Spitfire Water Pump rebuild/upgrade questions.

[aoie]

Questions before I send in a surplus pump for rebuild by a specialist to finally rule out the pump as the problem for my MKIV Spitfire running hot on long drives (195-205F), car has run hot since the day I bought it in 1990.

Over the years I have tried larger radiators (Currently have a GT6 radiator retrofitted), Different Temperature thermostat values (160, 180), and currently a cheap non-serviceable pump replacement from online retailer.

I also have a future project in mind to try and fit a serpentine belt requiring change of pully.

Question 1: Do the newer Triumph non-serviceable pump pulleys have a standard press fit size center hole, or should I source for older pump that has removable pully I could purchase and send in for rebuild/upgrades (not sure it’s worth going that route)?

Question 2: Is a smaller diameter pully available to move more water (pump fan has been deleted), is this an option, or would not make a difference (i.e. can only move so much water through the engine)?

Andy

[Nick Jones]

Don’t know about the pulley hole sizes. Is this a 1300 or 1500?  1300 has a smaller pulley than a 1500 (to match the different respective crank pulley sizes)or should have.

Some thoughts on the basic overheating problem. 
- Is the gauge known to be accurate? How has it been verified? Could it be over-reading and reporting a problem that doesn’t exist?

- Do you have any real overheat symptoms; ie boiling over 

Assuming you have a real overheat problem, have you ever checked inside the water pump housing, specifically the flat internal ring behind where the impeller will sit. These sometimes corrode quite badly making the pump less efficient, though mainly a problem when sat in traffic at low rpm. When the revs are up a bit pumped flow should still be plenty.

Also, lean running or regarded ignition timing can cause hot-running.

[aoie]

Nick

The engine is a 1300 with upgraded big valve (1500) head!

I have 2 separate temperature sensors: 1st sensor/gauge is a cheap combo replacement of the dash OEM Smiths/Jaeger I switched years ago trying to resolve temp problem giving a little more info and accuracy. 2nd sensor goes to my microsquirt with custom LED display showing live CAN bus info I selected. Both gauges match (in-sync) while driving.

Basic high temperature levels  have plagued me over the years and through upgrades of the ignition Points Distributor to electronic, now Ford EDIS unit hooked to microsquirt. Original carburetor switched to Weber DCOE, now throttle bodies! 

As far as I can tell I have the timing on, and AFR gauge settling in at 14.7 on long drives.

Water pump housing was also replaced years back due to a crack in the original near the thermostat, dummy (me) put the longer bolt in the wrong hole and cranked to hard!

The pully size has always been the same OD of 5.25", however that does not mean that it had been switched from a smaller size before I bought the car! Can anyone verify what an original 72 MKIV pully size should be, could something that simple really be my problem.

[Sigma hurricane]

Having recently cured a overheating 1300 engine that was in the hurricane there were a few things that I did.

Its running a single thermostat controller electric fan on the original radiator. (I would have thought the stock radiator would do a better job than a gt6 one?

I took the radiator to the shop that does all the tractor radiators for me for flow testing and cleaning.

I had the timing and carbs adjusted on a rolling road as modern fuel requires different advance to the book for old 5 star fuel.

I flushed the block and hoses, first with just the hose and then blocked the hoses off without the radiator on and pushed some evapo rust through the block. 
 

Later that day I drained it and flushed it a few more times and it has ran cool ever since! 
 

I hope that helps! 
 

I can check the pulley size for you in a couple of days if that helps on the 1300. But similarly I can’t guarantee it’s the correct one on mine! 

[aoie]

A few years after I bought the car a local radiator mechanic tested the original rad to help me fix the overheating. Set me up with a Honda radiator with much more cooling fin area and custom bracket to mount it in the car. Also added an extra electric fan in addition to the stock fan, heat problems continued.

The GT6 radiator came with electric fan and welded fan mounts, setup did improve the overheating a little.

I'm interested in the result of evapo rust on the block! Did you get lots of crud when you drained?

I have a potential replacement 1300 motor that I will be doing a full rebuild on, soaking the water passages with rust remover will probably need to be added to the list.

[zetecspit]

I have had a couple of engines that needed a good poke with pokey things to move hard crud, back of the black near the drain plug. 

On my sprint engine I poked wires etc to get as much stuff out as possible, then used hydrochloric acid (brick acid) to shift stubborn leftovers. That works pretty well. 

I made some "evaporust" at home quite cheaply. It really does work. (sodium carbonate is basic washing soda, very cheap from the supermarket. Citric acid from ebay, not quite as cheap but to make 10L cost me under a tenner)

Per 1 litre of water.

1: 100 grams Citric Acid.
2: 40 grams Sodium Carbonate or 63 Grams Sodium Bicarbonate or 30 grams Sodium Hydroxide.
After reaction has completed, add final ingredient.
3: Arbitrary amount of washing-up liquid.

 

 

[Sigma hurricane]

If your doing a rebuild you won’t need the evapo rust, I steam clean the tractor blocks, I spend an hour with the jet steam cleaner at the farm getting into every little hole with it. You’ll be amazed how much crud comes out. Some engine shops will have their own cabinets for that.

But yes lots of crud out with the evapo rust,

Ed china has a few videos on it and even does whole chassis’s with it now! 

[egret]

I remember reading somewhere that the water pumps are fairly sensitive to speed, so much so that the lemans spitfires ran larger pulleys on the water pumps to slow them down as at high revs they tend to cavitate and not move much water.  This sounds reasonable, but may just be a bit of manufactured mythos to further mystify the lemans cars.  

I'll check what size pulleys I'm running tonight, I honestly can't remember if I retained the water pump (and pulley) from the 1500 or if I got one with the mk3 engine I'm using.  Generally my car runs 3/4 hot on the gauge, but have only actually had overheating issues when the timing was seriously retarded during my ECU battles.  Maybe I'm running the wrong size pulleys?

To add to what Nick said, I have a water pump housing where the internal flange/ring is so badly corroded that its missing for about 1/3 of it's circumference.  I've also got an anecdote of a chap with a vitesse engine who had to fill it with vinegar for a few days to solve an overheating issue.

[Sigma hurricane]

4 hours ago, zetecspit said:

Per 1 litre of water.

1: 100 grams Citric Acid.
2: 40 grams Sodium Carbonate or 63 Grams Sodium Bicarbonate or 30 grams Sodium Hydroxide.
After reaction has completed, add final ingredient.
3: Arbitrary amount of washing-up liquid.

 

Just watched it, great find will keep that recipe handy!

[aoie]

Guess I'm not the only one that likes to get lost in YouTube rabbit hole!

Picture of Citric Acid recipe ingredient's I have been using on small objects, nothing big like an engine block!

[egret]

I've had good experience with electrolysis - soda crystals in tapwater, scrap iron on +ve side and the part on the -ve side of a battery charger, and leave in a ventilated space overnight.    Probably not great for an engine block, but great for things like suspension components.

[JumpingFrog]

A random thought, I've read about but not exactly sure how much of a difference it would make. Have you fitted a replacement heater pipe (under the manifold)? There is some talk of these being remanufactured without a restrictor in the bypass connector (from the T on the inlet manifold), this allows coolant to short circuit the radiator as it feeds back into the water pump.

It depends on the ambient temperatures where you are too, my experience is that even an upgraded cooling system (wide 3-core radiator, 7-blade fan, electric fan) was marginal in traffic at temperatures above 35c.

[egret]

I've currently got the following pulley diameters:

Water pump: 150mm
Alternator: 63mm
Crank: 115mm
 

Crank pulley is certainly mk3, I think alternator pulley is too, but I'm fairly sure the water pump is 1500 spec.

[Nick Jones]

24 minutes ago, egret said:

Crank pulley is certainly mk3, I think alternator pulley is too, but I'm fairly sure the water pump is 1500 spec.

I think that is correct. Have a 1300 water pump I can measure later.

[aoie]

Quote

3 hours ago, JumpingFrog said:

A random thought, I've read about but not exactly sure how much of a difference it would make. Have you fitted a replacement heater pipe (under the manifold)? There is some talk of these being remanufactured without a restrictor in the bypass connector (from the T on the inlet manifold), this allows coolant to short circuit the radiator as it feeds back into the water pump.

 

The lower return pipe to the water pump is a stainless replacement, and I'm pretty sure it had no restriction on the T bypass feed from manifold. Tossed the old pipe that had welded itself to the water pump compression nut fitting, so not sure if it had a restriction built-in.

Could easily add a restriction on the upper manifold coolant pipe T made out of 1/2" copper fittings, can't hurt to try anything new. It's a future project to clean up the plumbing in that area, so I will add that to the list of improvements.

I do wish to maintain the manifold coolant pipe and improve its surface area contact with the lower intake manifold, so I have not deleted it.

[aoie]

Quote

3 hours ago, egret said:

I've currently got the following pulley diameters:

Water pump: 150mm
Alternator: 63mm
Crank: 115mm

 

Egret

Your water pump pully size is confusing me, are you sure about the water pump pully size? 

My water pump pully outside diameter is 5.25" (133.4mm), and both of my old surplus pumps are the same.

Crank outside diameter is 5.85" (148.6mm), and Alternator outside diameter is 2.55" (65mm)

So if your crank pully is smaller than mine it would rotate the water pump pully slower, and if water pump pully is bigger the pump itself would rotate even less.

[PeteStupps]

4 hours ago, aoie said:

Crank outside diameter is 5.85" (148.6mm), and Alternator outside diameter is 2.55" (65mm)

So if your crank pully is smaller than mine it would rotate the water pump pully slower, and if water pump pully is bigger the pump itself would rotate even less.

Evening. I'm pretty sure all MkIV engines have the larger crank pulley, to go with their larger journals. Egret has a mk3 engine so smaller pulley, but it looks to me like he's got a later large water pump.

My mk3 water pump is 4 and 1/8 inch OD or 105mm, as best I can measure it on the car.

I think you've got the right combination of pulley sizes for the mkIV but am no expert.

If you've tried various combinations of pumps and pump housings it seems more likely to be blocked passages somewhere, rather than the pump.

Going back to your other original question, EP Services in Wolverhampton rebuilt two pumps for me: one was an old removable-pulley type and the other was a newer non-serviceable one.

Random thought: your exhaust manifold or downpipe joint isn't blowing is it? That wouldn't help temperature. Sounds like a long standing problem so probably not

[egret]

16 hours ago, aoie said:

Egret

Your water pump pully size is confusing me, are you sure about the water pump pully size? 

My water pump pully outside diameter is 5.25" (133.4mm), and both of my old surplus pumps are the same.

Crank outside diameter is 5.85" (148.6mm), and Alternator outside diameter is 2.55" (65mm)

So if your crank pully is smaller than mine it would rotate the water pump pully slower, and if water pump pully is bigger the pump itself would rotate even less.

I'm certain to about +/- 1mm.  My car is very much a bitza (very easy to do with triumphs) so the water pump came off what I recall is 1500TC engine.  It's ran marginally hotter since the engine change but as I said above not enough to cause issues.  I'm currently waiting on my Dad to mill, drill and tap a hole* so I can mount a second temperature sensor in a new water pump housing.  When that's installed I'll have coolant temperature sensor logging and can decide how marginal the cooling actually is.

*He's currently finishing up a gear tooth cutting attachment for his lathe to make a replacement clock mainspring sprocket.  I'm fairly sure I'm the next job on the list...

[egret]

Some quick maths suggests that on a Mk3 & Mk4 the water pump is doing approx. 1.1 revs per crank revolution, and my mishmash of pulleys is causing 0.8 revs of water pump per crank revolution, or approximately 30% slower.  This would also explain why my belt is so tight.  The car's belt that is. I know exactly why mine is

[Nick Jones]

Provided the temperature doesn’t “run away” causing boiling over its probably not worth getting too hung up on.

Vitesse runs quite hot (95 - 100C) when running fast in hot conditions, but cools off when I back off. It also gets hot when labouring up Alps behind camper vans but cools off when I get past them and go a bit quicker. It’s never actually boiled over though it must have been close a few times!

[aoie]

Quote

8 hours ago, egret said:

  I'm currently waiting on my Dad to mill, drill and tap a hole* so I can mount a second temperature sensor in a new water pump housing.  When that's installed I'll have coolant temperature sensor logging and can decide how marginal the cooling actually is.

 

Egret

If you can find a Stanpart 134681 Thermostat housing cheap, you can drill and tap-it for temp sensor. The cast metal quality of the housing I have was pretty poor so needed to be careful drilling and tapping. Attached picture is sensor that feeds my microsquirt ECU. The location does place the sensor on the engine side of the thermostat which I like, some don't.

[aoie]

Thanks all for the feed back!

I now have some new options to try, specifically flushing the block with Citric acid mixture. 

In closing if anyone has an opinion on going to a smaller water pump pully, i would like to know your thoughts.

Andy

[egret]

Bearing in mind your water pump will vary in speed by the same factor as your rpms, i.e over 8 times faster at redline than idle, a small % increase in speed is unlikely to make any difference.  Your issue is most likely coming from poor flow (hopefully solved by the citric acid), or a short circuit.  I'd look at both of those as culprits for major temperature issues, pump speed will be the final few % of improvement you can search for when optimising it.  It also looks like your raidiator is fully shrouded, and I can't see if you have the shrouding boards in front of it, could this be limiting airflow?

Of course advancing your ignition can help, and taking off that pops and bang map will do wonders too 😜

[zetecspit]

14 hours ago, aoie said:

 

I now have some new options to try, specifically flushing the block with Citric acid mixture. 

 

I would not want the rad fitted when you are doing that. I did and my rad sprung a leak shortly after. You could probably rig a few gallon water container/bucket with a takeoff for the bottom rad hose, and feed the top hose in so it isn't pressurised. Getting the fluid hot is a good thing, every 10degreesC approx doubles the rate of reaction, so going from a nominat 20 to 80 will make things happen 60 times faster!

Worth bypassing the heater for that operation too.... except maybe a very short blast and then flush with clean water.

[aoie]

Quote

12 hours ago, zetecspit said:

I would not want the rad fitted when you are doing that. I did and my rad sprung a leak shortly after. You could probably rig a few gallon water container/bucket with a takeoff for the bottom rad hose, and feed the top hose in so it isn't pressurised. Getting the fluid hot is a good thing, every 10degreesC approx doubles the rate of reaction, so going from a nominat 20 to 80 will make things happen 60 times faster!

Worth bypassing the heater for that operation too.... except maybe a very short blast and then flush with clean water.

 

 

Forgot about the heater core, Thanks!

I have a spare heater from a 78 Spit, will take a look to see if it has an aluminum or copper core.

If heater core is copper, I may just leave it in for the flushing.

Already planned on using a sacrificial radiator for the flushing!