Sprint heater bulkhead connection doublecheck.

[Andrew65]

Would like to doublecheck before I connect the heater hoses to back of heater box. Does the heater have a flow direction from water pipes? Got the hoses underneath the inlet manifold all connected back as far as the H piece. Looking at the pipes protruding from bulkhead is the left one connecting the front manifold pipe or the rear one. The parts book and workshop guides give no indication. Thanks in advance.

[Mad Mart]

Top one to the manifold, bottom one to the waterpump housing.

[Andrew65]

Thanks for the info. As my sprint is a 1977 the parts book shows the longer double metal pipe (TKC1196). The pipes overlap each other so switching sides compared to the early parts page you showed. As TKC1196 is no longer available I have gone the earlier route as per the early parts page. That shows the pipes running one above the other. So the early and late are on differing sides. Hence my query.

[Andrew65]

Is this pic therefore correct or are they the other way round?

As everything is back in the bay, don't want to change all this later? CHEERS!

[sprint95m]

That is correct.
(If you were to get this wrong the heater would not produce heat.)


Converting to the early Sprint spec is a good idea. You can make the hoses up yourself using a 90 degree 13mm bore silicone hose elbow
and lengths cut from a one metre 13mm bore straight silicone hose. You need the union for the inlet manifold (I think Chris Witor may
have these available in stainless steel?)
Please ensure the H-piece has beaded connections and please use proper hose clips (JCS).

[mahony]

Earlier set up is better (not so prone to leaks in my experience ) and easier to fit, i converted mine to early spec with a kit sprint spares used to do,most of the bit's can surely be sourced off the shelf

[matienzo]

Does the H piece (return or whatever you want to call it on the later type) have a restrictor in it? The restrictor would reduce the amount of "return bypass" when you have the heater on and therefore increase hot water flow through the heater matrix. I don't have one to hand and wondered if its working using the same principle as the bypass used on the OHV engines?

[Magenta Auto Sprint]

The H piece does have a cross hole in the middle to allow a small flow when the valve is shut. The Rimmer H pieces do not have flared ends as per original, even though they cost £26 each. Not sure how to solve that issue yet.

[Mad Mart]

Top one to the manifold, bottom one to the waterpump housing.

[Andrew65]

Thanks for everyones help.

At the risk of starting a fight online I thought you might like to see the old pipe laid on top of engine to show how the pipes cross. This way would indicate water pump top, manifold bottom???

If I had re-used this pipe the two hoses joining to heater must surely have crossed to achieve manifold top, water pump bottom?

[sprint95m]

You are correct, the hose from the manifold does indeed cross over the one to the pump.
It is the same on an 1850 too.


If you can't obtain a beaded H-piece there are a couple of options.....
Use an unbeaded H-piece as it is and employ a pair of hose clips for each connection, if space permits,
or, a better way is to
use 2 barbed T-pieces with a short connecting hose between them.
(You can use a smaller hose bore (11mm) here if you wish but I have found that doing this didn't improve the heater's output
noticeably.)

[Andrew65]

Thanks to all who helped, job all sorted.