coolant flow - (follow up to cooling diagram)

[missfixit70]

Blueprint part no was 59208, same as yours Steve.

[widdowson2008]

Blueprint part no was 59208, same as yours Steve.

Will be interesting to see how the disc can move relative to the main valve/stem before disc reaches shut-off position. Mechanically, it looks impossible. Not saying it doesn't - just curious to find out how it does it. Could prove informative. then again, the Bongo throws up some wierd anomolies from time to time.

[mikexgough]

I think.... and shoot me at dawn for suggesting............
That we should base the facts about the cooling system around the Mazda O.E Thermostat, I know a lot of work has been done with them and the opening/closing and it was based around the Blueprint one, but for the sake of this purpose and to keep it as close to "factory" as possible for the definative "How it works", it has to be the Mazda thermostat.
I think that after the weekends observations that this is the way to go.....
Link this together with factual Coolant information ..... then finally with how much the cooling fans really work and what parameters.... and the Cooling system will not be a myth or a legend anymore

[widdowson2008]

widdowson2008 great thread
can I ask what thermostat you are testing? it's just I replaced mine 20 months ago with a cheap one, anyway after 12 months I started to have boiling water coming out of the header tank. It started in April 09 and over the summer and up until Oct 09 I had 6 overheating / boiling water coming out of the header tank.
The last one being 100 miles from home, so on the side of the road I took the stat out cut the gubbings out of the middle and replaced the seal ring and drove home and like that for a month , Well with winter coming no heaters or antifreeze I fitted four silicon hoses, pink antifreeze and a new genuine Mazda thermostat fingers crossed six weeks later no problems .
So could it have been a cheap stat?
Just a thought and keep up the great thread.

PS boiling over after Bongo had been under load i.e. up hill or in traffic.

Looking back over this thread it appears that maxheadroom also goes along with the genuine Mazda stat. Whilst the Blueprint works OK, the genuine part would probably give greater peace of mind. I wonder how the new max stat is performing. I'll give him a nudge and find out.

[missfixit70]

He's in the middle of a head rebuild ATM I pmed him with the new info on the stat housing, mazda stat etc, in case it was useful during the rebuild, hadn't realised he already had a mazda stat in, think the damage had been done before that though.

[widdowson2008]

He's in the middle of a head rebuild ATM I pmed him with the new info on the stat housing, mazda stat etc, in case it was useful during the rebuild, hadn't realised he already had a mazda stat in, think the damage had been done before that though.

Head rebuild? What happened? Not cooling problems I hope.

[missfixit70]

Unfortunately so - http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=37983

[maxheadroom]

AS requested by steve hope they are of help

[maxheadroom]

[maxheadroom]

[widdowson2008]

Thanks Nic.
OK - this pic shows the external differences between the Mazda and Blueprint stats.
At the top end of the pic, on the spindle, there appears to be a black rubber seal thingy about 6mm diameter by 5mm long. This is NOT on the Blueprint version. What is this bit for? Without getting my hands on one to dissect, I can only hazzard a guess and that would be: (neck-out time again) That area is the only place on the stat where wax could leak out (which would cause malfunction).
On the Blueprint version, there is an internal seal between the spindle and the 'brass cylinder' part (I would also expect to see this on the Mazda version) but the external seal shown on the Mazda stat is not present on the Blueprint.
What does this mean? If I am correct in my assumption that this is an extra seal, it would mean greater sealing properties.

The other difference is (and this may be an optical illusion) the brass bit that butts up to the seal appears to be tapered (perhaps Max could confirm)
Again, no way of telling without getting my hands on one and butchering it. Anyone any thoughts?

Another point is that the Mazda stat has a number 'V....' stamped on the large brass bit nested within the larger of the springs (not on the Blueprint). Can you see the full number Nic? Could this relate to the volume of wax inside?

[Ian]

Steve, I have some genuine Mazda thermostats on order, give me a ring this time next week and I will donate one to the cause, and you can pull it apart etc etc......

[maxheadroom]

Steve, I have some genuine Mazda thermostats on order, give me a ring this time next week and I will donate one to the cause, and you can pull it apart etc etc......

Top Banana

[Ian]

Cheers, Maxcylinderheadroom

[widdowson2008]

Steve, I have some genuine Mazda thermostats on order, give me a ring this time next week and I will donate one to the cause, and you can pull it apart etc etc......

You are a scholar (or is that Skoller)