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OK so my problem is that the rebuilt 13b I just put back in my GSL-SE overheats immediately after I get it to "idle". And I mean like 2 minutes.
I am wondering if anyone has any specific insights into a freshly installed rebuilt motor would overheat so quickly or if it is just going to be the normal things.
Quick Background on motor:
1. 13b from GSL-SE
2. Large Street port
3. Motor is very hard to start: I have to pour oil in the spark plug holes to get it to start and then it dies under 2k rpm (I wedge a shim in the throttle). This as I understand is normal for fresh rebuild.
4. Used the old housing/irons. All other seals completely new.
5. Thermostat removed. Stock radiator. Electric fan.
6. e-shaft oiling changed to weber jets.
7. smooshed bypass valve and shimmed regulator. Oil pressure at 70lbs at ~3k rpm.
Now I get that the car isn't moving and maybe my fan isn't the greatest but given there is no thermostat so the coolant is flowing from start up the car shouldn't overheat immediately right???
I am at a bit of a loss, Should I just be looking for "airbubbles" in system (however that is fixed)?
More Background: I started the car it ran for like ~2 minutes. Temp crept to half way. Turned it off. Crept up to 3/4 then came down. I repeated this with the same results.
Any thoughts would be greatly appreciated. I am going mental with this thing. I have to go through the whole process of oil in the plug holes just to start it and after it dies it will not start again without the same procedure... Given that it overheats in 2 minutes I don't have too much diagnostic time so I am not sure what to do!
Do you have any kinks in your oil cooler lines? How old is the temp sending unit? does the wire have any possible spots where it could have grounded out (this would cause a false reading).
Also, keep the cap off the radiator for the first couple of minutes of run time. Keep an eye on it and fill it as the car idles. This will eliminate any air in the system.
Check your timing. The hard starts shouldn't be that hard. and timing will make the headers cherry hot; it won't cause over heating but its just a side note.
Do you have any kinks in your oil cooler lines? How old is the temp sending unit? does the wire have any possible spots where it could have grounded out (this would cause a false reading).
Also, keep the cap off the radiator for the first couple of minutes of run time. Keep an eye on it and fill it as the car idles. This will eliminate any air in the system.
Check your timing. The hard starts shouldn't be that hard. and timing will make the headers cherry hot; it won't cause over heating but its just a side note.
I didn't think for kinked oil cooler lines but I for sure will check.
Timing: I lined the distributor up with TDC to be in the stock location so I am assuming it's at stock. Like I said, I haven't been able to run it for long and it fills my garage with smoke (although the main startup smoke has diminished). Maybe I will have to have someone standing by for a quick check.
Why is the thermostat removed? Put it back in and try again, and burp the cooling system
Thermostat is removed because we were overheating during a race and that was one of out ditch efforts.
I realize having the thermostat in is a good idea but having out out does not explain overheating. In fact the motor should have trouble getting up to temperature!
Was the rebuild due to mods/renewal or a catastrophic incident with the former motor?
Were used parts magnafluxed to look for cracking or decked to check flatness?
Can you see water moving in the cooling system?
Did you burb any air out of the block and associated lines and hoses?
The water pump housing has a bypass so removing the t-stat doesn't do much for keeping it cool. I think if you run without a t-stat, you need to put a plug in the bypass.
Was the rebuild due to mods/renewal or a catastrophic incident with the former motor?
Were used parts magnafluxed to look for cracking or decked to check flatness?
Can you see water moving in the cooling system?
Did you burb any air out of the block and associated lines and hoses?
Yeah... non of that was done of course. The death of the motor was slow and painful due to coolant seal dying.
I have to check if the coolant is moving. and no it was not burped.
I have only ran the motor for a total of maybe 5 minutes between 3 starts so you can see how diagnostics like this are difficult.
What is your indicator for 'overheating' as the engine isn't running long enough to truly overheat with 2min at a run. If the dash guage is your only indication, my bet is that your block has a big air bubble right at the sender unit, and it gets too hot too fast without coolant flowing past the sensor.
First, put your thermostat back in so it will actually move coolant.
Next, remove the heater return hose at the top rear of the block and use this to burp air out of the system. You can use the firewall hose to the return to add coolant from the top until it overfills at the radiator cap.
Go from there. Hard starting could be a lot of things down to your build. Getting it running is more important for now.
What is your indicator for 'overheating' as the engine isn't running long enough to truly overheat with 2min at a run. If the dash guage is your only indication, my bet is that your block has a big air bubble right at the sender unit, and it gets too hot too fast without coolant flowing past the sensor.
First, put your thermostat back in so it will actually move coolant.
Next, remove the heater return hose at the top rear of the block and use this to burp air out of the system. You can use the firewall hose to the return to add coolant from the top until it overfills at the radiator cap.
Go from there. Hard starting could be a lot of things down to your build. Getting it running is more important for now.
Heater components are all removed and capped off.
I am hoping it is indeed an air bubble. I also learned you are not supposed to just dump water into a new motor all at once, which I did. This also pints to air bubble.
Motor is running perfect now! Starts on the first crank, stays cool and idles.
So I was battling this overheating problem, assuming the whole time the cooling system wasn't working when my dad, who was helping me start the car, starts waving his arms and tells me to cut the motor.
This is what I saw:
hmmm what causes the header to glow red after 2 minutes of running? A lean condition!
So I checked the timing and we were like 90 degrees retarded... I mean nowhere close.
I am not sure how this could have happened? I rechecked the pulley was lined up at top dead center, then checked the distributor was lined up correctly, which it was... I just don't get it. Doesn't matter I suppose.
Bottom line is we brought the timing to fairly close to stock and now the motor runs like a dream.
04-18-16, 12:55 PM
