![]() |
|
|
|
||||
|
Extremely Hot Running 350 Crate Motor. Possible Reasons???
Hello,
First post on the board and looking for some advice. Bought the basic 350 Chevy (260HP) with all the accessories (water pump, intake, carb, HEI, etc) for a daily driver old pickup. I used the headers that were on the old 327. Rotated crank to TDC (0 on damper) and dropped in the distributor so it lines up with No 1 plug wire post on cap. It fired up pretty quickly, but gets extremely, extremely hot within a matter of 3-4 minutes. Headers glow red and even ends of tail pipes are way too hot. Only advice I got was that timing was probably way off. I cranked it up today (distributor is still not bolted down) and it was about 0 degrees. By the time I got the timing light fired up and set timing to about 5 deg BTDC, the engine was already very hot and quit right about then. It does also backfire through the carb a few times, and as it quits running. Could distributor be off a tooth on cam gear and still start fairly easily? Could exhaust be plugged up somewhere? All suggestions are appreciated-I'm not a great mechanic to begin with and am out of ideas. Thanks RVH |
|
||||
|
Give us some information about the vehicle before you put this new crate engine in. If there was a previous motor, did it over heat? Was the previous motor an engine similar in size to what you have now or was it a 6 cylinder? Did the truck sit up for a while before you put the engine in? Did you mount the heads on the new motor or were they already on there? Did the over heating condition improve when you changed the timing as suggested in the previous post?
While your putting all this information together, you might grab the upper radiator hose right after the engine reaches operating temperature to see if you can feel water circulating thru the hose. If not your thermostat may be stuck closed. |
|
||||||
|
when filling fluids (cooling fluids) in for the 1st time its best to take out the thermostat and pour your cooling fluid directly into the intake.............once its full put the thermostat back in fill the radiator 3/4 full and start it.ill bet anything that you have no fluid in the motor thats why its running red hot......happened to me once..............its worth a try pull your thermostat ill bet 10 to 1 there is no fluid in the motor.....good luck
|
|
||||||
|
here is one of those duh suggestions.....it DOES have coolant in it right??? It didn't happen to leak out or anything? I had a problem with a bad radiator cap that made my engine overheat rather quickly. Didn't seem that would have been it to me but after I replaced it, it was fine.
|
|
||||||
|
Coolant is definitely an issue. A couple of things: You have to check, and recheck coolant when you start a new motor. IF your timing is retarded, it can cause your motor to run hot. If your radiator is not higher than your motor, air pockets will form and your motor will NOT cool. What is your compression? Is the old cooling system simply not able to keep up? Are you sure you're pressurizing the system properly (you need about 16 pounds, is your cap doing its job?)
You'll get her figured out, just make sure you don't burn it up- K |
|
||||||
|
Quote:
|
|
||||||
|
Something's seriously out of whack here. I doubt having an air lock would cause the engine to overheat so quick, and in that manner (IE, exhaust system glowing red). Make sure your balancer timing mark is true with top dead centre. Also are you capable of doing a degree check on the cam to confirm that it's in correct phase with the crank? It's not impossible that it's way out. I had a young mechanic do a head job on a Mazda e2000 van. After picking up the van the customer immediately drove it back saying it lacked power. Sure enough he was right. It would'nt pull the skin off a custard! I asked the mechanic if he double checked the cam timing and without hesitation he said "yeah sure". Man this thing was sicko and the catalytic converter was glowing red like a nuclear reactor! I spent maybe an hour double checking most things before I unbolted the cam belt cover only to find the cam out by 2 teeth on retard. The mechanic's embarrassment was his much deserved punishment.
|
|
|||||
|
like they said up there.
if your headers are glowing your timing is off. i installed a motor in a ta with the timing really retarted he had just installed header wrap and i started breaking in the motor and the header wrap caught on fire. start with your timing. |
|
||||
|
Thanks to all who wrote in.
Started to go through the suggestions and I found a big vacuum leak in the carb (where I forgot to install the 1/4 inch pipe plug for the brake booster-did I already say I was not a very good mechanic?). It seemed to start up much easier, but some emergency in the house prevented me from letting it run for a while to see if it still got too hot. Will test it out in the next couple days and post results. Thanks again- I was surprised by how many people took the time to write with suggestions. This board is excellent. |
|
|
| Recent Engine posts with photos |
| Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
| Thread Tools | |
|
|