new 408 stroker, running wayy to hot

bmob

bmob

Member
#1
#1
Hi everyone, I have been waiting for 9 months for my babies motor to come back from the machine shop, and she finally got home. 351w turned 408 stroker making 535hp and 565tq @ 5600rpm. A few friends and I got her installed and running but once she warms up she climbs in temp. I have the same cooling set up as before (huge aluminum radiator with electric fan). At first, the engine had NO thermostat in it, so I put one in, and it helped for a short while, but it started to climb temp. Once it hits 180 it climbs to 190 and sits there while idling, but as soon as I left my garage with her she jumped to 200, then to 205, then to 210. I burped the system (watched the bubbles come out and once the T-stat opened it lowered the coolant level so i added more). I shut her off near 205 and it went to 210 while sitting. The top radiator hose is burning hot and so is all along the outside of the therm (i couldn't reach my hand in the fan shroud to see if the middle is hot since my hand is too big). I even got that royal purple purple ice that is supposed to lower the temp (it did a little but not where I need it). Last year the thing would be tough to get over 160 when cruisin without the fan on! (By the way, once she hit 180 i put the fan on and even with the electric fan on she still climbs even when im crusin @ 55 and low rpm. I am so stumped on this one I don't know what else to do!:mad:
 
bmob

bmob

Member
#3
#3
its carbed 750 quick fuel, I don't have the receipt for the cam I forgot the lift and duration on it. I watched it on the engine dyno it was amazing ran and sounded beautiful but now when its in my car it thinks it can overheat on me :nono: . If I can't figure this one out it may end up going to the... *gulp* mechanic (typical of what happens when I get fed up to the point where I throw tools and yell at my stang tellin her im gunna trade her for a chevy, though its an empty threat:p). Ok, as for oil, it still has the bp x500 joe gibbs racing oil that came with it (checked the level added .25 quart to put it just at the full line). I was told by someone that if the timing is advanced too much it could run too hot (but even with my massive aluminum radiator, electric fan AND royal purple purple ice?)
 
Michael B

Michael B

Well-Known Member
#4
#4
yes, too much timing will cause an overheat as will too far retarded. carb too lean will cause an overheat also. check the plugs for color.
 
92BIGREDBEAST

92BIGREDBEAST

Well-Known Member
#5
#5
Michael B said:
yes, too much timing will cause an overheat as will too far retarded. carb too lean will cause an overheat also. check the plugs for color.
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I wouldnt think it would NOT be jetted to lean or rich if the engine was dyno tuned? Isnt that the whole purpose. You must be missing something. My car was running 190 yestrerday and i have a 160 stat in the car.....
 
bmob

bmob

Member
#6
#6
It was dynoed with a different carb. At the time my carb was no good to use (holley 650 and the electric choke was effed up). I had to get a quick fuel 750 and I just bolted it on. I have a feeling its the timing because when I was at the dyno that was base timing and when I left he said he would play with the timing until he could maximize the HP and TQ. I feel its running rich if anything not lean but I don't know S&!T about carbs (though I can tune efi lol). I'm gunna go to a local mechanic hes a good guy family run business and he is not expensive and has done some high po cars before. I will post what the problem was once I get back
 
92BIGREDBEAST

92BIGREDBEAST

Well-Known Member
#7
#7
bmob said:
It was dynoed with a different carb. At the time my carb was no good to use (holley 650 and the electric choke was effed up). I had to get a quick fuel 750 and I just bolted it on. I have a feeling its the timing because when I was at the dyno that was base timing and when I left he said he would play with the timing until he could maximize the HP and TQ. I feel its running rich if anything not lean but I don't know S&!T about carbs (though I can tune efi lol). I'm gunna go to a local mechanic hes a good guy family run business and he is not expensive and has done some high po cars before. I will post what the problem was once I get back
Click to expand...
Thisng are sounding off to me. FIrts off, the purpose of a "dyno tune" is to get the motor running the best and most efficient with the combo on the dyno. You say the car has a different carb on the motor when it was dynoed? The whole purpose of a dyno is to get the tune/ settings right for that combo! Meaning what is on the motor is tuned to make best power and efficiency. The dyno guy told you to adjust the timing to get more power? What was the gentlemens reason for dynoing this motor if he planned on having you bump timing and change carb? Doesn't make sense to me. A 650 cfm carb is too samll for a stroked 408 so i would think your running too lean and making your combustion chambers hot causing your hot condition. Just seems like a weird way to go abouts a dyno tune motor... GL!
 
bmob

bmob

Member
#8
#8
I must have not been clear sorry for the confusion. I started with a bare 351w block (the one that used to be in the stang) then brought it to the machine shop and they built it up (I tried to save $$ by using some of my old parts that were still good i.e. the edlebrock rpm air gap performer intake, all my new pullies from before, and my carb if it was still good). My carb (the 650) turned out to be not good and I didnt have the $$ for the new carb at the time so he dynoed it with the shop carb (similar to the one he would get me). He broke in the engine on the dyno and tuned the timing while it was on the dyno. The only thing that wasn't tuned was the carb. I got a 750cfm quick fuel carb now that he got for me but I got it after the engine got dropped back into my car. He was supposed to get me his carb guy to come and tune it on the engine but he isn't available for 2 weeks! (I wanna drive my car now damn it! lol) So I put the floats where they needed to be but I don't have an array of jets to do the jetting. I was talking to a friend of mine who does engines and he said something about an air pocket in the heater core. Could that really cause the system to overheat if its in the heater core?
 
bmob

bmob

Member
#9
#9
Here is a link to the video of my car when we first fired her up (open header)

[ame=http://www.youtube.com/watch?v=x4BlmwUhLCc]YouTube - ‪408 Stroker comes to life!‬‏[/ame]
 
DalzFordz

DalzFordz

Active Member
#10
#10
Why didnt it run hot on the dyno? What combo are you running to get 535hp out of the 408. Any bubbles in the radiator or overflowing, head gaskets ok, what is the timing? Pressure test the system. My 427 stroker runs at 195 degrees constant with an aluminum radiator and electric fan. Check it out before you lose some expensive parts.
 
EHA Racing

EHA Racing

Member Plus
#11
#11
Let's start with the basics. Do you have the correct water pump on it? If so is it moving enough water? You should be able to see the water moving through the fill in the radiator. If the pump is turnng the wrong way due to the belt routing it will cause the same problem.
 
bmob

bmob

Member
#12
#12
the pump is run the same as before, its a reverse fin pump special for the A/C delete and I'm 100% sure its on correctly (the belt is run the same as before the 408 kit was done, I even compared before and after pics :p) I lifted the front of the car to tilt so the fill neck was the highest point. It took a lil coolant in but then none. The car will idle with the fan on at 185 all day long, but when I take her for a spin she climbs to 190, then 195, then 200 then hovers around 200 until I get on her then she makes a slow climb to 210 and Before that happens shes back in the garage cooling down (I turn off the car, let the rad cool for 1 min then start it for a second to get the cool coolant into the engine to make sure it doesn't overheat)
 
bmob

bmob

Member
#14
#14
FIGURED IT OUT!!! After completely taking apart the whole cooling system (just shy of remove the engine to check the water jackets) I realized I am an idiot. My friend fried my fan box when we first put it in, so we hard wired the positive and negative of the fan to a switch. We wired it backwards so the fan PUSHED air instead of pulling thru the radiator. It even felt like it was pulling air thru but we put a piece of paper in front of the bumper and she was pushing air out like a monster. Reversed the wiring and now she won't go above 170 if the fan is on!
 
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