Hrm that doesn't make me a happy camper.

I've got one of the metal fans on with 16(?) fins. Are the plastic ones better?

Can you visually identify a 2/3 core radiator from the outside?


dewey

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dwightgunning.com

Fix low oil pressure quick!

Doc... wouldn't you expect a newly assembled donk to run a little hot? Not sure how many miles has been put on it whilst Dewey was off boarding.

The bores and rings are probably tight, the coolant system needs a flush prolly.....but most of all, shouldn't you get some miles onto a new engine before doing anything too drastic as far as major cooling system mods etc....is that right?

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"Show me the Mini!"

Shouldn't run that hot.. something is wrong, maybe ign too retarded?

16 blade metal fan OK, that's all I run.
You can look in the rad and see how many rows of cores it's got, usually.

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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.

.....yeah....or the twin 1.5s are really leaned off....not just at the top end!

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"Show me the Mini!"

The thing I like about the plastic fans comes when I need to pull the raditor out of the roundy (without pulling out the motor). You can move the blades a bit when pulling the shrouds off. Every little bit helps.

I would say check the water flow. Something is definately wrong

Check for obstructions in the water pump inlet. I've seen clumps of lead (solder) from the radiator lodge there (hi John )

Is it back on the coast? Can I come take a look?

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"Life is not like a box of chocolates... it's more like a jar of jalapenos. Whatever you do today, may burn your arse tomorrow."

The new engine has done ~200mi.

When we first kicked it over it took quite a while to get oil pressure. We primed the pump using a syringe of oil and a tube connected over the relief valve opening. It probably took about 60 seconds running the starter motor with no plugs in the engine before the pressure came up. After that we had about 75psi with the engine running using a workshop guage rather than my Smiths. I can't remember if the guage was reading lower when we connected it back up -- that was the 27th december. When we first fired it up yesterday the smiths guage was reading about 50psi and then as it warmed up gradually dropped down to abouut 30psi I reckon. Perhaps its just the guage reading low? I might be able to hook up another test guage to it in the near future.

Single SU too.

Zizzle, my number is 0402917935... maybe this arvo or tomoz would be good.

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dwightgunning.com

If he has put a 9/16" ball in the relief valve, instead of the plunger, the spring can push it sideways off the seat when pressure builds up. Then it doesn't seal, so pressure drops.
Pull it out for a look. If there's a ball in there, cut a piece of 5/16" (8mm) rod 40mm long. Put this inside the spring to keep it straight, and the problem will go away.

If it still has the standard valve plunger, I'd say it is getting stuck. I'd swap it for a 9/16" ball as above. Cut about 4mm off the spring to keep pressure the same (60-70psi).

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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.

I just searched for some background on the 9/16th ball bearing. Sounds like a good idea... are there any 9/16th bearings on the mini that I can salvage for the shed or do I need to visit my friendly bearing guy as you suggested you did in another thread?


<edit> And also, would cutting the head off a 5/16th screw suffice for for the rod that keeps the spring true?

dewey

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Outer C/V balls are 9/16"... but I'd go buy a NEW one at the bearing place, they all keep them!

You want a straight piece of 5/16" or 8mm rod. No threads on it. You could cut up a long bolt, make sure it fits inside the spring first!

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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.

I just did the 9/16" ball bearing & 40mm 5/8th rod trick. I cut the spring back to 70mm (it was 73 at rest) and the car still idles at 50psi when you first start it. Drops a fraction as the engine warms up and sits on about 40-45 after cruising for 10 minutes or so. Didn't drop far on idle when I put it back in the garage with the car still warm.

With regard to the temperature, it runs on perfect temp while the car is moving... even pretty slowly. When I stop it starts to creep up. I think its getting a bit better. I turned it off with the guage just a fraction above 1/2 way... and with no fan on the radiator it went up to just over 3/4 before the engine started to cool down.

I haven't driven it out in traffic since I got it home from lismore. You guys have me sketched out about it!!!


My plan of attack is:
(1) Get the dellorto on it so it should run with a better fuel mixture.
(2) Buy a workshop oil pressure guage and get an accurate reading. I've got my fingers crossed that my guage is just reading low.
(3) Drive it in some more and see how the temp goes. Am I likely to crack the head if the temp goes to 3/4 at a set of lights??? I've got an overflow bottle and high pressure cap on the radiator so I should lose the fluid.

I must say, aside from these little niggles that mean I can't really get out and enjoy the thing yet... I'm loving the sound, the torque and the precise shifting with the reco'd gearbox!!!


dewey

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If you don't have an oil cooler you might notice pressure drops a bit after freeway running. But it comes back..

No you won't crack the head unless it boils and runs out of water. Then maybe, but probably not.

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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.

So I should chill out a bit and enjoy the thing?

I went for a longer drive this arvo and the temp wasn't such a problem. Still creeping up a little at the lights but didn't have to take too much evasive action. I ran the car pretty conservatively for about 15 minutes on the road, stopping a few times at lights but I didn't cop any long waits for an entire sequence to go through. The temp was no real problem when stopping for 2-3 minutes so I was becoming a bit more confident. Oil pressure was steady at a shade below the 50psi marking. Then I gave the car a bit of a poke coming through a medium left hand corner, trying to get the cam to kick in with dad in the car (I was picking him up from work cause his Harley is off the road). After the corner I burned along at 50mph for about 1km and then when I got off the gas for a set of lights, the oil pressure made a definite drop towards the 25 marking. I drove it straight home, no more than 5 minutes after that. Little concerned. I'll try for a longer run tomorrow and see how it goes.

I've noticed some oil is still coming up through the breather hoses as well. I think I'll chuck them into a milk bottle with some holes punched into it as you suggested. I've been noticing a few interesting smells and I wouldn't be surprised if the oil is coming out of the breathers onto the manifold.

dewey

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dwightgunning.com

I really think you should take a deep breath and plan a long run without lights where you can vary your revs/speed up and down.....do not let it "lug" ....changedown early (don't over rev...be gentle and smooth)...try to drive off the torque curve rather than the power curve!!!

If it dosn't "free up" or "come good" after say 500 odd miles maybe further investigation is warranted.

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"Show me the Mini!"

It's normal for oil pressure to drop at idle when hot. Should have a bit more than 50psi max though- most Minis had 60 or so. Coopers had 70. Maybe the spring is now a bit short!
If you want to increase it, put a small washer or two inside the 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.

I just went for a bit longer run this morning through traffic. The 1275 is definitely more fun

The oil pressure was fine for about 15 minutes until I got a pretty long traffic light and the temp went up to about 3/4. As the temp creeps up the oil pressure creeps down. As soon as I drive away the temp drops but the oil pressure stays a little lower. I've come to the conclusion that the oil is thinning right out when the temperature goes up and then the oil is retaining that heat (since I don't have an oil cooler) and staying quite thin.

Make sense?


dewey

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