Ok, the new pump, hoses, rad fan and other assorted goodies are in....

Notices something weird....

Car is cold.. not started....
Fill radiator
Start engine
drips appear on the radiator overflow after about 45 seconds
removing the rad cap sends a HEAP of water out of the cap.. its all COLD though....
topping it up while still running seems to allow the water to stay in there.....
its hot now and NOT spouting heaps of water out ???

Is there something weird I'm missing here ?

Car is facing slightly uphill as i fill the rad, NO heater so no real air-bubbles should be in the system, well, not big enough to spout out about 1 litre of water !

Ok.... I'm thinking its the rad cap at this stage, but wouldnt the symptoms also appear when HOT ?

weird.....
J

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Jim,
Do you have a thermostat in there? If not It may calm things down.

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Over 1,000,000Km, but now my retirement restoration project

Following is my experience. Fill rad until just under collar where cap sits, start engine.
Water rises and falls as block and/or heater fill, run engine without cap until warm (won't get hot 'cos no cap) When the water level has settled, fit cap and run until hot.
Then leave until much cooler and re-check water level. If you try and remove cap when hot it can be very dangerous. Water is under pressure and can exceed boiing point.
If you can't wait then wrap something baulky (an old towel ?) around the cap and release very very slowly I don't recommend this bit at all.
If there is no 'stat the water won't get as hot as it should, just keeps circulating.

Another thought. Did you rinse out your rad as part of the re-fit ? Also a back flush can help too.

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'98 Mpi Sportspack + 7 port alloy head

did you check the thermostat was working..
what temp (no real reaon just asking what you put in)

how did you clean out the water gallers in the block and Head
New pump and Hoses and no heater!
is the rad cap the correct length, and since does it still sturt out water or has it settle correctly

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Stop Licking the Dog...I Don't Care Who Started It

can you put the pump in backwards??

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1974 Moke - 998cc
76 Clubman B16a2 Vtec AWD Turbo 12.9@105mph
https://www.youtube.com/watch?v=V9PW49e1hYs

No

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Stop Licking the Dog...I Don't Care Who Started It

I hope you are using the short neck cap, not that long one that blew all the hoses and welch plug last time..

If you fill the tank fully it will blow 1/2 it out when it expands, so will be 1/2 full tank when cold. This is NORMAL. Clubbies have a level indacator in there 1/2 way up the tank.

I'd start and run until hot with cap off, then fit cap.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

ah probly a blown head gasket mate,,,give the car to me & be done with it

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

blown head gasket

Nah, it's a new 1275 gasket, BK450 with a just decked 1275 head. Pretty hard to blow these... unlike those POS smallbore ones...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

"blown head gasket"
its definitely NOT a blown head gasket.... I've seen enough of them, let me tell you !


Checked the tank was still full, brought it up to temp,
Took it out for a run and wasnt real gentle with it - got temp up to about 100' up a steep dirt hill - around 4 miles long....
started the downhill decent.. temp dropped to about 82' in about 3 minutes....

I'm guessing that MiniBob was right in this case... "Water rises and falls as block and/or heater fill,"

I'm guesstimating that my new 82' thermo was trapping a heap of air under it, and when i started the engine, the air expanded and pushed the water out on top of it... once the engine was up to temp and re-filled with water, there is no hassle.....

will re-check in the morning, but all is well in Brick-land....
(except that stupid 92 octane i HAD to fill up with during the 98 octane shortage....I'm in Ping City here....)

J

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Yep, whether it's a 74, 82 or 88C thermostat you need to run until thermostat opens (top tank gets hot), then top it up and fit cap. It'll just dump out what it doesn't need..

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

When filling cooling system for the first time after doing work I leave the radiator cap of and fill to near the top. When the thermostat opens you can add more if need be.
Turn engine off and allow to cool. If you have an overflow then when you check it again you can fill to the brim. If you don't have an overflow (expansion tank) then only fill to about an inch from the neck of the tank.
It will get hotter under load such as up a hill and when under no load of course it will really cool down fast, even closing the thermostat.

Yep, thanks guys.. confirming my thoughts....

I think it would have stayed cooler without that frikken detonation....

anything over 8Psi boost was just ping ping ping ..... it can usualy take 15-16 PSI when running 98 Octane.... so the detonation, combined with the days heat, (over 30' i think) didnt really scare it that much.....
Ok, I'll run it again tomorrow and see how it flys.... (see rocket-fuel thread)

J

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