853 replies to this topic

[timmy850]

So an update on the double head gasket experiment:

For most of the time I've been struggling to get the timing under control I was having pinging at around 3000rpm. It was only at part throttle, the plugs were changed to cooler ones, the timing was reduced to 15 degrees, the fuel was on the rich side, I used 98 octane fuel and octane booster, removed the vacuum advance etc but it never cured the problem. I ended up with a strange inverted timing curve. (The base timing was set at 10 degrees, so all the advance numbers here have 10 extra on top)


Now I've got a proper shaped timing curve and the vacuum advance is hooked up too. At 3000rpm the advance is set to 25 degrees and it's been running really well. Idle is smoother than before, starting is good, no run-on, no pinging. In terms of performance it seems much the same, so possibly the extra timing has offset the lower compression


I've been out for a couple of drives to work and the carb tune is much the same as before. The needle still isn't perfect, the main issue is that it goes a bit rich under full throttle. It idles and cruises at a good mixture


I had moments where I thought I'd cured the coolant leak


However it's still leaking from the bottom hose! I've tried tightening the clamp when hot and that didn't help either


Overall the double head gasket has been a huge success, it's not a long term solution but it's given me an idea of how to get it running better in the future. I will need to investigate the best way forward:
Dish the pistons and/or open up the head to lower compression
Go to a longer duration camshaft to reduce effective compression
Change to a different head like a 12G295 which has bigger chambers
Drop back to a 998 crank

[sonscar]

I was taught to fit hose clamps close to the end of the pipe,you may be clamping too near the flare.Just my thoughts,Steve,

[timmy850]

Perhaps from the photo it's a bit hard to tell, but the hose goes on the radiator a fair distance, so the clamp is still away from the flare. I'd removed the radiator a few weeks ago, cleaned the radiator end (back to bare brass) and inside the hose and tightened the clamp up while it was out of the car. 

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[PoolGuy]

How tight is the hose on the radiator? I always like them to be a real bastard to fit, I've had some rubbish in the past that my 7 year old could push on. 

[KTS]

..is it a new hose ?  if the old one didn't leak then it's worth a close look at the inside of the hose to see if there's anything untoward going on

[timmy850]

How tight is the hose on the radiator? I always like them to be a real bastard to fit, I've had some rubbish in the past that my 7 year old could push on. 

 

 

..is it a new hose ?  if the old one didn't leak then it's worth a close look at the inside of the hose to see if there's anything untoward going on

 

The radiator is a C-ARA4442 Minispares "super 2 core" https://www.minispar.../C-ARA4442.aspx

The lower hose is a GRH240KEVLAR from here https://minisport.co...h-heater-outlet

I assume (as per most of their parts) that the Kevlar hose comes direct from Minispares. 

 

So up till August I was using my old radiator hose that never leaked. It's been on for maybe 8 years and the ends were starting to get a bit torn up from being on and off a few times. When I had the radiator out to check on the crank pulley I thought it would be a good idea to put in new radiator hoses. My normal supplier didn't have any in stock so I got this one from Minisport Australia (not connected to Minisport UK)

 

I installed the new hose the first time with the radiator out (after I cleaned the radiator outlet). I removed the radiator and hose and cleaned it again a second time with the same results. I did get the coolant leaks out of all 3 ends of the radiator hose, so I don’t know if this 1275 “Kevlar” hose is just a bit long for my setup, or maybe it’s a bit too stiff and not fitting the water pump and radiator ends properly. I’m still yet to decide what to do next. I might just get another hose or maybe take the radiator and hoses to a radiator shop and get them to pressure test it with the hoses on.

 

I found out much later that they sold Australian made hoses for small bore engines which are a bit shorter. However I couldn't find it the first time I was ordering as they didn't think to use the word "radiator" in their description of a radiator hose!

https://minisport.co...h-heater-outlet

[timmy850]

One thing I did when the head was off was I swapped the LH tappet cover. It used to have one with a breather canister on it, but when working on that side of the engine (getting the exhaust manifold on or off, getting to the radiator hose, getting to the fuel hose etc) it was a bit inconvenient to work around and a pain to line up and get the bolt in. Now it's got a plain one like the other side


Now it just has a single breather port on the flywheel housing & it's connected to the port on the carb. It has a decent suction from the carb which means all the crankcase vapours are burnt and stops the smell. I've also done an oil change and checked the tappet clearances and after a few more drives it appears the coolant leak has subsided for now. One slightly annoying thing was the clutch master cylinder extension sleeve started leaking from the O-ring and it's ruined the paint on the bulkhead already. I've now drained all the extra fluid with a syringe and removed the extension sleeve so I'll need to clean up and sort out the paint. The brake fluid also soaked up into the bulkhead insulation blanket and held it against the paint, so that needs a good clean out before I can use it again


On the weekend we had a small turnout for the MITG run to Thirlmere. We did about 200km and the new slightly lower compression hasn't harmed the performance at all, in fact I think the extra timing at lower RPM has improved it


My uncle let me know one of their neighbours was getting rid of some imperial sized tools, so I scooped these all up before they went to the tip.

[timmy850]

End of the year update:

In October we had a Minis in the Gong trip up through the Southern Highlands, morning tea stop at Moonacres in Robertson & had another nice lunch at Sutton Forest Inn. There was only a few minis along for the trip, but we had a nice smooth drive and not much traffic

 

I was happy with how well it’d been running, so for the past few months I’ve been driving it to work once or twice a week. It’s been nice to have it fire right up, idle smoothly and generally work like a car without any problems. I’ve also been happy with the mixtures on the HIF44 and I’ve taken out the O2 sensor for the moment. I think ultimately it's not quite as responsive and fast as with the Dellorto, but it is definitely "nicer" and easier to drive

 

 

On the middle December weekend we headed up to Warragamba Dam for the Mini Club Christmas picnic. There was a great turnout & we found some nice roads on the way there and back via Cobbity and The Oaks

 

 

 

 

 

 

 

On the way home I ended up with a few freebies, one being a disassembled remote gearbox and the other being a mystery rocker covered in masking tape. 

 

 

It turned out to be a chromed Aussie rocker cover

 

 

And a few months back I spotted a Maxrob on facebook marketplace for a super good deal. It's a mini boss & horn trim ring, unfortunately it must have been held together with sticky tape and needs a good polish. The trim ring I think will end up on my 15" wood rim (that I finished a year ago and still haven't fitted)

[timmy850]

I decided it was finally time to get the rear radius arms rebushed. The LH side has had a little bit of play for a while, and I'm due for a new set of tyres soon and prior to that I'd like to install my KAD rear camber/toe brackets to get the new tyres wearing correctly.

I'd previously worked out that I could remove the rear radius arms without removing the shocks (as I didn't want to have to remove the fuel tanks at this point in time) so this was the plan:
Remove radius arms
Get arms rebushed
Assemble using the KAD camber toe brackets
Get a 4 wheel alignment
Get some new tyres

Day 1 - I started on the LH side. Drums came off next, hub grease caps, hubs, brake backing plate, Hilo and cone, handbrake cables.

As this was the first time I'd attempted to remove any rear arms it took a while to work out the order (and attempt to work around things like the fuel pump which was in the way of the inner radius arm nut). Unfortunately one of the bolts into the subframe broke on the way out, but at least the pin was confirmed to be quite worn and pitted.

The bush inside the arm was also scored and worn

There were some good things, like how nice the subframe looked in a few spots like behind the cone.

Day 2 - After the struggle of the LH side I thought that the RH side would be a little easier as I'd worked out the disassembly order. I spent a long time trying to undo the inner radius arm nut as it was obscured by the brake line from the limiting valve to the RH softline. I ended up having to remove the short line to get access (after spending too much time trying to do it the "easy way"). Cleaning up the dirt in the wheel tub revealed the original red painted sound deadening, which was nice to see.

Day 3 - I cleaned up the arms as they had 60 years of solidified grease and dirt. I found some paint splotches on the bottom, which might be factory marks? The LH arm had a grey/orange colour and the RH arm had blue.

The RH arm was actually in decent condition considering I think it's the original. The rubber seals were also still soft and stretchy

Day 4 - At this point I'd come to terms with the fact I'd have to drop the subframe to repair the broken bolt. I removed the exhaust, fuel pump, brake line to the limiter valve. I started to wind the 4 front mount bolts in and out to try and make sure they weren't seized. Both long top bolts came out and looked really good. Both lower ones didn't come out as they started to get very tight. I did about an hour of winding them in and out while adding penetrating oil before I managed to get them all loose. The lower ones got wire brushed so they'd go in and out easily

Day 5 - I was expecting to come in, undo the 8 subframe bolts and lower it down.

I went to undo these rear bolts and realised that I couldn't access the bolts from the boot as the tanks were still installed. This was the one job I was trying to avoid

The flip top fuel caps I'd installed a few years ago were preventing me from taking the tanks out. I wasn't going to keep them long term as they leaked worse than the factory caps and they were starting to corrode. They were a firm press fit with a hammer so weren't going to come off easily.

I came up with a 2 jaw puller, a big tapping die and a washer

They ended up coming off smoothly with the puller. I will be going back to a normal screw on cap

Next up I removed the tanks. I had about 3/4 full in each tank, so I removed the RH tank and capped the hoses and removed it with all the fuel in it. The LH tank has the drain valve which pokes through the boot floor, so I drained it first and removed it too.

After an hour or so of petrol fumes and frustration I undid the 8 subframe bolts with little fuss and dropped down the subframe. It all looked fine with no surprises under the floor or on the subframe. Once slightly strange thing was one part of the floor was rubbing on the subframe

I took the subframe over to Justin and he was able to weld a nut onto the broken bolt and remove it!

Kev has also finished rebushing the arms

So where I'm up to now:
I'm considering getting the subframe sandblasted and painting it
The underside of the boot is covered in decades of dirt and grease, so I'm considering stripping it all back and seam sealing and undercoating.
The drums need a coat of paint
The rear brake lines need to be cleaned and may need to be replaced

[KTS]

typical mini maintenance mission creep 

 

something else to consider whilst you've got the tanks out now, is whether to cut access panels into the rear seat back so you can get to the shock absorber top nuts without having to take the tanks out in future

[Designer]

Hi,

 

 

something else to consider whilst you've got the tanks out now, is whether to cut access panels into the rear seat back so you can get to the shock absorber top nuts without having to take the tanks out in future

 

Now that is interesting in that not only has it been mentioned before but also from the point of view in a post about the electrification of a classic Mini on here the car was declared a right off because a couple of extra holes had been drilled in the body shell for the electric cables to pass through. The regulating authorities I believe would not allow the car back on the road even if the holes had been welded up and the cables rerouted somehow or even if it was returned to ICE power.

What is the difference between those holes and the holes you suggest are cut into the rear seat back? That panel bust be structural within the body shell's design.

Also a modification that would need to be mentioned to your insurance company I would have thought.

Two more reasons we are keeping the Moop as close to factory original as new parts allow.

 

Paddy

[timmy850]

Now I’ve removed the threaded collars off the fuel tanks it won’t be so bad in the future if I need to get to the shock top mounts. I’m also going to change to normal rubber hoses on the twin tank link pipe instead of the braided ones to give a bit more wiggle room and less chance of stabbing my fingers

[timmy850]

One step backwards but thankfully also one forwards!

I started to wire brush the subframe yesterday to remove the crusty paint & grease. After about 20 minutes of making mess unfortunately I found a rust hole



The inside had about an inch of dust and it’d corroded the inside of the subframe significantly. The captive nuts were half gone and all the inner metal was getting thin. It could probably be repaired with some time and a welder (and I’ve got neither)


I put out the call to a few local mini guys and Justin saved the day again. He had a spare dry subframe in his workshop and even dropped it off on his way home


This one seems much better than mine from the initial look at it, once the layer of dust is cleaned off there’s still a lot of factory paint.


It even has the factory stencilled paint markings on the front

Edited by timmy850, 20 January 2025 - 02:59 AM.

[timmy850]

The subframe cleaned up nicely and it had the factory stars and assembly number



The initial test fit was good too


One of those jobs "while you're there" was to change the taillight gaskets. I'd ordered these in 2018 but then realised I had to remove the fuel tanks to get the lamps out, so now was the perfect time. For some reason both taillights had all the wires cut and crimped back together, and one wire fell out of the crimp, so that was fixed up too. The foam gaskets were a bit rough and looked like they'd been torn rather than cut, but at least they aren't visible once fitted


After a few more evenings in the garage I finally had it back on the wheels. I used the stock radius arm brackets to get a baseline measurement on the toe to copy onto the KAD brackets, and then I used the trusty iphone level to get the camber about -0.5 degrees on both sides. This will get checked at a proper alignment shop, then I'm considering putting a roll pin in the brackets to lock in the toe. There's a lot of weight missing from the back so it was sitting a bit high


At this point I still needed to install the fuel tanks, fuel pump, exhaust and bleed the brakes. I started bleeding the brakes first


Bleeding the rear brakes means finding a 7mm spanner for the bleed nipple. I couldn't find one so this was my next option


After that was all done I finally got it pushed outside and the engine started right up once the fuel pump primed. I'd put the battery on to charge so it spun over nice and quick


I did a 30 minute drive to get some petrol and get the suspension to settle over some of the many pot holes on the back roads and it drove much the same as before, so the rear toe must be in a decent position. After that I gave it a much needed wash


The next thing I've been working on for a while was another set of seats. I bought these back in 2021 and had been trying to decide what to do with them, so I finally got some seat brackets to suit a mini. The original 850 seats look good and I replaced the lower trim piece with NOS trims from Mini King, but the upright sections are splitting apart


Most of the vertical folded sections have had the stitching come out, and they have stretched and torn in a few spots.


The top of the passenger one is also a bit torn at the top where it touches the windscreen when folded forwards. I'll keep the seats in storage to preserve them, and will try and track down some more trim to redo the upright sections


They fit in nicely and seemed comfy on the drive around the block. I've got a longer drive on next weekend to really try them out