Coolant Pump

[Malsprint]

Looking at the fitting instructions for the pump housing (12 vane) and the need to use different gaskets of different thicknesses. I assume that the dimension between the rotor and the bottom face of the pump housing is critical to the efficiency of the pump.

Mine is very badly pitted. Or at least I think it is but I have never seen a new one so I am not sure what is expected or acceptable.

I notice that replacements are very cheap which make me concerned about the quality. Mike (Project PFJ) where did you get your pump housing from and how is the quality.

Second question. What is the size of the heater hose fitting. I very much doubt I am going to get it out.

[Magenta Auto Sprint]

I don't think the pitted face will affect the efficiency of the pump. The shims are to limit the end float and to ensure that the vanes do not rise up excessivley and make contact with the chamfered face.

The dimension/clearance between the vanes and the chamfer is key to the efficiency of the pump.

Malcolm

[USSprinter]

Looking at the fitting instructions for the pump housing (12 vane) and the need to use different gaskets of different thicknesses. I assume that the dimension between the rotor and the bottom face of the pump housing is critical to the efficiency of the pump.

Mine is very badly pitted. Or at least I think it is but I have never seen a new one so I am not sure what is expected or acceptable.

I notice that replacements are very cheap which make me concerned about the quality. Mike (Project PFJ) where did you get your pump housing from and how is the quality.

Second question. What is the size of the heater hose fitting. I very much doubt I am going to get it out.

Just saw your queries. On the heater hose fitting, I got mine for $9 plus $5 shipping from Ohio, so it is not worth the effort to try and recycle the old one:
https://www.ebay.com/itm/273973719921?h ... Swx8pdXLQd
The correct 1/2" British Pipe Standard size is identified as "12 mm hose -to- 1/2 pipe" in the drop down menu. The 1/2" heater hose is close enough to 12 mm so there is no metric fitment issue for the hose end. 1/2" BSP is the crucial requirement. Probably not necessary to say, but use a good quality thread sealant to install the fitting into the pump cover (I used Hylomar Blue Universal Jointing Compound, leftovers from an old E-Type project).

I got my 12-vane pump cover for GBP 18.25 from the usual suspect in the UK:
https://rimmerbros.com/Item--i-PKC437
It looked cheaply made (even uglier than the photo on their website), but the functional part of it looked to be OK:


I now have the new water pump installation complete and have run the engine a good bit - all seems to be well (for now!). I will be posting fuller details on the PFJ thread in the next couple of days.

The fitting procedure for the new pump cover is a bit of a rigmarole. For me the biggest PITA was the measurement of the free gap between the pump cover and the block. I spent LOTS of time with feeler gauges to try and get a consistent gap measurement around the perimeter of the cover. Then it dawned on me that to this *precision* measurement, one adds anywhere between 0.0125" - 0.0250" (with no advice given on where one should aim for in this spread), so the overall accuracy required must be rather loose. I ended up using the single 0.030" gasket for the install. The new 12-vane pump seems to run quite happily.

Note that the shipping costs from the UK to the US can eat one alive, unless one is willing to wait for up to 50 transit days for the cheapest shipping service. My water pump parts order was part of a larger order for GBP 388 in parts so I felt that I could "amortize" the nose bleed GBP 55 shipping cost for air express over the whole order. I got my order from the UK in five days' time - can't even get a letter from SC to NC that fast.

[xvivalve]

For our Stateside members, worth reminding them perhaps that the pump and cover are identical to the TR7 and the pump itself identical to the Stag, so there may be supply of parts over there with less eye-watering postage elements.

[USSprinter]

For our Stateside members, worth reminding them perhaps that the pump and cover are identical to the TR7 and the pump itself identical to the Stag, so there may be supply of parts over there with less eye-watering postage elements.

The water pumps are interchangeable, but I think (at least for some years) the US-spec emissions controlled TR7 had a water pump cover that would not fit a Sprint without some significant mods (if at all).

[sprint95m]

For our Stateside members, worth reminding them perhaps that the pump and cover are identical to the TR7

I am not familiar with TR7s but I have seen a water pump cover advertised which had two hosetails.
This may have been foe a TR7 EFI?

Anyhow,
The design did rather appeal because it would mean doing away with the bypass tube………


Ian

[Malsprint]

The pitting I am concerned about is on the chamfered face. This photo shows it up better than the previous one.
I expect that this would decrease the efficiency of the pump.

[Malsprint]

I managed to get the fitting out using a g-clamp to put pressure on the spanner.
I am will still get a one as recommend by Mike since the hose fitting is quite pitted.

[Malsprint]

I got a new pump housing from RBros.
Given the price of GBP23.00 I was expecting it to be very poor quality. Much to my surprise its actually not bad. There is a little bit of porosity, the machining looks quite good. The only stupid issue is that the machined flat on top of the bolt holes is too small to take a flat washer. Even a spring washer is a tad too big. It would have been just as easy to machine this to the right size rather than the wrong size.

I have reduced the diameter of some spring washers by filing them while spinning them in a drill.

[dursley92]

I managed to get the fitting out using a g-clamp to put pressure on the spanner.
I am will still get a one as recommend by Mike since the hose fitting is quite pitted.

I find the best way to undo fittings like that in aluminium is a GENTLE amount of heat. Brute force often breaks stuff and don't ask me how I know that. I warm it gently over an old camping stove and it works every time.

[Malsprint]

I take back my original comment about the pump housing being of reasonable quality. From the photo you can see that the bolt holes are rotated anti clockwise. To the extent that the head of a bolt fouls on the body of the pump. This also causes the pump to be rotated out of position when fitted so that the bypass tube doesnt align with the hole in the manifold above.

I have asked RBros to check if all of their stock is like this and if not to provide a replacement. I will keep you posted.

[xvivalve]

I have a few serviceable used pump covers, both 6v (early and late) and 12v