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#1
05-14-2018, 12:23 AM
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I think I have a cooling isssue in my '65 GTO
I have a Butler built 1965 421 that has been bored and stroked to 453. I have 670 heads that have been ported by Butler. On top of that is a fully restored 65 tripower by Mike Wasson. This motor produced just under 500 Hp on Butler’s dyno.
I have it installed in my 65 GTO. I replaced the original radiator with a 4-core original style radiator. It has a new clutch fan as well as an electrical fan. That has adjustable thermostat that is set at 195 degrees. The thermostat installed in water neck is a 160 degree. I drove the car today in 91 degree weather for 20 miles and it stayed at 200 degrees. I stopped to buy gas for about 20 minutes. The drive back home was 205 degrees. I believe this is too hot but I am not sure what to do next. When I first start the car it idles at about 700 RPM. After it warms up it idles at about 1000rpm. When I turn off the key at 1000 rpm it has trouble shutting down. Do I need to check my timing? Is there a hot idle cam that lols in when warm? I know there is an hot idle compensator that I am thinking about blocking off to eliminate the whistle noise it makes. |
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#2
05-14-2018, 06:20 PM
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Check the sticky a few posts above by PMDRacer, Chalk...
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********** Don't be jealous that I've been chatting online with babes all day. Besides, we both know that I'm training to be a cage fighter. |
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#3
05-14-2018, 07:08 PM
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You state you have a new clutch as well as electrical fan. Are you running a standard clutch fan, AND an electrical pusher?
So... assuming that your water pump divider plates aren't making gaping inefficient recirc flow paths (see divider plate sticky), I have just a few questions. What size water pump pulley are you running? Smaller means faster, which means more flow, which is good. What style of timing cover and pump are you using? 11 bolt covers/pumps are assumed to be slightly more efficient. Are you using the heater hose? What style of electric fan is in use? The wrong electric setup can cause air flow restrictions. What mechanical fan style you are running. 18-19" 7 blade fans used with a fan clutch are usually plenty capable of moving enough air.
__________________
"...ridge reamer and ring compressor? Do they have tools like that?" |
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#4
05-16-2018, 11:02 PM
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Quote:
Mechanical fan is a 7 blade 18” with clutch. New 4 core radiator original style. Fan set to come on at 195 degrees. 160 degree thermostat. I really like someone’s opinion on whether the 200 to 205 degrees is too hot and if so what would be the next step. I have read all the sticky and there is a lot of things to try. Just need some guidance for the next most logical step. Thanks guys! |
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#5
05-16-2018, 11:04 PM
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205 degrees is not too hot.
__________________
1964 Tempest Coupe LS3/4L70E/3.42 1964 Le Mans Convertible 421 HO/TH350/2.56 2002 WS6 Convertible LS1/4L60E/3.23 |
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#6
05-16-2018, 11:43 PM
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Quote:
So I don’t really have to do anything, right? |
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#7
05-17-2018, 12:20 AM
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Leave it be if it runs at 205.
I'd be concerned if it saw over 220. 230 would be overheating.
__________________
1964 Tempest Coupe LS3/4L70E/3.42 1964 Le Mans Convertible 421 HO/TH350/2.56 2002 WS6 Convertible LS1/4L60E/3.23 |
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#8
05-17-2018, 07:11 AM
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I would check the temperature with a laser heat measuring gun at the thermostat housing after the car warms up.
Could be your gauge, |
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#9
05-17-2018, 10:45 PM
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It seems like you have some high quality components, and have checked almost all of the boxes.
When you say you have the heater core bypassed, is it straight from the head to the timing cover? I like to provide a little resistance in the heater line if I am not running a heater core. Flow through that line helps to equalize front to back temps (good). But since all 3 coolant flow paths (radiator, heater, timing cover recirc hole) are all in parallel, changing the flow in 1 of those parallel paths causes a change in the others. I have a quarter turn valve in the heater bypass on my Lemans to throttle back on the flow due to a lack of heater core. It forces more water to take the radiator path. Just a thought. Do you run vacuum advance? I like manifold vacuum on the advance, 10-15 degrees. It helps with temp and idle quality. 205 is OK, but with everything you have done it seems like it should do better than 205.
__________________
"...ridge reamer and ring compressor? Do they have tools like that?" |
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#10
05-17-2018, 11:47 PM
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Quote:
How much do you close off the quarter turn valve? I do not use vacuum advance. This is what Butler setup and recommend I don’t change it. Thanks for response. |
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#11
05-18-2018, 11:04 AM
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1000 RPM and an engine at 205 will most likely have issues shutting down. if you can, slow the warm idle RPM down. That may cure that issue.
George
__________________
"...out to my ol'55, I pulled away slowly, feeling so holy, god knows i was feeling alive"....written by Tom Wait from the Eagles' Live From The Forum |
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#12
05-18-2018, 06:14 PM
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Quote:
Is there a warm idle adjustment? |
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#13
05-20-2018, 09:26 AM
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I didn't see any mention of a fan shroud. If you don't have one, installing a shroud should help lower the temp
__________________
 66 GTO, 495, M22, Strange S-60 w/4.10 Sold new at Ace Wilson's Royal Pontiac http://www.youtube.com/watch?v=cUHC-Z8xhtg |
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#14
05-20-2018, 07:22 PM
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Idle speed screw on center carb? I don't have tripower, but there has to be an idle speed screw.
George
__________________
"...out to my ol'55, I pulled away slowly, feeling so holy, god knows i was feeling alive"....written by Tom Wait from the Eagles' Live From The Forum |
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#15
06-03-2018, 03:09 PM
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I just installed a fan shroud and a severe duty clutch and still showing 205 on temp gage. I bought a laser temp gun and place it on manifold by temp sensor and it reads 218.
I am using Dex Cool 50-50 coolant. Do I need to switch that out for something different? I also bypassing heater core with straight hose from head to water pump. Should I try plugging both of them? Fan shroud has a little gap between it an radiator at the top. I am going to see if I can get that to fit better. Nothing seems to be helping. |
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#16
06-03-2018, 08:21 PM
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Is the diameter of the fan correct for the shroud? If your fan is 18”, might need a larger fan. Also the depth of fan should be half in/half out of shroud
__________________
66 GTO, 495, M22, Strange S-60 w/4.10 Sold new at Ace Wilson's Royal Pontiac http://www.youtube.com/watch?v=cUHC-Z8xhtg |
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