Rally Retirement
Discussion
Geoff Loos and I retired from the Carpetbagger Rally last weekend for an old reason we had probably forgotten about.
On a rather rought bit we hit a big bump with the result that the fan shroud, an early 2 piece one, moved relative to the fan and the fan blades and shroud stiffening flange all bent. This caused the fan/water pump pully to jam which then caused a broken fan belt. Thus 'game over'. The rubber grommet on the bracket allows up to about 1/8" deflection by the shroud.
On my car, and Geoff will now do this to his, I always mig weld the bottom of the shroud onto the radiator support bracket and then bolt this solidly onto the engine bracket. This has two advantages, the first as obvious on a rally car, and the second that it gives more clearance when fitting the fan belt. When fitting it may be necessary to shim up from the engine bracket and to get in to do this you need to cut away the inner wing at the lower edge. This helps with access to that area for changes of engine mounting as well.
On a rather rought bit we hit a big bump with the result that the fan shroud, an early 2 piece one, moved relative to the fan and the fan blades and shroud stiffening flange all bent. This caused the fan/water pump pully to jam which then caused a broken fan belt. Thus 'game over'. The rubber grommet on the bracket allows up to about 1/8" deflection by the shroud.
On my car, and Geoff will now do this to his, I always mig weld the bottom of the shroud onto the radiator support bracket and then bolt this solidly onto the engine bracket. This has two advantages, the first as obvious on a rally car, and the second that it gives more clearance when fitting the fan belt. When fitting it may be necessary to shim up from the engine bracket and to get in to do this you need to cut away the inner wing at the lower edge. This helps with access to that area for changes of engine mounting as well.
Shame 
Better luck next time peter
(oh and by the way sorry about not replying to ur mail yet its just my machine through a hissy fit so i formatted it along with ur mail)
Have you still got it if so can u re-send it?
Oh and do you actually make carbon parts peter or are you design?
Cheers
Better luck next time peter
(oh and by the way sorry about not replying to ur mail yet its just my machine through a hissy fit so i formatted it along with ur mail)
Have you still got it if so can u re-send it?
Oh and do you actually make carbon parts peter or are you design?
Cheers
Cooperman said:
Geoff Loos and I retired from the Carpetbagger Rally last weekend for an old reason we had probably forgotten about.
On a rather rought bit we hit a big bump with the result that the fan shroud, an early 2 piece one, moved relative to the fan and the fan blades and shroud stiffening flange all bent. This caused the fan/water pump pully to jam which then caused a broken fan belt. Thus 'game over'. The rubber grommet on the bracket allows up to about 1/8" deflection by the shroud.
On my car, and Geoff will now do this to his, I always mig weld the bottom of the shroud onto the radiator support bracket and then bolt this solidly onto the engine bracket. This has two advantages, the first as obvious on a rally car, and the second that it gives more clearance when fitting the fan belt. When fitting it may be necessary to shim up from the engine bracket and to get in to do this you need to cut away the inner wing at the lower edge. This helps with access to that area for changes of engine mounting as well.
my mind continues to boggle at the sheer amount of information about minis you hold in your brain. and I suspect we've only seen a small part of it!
and sorry to hear about your retirement in the rally - I had to retire once on a road rally and p1ssed off was just not adequate!
I guess a thin rad would be allowed, but I always wonder if the cooling is as good. Advice from experience would be good here.
Remember, on a proper rally car part of the rad could get a bit 'bunged up' with mud and reduce the cooling area. The problem we just had was really the 2 piece rad shroud. There is good and bad to using this set-up. The good is that you can change the fan without removing the rad or draining down. The bad is that you could have the problem we had. We were just unlucky that the joint of the two shroud pieces happened to be the point of minimum clearance and the bump moved the shroud & rad in the worst possible direction.
One point to remember if you feel that cropping the fan blades would be an answer. The Mini fan is what is known as a 'ducted fan'. With a ducted fan, the clearance between blade tip and shroud is quite critical in terms of air flow. Air flow is critical on a hot 1275 engine at the best of times, so I try to keep it to a minimum.
I once worked on the design of an aircraft wind tunnel. The diameter was 3 metres and the tip clearance for the huge fan was, wait for it, 3 mm to 5 mm. Any more than this and the efficiency dropped off rapidly. It amazed me, but the same logic applies to Mini fans and shrouds.
The answer is to set up the fan and shroud, then make sure that one cannot move relative to the other.
Off home now to get the engine of my 1292 'S' ready to go back in for my next event as a driver in Feb - The Gremlin Welsh Championship and Historic Championship qualifier.
Remember, on a proper rally car part of the rad could get a bit 'bunged up' with mud and reduce the cooling area. The problem we just had was really the 2 piece rad shroud. There is good and bad to using this set-up. The good is that you can change the fan without removing the rad or draining down. The bad is that you could have the problem we had. We were just unlucky that the joint of the two shroud pieces happened to be the point of minimum clearance and the bump moved the shroud & rad in the worst possible direction.
One point to remember if you feel that cropping the fan blades would be an answer. The Mini fan is what is known as a 'ducted fan'. With a ducted fan, the clearance between blade tip and shroud is quite critical in terms of air flow. Air flow is critical on a hot 1275 engine at the best of times, so I try to keep it to a minimum.
I once worked on the design of an aircraft wind tunnel. The diameter was 3 metres and the tip clearance for the huge fan was, wait for it, 3 mm to 5 mm. Any more than this and the efficiency dropped off rapidly. It amazed me, but the same logic applies to Mini fans and shrouds.
The answer is to set up the fan and shroud, then make sure that one cannot move relative to the other.
Off home now to get the engine of my 1292 'S' ready to go back in for my next event as a driver in Feb - The Gremlin Welsh Championship and Historic Championship qualifier.
I'm running a MiniSpares 2 core rad in mine at the moment. It seems to have made a difference, the car seems to warm up a little bit quicker (lower volume of water ??) and run cooler than it did. Apart from at track days it didn't really suffer from high temps on the standard rad. "Everone" says modified mini's run hot, but I never really had a problem on the standard rad, even in standing traffic in the summer. I do have the additional electric fan Rover fitted on the late model minis though......
I guess a rally car with a low diff, running full load most of the time for (relatively!!) low forward speed cooling can be a real issue !! This must be why MiniSpares still recommend the 4 core rad for grassers/autocross, that and greater volume of water again. Was this the car in the magazine feature a couple back Coop's ??
As for ducted fans, I'm about to modify the fans on my MGB V8. The fans fitted are the 4 blade yellow lucas jobbies, but completely unshrouded. Most of the "air" moved by the fan goes outwards rather than forwards, so I'm going to make a shroud out of......... a cut down plant pot just to see how much difference it makes.......
I guess a rally car with a low diff, running full load most of the time for (relatively!!) low forward speed cooling can be a real issue !! This must be why MiniSpares still recommend the 4 core rad for grassers/autocross, that and greater volume of water again. Was this the car in the magazine feature a couple back Coop's ??
As for ducted fans, I'm about to modify the fans on my MGB V8. The fans fitted are the 4 blade yellow lucas jobbies, but completely unshrouded. Most of the "air" moved by the fan goes outwards rather than forwards, so I'm going to make a shroud out of......... a cut down plant pot just to see how much difference it makes.......
I can't get the 'thick' 4-core rad into my 'S' as it is a Mk 1 with the metal frame on the inner wing carrying a rubber strip seal. I really have not had any problems with overheating since I fitted the additional electric fan.
It always seems with the modified 1275 and bigger engines that the temp is OK even on hot days until you go slowly or stop in traffic (or at the start of a special stage or test). Once the temp does go up, however, it is very hard to get it to come down again.
Yes, Phil, that was my car in the mag.
Your ducted fan idea for your 'B' seems a great idea and I love the thought of plant-pots as the ducts!
AS an aside, on my last rally the engine seemed down on power and was running very badly at low and mid range. I took it to pieces and could find nothing seriously wrong, but on starting to re-assemble last evening I found the twin pipe piece of the LCB to be badly damaged and squashed down to about 1/2 of its normal diameter just below the joint point. Now, this has never happened before, ever, and I think it may be due to the fact that for the first time I tried wrapping the lcb with a heat wrap tape. This, perhaps, caused the pipes to get too hot and bend/distort when I hit the exhaust over a bump (or two). I'm not going to heat wrap the new lcb.
Engine back in this weekend, I hope.
It always seems with the modified 1275 and bigger engines that the temp is OK even on hot days until you go slowly or stop in traffic (or at the start of a special stage or test). Once the temp does go up, however, it is very hard to get it to come down again.
Yes, Phil, that was my car in the mag.
Your ducted fan idea for your 'B' seems a great idea and I love the thought of plant-pots as the ducts!
AS an aside, on my last rally the engine seemed down on power and was running very badly at low and mid range. I took it to pieces and could find nothing seriously wrong, but on starting to re-assemble last evening I found the twin pipe piece of the LCB to be badly damaged and squashed down to about 1/2 of its normal diameter just below the joint point. Now, this has never happened before, ever, and I think it may be due to the fact that for the first time I tried wrapping the lcb with a heat wrap tape. This, perhaps, caused the pipes to get too hot and bend/distort when I hit the exhaust over a bump (or two). I'm not going to heat wrap the new lcb.
Engine back in this weekend, I hope.
Cooperman said:
I guess a thin rad would be allowed, but I always wonder if the cooling is as good. Advice from experience would be good here.
I can only comment on a road car installation. My uncle had a tuned turbo Metro lump (running a 45DHLA Dellorto from an Esprit Turbo no less!) It had serious difficulty geting rid of enough heat, even with the 4 core rad but he managed to fit a Mk2 Metro rad behind the grill which pretty much cured the overheating problems.
However, it was a tight fit and it wouldn't have taken much of a tap to push the rad into the distributor cap (the later mini's had distributorless ignition, so lots more room). Possibly not ideal for a rally car that going to get the odd stone thrown up.
I've always wondered if exhaust wrap was a good idea. The manifolds get plenty hot enough in open air; wrap them up in thermal insulation and they must be approaching melt-down.
The engines in a GTM Cox now, driving the proper wheels
(dons thermal exhaust bandage)Unfortunately we're not allowed an additional rad in Historic Rally Minis, only in post-Historic (i.e. 1968 onwards). I once did an Historic International event in Belgium where the outside air temp was 102 def F. I was in a 1071 'S' which does not get as hot as a 1275, but we had to run the heater full on to keep the temp down - and that was whilst wearing 2-layer Nomex racing overalls. I reckon I lost half a stone in 2 days. Worth it, we won our class and 8th overall.
As an additional rad on a road car, or a later rally car one can use a heater matrix. They will mount in the front and if you cut away the grille they mount next to the oil cooler. The heater matrix is much stronger than the radiator matrix as well.
As an additional rad on a road car, or a later rally car one can use a heater matrix. They will mount in the front and if you cut away the grille they mount next to the oil cooler. The heater matrix is much stronger than the radiator matrix as well.
Cooperman said:
.... we had to run the heater full on to keep the temp down - and that was whilst wearing 2-layer Nomex racing overalls. I reckon I lost half a stone in 2 days. Worth it, we won our class and 8th overall.
I was thinking about this, and, becasue I've removed the fresh air feed to the heater (got in the way of the rollcage front triangulation) I was thinking about re-ducting the in-car heater vent to blow the hot air out of the car in the offside wheelarch instead of into the car, giving me extra cooling capacity for little effort?
Cooperman said:
As an additional rad on a road car, or a later rally car one can use a heater matrix. They will mount in the front and if you cut away the grille they mount next to the oil cooler. The heater matrix is much stronger than the radiator matrix as well.
That's a bloody good idea - might give that a go when I get back to the mini...
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