Well now.. its been a few weeks and time for an update. So far the Imp has been reliable and not let us down but it has also been true to its English form and left a few little puddles about. I'll talk about them soon.
We took it on its first big road trip which was fun, although a bit noisy. I couldn't really cane it super fast on the hills because Kevin the cat had to come on the trip with us. It was a few days away to visit my parents so we cant just leave the kid at home...
The car did the trip with no hassles and returned an OK 35mpg, not bad considering its geared quite low, has had heaps of sitting on the spot being tuned and due to the constant annoying flat spot right off idle I had to accelerate faster then I'd normally bother in average driving. It certainly hoons along very very well although it has an exhaust boom right around 60mph, which is around 4000rpm thereabouts. It became a bit too tiresome however should be better now I have added a load of sound insulation on the back parcel shelf.
I am super impressed with the Datsun A12 engine!! Its really peppy and fun, very smooth (allowing for the annoying carb issues) and just works so well. I can totally see why they have such a cult following around the world. Everyone who chats to us about the car (and its ALOT of people.. its a right little magnet this car) think that the Datsun conversion makes so much sense. More often than not folk are full of praise for the Imps they knew, had, learned to drive in etc , except for the standard Imp engines reliability. This is a shame because I think the standard Imp engines are great however one must accept that they do need to be cared for a bit more than many owners obviously could be bothered. But the Datsun engine- first comments are usually " what a great swap- those are bomb proof engines " usually followed with the comment "it must be hard to get those engines now because all the ministock racers have got them all"...
Now these comments are quite possibly a Kiwi thing due to the love and admiration of the reliability we have here for Datsuns and other old Japanese cars. It would be interesting to see what the response would be in the UK? I know Datsuns sold well there but is there the same admiration for them?
So anyway.. the wee Imp ran well and got us to Blenheim and back. But before that big trip I wanted to sort a few things. One job was to build a cold air fed filter box and carb lid to let the engine suck on some cooler air rather then the super hot air floating about in the top of the engine bay, due to Imps not having the luxury of lots of cold air running through over the engine.
So I built a filter box, sized to take a modern Honda filter. I have made the box large enough to handle bigger pipes and the volume that might be needed when I plan to upgrade the induction. Box...
With filter in place...
This box fitted under the parcel shelf above the gearbox. Sort of out of the way and hidden but easy enough to get to. It was fed with a flexy alloy pipe from under the car. Another section of pipe headed backwards to a plenum/tophat thinggee I made for the carb...
It was all going so well I thought. I splashed some black paint on it all so it looked a bit neater...
Then I fitted the tophat to the carb. This is where things went a bit... tight. It seems that I had completely forgotten to measure how much room I had just above in front of the carb. Not enough it turns out
....
The engine lid wasn't able to go back in place! A few choice words that somewhat rhymed with duck along with a sentence that sounded quite similar to 'well you stupid punt' were uttered.
I then calmed down, realised that at least I have now got a filter box sorted for future upgrades and with that I removed the lot and refitted the previous air filter I made.
At least its winter so a bit of hot air cant hurt :-)
I did another couple of jobs before the trip. I swapped out the fuel gauge which wasn't reading correctly for a spare unit I had..
I was also fed up with trying to adjust the clutch. The slave cylinder fitted had a 7/8" (22mm) bore and being pushed by the standard Imp 5/8" (16mm) master cylinder, which happens to be the same size as what the Datsuns use. However- Datsuns use a smaller 17mm slave to get the correct amount of stroke at the slave. I wasn't getting enough stroke so the clutch pedal and release fork clearences had to be set very tight to clear the gears. But I did have a very light pedal...
So I worked out that the amount of stroke available from the Imp pedal, whilst being very close to that on a Datsun, was not quite enough I could get a good working system with a slave of around 3/4" (19mm). However- there didnt seem to be any slaves available out there that had the same mounting lugs, in 3/4" bore, with a metric fine hose thread.
But I did have some spare random 3/4" seals, some stainless bar for a new piston and a big lump of alloy. So I made a new slave cylinder to suit. I could have sleeved the existing one down and I have a 3/4" reamer to help but I wanted to keep that one intact in case it all went pear shaped. Plus...its more fun making things !
I offset machined the lump of alloy down in the 4 jaw, bored and reamed it to suit, milled the shape up and machined a new piston to suit. But I was having too much fun and forgot to take many photos..
New next to old...
It works heaps better! I can now have a bit of slack at the pedal and at the release bearing and still get my gears.
Another job was to take the carb apart for the 14th time. I'm getting very quick at this and can field strip a Hitachi 306 carb in under 15 seconds, blindfolded, with both hands tied behind my back, whilst under water breathing through a straw.
The carb had a few leaks. I realised that the top lid was pulled out of shape...
I carefully filed it and the body flat, cleaned it out again for the 10th time and made a new thicker gasket to suit...
On the next test drive the leaks had gone but I had still had not cured the flat spot. So I gave up and made a parcel shelf instead. I did have an original Imp one but it was a bit wobbly and a pain to fit. I made a new wooden one for the passenger side so now actually had somewhere to sit our phones, wallets, bag of Werthers originals, old parking tickets, a broken pen, out of date fuel vouchers and, most importantly, a screwdriver for constantly tweaking the carb settings.
Again, so much fun but no photos. I finished the shelf the morning we set to leave. We plonked Kevin the cat into the car and set off. A lovely trip was had with the only downer being that the cold I had caught at fire brigade practice a few days before was really kicking in to full runny nose time, while the weather was a bit... Wintery. Got to test the wipers out though (must fit intermittant control kit I have)
On the way over to Blenheim. You can spot Kevin.
I took my Dad out for a hoon in the car. He loved it and only complained about the wipers being in the way of his view. Not a car fault but more down to the fact he must only be about 4'5" tall now...
Back home and more recently things have happened. I weighed the car at the local tip...
750kg. The guy said the scales are within 10kg. So its in the ballpark for what I was guessing. A bit heavier then a standard Imp to be expected with a heavier engine, seats, exhaust, radiator and associated cowling, water pipes etc. But still light enough
I think standard Imps are around 700KG ?
More recently- one of the output shafts on the box leaks. I think it might be the shaft moving out just a touch too much on certain corners and the seal running off the land its meant to seal on. Or the seal land on the shaft is too worn. Or the new seal I had fitted has moved. The car will soon go on the hoist and I'll have a look. Cant really drive it until I sort this. Expensive stuff this oil- even more expensive if its loss means a buggered transmission.
In other news I have made a parcel shelf for the drivers side. Now I can stash all my own curse word within easy reach ..
I am going to make some speaker boxes to mount under the shelves alongside a headunit. At a later date when I can afford to do so I'll fit an Amp and sub. I do like my music and there is only so much of Datsun A12 at 4000 RPM booming I can cope with so I need to drown it out.
That is about all for now. Wish me luck with my seals...
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