Post by Deleted on May 20, 2022 21:37:07 GMT
Following on from this thread
thunderboat.boards.net/thread/4868/life-times-bowman-heat-exchanger
So attention turned to getting Fairlight cruising ready after 3 very slack years. Following the awakening from the winter slumber I noted the raw water pump was very slow to prime - an elderly Jabsco 4900 keeps everything cool, many parts being unobtanium - including this most important part
Once the end plate gets as worn as this priming becomes difficult if not impossible; I had two choices - replace the pump with a not like for like unit and all the engineering hassle that goes with it or roll the dice for a secondhand pump off eBay and hope the end plate was better than mine.
After a session with a piece of plate glass and some grinding paste we end up with this
Not perfect but perfectly serviceable!
Off we go right? Umm no, the old girl is getting a bit hot under the collar, 200 F at sub 1500 RPM, not even a thought of running on boost. Rats!
two realistic causes - a blocked heat exchanger; unlikely as she was cooling ok before the winter layup, freshwater muscle larvae have been known to cause havoc with cooling passages but I didn’t think it would be the cause TBH.
The other likely cause would be a faulty thermostat.
Both required the heat exchanger to be removed - a job I last did 3 years ago.
On inspection the tube stack was indeed ok, a quick descale with Sentinel X800 and a sweep of the tubes and we are good to go on that side of things.
As expected it was the stat that was at the root of the hot running issues - I forgot to take a photo but here is the express delivery replacement stat and gasket from good old Calcutt, a better than 24 hour turnaround by them and Royal Mail 👍
The switch is from a different but equally impressive supplier - destined for my mates Waeco fridge.
While the HX was off I took the opportunity to replace the worn filler neck, bit of a pig as it is a solder on job, brass to aluminium; epoxy adhesive can be used but seeing as I hadn’t got any to hand I did it how the Brummies did 4 or 5 decades ago and broke out Harry the hot lamp 🍻👍
Ready to go back on.
Refit this weekend and an absolute spanking will be the order of the day to make sure she is fit for a decent run 👍
thunderboat.boards.net/thread/4868/life-times-bowman-heat-exchanger
So attention turned to getting Fairlight cruising ready after 3 very slack years. Following the awakening from the winter slumber I noted the raw water pump was very slow to prime - an elderly Jabsco 4900 keeps everything cool, many parts being unobtanium - including this most important part
Once the end plate gets as worn as this priming becomes difficult if not impossible; I had two choices - replace the pump with a not like for like unit and all the engineering hassle that goes with it or roll the dice for a secondhand pump off eBay and hope the end plate was better than mine.
After a session with a piece of plate glass and some grinding paste we end up with this
Not perfect but perfectly serviceable!
Off we go right? Umm no, the old girl is getting a bit hot under the collar, 200 F at sub 1500 RPM, not even a thought of running on boost. Rats!
two realistic causes - a blocked heat exchanger; unlikely as she was cooling ok before the winter layup, freshwater muscle larvae have been known to cause havoc with cooling passages but I didn’t think it would be the cause TBH.
The other likely cause would be a faulty thermostat.
Both required the heat exchanger to be removed - a job I last did 3 years ago.
On inspection the tube stack was indeed ok, a quick descale with Sentinel X800 and a sweep of the tubes and we are good to go on that side of things.
As expected it was the stat that was at the root of the hot running issues - I forgot to take a photo but here is the express delivery replacement stat and gasket from good old Calcutt, a better than 24 hour turnaround by them and Royal Mail 👍
The switch is from a different but equally impressive supplier - destined for my mates Waeco fridge.
While the HX was off I took the opportunity to replace the worn filler neck, bit of a pig as it is a solder on job, brass to aluminium; epoxy adhesive can be used but seeing as I hadn’t got any to hand I did it how the Brummies did 4 or 5 decades ago and broke out Harry the hot lamp 🍻👍
Ready to go back on.
Refit this weekend and an absolute spanking will be the order of the day to make sure she is fit for a decent run 👍
