455 overheating issues at intake , not the block

wskirvin

wskirvin

Greasemonkey
May 22, 2017
246
63
Indianapolis, In
Get some felpro blues and spary both sides with this

Thats actually what i have Sitting in the garage right now. I bought the Felpro head set that has the blue gaskets and i already have a can of the copper coat. so hopefully i'll get it going soon.
 
olds307 and 403

olds307 and 403

Geezer
Oct 14, 2008
5,632
113
Melville,Saskatchewan
My 88 looks like it is Copper coated, so go with the theme. Just be safe and do everything. Honestly, I have never blown or had Felpro gaskets leak. I have blown a Corteco head gasket. To be fair, it was 1/2" 5A heads on 7/16" 76 Olds 350 block without adapters.
 
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wskirvin

wskirvin

Greasemonkey
May 22, 2017
246
63
Indianapolis, In
Well I'm definitely hoping I'm outta the woods now. Pulled the top end apart and took the heads to be pressure checked and magnafluxed just to be safe, installed exhaust cross over plugs. Then put everything together with new Felpro blue head gaskets. while i had it tore down, i went ahead and replaced the milodon water pump for a flow kooler one..... same housing, but new one has a billet impeller with more fins. had it running and sounds good, temps at their highest got up to 205-210. probably could use a better radiator and fans than the cheap $180 ebay stuff i have, but temps were way better and no boiling or compression in the coolant!
 
M

Mrrjay243289

n00b
Sep 14, 2019
1
1
Your heads may be cracked. Mine did the same thing then stalled on me while driving once I looked up under the hood the carburetor had gotten so hot it warped the base plate but the engine still ran a block or something before stalling again, once I took the heads off the engine the driver side head had 4 cracks in it and the passenger side had two cracks in it
 
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Drkuhar

Drkuhar

Master Mechanic
Sep 27, 2018
250
63
When i built my 455 i had a few years back i had a overheating issue that i tracked down to the water pump. Rebuilt water pumps from napa and the problem one had an impeller that was smaller and left about a 3/8-1/2 gap around the perimeter. The replacement pump had an impeller that went almost all the way out leaving maybe a 1/8 gap around the perimeter. Changing the pump cured the issue
 
olds307 and 403

olds307 and 403

Geezer
Oct 14, 2008
5,632
113
Melville,Saskatchewan
Sounds like he has it fixed. The 455 is nearly as hard to cool as the 403. Get a 2 core with 1" or larger tube aluminum radiator and good fans that move a lot of air.
 
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wskirvin

wskirvin

Greasemonkey
May 22, 2017
246
63
Indianapolis, In
Sounds like he has it fixed. The 455 is nearly as hard to cool as the 403. Get a 2 core with 1" or larger tube aluminum radiator and good fans that move a lot of air.
thats exactly what i did! as well as added a 160 thermostat. at idle in gear on a hot day its came close to 190 but usually as soon as the fans kick on at 185 it doesnt stay there long and then drops to 165 going down the road.
 

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