52 replies to this topic

[Cooperman]

When I bought a new 998 Cooper I fitted a sump guard. Then I drove up the M1 at a steady 75 to 80 and within 20 miles the oil pressure at 4000 rpm had dropped to 30 psi and at tickover it was very low. that was just due to the oil getting too hot, so I fitted an oil cooler and the full pressure returned.

So, yes, hot oil will lose a lot of pressure. You need to know what the pressure is at given accurate temperatures.

I don't think you have any problems. What oil are you using?

[Dusky]

Hmm, sounds like the engine isn't comming out again too soon then ( im imagining the worst case scenario's).

Using champion actif defense until the engine is ran in ( already did +- 100 kilometers) then im going to use VR1 ( might even be solved with VR1 if champion is crap oil?)

 

cheers! Very gratefull for the advice!

[Cooperman]

That oil is not likely to hold the pressure up when hot in the way Valvoline VR1 will.

Change the oil NOW, plus the filter, maybe advance the timing very slightly, check the mixture to ensure it's not running too lean, then drive it around.

The oil pressure should be not less than 20 psi at 1000 rpm when fully warmed, then increasing by around 10 psi per 1000 rpm, so that at 4000 rpm it should be about 50 psi and at 5000 rpm expect 60 psi when fully warm. If you get these numbers you have no problems.

But also check the actual temperature by fitting a capilliary-type gauge as soon as possible.

I'm sure you have no problems, so don't worry.

[Dusky]

That oil is not likely to hold the pressure up when hot in the way Valvoline VR1 will.

Change the oil NOW, plus the filter, maybe advance the timing very slightly, check the mixture to ensure it's not running too lean, then drive it around.

The oil pressure should be not less than 20 psi at 1000 rpm when fully warmed, then increasing by around 10 psi per 1000 rpm, so that at 4000 rpm it should be about 50 psi and at 5000 rpm expect 60 psi when fully warm. If you get these numbers you have no problems.

But also check the actual temperature by fitting a capilliary-type gauge as soon as possible.

I'm sure you have no problems, so don't worry.

Thanks!

Ordered a timing light from simonbbc, when it arrives I'll change oil and set the timing correctly.

 

Out of intrest, do you know if there is a lot of difference between the cooling capacity of a 11 blade and a 4 blade fan?

I used the 4 when the car ran fine, but it got bent so swapped to my old 11 blade plastic fan.

 

Many thanks!

Diego

[Cooperman]

The 11-blade is normally fine for road going Minis of all engine sizes. The old 16-blade fan was dreadful as if you revved the car you got 'cascade effect', also known as 'discing', where the fan effectively becomes a solid disc and can flow no air at all.

IMHO the best fan for ultimate cooling is the 6-blade 'export' fan That is what I run on the 1310 cc rally 'S', but that is very low geared and revs a lot.

I'm sure you have covered this, but make absolutely sure the fan is on the correct way round. I once saw a BMC 'Works' mechanic fit a fan the wrong way round! It's so easy to do.

[Dusky]

Fan is on the right way :)

 

Hmm, given the fact that my engine only started overheating after I fetteled with the timing; ( so its retarded now), could that mean that I need a new ( high torque?) starter? ( couldn't start without jumpleads of another car when the engine ran fine).

Although I'm only at 10.3:1 compression . Don't know if starters lose power over time either? Might be a stupid thing..

 

cheers all :)

[Cooperman]

If the static timing is correct a standard starter is fine. I run a standard starter with my 1310 cc 'S' and that has a CR of 11.1:1. The problem you have is that there is insufficient mechanical advance in your distributor. I had that same issue with the 'S' and when the advance was set for max power at 6400 rpm it would not turn over. So Aldon re-curved a distributor (I have to run with points) and gave me an additional 4 degrees of mech advance with a slightly slower advance curve compared to their 'red' dizzy which I had been using and the difference was amazing.

Your overheating is because the engine is now running retarded so that it will start. Your distributor is the problem, not the cooling system

[nicklouse]

Fan is on the right way :)
 
Hmm, given the fact that my engine only started overheating after I fetteled with the timing; ( so its retarded now), could that mean that I need a new ( high torque?) starter? ( couldn't start without jumpleads of another car when the engine ran fine).
Although I'm only at 10.3:1 compression . Don't know if starters lose power over time either? Might be a stupid thing..
 
cheers all :)

This starter must be getting on for 30 years old. Has been on/in a dozen or so road cars and on this engine that has been in 3 race cars.

CR is nice and high and starting is never an issue.

As has been said. Sort your timing out. Don't worry about your fan until you have an idea what the actual water temp is rather than guessing. I used the standard plastic fans for years on a number of hot motors with no issues. But did change to a four blade metal fan on the last road car as I trashed the plastic one.

[Dusky]

Running aldon yellow distributor now, so will probably be okay to start ( not much more static than the standard dizzy).

Can't wait on the timing gun and (hopefully) drive the car if it wants to restart then. I've got a water temp gauge  wich should work now ( capilary tube)

 

cheers

[carbon]

Dusky - what grade of fuel are you using, and does the dizzy have vacuum advance?

 

I think Aldon Yellow has 12 deg of mechanical advance, with 99 octane fuel such as Shell V-Power you should be able to use up to 10 degrees of static advance but this really needs checked out properly on rolling road.

[Dusky]

98 ron fuel ( guess thats 98 octane), 10.3:1 comp and vac advance as it's going to be a little road car :)

Might try a different starter if mine would start nagging with the timing in the correct place.

 

cheers

[Cooperman]

It's not the starter motor, it's lack of sufficient advance in the distributor.

You need a distributor which will allow static advance which will allow the starter to do its job and which has enough available advance to get max power at the revs for which the cam is designed to do so.

The Aldon Yellow may not be right for your engine. An Aldon Red might well have what you need.

[Dusky]

It's not the starter motor, it's lack of sufficient advance in the distributor.

You need a distributor which will allow static advance which will allow the starter to do its job and which has enough available advance to get max power at the revs for which the cam is designed to do so.

The Aldon Yellow may not be right for your engine. An Aldon Red might well have what you need.

Ooh I always thought red would be worse as they tend to run more static advance?

This is how it sounds when I tried to crank with the unknown advance, but the engien ran good then

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[Cooperman]

The way the timing should be set is to start initially with a nominal advance for start-up. I normally use 5 to 7 degrees BTDC.

Then once the engine has been running for a bit I turn the distributor a bit to gain some advance and see if that improves it. Then, once it has run a bit it goes onto the rolling road where after getting the ignition approximately right the mixture is set and the carbs balanced (if 2 are fitted). Then a full power run is made to the rpm at which the fitted cam is meant to give max bhp. For example, with a 276 cam this will be 6100 rpm whilst a 286 will be 6400 rpm. The revs are held there by the dyno with throttles fully open and the distributor is 'swung' slowly until max power appears on the dyno read out. Mixtures is finally optimised, tickover set and it's done. The static timing is then whatever it turns out to be, but the correct distributor will still allow the engine to turn over on the starter, even when fully warm.

[KernowCooper]

Aldon red is Race only though they need more static as they only have 10degs of mechanical advance which would make Duskys problem worse, Lets see whats it saying the setting in now with the Aldon Yellow which has 24degs of Mechanical when the timing light arrives