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Overheating during break in? Electric fan not strong enough?
When I finished the break-in for my new engine (91 TBI 350 block, Aluminum 64cc heads, .490 lift Comp XE274 Cam, Springs, roller-tip rockers, headers, etc), she started to spit steam out of the vent hose on the reservoir despite the new electric fan running at full-speed.
The outside temperature was 95 degrees with no humidity (Vegas dry weather). So my Radiator was working perfectly before and seems to be in great condition (PO replaced it with a $600 Rad about 13 years ago and drove only 2,000 miles).
My break-in process was to rev between 2k-2.5k for 30 mins
I'm thinking maybe I need either a shroud or a stronger fan (fans?). What do you guys think? (I believe my current one is rated at 2,000 CFM. Flex-A-Lite Syclone)
(Temporary wiring was just to have it working for break in)
Edit: Pulleys and belts were both installed during break-in. Only removed them a couple hours before the pictures were taken
Hi Sd,
I'm a pretty poor mechanic… but in your photo, what's driving the water pump?
Regards,
Alan
Oh yeah, I just took the pulleys off a few hours ago to replace them. During break in, pulley and belt were both installed
So I'll check the thermostat. That's one thing I didn't replace during the engine build. Timing shouldn't be retarded, I got it pretty spot on 0. The fan definitely cools, but I don't have a working temp gauge at the moment so I can't tell you exactly how much it cools
most auto parts store will have a cheap water temp gauge you can stick in your head just for the sake of monitoring it takes minutes to put in.
May as well get a new stat , drill a couple 1/8 in holes around the outside ring to help burp any air out
very common for things to get toasty while sitting still and breaking in a cam. No airflow and a lot of heat built as things get acquainted with each other.
I remove the T-stat all together. I place a box fan somewhere to help remove heat from engine area. I also keep a water hose handy to mist the radiator while it's running. I set the timing higher than normal to keep it cool. And richen the idle screws to let some fuel flow.
Actually my bad. Had a friend helping with the timing while I ran her. Says he set it right about 10 degrees before.
It is possible I was running a bit lean as well, but I'm gonna remove the thermostat before I do anything else. I'll do a more thorough tune according to Lars' documents and see if that helps
I remove the T-stat all together. I place a box fan somewhere to help remove heat from engine area. I also keep a water hose handy to mist the radiator while it's running. I set the timing higher than normal to keep it cool. And richen the idle screws to let some fuel flow.
JIM
^^^^^ This. 16* idle at a minimum. I would just run her up and advance by hand and ear. With no load, it can take quite a bit.
your missing half your radiator, you must use a shroud to direct air flow around all of your radiator, without it your missing hugh amount of cooling capacity.
you must use a shroud.
your missing half your radiator, you must use a shroud to direct air flow around all of your radiator, without it your missing hugh amount of cooling capacity.
you must use a shroud.
^^^^^Also a very good idea.
Just as a side note. My radiator guy loves those ty wraps thru the core.
They vibrate, have teeth, and over time file thru tubes.
Consider a shroud mounted NOT to the core.
dont time it by ear, I did that once out of laziness just to break in a cam, was way off. So retarded I ruined a brand new set of jet coated headers and fried my exh gaskets;had a few exh springs break quickly wondering if the valves got too hot headers were literally glowing
some guys will use some junk exh manifolds (make sure they arent lean/rich) then install the headers
dont time it by ear, I did that once out of laziness just to break in a cam, was way off. So retarded I ruined a brand new set of jet coated headers and fried my exh gaskets;had a few exh springs break quickly wondering if the valves got too hot headers were literally glowing
some guys will use some junk exh manifolds (make sure they arent lean/rich) then install the headers
Allow me to clarify.
I said set it at 16* at idle, and ADVANCE it by ear while running. IE, way up there. At 2000rpm, you could set it at 40* and it would be fine.
I've helped friends do this. They start it, the manifolds get hot, and I grab it and twist it advanced till it cools down. If the rpm backs down, I retard it to the sweet spot.
I then set it up with a timing light after the break in. 36* at 3000RPM, vacuum plugged.
I hear what youre saying we all used to do that I just screwed up royally it looked like that posters pic so much for the new engine smell it was not pretty. lol
how many of us got lucky back in the day with the "advance it til the starter just starts to kick back then go backwards a hair" and really believe it.
07-25-2017, 12:50 PM
Overheating during break in? Electric fan not strong enough?
0 would be seriously retarded for normal running.
