Timing vs overheating question.
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
Timing vs overheating question.
I am still fighing an over heating problem although I am running a Victor Jr aluminum WP, Dewitt rad, dual spals and Indy front spoiler.
I have the following parameters set.
454 +.030\Aluminum heads intake\Demon carb\solid cam\10:1 comp.
180* stat
70/30 water vs anti freeze mix with water wetter.
low fan setting on spals kicks on at 160f. High kicks in at 200f
advance @ idle is 15*
36* advance all in @ 3000
The car is raising to 230* not in traffic!
Also getting a lot of run-on after I shut the car off and smoke comes back up through the carb.
I am figuring the problem lies either in the timing or the carb setting. Ideas???
I have the following parameters set.
454 +.030\Aluminum heads intake\Demon carb\solid cam\10:1 comp.
180* stat
70/30 water vs anti freeze mix with water wetter.
low fan setting on spals kicks on at 160f. High kicks in at 200f
advance @ idle is 15*
36* advance all in @ 3000
The car is raising to 230* not in traffic!
Also getting a lot of run-on after I shut the car off and smoke comes back up through the carb. I am figuring the problem lies either in the timing or the carb setting. Ideas???
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
I assume you have all the foam atound the rad etc.
Try shooting the water outlet etc with a temp gunto establish the gauge accuracy.
Also the in rad temp vs the out rad temp to find the temp difference.
Try one of these tstats with much greater flow.
You may also try to block off the pump bypass. See Stewarts Pump Tech articles.
Lastly make sure your carb jetting isn't too lean.
Try shooting the water outlet etc with a temp gunto establish the gauge accuracy.
Also the in rad temp vs the out rad temp to find the temp difference.
Try one of these tstats with much greater flow.
You may also try to block off the pump bypass. See Stewarts Pump Tech articles.
Lastly make sure your carb jetting isn't too lean.
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,390
From: At my Bar drinking and wrenching in Lafayette Colorado
Run your vacuum advance from a manifold vacuum source so you get an additional 16 degrees of timing on top of your 15 initial. This will give you 31 degrees of timing at idle, and this will run your engine significantly cooler.
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
Thanks lars I will try that tonight. One other question for you. When I installed my distributor the first time I did it 8 * advanced so I need to add that 8* to whatever the timing light is set at correct? Examble if I dial into the gun 15* and move the distributor to whiere the light pulses on the o* mark on the balancer I would essentially have 15* + 8* = 23* correct?
thanks
wade
Burning Brakes
Joined: Feb 2006
Posts: 1,024
Likes: 1
From: AL
BlackRat; you can test that yourself before starting any changes: you say it is set at 8 deg at idle now, so with your timing light, dial it to 8 deg, and the 0 deg line on the balancer should line up with the 0 degree mark on the timing tab.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Thanks lars I will try that tonight. One other question for you. When I installed my distributor the first time I did it 8 * advanced so I need to add that 8* to whatever the timing light is set at correct? Examble if I dial into the gun 15* and move the distributor to whiere the light pulses on the o* mark on the balancer I would essentially have 15* + 8* = 23* correct?
thanks
wade
thanks
wade
No that is incorrect. If you set the timing light at 15 degrees and it shows up 0 you are at 15 degrees. If you set it at 23 and it shows up at 0 you are at 23. It does not remember where you are set at.
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
Ok so if I inserted the distributor with the balancer 8* adv mark lined up with the 0* on the timing tab I do not need to compensate for that when setting the timing?
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Melting Slicks
Joined: May 2002
Posts: 2,717
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Black Rat take a look at this thread and read through it, I've been doing some work on my cooling system;
http://forums.corvetteforum.com/show....php?t=1677145
I have my vacuum advance conected to a manifold port as Lars is suggesting, this works great.
My next move is to install a Stewart stage 2 pump for the extra flow at idle.
Do as noonie has said, the Robert-Shaw is the best T-stat design I have ran across.
Neal
http://forums.corvetteforum.com/show....php?t=1677145
I have my vacuum advance conected to a manifold port as Lars is suggesting, this works great.
My next move is to install a Stewart stage 2 pump for the extra flow at idle.
Do as noonie has said, the Robert-Shaw is the best T-stat design I have ran across.
Neal
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
Black Rat take a look at this thread and read through it, I've been doing some work on my cooling system;
http://forums.corvetteforum.com/show....php?t=1677145
I have my vacuum advance conected to a manifold port as Lars is suggesting, this works great.
My next move is to install a Stewart stage 2 pump for the extra flow at idle.
Do as noonie has said, the Robert-Shaw is the best T-stat design I have ran across.
Neal
http://forums.corvetteforum.com/show....php?t=1677145
I have my vacuum advance conected to a manifold port as Lars is suggesting, this works great.
My next move is to install a Stewart stage 2 pump for the extra flow at idle.
Do as noonie has said, the Robert-Shaw is the best T-stat design I have ran across.
Neal
Thanks guys I will try some of these suggestions. lars\Neal are ya'll saing to actually put a vaccum fitting into one of the intake ports and run the advance from there and not to the manifold vac port on the base plate of my Demon?
thanks
Wade
Melting Slicks
Joined: May 2002
Posts: 2,717
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Neal
Melting Slicks
Joined: Jul 2004
Posts: 3,302
Likes: 8
From: Avon, Indiana
Just for the heck of it, I switched my 383 from manifold to ported. It seemed to run a little better, but when I spent some time at stop signs the usual 180 went to 220. I was surprised that it could make this much of a difference.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I always had heating problems with twin spals and everything. The cure is to overdrive the pump. I also went to circle track washers instead of a thermostat. It is still pretty cool here and I'm now running the 1/2 inch hole. My motor would not ever heat up when i had the 7/8 inch hole. the washer set came in 6 sizes
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
The water pump is the problem. Just like my Weiand Team "G" aluminum pump. They are made for high rpm race cars. I came across a rpm VS gallon per minute chart on my Team G at sub 4000 rpm it did not even put out 5 GPM and then it kicks in and increased to 38 GPM clear out to 9000 rpm.
I always had heating problems with twin spals and everything. The cure is to overdrive the pump. I also went to circle track washers instead of a thermostat. It is still pretty cool here and I'm now running the 1/2 inch hole. My motor would not ever heat up when i had the 7/8 inch hole. the washer set came in 6 sizes
I always had heating problems with twin spals and everything. The cure is to overdrive the pump. I also went to circle track washers instead of a thermostat. It is still pretty cool here and I'm now running the 1/2 inch hole. My motor would not ever heat up when i had the 7/8 inch hole. the washer set came in 6 sizes
Thanks
Wade
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
The cost of these mods is high. It is probably cheaper to just get an aluminum higher volume pump. Or you might try the restrictor washers like I have instead of a thermostat. I don't even have to turn on my fans now where before I usually had them both running.
The width of the aluminum pulley did not clear the pump housing - So more milling time
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
Thanks. I noticed that you have all of your ports plugged on the water pump. I am not running heater hoses but I do have the bypass line hooked up from the op of the pump to the base of the manifold. Would I gain anything by eliminating that and plugging the hole?
I will try the washer method as well. did you buy those as a kit Where?
Wade
I will try the washer method as well. did you buy those as a kit Where?
Wade
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Thanks. I noticed that you have all of your ports plugged on the water pump. I am not running heater hoses but I do have the bypass line hooked up from the op of the pump to the base of the manifold. Would I gain anything by eliminating that and plugging the hole?
I will try the washer method as well. did you buy those as a kit Where?
Wade
I will try the washer method as well. did you buy those as a kit Where?
Wade
The bypass does just what it says. It bypasses the block. that just does not help cool anything. I just don't think that even my high flow thermistats could flow enough. Like I said right now I'm using a 1/2 inch hole. when it gets up hotter I'm going to monitor it and probably end up using a 5/8th or 3/4 hole
http://www.jegs.com/webapp/wcs/store...51807_-1_10129
Melting Slicks
Joined: May 2002
Posts: 2,717
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Black Rat try the Stewartcomponents web site and read through the Q&A forum, tech section, and the 10 most asked questions, also on the tech section at near the bottom of the page there are some links to other pages that give the flow charts for pumps. Water flow is critical but so is air flow.
Neal
Neal