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I'd just use a thermostat, or at least a thermostat plate with the gubbins lopped off.

 

I'd be wary about using an electric pump in tandem with the the mechanical pump as the flow of the mechanical pump will vary hugely with rpm and the electric pump won't so the system is unlikely to be happy over the whole operating range - or even much of it.

 

It may all be a red herring.  The engine is only around 20% efficient so much of the missing 80% will be heat generated.  As the engine is tuned to produce more power the heat the cooling system has to dissipate goes up proportionately.

 

Nick

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The orifice plate in the thermostat housing has a hole the same size as that in the thermostat, without the gubbins.     So it may provide less resistance to flow.  The obvious test is to replace the thermostat.

 

Ah, so!   CRANK pulleys are different!  Yes, they are!   I had been researching water pump,pulleys and I think they are all the same.    Doh!

A further development of this project will be electronic ignition and the present crank pulley has been extensively modified to provide a trigger wheel.    I'm not inclined to change it!

 

Electric/mechanical conflict.    I had considered removing the water pump unit from the housing, closing the gap with a plate and relying on the electric pump, but this would mean that the 'fan belt' now only drove the alternator.    The arc of adjustment of that had a tiny 'sweet spot' in that mode, so very easy to lose tension.  Might not be a problem!   The battery won't go flat in a twenty minute race, but I do use the car on the road as well!  Maybe grind off the vanes from the rotor and leave it as a housing and conduit with an idler attached.

 

Thanks again for your continued interest and advice in this problem.

John

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YES!  I have the larger pulley fitted, AND I have some of the smaller ones.

In fact I have one set that has both large AND small fitted to the same damper!   I suspect the second is for a steering pump.

 

So, hmmmmmmmmmmmm!   Can I refit the smaller pulley?

Thank you, Nick, it IS good to talk!

John

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Of course I can;  it's just that it will require the project to be changed.

 

I had used a large pulley/damper to which I had fitted a trigger wheel,  and a sensor to use it, with the intention of moving to MegaJolt once the engine was running well.    "Change one thing at a time".

Because there is so little space in front of the Vitesse engine, I had used a very nice galvanised steel wheel that bolts to the back of the damper.

I got from a member, here or CT, can't remember now (Sorry!) who had a batch done by laser cutting.

It was a tricky procedure to centre and secure it, and anyway, the smaller pulley also has a smaller damper disc, so this wheel will overhang by a lot, which would make reading the crank timing difficult.    The actual rubber damper rings are the same diameter.

See pics below.

 

The larger one I used was  a NEW one I obtained, when every other had forty years of use in them.

So, I was loathe to change it, and undo all that previous work.

BUT, I'm not ready to fit MegaJolt, and neither is the engine, so let's change course, and risk using an old damper, to get the smaller pulley.

 

Thanks for the advice!

John

 

PS Which engines had the big and small dampers?    The obvious answer must be 2.5 and 2 litre respectively.  Anyone know for sure?

 

 

post-690-0-88043500-1438534402_thumb.jpg

Edited by JohnD

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Big dampers are 2.5 - I had to embiggen mine when I fitted a 2500 crank to my GT6. And change the timing cover, as the 2L's timing pointer fouled the larger 2.5 damper-pulley.

 

I had my 2.5 damper's rubber ring replaced too, as I didn't trust 40 year old rubber.

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Doh!  Of course, you are in Oz!

I fear that the postage both ways for a massive damper pulley would be also massive.

But please ask?

The alternative would be a "Rattler" which are available from about £400.

JOhn 

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I've asked Terry at Road and Track, who machined my engine. He says that the company he's used for 30 years won't do them commercially any more, but one of their retired guys goes back to the vulcanising plant and does them as a part-time task. If we can get a damper-pulley or two to Road and Track in Ipswich (QLD not UK!) they can organise the re-rubbering.

 

Anyone else interested in a new rubber ring (ohh err)?

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Thank you, V8 Nick!

For the record, I've just weighed some dampers.

A small pulley one weighs 1590 gms and a large pulley one 1980, so lets say 2kg with packaging.

 

I thought to offer to collect any dampers that people in the UK wanted 'redoing', with the thought that posting several at once would be cheaper.

In fact, the Good Old Post Office with its usual devotion to logic would charge £25 to take one to Oz, and £146 to take 4!

 

How much would the Retired Guy charge to do this?

No offence, but before we start this round the world gig, I should try to find out if anyone in the UK can do it, and how much.

John

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Postal charge from Germany to OZ is 42 Euro (30 GBP) for 5kg and 59 Euro (42 GBP) for 10 kg.

Cheapest postal charge back is 70 AUD for 20kg via Sea Mail.

But I haven´t yet found companies that would re rubber these pulleys here in Germany. 

Martin

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Back to keeping things cool.

 

I've dismantled the whole of the front of the engine, to fit a timing cover with the timing indicator nearer the narrower damper that goes with the narrower pulley.

I've fitted the thermostat, with as advised by Davis-Craig, two 5mm drilled holes in it.

Also as advised by D-C, I've 'disabled' the mechanical water pump,  To retain the water pump pulley as an idler, I ground off all the vanes on the pump rotor, and as much of the rotor boss as I dared.

Now, with the smaller crank pulley, I cannot get the 'fan' - now solely alternator - belt to tighten, and I cannot find a belt that isn't either too short or too long.  It's not the OE alternator, but a more powerful one, with a 64mm diameter pulley.

So, I've trying to find a larger alternator pulley, that will also make that run more slowly, no bad thing at high revs.   But from my small stock of three on other alts, one is too wide, and the other is for a narrower alternator shaft.

A search of eBay and Amazon found no simple bolt-ons and very few that might be suitable with a little machining.  So I've crossed fingers and ordered one of those.  81mm wide!   That should slow it down, and open up a whole new bag of ferrets in belt sizes.

 

I must remember to run some radiator cleaner through the cooling system when it's all back together - even with strong (too strong) antifreeze/corrosion inhibitor in there, the coolant came out mucky.

And give some more thought to timing - overheating might be caused by it being more retarded than I thought - that takes us back to the damper, and the rubber having let go, so the timing marks are out of position

I've checked again with the 'new' smaller pulley/damper, and as well as I can say, without having the head off, this damper is accurate.

 

Ain't old cars fun?

John

Edited by JohnD

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Thanks, esxefi!     Could do that, just spent several days, on and off, building a Megajolt timing wheel sensor bracket -  I could make one to hold that idler.

But not sure without some thought (more days?) where I could fit it!

And I've 'disabled' the pump now.   Decisions, decisions!

 

Spit131,

Great minds and all that - that's the Online Shop I've ordered from!

 

Parts should be with me tomorrow.  Back in the garage, out the hair of 'er indoors!

 

John

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Hi Chaps,

there is a company in New Zealand (keeping it in Her Majesty's Commonwealth) that does dampers....

http://damperdudenz.tripod.com/.

 I asked for a quote 2 years ago but I can't find it now. (Think the wife has an "auto delete sub-routine" running on my computer to remove car related emails over $10!!!!!!) It was horrifically expensive..... What figure comes to your mind V8Nick?

 

Cheers,

Doug

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I think it was a coupla hundred - I'm not home so can't check the figures. Terry's asking the company that does / did them how much the next batch will cost.

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Started the engine this am - and it rapidly brewed up!

Blowing water and bubbles into the header tank, and out through the overflow line.   Oh, blagger.

It all drained back into the radiator, and after cooling down, lots of space in the radiator for a refill.  

 

I hope, may have been due to air trapped in the system - the radiator filler is lower than the thermostat housing.

I'll circulate with the electric pump more before starting next time.

Does radiator cleaner  produce gas?    As what drained before the revision was rather mucky antifreeze, I refilled with cleaner, and will drain that after a test drive.    But if the reactions do produce gas, like CO2 from lime scale and acid (cleaner isn't acid, I think) then maybe it has done that now.

Anyway, cross fingers for tomorrow.

 

John

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Tried again, after carefully excluding as much air as possible from the system.

Warmed up without the rad cap.  Some bubbles rose and burst, topped up, and went for a test run.

Temperatures stayed in normal range, but then it did before on the road!

Tried running one gear down from normal to use more revs, but can't use race speeds on the public road.

The rad cleaner came out just cloudy, so another water change, and some antifreeze, more dilute than a before.

 

Also changed the oil after it had over heated, and Im goodfor another test day.

 

Thanks for all the helpful discussion!

JOhn

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Same behaviour, after draining the plain water flush and replacing with 20% antifreeze/anticorrosion.

This time it blew off a hose, which points to air trapped in the system, so after refilling I ran up to working temp with the rad cap off, an agaon saw many bubble rise and burst,

Then with cap on it behaves.

I blame this on fitting the thermostat!  It never did this before, and even adding the D-C pump hasn't changed the cooling system layout.  Even with two 5 mm holes, as recommended by Davis-Craig, surface tension makes it roo difficult to flush air around the system and out to the rad.

 

John

 

PS I note esxefi's comments in the parallel Vitesse water pump thread.     This one runs in the plumb normal range on the road.    Another race speed test is required to know if the mods are sufficient..

Edited by JohnD

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Have you thought of using a 1500 MG Midget thermostat housing? It's got a "fill" hole right at the top and is useful for bleeding air out the system. It's also got a c.15 mm "tap-able" blank hole in the side which could be useful for a radiator fan switch. It's a direct replacement for the Triumph version. 

 

Mike

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Thank you, Mike!

But if you look at my set-up (post 2) I have a fabricated housing, necessary because of the connector lay-out of my Honda radiator.

A reversed MG housing would be very like a Spitfire/Herald  one, and would foul the Pi idle screw.

 

BUT, the idea of a bleed vent is one I had been toying with, except that headroom above the housing is minimal - I had to slope the welded top plate to clear the bonnet!

There might be room to insert a bleed screw on the side at the back left, or else in the connector between the straight and U-shaped hoses.

I think I might go for the second, but headroom is also minimal there.  A very flat drilled and threaded ring, welded in, plus a flatter-headed bolt or slotted grub screw, might do it, and I do know a TiG welder, as the connector is in aluminium.

OR, a ring drilled twice, so that the vent came out forwards?  Hmmm.  Needs thought and measurement.

  Thanks again for the inspiration!

 

For the moment, I think I'm OK, but a track test, I hope this week, will tell.

JOhn

Edited by JohnD

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