an idiot. So the coolant wasn't able to circulate and the heads weren't getting any coolant. I'm going to tear it back down this weekend to replace the head gaskets but my question is, should I be concerned that I warped the heads? Thanks for the help. Chad

10-13-2023, 09:29 AM	#2
Jason Banks Senior Member Join Date: Dec 1999 Location: TX Posts: 1,519	Re: How hot before heads warp - L83 A friend of mine had problems with his electric fans on LS3 and was regularly hitting 230-235 and had not problems. I can't imagine 240-250 would hurt you too bad.

10-13-2023, 11:07 AM	#3
gofast321 Registered User Join Date: Sep 2010 Location: Pittsburgh, PA Posts: 38	Re: How hot before heads warp - L83 Thanks Jason. I appreciate the feedback.

10-13-2023, 04:39 PM	#4
LS short box Registered User Join Date: Jun 2015 Location: Carlos MN Posts: 1,923	Re: How hot before heads warp - L83 If you have a real good metal scale (machinist ruler) and a feeler gauge you can check the heads yourself. Or a machine shop can easily check. Either way make sure they are super clean on the block side.

10-14-2023, 08:32 AM	#5
Joyridin Registered User Join Date: Sep 2020 Location: Cleveland, Ohio Posts: 478	Re: How hot before heads warp - L83 I am not sure if you have studs or head bolts, but if you are using factory style head bolts, be sure to buy a new set. I doubt you hurt the heads, but I would do what LS short box states above and have them checked anyhow.

10-14-2023, 03:29 PM	#6
gofast321 Registered User Join Date: Sep 2010 Location: Pittsburgh, PA Posts: 38	Re: How hot before heads warp - L83 Thanks for all the information guys. I appreciate the help. But I chickened out, I'm going to send the heads to a machine shop close to my house on Monday just to be sure. His prices were pretty good and he can turn them around in a week so I thought it was worth the time and money just for the peace of mind. I'm grabbing all new head bolts, gaskets, etc in the meantime. Chad

10-14-2023, 04:37 PM	#7
LS short box Registered User Join Date: Jun 2015 Location: Carlos MN Posts: 1,923	Re: How hot before heads warp - L83 Just a note. Make sure before you bolt the heads back on to get all the coolant out of the bolt holes in the block.

10-20-2023, 03:55 PM	#8
gofast321 Registered User Join Date: Sep 2010 Location: Pittsburgh, PA Posts: 38	Re: How hot before heads warp - L83 Just got the heads back from the machine shop. No cracks or major issues. They did deck them down .004. Ultimately they probably would have been ok to just install but now I know for sure. Going to install them this weekend.

10-25-2023, 12:07 AM	#9
Accelo Registered User Join Date: Mar 2015 Location: washington Posts: 2,161	Re: How hot before heads warp - L83 I am going to reiterate what LS Short Box mentioned. "Get all the coolant out of the bolt holes in the block. " Many a bock has been ruined because this rule was not followed. They hydro-lock and crack the block.

10-25-2023, 10:36 AM	#10
gofast321 Registered User Join Date: Sep 2010 Location: Pittsburgh, PA Posts: 38	Re: How hot before heads warp - L83 Good note guys. Yeah I spent a lot of time using the air compressor to blow all of the water out of those bolt holes and then I let them sit an extra day to fully dry. I got the engine all back together last night and got is started. Everything seems to be working as it should and cooling is now working. Thanks everyone for the info and suggestions. My take away from this project... Take your time and don't rush.



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