We have converted our Dolomite Sprint using a electrical waterpump, we have removed the original waterpump and inserted the waterpump bung. All this is working ok, however the heating inside of the car is not working verry well. We have been looking for the root cause of this and found in some articles that we should replace the bypass tube with a bypass tube as shown on attached picture.
Can anyone let me know where I could get such a bypasstube.
As I am not so sure that the picture will be visible, the bypass tube I am loong for has just a verry small hole at the top of the tube
This would be very helpfull to complete the work on ourt Dolly
Thanks for any advice
Nico
Don't know where to buy them from, but try taking your original by pass tube to a machinist, so he knows the dimensions of the original and they can modify it to your needs, that's what i did
I am at a similar stage in fitting an EWP as you (see https://forum.triumphdolomite.co.uk/vie ... =4&t=37619).
I don't think that the alternate bypass would help your heater flow, although the Sprint heater connections are different to my TR7 Sprint.
You have to remember that the standard heater flow is designed to come back into the water pump at the suction side. As you have now moved the pump, the heater has no flow direction.
I re-routed the heater outlet to the inlet side of the EWP using a connector from T7 design. https://www.t7design.co.uk/t7design-hea ... c-6e6.html
See attached photo - you can see the heater pipe circled.
How did you blank off the bypass tube? That is where I am getting an annoying leak.
Jerry
Attachments
heater connection.jpg (190.46 KiB) Viewed 5392 times
When you fit an EWP the in-car heating does become intermittent or even non existent. The answer is to tap into the back plate on the cylinder head and take a hose from there and tee in to the existing heater hose flow.
Sprintless for the first time in 35+ years. ... Still Sprintless.
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Mad Mart wrote: ↑Mon Jan 09, 2023 9:56 am
When you fit an EWP the in-car heating does become intermittent or even non existent. The answer is to tap into the back plate on the cylinder head and take a hose from there and tee in to the existing heater hose flow.
That rear take off is what is used on the TR7s. The few real TR7 Sprints they made had a special rear takeoff casting but they are incredibly rare.
I have Sprint engines in my TR7s with a simple adapter plate sold by Rimmers, fairly crude but does the job. Basically just a plumbing elbow fitted into a Sprint plate.
The Davis Craig EWP is designed to function WITHOUT the benefit of the normal engine thermostat. On the Sprint engine this thermostat performs a double function, the "foot" on it closes off the bypass pipe when the stat opens, the bypass pipe only functions during warmup.
The brass "pinhole" bypass pipe is DC's solution to the problem of cooling path confusion from not having the stat. It allows a miniscule amount of water to pass the "wrong" way when running but crucially it lets air rise up to prevent airlocks when filling etc that might otherwise prove hard to dislodge.
HOWEVER, Ian above and others have proven by experience that blanking off the bypass with a couple of core plugs is not fatally detrimental, does not inevitably lead to hours of frustrating airlocks and has the distinct advantage of rarely being a source of leakage, which is more than can be said for the bypass tube, standard OR modified.
NEITHER will make you heater work better!
To give the heater ANY chance at all, you MUST re-route the heater return to BELOW the pump (ie between bottom hoseneck on rad and water pump) and blank the original return on the engine water pump housing.
Further benefit is gained by using the TR7 Sprint style hoseneck for the supply to the heater and blanking the original under manifold fitting as the backplate area draws the hottest available water.
Most people who have got this far will now introduce a "proper" clear header bottle and pressure cap into the system, Tee-ing it's feed into the bottom hose and tee'ing the heater return into the feed from the header.
Sorry if this sounds confusing, i've done a flow diagram to explain it but can't find it since my photobucket account died.
Finally, if you still don't have the heater you want, DC offer a small in (heater) hose electric pump purely to speed up the flow and make the heater work better. It's not elegant and fixes the symptoms rather than the cause - but it does work!
Or you can do what I did and put a Vauxhall engine in, all my Vaux powered Dolomites have excellent heaters! But its a bit of a sledgehammer solution!
Steve
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!
Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.
dursley92 wrote: ↑Mon Jan 09, 2023 3:49 pm
That rear take off is what is used on the TR7s. The few real TR7 Sprints they made had a special rear takeoff casting but they are incredibly rare.
I have Sprint engines in my TR7s with a simple adapter plate sold by Rimmers, fairly crude but does the job. Basically just a plumbing elbow fitted into a Sprint plate.
I bought one from Sprintspeed.
It is also tapped for a temperature gauge sender….
Ian
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Mad Mart wrote: ↑Mon Jan 09, 2023 9:56 am
When you fit an EWP the in-car heating does become intermittent or even non existent. The answer is to tap into the back plate on the cylinder head and take a hose from there and tee in to the existing heater hose flow.
That rear take off is what is used on the TR7s. The few real TR7 Sprints they made had a special rear takeoff casting but they are incredibly rare.
I have Sprint engines in my TR7s with a simple adapter plate sold by Rimmers, fairly crude but does the job. Basically just a plumbing elbow fitted into a Sprint plate.
Carledo wrote: ↑Mon Jan 09, 2023 9:39 pm
The Davis Craig EWP is designed to function WITHOUT the benefit of a thermostat
Sorry Steve, cannot resist commenting…
Your comment is absolutely true, given that Panasonic designed they pumps for washing machines…
I have trouble accepting that this pump is really suitable for running hours on end?
Ian
Well you learn something new every day! I wasn't aware of the ancestry of the pump, not that it really matters, a pump is a pump, so long as it delivers the requisite LPM, it's OK. Granted that my statistical sample is too small to be significant, but I can't recall one of these DC pumps ever failing. I've had one develop a leak and a couple with very erratic electronic control units but no total pump failures, nor do I personally know of anyone else who has had one fail.
If you use the control ECU that is meant to work with the pump, this makes the pump run in pulses and it rarely runs continuously for long, you'd need a big traffic jam on a very hot day to get it flat out. Whereas I suppose if you just cheapskated it and fitted it set it run all the time, ie with no control unit, this might well accelerate wear and failure.
My point was more about the fact that Davis Craig is an Australian company and develops it's products to work in their native climate where daytime temps can exceed 140 degrees Fahrenheit and a working heater is not a major consideration. Adapting the EWP system to our less than sunny climes has obviously caused them a bit of an unexpected problem.
Steve
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!
Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.
....My point was more about the fact that Davis Craig is an Australian company and develops it's products to work in their native climate where daytime temps can exceed 140 degrees Fahrenheit and a working heater is not a major consideration. Adapting the EWP system to our less than sunny climes has obviously caused them a bit of an unexpected problem.
Steve
The thing I find amusing about these EWP 80's that we use in the Sprint, is that in Australia they are actually used as far as I recall as an auxiliary pump to the main cooling circuit pump to push the water round the demister/cabin heating circuit and a proper man sized one is used in the engine cooling system.
As an aside I wholly concur with your thoughts about the pulsing aspect of the controller - on my race car the only time I have ever had the pump run full chat for any length of time when it is on the dyno with limited air flo...I wouldn't contemplate running the pump without the control unit...
If it's of any help, I run my car on Webers and so the cooling system is a little different that when using the std carbs, to this end, I run a small coolant fed cabin heater that takes coolant from the back of the head, runs it through the heater and then returns it to the block via the hose tail on the top of the std water pump casing...I don't have a bypass tube as the top of the water pump housing and the bottom of the inlet manifold are blanked off.
Come and see some pretty shoddy, slow driving of a really well prepared competition Sprint here!
While racing my maple Sprint over the course of 17 years, the main cooling/ overheating issue I experienced was not during the race, but on return to the pits after the race. Even on an Auckland summer's day (low 30s centigrade) the standard Sprint pump at higher revs would circulate sufficient coolant to keep the temperature in the high 90ᵒC range (with a bigger alloy radiator, water with ‘water wetter’). Temperature would rise on the ‘cooldown’ lap and continue once stationary in the pits, engine running or not. At times this ended up with localized boiling. This was resolved after I fitted a Davies Craig EWP115, with the electronic controller. After stopping the engine, the controller continued to run the pump, plus the radiator fan, thus circulating coolant around the system until the engine cooled to a predetermined setting.
I’ve not found the need to fit one to either of my road Sprints, although on both I do have the electric radiator cooling fan wired (via relay) through a Revotec fan controller, coupled with an override switch under the dash. If the Davies Craig pumps were a lot cheaper, I would seriously contemplate fitting them as, again, high coolant temperatures usually only result when in slow traffic in town when coolant flow from the standard jackshaft driven pump is poor and not on the open road. Would I fit one without the smart electronic controller? Definitely NOT.
Yes, used a solid bypass tube, no small hole, and it worked fine. Never thought of the idea of using core plugs, but as long as they don't leak, it sounds like a reasonable idea.
Another point is that it is prudent to open up/enlarge the outlet from the pump housing into the head to allow for increased flow when fitting an EWP, especially for any competition use.
Carledo wrote: ↑Thu Jan 12, 2023 2:42 pm
Granted that my statistical sample is too small to be significant, but I can't recall one of these DC pumps ever failing
Google searches suggest otherwise…..
I found one thread on an Australian forum concerning a Saab 99,
an early one with a Triumph engine (1700cc) and stainless steel bumpers that is
(I had expanded the search to include they Saabs given their pertinence).
This was a tale of woe which didn’t have a happy ending as the DC pumps managed only
5 or 6K, kilometres that is. I think they had replaced the first two under warranty but then the owner
was time barred?
I have bought a Stewart pump, it is 200litres/minute and is rated for 10,000 hours
and is designed to work as a straight replacement for a more conventional pump
so works with a thermostat
Ian
TDC Forum moderator PLEASE help us to maintain a friendly forum,
either PM or use Report Post if you see anything you are unhappy with. Thanks.
... Still Sprintless.
