Heater unit removal, water pipe bypass?

Anonymous · Post by **Anonymous** » Sun Apr 05, 09 6:05 pm

Just removed the old heater unit which didn't work anyway.

Is there any reason why I need to put it back in at all?

If I just feed the water inlet pipe into the outlet pipe on the water pump and just don't mind not having a heater is that going to damage or prevent me from doing anything else?

Just asking

Dave-R · Post by **Dave-R** » Sun Apr 05, 09 6:14 pm

Yes you can just loop the hose over. If you can get the pipe fittings out of the water pump housing I think I have a couple of spare blanking plugs you can have to block them off.

Anonymous · Post by **Anonymous** » Sun Apr 05, 09 6:20 pm

Lovely Dave, thanks very much again. I have already praised you on my other thread.

If you need any legal advice regarding your altercation I have a very good mate who is a lawyer that I'm sure could offer you any pointers if required.

Thanks again boss

Anonymous · Post by **Anonymous** » Sun Apr 05, 09 6:31 pm

Loop the heater hose fittings across the water pump , if not the block will boil , if you plug em the water can't circulate & will crack the block when the stat opens.

Dave-R · Post by **Dave-R** » Sun Apr 05, 09 6:33 pm

No it won't. Everyone blocks them off with no effect at all.

Anonymous · Post by **Anonymous** » Sun Apr 05, 09 6:41 pm

If you remove the stat then fine , with a stat fitted there's no way the water can circulate round the block when the stat is shut.

Dave-R · Post by **Dave-R** » Sun Apr 05, 09 6:47 pm

Really?

Dave-R · Post by **Dave-R** » Sun Apr 05, 09 6:48 pm

I have ran my block for years with the heater outlets blanked off.

Anonymous · Post by **Anonymous** » Sun Apr 05, 09 6:54 pm

The ONLY way back to the suction side of the pump is either through the heater matrix or through the rad , if the heater matrix is blocked off with no bypass then the stat has to be removed , the block will either crack due to local boiling , or the stat opening will Bananarama! off due to shocking the block with cool water.

Maybe you got lucky Dave , the fitting of a short bypass hose..........................

Anonymous · Post by **Anonymous** » Sun Apr 05, 09 6:57 pm

Rebuild the heater and put it back in.

Foam seals and stainless screw kit for that heater - Detroit Muscle Technologies.

New heater matrix - Year one

Slap 12V on the motor and see if it works. If it doesn't, get it rebuilt, if it does, re-use it.

The motor problems will be the most expensive. The rest of the bits are cheap as chips.

Dave-R · Post by **Dave-R** » Sun Apr 05, 09 7:11 pm

Brutus wrote:The ONLY way back to the suction side of the pump is either through the heater matrix or through the rad ,

Hang on though.

When the thermostat is closed is there not water flow from A to B (or is it B to A??) on my drawing below? There should be water flow through the block from one side to the other shouldn't there?

Anonymous · Post by **Anonymous** » Sun Apr 05, 09 7:23 pm

Side 'A' is inlet/outlet , side 'B' is inlet/outlet , without a route back through the stat (top hose) , the only other way it can circulate is through the heater matrix.

Strangle the heater hose & go fire the motor up , see that temp shoot up through the roof (stat fitted).

Blue · Post by **Blue** » Sun Apr 05, 09 7:49 pm

Sorry Ad, both mine and Jems cars are plugged with no ill effects or over heating. Mines been like it for the last 15 years and the car before that, it ain't a problem.

Dave-R · Post by **Dave-R** » Sun Apr 05, 09 7:56 pm

Brutus wrote:Strangle the heater hose & go fire the motor up , see that temp shoot up through the roof (stat fitted).

Like I say. I have not ran a heater hose for many, many years. The engine warms up as normal. Not fast at all.

I understand what you are saying but I just have never come across this in practice.

The last time I used the car on the road I fitted a 'stat with holes drilled in it. That slowed the warm up process down a bit but it still takes a good 10-15 mins for the water to heat up to full temp.

Now of course the temp sender is in the pump housing. So maybe I don't see a temp rise because the local temp is lower than the water jacket temp.

But if that were the case I would expect too things.

If hot water from the block suddenly started to flow when the 'stat opens I would see a sudden rise in water temp at the sender. I have never seen that. The temp rises slowly. Then when the 'stat opens I get a slight drop.
Also I would have seen an early rise in the oil temp? Then a sudden drop when the block got "shocked" by the cold water?

But in practice my oil temp has always kept pace with the water temp and I have never seen sudden changes.

You are the plumber so I bow to your superior knowlege on such things. I have just never seen the effects of what you are telling me.

You have me worried though.

Pete · Post by **Pete** » Sun Apr 05, 09 8:02 pm

Very interesting thread

Both the Sox and the '67 Dart have the matrix ports blocked off with NPT plugs. No issues, the Stat in place and warm up just like any other car. Driven to Shakey and back with no problems, motors have always run cool.

Do any other members have experience of problems?