Overheating!! Help!! Ideas - Page 2 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

4x4Poet · 06-05-2006, 01:18 AM

You might try a Robert Shaw high performance thermostat. Stock replacement T-stats do restrict the flow quite a bit. This stock T-stat restriction is no problem for stock engines with low compression that have low cooling needs, but high compression engines that create a lot of heat need the coolant out of the block sooner/faster, IMO. Not so fast as with no T-stat, as you discovered, but faster nonetheless.

I knew a guy with a big block with around 9.5:1 to 10:1 compression that ran at 240-245º at idle. Installing a RS T-stat dropped the temp 10-15º at idle. Didn't solve the entire problem, but it helped.

Flowkooler sells RS T-stats along with their excellent waterpumps. Jegs and Summit also sell them rebadged as Mr. Gasket T-stats.

Longhorn Man · 06-05-2006, 05:06 AM

Goodwrench 350, stock pistons, crank, rods, replaced heads with Iron Vortec. Aluminum vortec intake, mild flat tappet crane cam .454 .480, double roller timing set, roller rockers. Compression is around 9.25:1 seems a bit mild for having those problems.

toddtheodd · 06-05-2006, 06:26 AM

What exhaust do you have?
I changed out the intake and carb on my 350 awhile back from stock to rpm performer, and started having all sorts of overheating problems. I changed the water pump, t-stat, radiator, hoses, heater core, 160 t-stat.
The motor would actually get hotter the faster I went on the highway, so I knew it wasn't just a fan thing.
After exhausting (no pun intended) all other options, I started thinking about what I had changed on the motor, and the only thing was the intake and carb. I figured that the motor was now sucking in more air than it could easily push out, so it was overheating because it was litteraly having to PUSH the exhaust out.
I put on a set of hooker long tube headers and 2 1/2 pipes, and no more overheating.
I even had to put the regular t-stat back in because after the header change my truck started running too cold.
Toad

**53burb** · 06-09-2006, 04:39 AM

It was mentioned earlier to check your timing. I second that. When I replaced my engine almost a year ago, I didn't have my timing set correctly, and it overheated until it was set correctly. For a SBC, I believe you should be at anywhere from 8-12 degrees BTDC...

06-05-2006, 01:18 AM	#26
4x4Poet Registered User Join Date: Nov 2004 Location: "Under Montana skies." Posts: 1,836	You might try a Robert Shaw high performance thermostat. Stock replacement T-stats do restrict the flow quite a bit. This stock T-stat restriction is no problem for stock engines with low compression that have low cooling needs, but high compression engines that create a lot of heat need the coolant out of the block sooner/faster, IMO. Not so fast as with no T-stat, as you discovered, but faster nonetheless. I knew a guy with a big block with around 9.5:1 to 10:1 compression that ran at 240-245º at idle. Installing a RS T-stat dropped the temp 10-15º at idle. Didn't solve the entire problem, but it helped. Flowkooler sells RS T-stats along with their excellent waterpumps. Jegs and Summit also sell them rebadged as Mr. Gasket T-stats. __________________ '71 GMC K20 Suburban, '71 GMC K10 Suburban, '72 Chevy C10 CST Suburban, '72 Chevy K20 clunker pickup.

06-05-2006, 05:06 AM	#27
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Overheating!! Help!! Ideas Goodwrench 350, stock pistons, crank, rods, replaced heads with Iron Vortec. Aluminum vortec intake, mild flat tappet crane cam .454 .480, double roller timing set, roller rockers. Compression is around 9.25:1 seems a bit mild for having those problems.

06-05-2006, 06:26 AM	#28
toddtheodd The oddest Todd around Join Date: May 2004 Location: Miami, Florida Posts: 1,418	Re: Overheating!! Help!! Ideas What exhaust do you have? I changed out the intake and carb on my 350 awhile back from stock to rpm performer, and started having all sorts of overheating problems. I changed the water pump, t-stat, radiator, hoses, heater core, 160 t-stat. The motor would actually get hotter the faster I went on the highway, so I knew it wasn't just a fan thing. After exhausting (no pun intended) all other options, I started thinking about what I had changed on the motor, and the only thing was the intake and carb. I figured that the motor was now sucking in more air than it could easily push out, so it was overheating because it was litteraly having to PUSH the exhaust out. I put on a set of hooker long tube headers and 2 1/2 pipes, and no more overheating. I even had to put the regular t-stat back in because after the header change my truck started running too cold. Toad __________________ "The greatest pleasure is to vanquish your enemies and chase them before you, to rob them of their wealth and see those dear to them bathed in tears, to ride their horses and clasp to your bosom their wives and daughters." Ghengis Khan IIOY???

06-09-2006, 04:39 AM	#29
53burb Senior Member Join Date: May 2004 Location: Queen Creek, AZ Posts: 1,007	Re: Overheating!! Help!! Ideas It was mentioned earlier to check your timing. I second that. When I replaced my engine almost a year ago, I didn't have my timing set correctly, and it overheated until it was set correctly. For a SBC, I believe you should be at anywhere from 8-12 degrees BTDC...



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