Condensed nearly 100 posts from my previous thread into this one to make life a little easier.
ser no OW385827
model MCM 5.0MPI (single point drain)
nov 2005 engine Fitted 2006 -65 hrs use. the last 40 hours in fresh water.
original outdrive. previously fitted was a carbed 5.7 v8
outdrive alpha 1 gen 1
ser OC893180
1990
Problem; Engine overheats at idle, 550rpm. Engine temp will just keep increasing then if i pick up the revs it goes down to 165f.
Already done; serviced outdrive to include new pump bellows water hose and checked for blockages- all ok. tested output when in water and results show pumping way more than the minimum specified.
1000rpm for 15 secs = 4 quarts, minimum is 3 quarts
550rpm for 15 secs = 2.1 quarts
flow is very good with no air bubbles
checked all plumbing on engine p/s cooler, fuel cooler, check valve and replaced thermostat which was faulty anyway. removed manifolds and risers and all in good condition and clear. the only part i havent removed is the circ pump on the engine.
you can see some pics of the cooling system via this link http://forums.iboats.com/showthread.php?t=374168&page=2
there has been some uncertainty with myself whether or not this is a long standing problem. it could have overheated without me knowing as the instrument buzzer is missing. i only bought the boat last year.
TODAY!! Tested the engine again this time squashing the hose, that tee's and feeds the two elbows, by 80%, ish, and this helps the engine to run at a constant 175f.
With the hose resticted and at 2000rpm the hottest the manifold got was 185f and the elbows ran between 100f and 135f. The stbd side was hotter than the port side?
I think what don and bond-o are saying is true. i am going to have to alter the cooling system. can i just add two ball valves before the elbows to manualy balance the flow or should i look into fitting the blue ball system bond-o was talking about?
What is the hottest a manifold surface temp should be?
Ive had some great help so far... Don, Chris, Jason, Bond-o etc ..... thank you
ser no OW385827
model MCM 5.0MPI (single point drain)
nov 2005 engine Fitted 2006 -65 hrs use. the last 40 hours in fresh water.
original outdrive. previously fitted was a carbed 5.7 v8
outdrive alpha 1 gen 1
ser OC893180
1990
Problem; Engine overheats at idle, 550rpm. Engine temp will just keep increasing then if i pick up the revs it goes down to 165f.
Already done; serviced outdrive to include new pump bellows water hose and checked for blockages- all ok. tested output when in water and results show pumping way more than the minimum specified.
1000rpm for 15 secs = 4 quarts, minimum is 3 quarts
550rpm for 15 secs = 2.1 quarts
flow is very good with no air bubbles
checked all plumbing on engine p/s cooler, fuel cooler, check valve and replaced thermostat which was faulty anyway. removed manifolds and risers and all in good condition and clear. the only part i havent removed is the circ pump on the engine.
you can see some pics of the cooling system via this link http://forums.iboats.com/showthread.php?t=374168&page=2
there has been some uncertainty with myself whether or not this is a long standing problem. it could have overheated without me knowing as the instrument buzzer is missing. i only bought the boat last year.
TODAY!! Tested the engine again this time squashing the hose, that tee's and feeds the two elbows, by 80%, ish, and this helps the engine to run at a constant 175f.
With the hose resticted and at 2000rpm the hottest the manifold got was 185f and the elbows ran between 100f and 135f. The stbd side was hotter than the port side?
I think what don and bond-o are saying is true. i am going to have to alter the cooling system. can i just add two ball valves before the elbows to manualy balance the flow or should i look into fitting the blue ball system bond-o was talking about?
What is the hottest a manifold surface temp should be?
Ive had some great help so far... Don, Chris, Jason, Bond-o etc ..... thank you
