1965 Hillman Imp with Honda Goldwing flat 6. Chasing sounds - new exhaust box time...

[911hillclimber]

I don't recall my mates Imps having reflectors in the tail lights, not sure either if it was a UK requirement back in the day, probably wrong!

Where are you with the Hyper-Car engine now?

[yoeddynz]

I need to order a replacement clutch concentric slave cylinder (at double the price they are in the uk... ) and I'll order a higher temp thermostat too. I'll possibly pop the sump off and have a look at how the oil pump chains have settled in.

I also want to machine a new pulley for my TB. Even more offset to gear down the first bit of throttle action for smoother, easier action in town.

[Hugo 356]

Mentioned in Autocar dispatches and a suggested engine succession plan

https://www.autocar.co.uk/opinion/new-c ... n-have-fun

[yoeddynz]

Cool. Yeah I had seen that bike on other websites earlier this year. I can see those engines making their way into small cars

[yoeddynz]

I've been whittling away on various things I wanted to repair or upgrade on the Honda engine before re-fitting it.

First thing was the throttle body pulley. Even thought its an off centre progressive design its not progressive enough. So I made another and offset the centre hole a further 10mm.



I had to slot the cable outer barrel adjuster bracket further to align the cable entry.



I then popped the engine onto the big wheely table. Easy as because I made the engine stand the same height as the table and work benches..



Remember the nice alloy garnishes Id machined to fit on the cam covers where there used to be plastic badges. They looked lovely.

For a while.

Because on about the 2nd drive the double sided tape decided it didn't like heat and they both fell off onto the road not far from us. I did manage to locate one of them but it had been driven over a few times and looked a bit sad...



So I had to machine up some new ones...



This time round I painted them alloy silver and then sanded off the tops. They just looked nicer for it. I then glued them in place using some Sikaflex. I don't think they'll fall off now.



In place..



Next job was the one I deemed most important.

I discovered upon stripping the engine 4 years ago that they don't have very large crankshaft thrust bearings. They dot really need to because there's no clutch forces exerted upon the crank, the clutch unit being on a separate layshaft. It was something I had never thought about before getting the engine and its played on my mind the whole time. I consider it the weakest link. I may well totally be a non-issue but I'd rather see if there was a way I could help it last.

There's about .006" of thrust movement stock - measured as such...



I had thought it out and came up with a simple solution involving some expensive, hard, slippery engineering plastic designed for high heat. This was sandwiched between the rear engine plate and the back of the flywheel and had just a few thou clearance so being a backup thrust bearing when the clutch is pressed.

Help share the load I thought.

The plastic thought different. I knew it had decided to leave the party early because I could see its melted edges through the bellhousing drain hole. But how bad it was I wouldn't know until I removed the flywheel..



lol...



Ha. So that didn't work as expected then.

Version 2 time

I've been thinking about this a while. I looked into very large, thin section thrust bearings. Found an ideal item in the UK but it was 1300 quid.

Back to my drawing board. I came up with an idea that uses $10 bearings. I needed a big chunk of alloy to machine up. Local alloy stockist no longer sells 16mm alloy sheet cut to size. They want to sell me a square metre.

I went to a Nelson based fabrication outfit that has a water jet and the nice fella gave me a bloody large section of 20mm alloy. I only barely fit into the frunk of my imp (so improving the handling no doubt..)

Cut it to size in the trusty table saw that has amazed me..



Into the lathe where I created a massive amount of swarf.



Milled out some slots..



Drilled some holes. Very critical this one! They had to be bang on.



Machined up some tiny pointy domed sleeves for the bearings..



Assembled it (notice I'd even got out my surface table for marking duties)



I shimmed it out, testing and measuring until I had about .005" thrust. Just enough so it'll only touch when the clutch is pressed in.

Finally in place...



The other main job to do was sort out the reason why I had ended up removing the flat six in the first place. That leaking clutch slave cylinder. Even though I had made an alloy plate to support the mounting face it was not burly enough. This coupled with the fact that I had already burst the slave cylinder previous and its was never squished back together as neatly as it could be.

So I reluctantly shook the moths out of my wallet and bought a brand new slave cylinder.

I than machined down the mounting points I'd added to the Subaru transmission to allow for a steel clamping plate.





I don't expect to have any issues with it now !

I then flipped the engine on its end and gave it a clean around the head gasket seam on the oil return galleries.



Its always weeped a tiny amount of oil on both sides at these points...



Not enough to drip but enough to slowly make a mess and run down the sides. Not very easy to clean and seal with the engine in the car. Now's my chance. I masked the areas..



Then another Sikaflex product was used..



Sealed up..



I'll see how it goes.

Another job that I decided to leave was cleaning up the window on the Mandolorian spaceship.

Now that's not something you'll hear many mechanics say But its getting a bit oily inside from general fumes, as I expected it might. I undid the machine screws holding it down but it wasn't going to lift off easily. The foam seal has stuck it in place. I knew if I forced it would crack. Maybe a job for another day. ot important now. At least they are still visible and the leds still light it up nicely.

Exhaust box had one baffle that was vibrating at idle. Very annoying. So took it apart and fixed it.



Gearbox mounts were knocking the subframe so I gave them a tickle with the cutoff wheel and welded them back up.



The gear linkage rod linear plastic bush is something I want to improve in the future with a proper linear bearing and some seals. But for now it got a clean and some grease.



I also installed a hotter thermostat. Up from 82c to 88c.

So with these jobs done and the weather forecast of two days of rain I set about removing the Datsun engine. I timed myself and it took about an hour because the rear valance has to be removed.



swapped the driveshafts across. About 45 minutes because bearings need to be swapped too. I might get some new bearings so both axle sets have their own.

Then bolted the Honda in place. This took 15 minutes. Smug faced me then realised I'd forgotten to attach the first part of the gear shift shaft. Whoops. Back out, fit shaft, back in.

Plugged everything up and went for a starter turn to build up oil pressure. But starter kept blowing the 10amp solenoid fuse (I'm so glad I actually made a circuit just for the solenoid now!)

I'm not sure what was happening but I took the starter out stripped it, cleaned it, pondered it, reassembled it and it then worked fine.

Now a engine turn over.

Whir whiiiiiir whiiiiir whiiiiir.

Something wasn't right. It should turn over quicker than that! Took the engine out again. Removed the box. Engine was hard to turn over. Removed clutch and flywheel to discover that the clutch bolts were just protruding through enough to rub the alloy thrust bearing 2000 plate. Whoops. So I clearanced the plate, flap disked the protruding bolts down. Reassembled and all good.

Bolted the lot back in, tested the starter and this time its turned over fine. With the clutch bled, the fuel lines etc attached I started the engine. It started up mint just like it was running yesterday.

Tested the clutch. The thrust bearing 2000 rollers made a sound not unlike a noisy clutch release bearing and initially I was thinking 'well that won't do!' but they soon settled in. Still a noise but I know what it is and why its there. Better then potentially wearing away the crank thrust bearing

So with the engine all back together and in place...





So we went for a drive.

Coolant still doesn't get as hot as I'd like to see but it could be that the pump controller had reset to the default so I'll have a play there. Otherwise get an even hotter thermostat.

The engine runs fine. The new throttle body pulley makes for much easier driving off from standstill and smoother when crawling through our local village with the many speed humps.

But the fumes from the exhaust getting sucked into the cabin when we lower a window is terrible. Its the number one fault now. I have tried blocking off the through flow vents sited just above the rear window but its not fixed it. The gearstick base plate has a gap - could it be possible there's a low pressure zone under the car and the gas can creep forwards along the tunnel and enter there?

I'm going to design and make a new exhaust muffler setup. I'm still not happy with the exhaust sound and low rpm, it still drones and only really sounds like a flat six when above 3500rpm.

I know these Goldwing engines can sound much better. More Porsche. Less Cifero.

Possible benefit will be less fumes if I go side exit exhaust. The Datsun has a side exit and its much better with regards to fumage.

I'm also not entirely happy with the look of my current exhaust box either.



So I have taken some measurements and will start doing some design sketches along with more research.

[911hillclimber]

Snagging can be a pain, and those fumes are the worst as it 'gets to you' all the time.

All progress though, so soon all done.

Happy Xmas down -under !

[yoeddynz]

Thanks man. Happy xmas back.

I'll sort the fumage out in time. New exhaust muffler build I'm excited about as for ever chasing the idea flat six sounds

[yoeddynz]

Because I'm such a hardcore party animal on new years eve here I am doing an update.

The imp needs more fresh air via face vents. See this grill here..



Removed there's this...



Air inlet for main ventilation system is here in the left..



I wanted more air. So on this side here...



I cut a hole..



Filed it smooth, painted the edges and moved on up to the passenger side bulkhead where another hole appeared..



From the inside, once cleaned up, matching hole in bulkhead cover and fire extinguisher moved below the shelf..



I'll connect these holes with more 2" alloy flexy tube and create some sort of scoop/nasa style duct to help channel air at entry point.

Moving to the back. I have never really fully clicked with the look of the all black leather covered rear bulkhead garnish that I'd made to hide the access cover above the engine. Its a bit too much black which makes the bay feel smaller and darker..



So I removed the lower half of the leather right below the bottom alloy strip...



It was stuck on harder than I expected. Then spent ages cleaning off the contact adhesive residue left..



Prepped it for paint, masked it up and set up the paint shop..



Sprayed lots of blue about with most of it hitting the target and leaving my characteristically custom 'leather pattern paint finish.tm' .....



Once set hard enough enthusiastic me could remove the masking tape and fit it in place. It looks much better me thinks! ...





There's a side panel I want to make next to tidy up the drivers side inner bay and I'll be pretty happy with the bay then.

[PeterK]

A small change but a world of difference. I’m surprised by how much better that blue looks.

HNY

[911hillclimber]

Agree!
Looks smart and a 'wire-free-zone', always tricky to do.
Will you add a small electric in-line blower to the cabin ventilation like used in caravan systems, otherwise, hot going slow, cool going fast?

Your wife might thank you!

[sladey]

Looks much better

[yoeddynz]

I might add a tiny inline fan if I can find one. There's one on the other side. If it gets hot then hannah can drive and I'll sweat it out in the hot seat.

Or we'll just go to a beach instead.

Happy New year (well for 7 hours of the world so far..)

[yoeddynz]

Still been clocking up the miles on this and its been great fun.

almost 2 months since last update. been doing summery things and Hannahs mum has been here the last month so holiday mode all round. As I'd mentioned in the last post there was a cover for the right hand side of engine bay to make. It covers the messy internal panel that has grommit covered holes left over from heater pipes plus a functional, but not very pretty repair section.

I made this..





that goes here..



Next up was the sound proofing and fit some carpet. I removed the seats and gave the floors a clean.



I'd bought a large roll of self adhesive bitumastic type sound deadening stuff...



Quite a fun job cutting out and applying this where ever I felt the panels could 'thrum' or 'ping' from vibrations. I also added it to some other areas where it worked to smooth out factory seams or welds so making the leather covering job to follow easier and neater.



I used a mixture of leather and fake leather to cover the inner sills and wheel arches..



The wheel arches are a kind of complex compound curve and couldn't be done with single pieces so I dusted off my 1979 Pafaff sewing machine.



With some folded over edges then sewed I was able to make a neater job of anywhere that the coverings overlapped. With a bit of masking tape I carefully applied contact adhesive..



Then started the covering job...



I'd bought a roll of automotive carpet quite a few years ago and its been waiting for this moment for a couple of reasons - when I knew there would be no more changes to the floor layout and when I felt confident in my British car to not let any water in. I covered the tunnel first and then made floor mats to suit. The passenger side floor sits higher by about 50mm due to the false floor over the coolant pipe channels. I made the mats over lap and the drivers side was shorter so not to get squished by the pedals. I'd put some vinyl on the floor behind the pedals to neaten that area up.

Under the carpets is a firm foam underlay cut to shape. All easily removable for cleaning or work.



Sewing time again. I'd bought some heavy cotton in the colour I wanted and cut strips from it. Folded over and double backed then sewed I carefully edged the new mats. Not perfect as it was pretty tricky and I went through a few needles until I honed the method. Happy with the result though! I also made rear mats and a mat for the rear parcel shelf which also got edged. I ended up having just enough carpet to do the lot. Phew!



Finished result..







I had a car show to go to. The Moutere Hop. I decided to have another go at removing the Mandalorian windscreen..



Success this time. The foam was squished into more like a double sided tape but a thin butter knife was ideal to slice it through. The windscreen was pretty oily brown from the airborne residue that sneaks through the breather catch can.



But it cleaned up great and the screen looked much better. It was super clean inside..



I'll see how long the lid stays clear. I think after the next show I may well remove the Mandos from their role and make a permanent alloy lid.

Maybe... I'll see. It is really quite fun seeing peoples reactions upon them spotting the lights and figures.

We went to the show. I gave the engine a quick clean..



The car also seemed to have people around the back checking it out whenever we looked. Lots of interest and really nice comments from those I spoke to. I'd scribbled down a basic list of the details and info on some A4 paper that morning at the show and stuck it to the bumper because no one could work out what the engine was from. I think I'll do a better info board before the next show in a few weeks.

It was a stinking hot day so we left the show early and went went for a decent swim at the Motueka river. Good way to round off a nice day out..

[Nine One One]

Looking nice.

[yoeddynz]

Cheers. Its a much nicer quieter place to be now!

New exhaust box design next.