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Fitting the water pump bung
Posted: Mon Sep 19, 2022 8:58 pm
by JerryTR5
I have searched the forum with no joy. Is there a fitting guide for the Club pump bung?
I assume that it is held in place by a bolt screwed in to the centre and the pump cover, but why is it threaded with a left hand thread? I'll have to drill & tap it - who keeps left hand thread bolts in stock? Or am I missing something?
Secondly, what methods are used to block off the bypass tube if one removes the thermostat and lets the EWP control flow?
I have seen a photo of a solid plug with a small hole drilled and I had assumed that this would come with the bung. Thinking about it, it would be better to blank off the bypass completely and eliminate two potential leak points. If the waterpump housing needs an air bleed one could be fitted to the heater inlet.
Jerry
Re: Fitting the water pump bung
Posted: Mon Sep 19, 2022 9:49 pm
by Magenta Auto Sprint
Not quite clear what the bung is? are you fitting an electric pump?
the only left hand thread is the bolt that secures the impellor to the drive shaft, this is done to stop if from unscrewing when in use.
All other hose connectors are righthand threads.
Malcolm
Re: Fitting the water pump bung
Posted: Mon Sep 19, 2022 10:27 pm
by JerryTR5
Yes indeed. The bung replaces the water pump when fitting an electric one.
I can understand the left hand thread on the rotating pump impellor, but not in the fixed bung.
Jerry
Re: Fitting the water pump bung
Posted: Tue Sep 20, 2022 2:58 pm
by new to this
When i fitted my pump bung, i dont think it was a left hand thread,
Re: Fitting the water pump bung
Posted: Tue Sep 20, 2022 4:41 pm
by MIG Wielder
If it does have a L.H. thread I can see a reason why.
You will have just extracted the water-pump with a slide hammer and adaptor with the L.H. thread.
So you press in the bung. If you need to remove it to, say, replace the O-rings then you'll also need the slide hammer with adaptor.
Tony.
Re: Fitting the water pump bung
Posted: Tue Sep 20, 2022 4:57 pm
by sprint95m
JerryTR5 wrote: ↑Mon Sep 19, 2022 8:58 pm
I have searched the forum with no joy. Is there a fitting guide for the Club pump bung?
I assume that it is held in place by a bolt screwed in to the centre and the pump cover, but why is it threaded with a left hand thread? I'll have to drill & tap it - who keeps left hand thread bolts in stock? Or am I missing something?
Secondly, what methods are used to block off the bypass tube if one removes the thermostat and lets the EWP control flow?
I have seen a photo of a solid plug with a small hole drilled and I had assumed that this would come with the bung. Thinking about it, it would be better to blank off the bypass completely and eliminate two potential leak points. If the waterpump housing needs an air bleed one could be fitted to the heater inlet.
Jerry
I used core plugs to do away with the bypass altogether
which permits the use of studs for attaching the manifold.
Steve (Carledo) reckons you need a solid bypass tube with a tiny hole to allow any trapped air to escape
but I disagree because I understand that coolant flowing at 200 litres/minute is going to drag any air up
to the highest point in the cooling system….
Ian
Re: Fitting the water pump bung
Posted: Tue Sep 20, 2022 10:42 pm
by JerryTR5
Core plugs - brilliantly simple, I shall follow your lead. I'll take an air bleed off the heater return.
It's definitely a left hand thread. Take your point Tony about removal, however making the thing stay in place is my current issue. May I suggest to the club that the next batch are made with a right hand thread, no doubt if a slide hammer is required in the future, it will be simple to get a RH thread adaptor.
So, once I re-tap the centre I need to follow the same procedure for fitting a pump ie use a feeler gauge to measure end float and adjust the bolt and/or gaskets so that the bung is held firm by the cover. Probably needs a few thou for expansion I guess.
Thanks for your comments.
Jerry
Re: Fitting the water pump bung
Posted: Sat Jan 07, 2023 11:18 pm
by JerryTR5
Dragging this topic back up again as I finally got the rebuilt engine fired up with the EWP.
Question: Having blocked off the bypass with core plugs, the one in the pump cover appears to be tight, but the one in the manifold is weeping. I'm wondering if the different expansion properties of alloy manifold and stainless steel core plug is incompatible? Could of course just be me being incompetent.
Maybe Carledo (referred to earlier) has a point about using a blanking tube with an air bleed.
Any thoughts?
Otherwise, all working well. The next question will be about re-torquing the head but I'll search the forum first and start a new thread if required.
Jerry
Re: Fitting the water pump bung
Posted: Mon Jan 09, 2023 1:05 am
by Gerard
My sprint has bypass blanked off with core plugs. This is a common procedure in Perth Australia. Car running standard pump and cooling at present. The mod is 3 years in and I don’t think I’ve experienced any detrimental issues by doing so. Disclaimer, I did blow a head gasket, but I put that down to being unlucky, along with not having head re-torqued frequently enough once built engine fitted and run in.