500 (Classic) '65 RHD F Restoration

Added by Goldnrust
Create date Oct 27, 2021
Updated Feb 18, 2023

Overview Updates (12) Gallery Discussion

Introduction

Hi guys

My name is Steve, and I'm a rusty-old-car-aholic

I've been quietly browsing the forums for a while, and slowing collecting knowledge while looking out for a 500 project. A few weeks ago I took the plunge and bought a project, it's definitely not the best starting point, but it's also far from the worst.

It's a RHD 1965 500F in dark blue. It appears to have been off the road since the mid 80s, and was recently purchased by a trader who was clearly looking to getting running and flip it for a profit before he realised just how much was wrong with it (and there is quite a lot wrong) beneath the surprisingly shiny paint job.

This means it's come to me already mostly disassembled. I'm aware this is a bad idea, especially as this is my first 500 and so I'm not familiar with how it all goes back together... It can't be that complex though can it?!

In the photos you can see how it looked as delivered to me, and also how my other classic (also resurrected from a 30+ year lay up period) dwarfs it!

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Latest updates

Engine Reassembly

Feb 18, 2023

These past few weeks I've been working on my budget engine rebuild/reassembly.

Starting with the head, I had decided to replace the valve guides, so the first step was to remove the old ones. Having watched various videos online about changing valve guides, I made a little tool up from an old bolt so I could drive the guides out with the air hammer and was pleased to see it made light work of it.

Now with the head fully stripped I could get it cleaned up. I got the worst of the grime off with some white spirit and brushes and then threw it in the blaster to tidy it up a bit further. It's not perfect, but its plenty good enough for now

After that I heli-coiled the exhaust bolt holes, I will probably use studs instead as I have seen others do, and then drove in the new guides and then ran a reamer through them to make sure they would be the right size for the valve stems.

The valve gear got an overnight bath in some TFR, which did a reasonable job of cleaning the worst of the grime off. I did still need to manually remove the worst of the carbon build up from the valve heads with a wire brush in the drill though. You can see how much grime had come off the valves by the disgusting colour of the TFR I the morning! haha.

I could now put the valve back in the head, but this is where I ran into a problem, and one I had potentially foreseen. Despite my best efforts to keep things aligned, the new valve guides were holding the valves at a fractionally different angle to the originals (possibly even just how the valve seats had worn with worn guides?) and so the valves were not seating right. Demonstrated here by the light you can see between the valve and the seat when it is touching the seat on the other side.

Having the valve seats re-cut I would presume is the 'right' thing to do, but if I was doing that I would also be silly not to have the valve seats changes for ones that are 100% unleaded safe and obviously fit new valves, then I should probably put a set of valve springs in really... and so on. As this was meant to be the budget option, I thought I'd try just giving them a serious lapping, worst case it didn't work and all I'd done it knackered some valves and the seats that would be junked otherwise anyway. I'm pleased to say, while it was a slow and tedious job, it works and there is now good seat contact all the way round. No light shining through this picture now!

I read mixed things about unleaded on the stock valve seats, same as I did with my Lancia and Daimler. Both of them, like the Fiat, had aluminium heads but there was concern that the material the standard valve seats were made from would still not be up to it, either way I did 20k miles on my Lancia engine on unleaded with no valve seat issues and have done 5k so far I the Daimler with no problem so I have no intention of doing anything different with the Fiat!

With that done it was time to look at the bottom end! The bottom end work started with cleaning the best part of 60 years worth of slime off the crank case.

Much better!

With it all clean, the next job was to heli-coil the threads for the oil pressure switch. Picture of case with stripped out threads before I started, didn't take an after picture apparently!

The engine came with a random bolt wedged in the case here with lots of PTFE tape and RTV. It was only after I'd started on the rebuild I realised this should have been the oil pressure switch. Fingers crossed it was just a 'solution' to the stripped threads and not that someone removed the oil pressure switch to hide the low pressure! (On the autopsy stage there was nothing to suggest a reason for low pressure...)

Next the crank got cleaned, and I removed one of the freeze plugs so I could clean out the sludge trap. Not too much in here, which is good news.

I fitted a new plug and firmly staked it in. I'm aware that these plugs can loosen or even fall out when the engine is run at high RPM, causing catastrophic oil pressure loss. The fix is to weld them in place, but as this engine is standard with no intention to do the mods required to run it at higher revs I decided to just go for a standard staking this time round.

The crank could now go in the cases, with the cleaned up original bearings.

I put the cam in next, with a new timing chain and sprocket set. The old chain was noticeable slack, whereas this is taught, so definitely a wise choice to replace.

The timing chain cover was looking a bit grim still.

So that got a blast and clean up, and I stripped and cleaned the oil pump too and packed it with vaseline to give it something to suck on for first start.

Time to look at the barrels next. I gave them a light home hone, which they seemed to respond to well. Checking the new rings in them, I had gaps that were just larger than the factory spec, but well within the wear limits. So as expect the bores have some wear but it's not too bad.

Now I knew the bores were ok, I gave the barrels some cosmetic clean up. I'm trying to minimise oil leaks and get all of the engine parts nice and clean, because the heating uses the air thats been blown over the engine for cooling. I'd like to minimise the amount of hot oil smell inside the car, haha.

I could then install the pistons with said new rings in the barrels. It turned out I'd lent my ring compressor to a friend, so I just eased the rings in one at a time by hand, made possible/easler working with an air cooled engine with separate barrels

Might as well get them fitted to the engine, and then the sump can go on and it can be stood up and starting to feel like we're getting somewhere!

And then the head could go on too. The pushrod tubes aren't great cosmetically, but they are clean and will do the job and I put a smear of RTV round the new seals to give them best chance of not leaking!

Excellent.

Flywheel and clutch was next. A new clutch seemed a prudent choice as while both the clutches I had were not 'worn out', they were worn.

And then the oil filter/front pulley assembly.

Fuel pump was next, I pulled apart my old one intending to clean it, but it was not looking healthy...

With rebuild kits looking thin on the ground, a new one was at least an easier solution and not expensive.

I thought I'd look at the carb next. It's a bit of a tired old thing, plenty of bodges along the years and has a section of casting missing from where the intake air tube mount to the top. The important bits are there though, so will do for now! Clearly a deep clean was needed though.

Good job I did a big clean, here's a before and after of the emission tube! Would have never run right like that...

I also checked the carb mounting flange on a flat surface and found it to be warped, very common on these which is why I thought to check! With some oiled wet and dry I was able to flatten it back out easily enough.

At this point I ran into a snag that it appears I've managed to order the wrong carb rebuild kit, so there gaskets I have wont fit. Easily remedied, but not this weekend!

So that's where I've got to on the engine front. On the more mechanical side I've go the distributer and dynamo still to clean up / sort out. Other than that it's just cosmetic tidy up of the fan shrouding and valve cover, and that will be the engine part of this project done

As the weather is starting to warm up a bit this past week, I have also started making use of a couple of daylight hours I can grab to get stuck back in to the body work. Lots of sanding, endless sanding but the filler on the rear quarters is coming along. I'm working in thin passes, filling in low spots and finding high spots, just a few details to sort on the passengers side (pictured) but there's further to go still on the driver side still.

Still it's positive to be able to be back on the bodywork. I will be very pleased when its painted and done, it will really feel like I'm on the home leg of the project then and the idea of getting to drive it will feel within touching distance.

Reactions: lazylobster and Toshi 975

Engine Autopsy

Jan 23, 2023

Engine autopsy time! Always interesting, often a bit depressing for the wallet! haha.

So here is the 'new' engine, I bought last year. It was 'a good runner' when removed but you never know how these things are stored, and it was under a tarp in a garden when I picked it up...

Let's start by pulling the head and looking for any obvious problems.

I think we've got a bit of an oil burner here, especially on the cylinder nearest camera. Not a great start. Disassembling the head I found that there were no valve stem seal o-rings, along with a reasonable amount of valve guide wear. So that could well the be culprit of the oiling.

Flipping the head over and we can see that one of the cylinders has eaten something at some point as theres some good dents / marks in the combustion chamber. There is also signs of minor cracking between the valves in both chambers, which from searching up some old threads on here I've read is common on these engines to the point where most cylinder heads would have some level of it if removed and inspected. I gather some people are concerned that the cracking can cause the valve seats the loosen and drop out, with obvious catastrophic results, and if the cracking gets bad it will go deeper than the valve seat and allow air to leak between the intake and exhaust ports. Comparing this to images posted in those threads, this is very minor, and having cleaned the carbon off the port just behind the valve seat I can confirm that the cracks do not extend past the seats.

Working our way down the engine. The barrels/bores have got plenty of vertical scratches / scoring, they also appear to be over bored to 68mm, from the standard 67.4mm. So this engine has done some miles and had some previous work I think.

I gave the piston tops a quick clean up and found matching foreign object damage on top of the one piston. A quick check of the top ring gap showed it to be 0.65mm, which is past the 0.5mm suggested wear limit in the manual.

Moving on to the bottom end, pulling the sump I unsurprisingly found a bunch of sludge. this was fairly dirty / gritty at times and there were some little bits of what looked like coarse wire wool, both in the sump and stuck I the bottom of the oil pick up, not promising!

Fearing the worst I pulled the rods and was surprised to find that the rod bearings looked really good (to my amateur eyes, happy to be corrected!)

The rod journals on the crank too looked good, better than any of the ones on my Daimler crank did...

... and I was pleased to see no signs of scoring or damage on the cam.

At this point I thought it worth a pause to collect my thoughts and also to go back and compare these findings to my original engine. So far I'm not seeing anything catastrophically wrong with this engine, but it's looking like its lived a fairly hard life!

So back to the original engine. I had already seen some signs of cracking between the valves in the head (which I now think I was over reacting to) and knew the top piston rings were broken with some scoring in the one bore, fearing the worst this is why I'd bought the replacement engine, but what else would I find?

Starting at the top, under the cap in the valve cover I found this disintegrating oil vapour filter. It's filled with wire wool type material... this was missing from the other engine so I presume it had been previously removed due to it falling apart. Another reason for the oily piston if the engine is breathing a lot of oil vapour back into the intake...

And so checking the sump I also found bits of the same wire wool type material in the pick up. A lot more black sludge in this pan, generally the inside of the engine is covered in a much deeper coating of carbon, but it was smooth and not gritty like the other engine.

Anyway, we were looking at the heads. Comparing the combustion chambers, only one of the chambers in my original head has a crack in it, and again it's small and doesn't extend below the seat.

The seats themselves are noticeable less worn, suggesting the other head had had them recut / lapped and done more miles. The valves are still sloppier in the guides than I'd like but they are better than the other head. You can also see more of a lip at the edge of the combustion chamber in this head, suggesting the other has been skimmed in there past (or at least skimmed more than this one?!)

The rod bearings, rod journals and cam looked pretty identical to the other engine, you can see the layer of carbon covering the inner of the engine here in this picture of the rod journal.

Revisiting the bores, they appear to be stock size, and the scoring in the one bores actually doesn't look too bad now I've got the piston out and wiped it down

As the original engine is actually looking better now than the replacement, I carried on and completely stripped this down, only really the crank and timing gear left to remove anyway!

I didn't photograph it, but the timing chain seemed fairly slack to me, so one to replace I think. The rear main bearing and the cam followers both looked great to me, which is good news.

The front main bearing is the only one really showing any signs of wear. It's lightly scored with a fair amount of ingrained dirt. It's worth remembering these engines only have a centrifugal oil filter, so as the first bearing to receive oil from the pump I guess this is the one that bears the brunt of that.

The front main journal on the crank was also lightly scored but again probably less so than all of the journals on my Daimler crank and that's happily done 5,000 miles since I put it back together.

So lots to take in there, but once again good news of nothing really horribly wrong, just some wear and tear.

I think my plan will be to do a budget rebuild on my original engine. I will clean everything up and then reassemble it with a minimum of new parts to get me out on the road. It will obviously need a set of rings, I'll give the bores a light DIY hone and a new timing chain & sprocket set makes sense. I'm not sure what to do about the front main bearing, my first step will be to finish stripping the new engine incase that bearing is better but I'm not holding out any hopes? Otherwise I'll probably just clean this one up and reuse it, Im sure it's been like this for thousands of miles and will be fine for a while yet. It's easy to get paranoid about these things! The head will mostly just get cleaned and reassembled but I am going to change the valve guides. I've seen some things online about changing valve guides at home, so I'm going to give it a shot.

I'm going to try and not get carried away and just focus on getting an engine together that will get me out of the road this summer and then I have got a complete spare engine here in need to rebuild which can get the full works and performance improvements for the future.

I gave to say it’s been a pleasure working on this little engine. It reminds me of working on a motorbike engine, so much easier than dealing with the bulk and weight of a ‘normal’ car engine, certainly so than the v8 I last rebuilt!

Reactions: fiat500 and Toshi 975

Gearbox

Jan 14, 2023

Now seems as good a time as any to do an update on the gearbox!

Had I realised what a pain it was to change the drive shafts when I purchased them, maybe I'd have been more inclined to stick with the bodged originals, haha. Anyway, last time the diff/bearings/shafts assembly was out of the gearbox.

The centre of the diff is two sections bolted together, this both allows for adjustment of the spider gear mesh via shims (more on that later) and that once separated you can slide the driveshafts out of the centre out of the diff. It was only when I'd got it in two halves that I realised that my welded up shafts woulds have to be cut before they could slide out. I wish I'd realised this when the box was fully assembled as I didn't have to be quite so careful of metal filings getting about the place!

Anyway, with that sorted it was fairly straight forward to slide the old shafts out, slide the new shafts in and bolt it all back together again.

Excellent, apart from the diff now wouldn't turn! It tuned out that somehow the shim or the side gear that rides on the shim, had hung up when I was assembling the diff and not seated properly jamming the whole unit. Once I'd finally figured that out I was able to reassemble it while keeping pressure on the side gear so that it couldn't drop out of place again. Bit fiddly, but glad I noticed now and not later!

I had mentioned in the previous post that I wasn't sure if the input shaft bearing was a bit rough as there was some noise. This turned out to be a false alarm, as having moved the gearbox off the resonant table top, then the noise totally disappeared! I think the noise was just the sound of the constant mesh gears turning and resonating through the work bench. I took the inspection plate off the top and had a look around and could find nothing too concerning.

So there was nothing for it but to do a bit more cleaning up of the critical surfaces, where the case halves meet for example, and to freshen up a few of the covers with a bit of satin black paint and to bolt it all back together!

So close, but falling at the last hurdle, I managed to pinch the new o-ring seal on the input shaft seal/bushing holder thing. It might have been me, but I felt the new o-ring wasn't a great fit when I put on and might have been part of the problem, so I measured up and ordered some new o-rings with a slightly smaller ID and will try again.

So, presuming the new o-ring goes in without snagging, that should take just 5 minutes, then I can put a tick next to project gearbox and move on to the engine! Thats exciting.

I've not dug the engine(s) out of the other shed yet, but in the mean time a bit of back story and a plan; My car came with the original matching numbers engine, which looked fairly complete if a bit rough. But it turned over ok by hand and had some form of compression. The seller claimed it ran when he poured a bit of petrol down the carb and stuck a battery on it.

Way back in December 2021 when I was bored one afternoon I decided to investigate a bit further and whip the head off and have a bit of a poke around.

What I found wasn't promising. For a start the bores were scored and the top piston rings fell out in two parts...

The cylinder head didn't look amazing either, with some possible cracking between the valves which I believe is not uncommon. Anyway, I didn't look too deeply as I knew it wasn't a priority, I just packed up the parts and buried it in the corner of the shed for later.

Fast forward to April 2022, and I was browsing eBay when I spotted an auction for a 500 engine just 5 miles up the road which wasn't attracting much attention, it seemed worth a punt, especially if it went for less than the cost of a rebore and pair of pistons for my original. I stuck in a low bid and a couple of days later won it for £80!

I was told it was a good running engine when it was removed from the car to be replaced by the usual 650cc 126 engine, but aside from checking it turned over by hand before lifting it into the boot of the Daimler (not a great move as I didn't think about the fact that the distributer was missing when I laid it down and it dumped a bunch of oil in the back of the Daimler...) I've not looked into this any further!

Plan A is to go through both engines properly and then see how cheaply I can put together a reasonable standard engine. Best case scenario I can do some cleaning up, a new set of gaskets, a bit of valve lapping, maybe just break the glaze on the bores with a home hone and have a standard engine that I can hit the road with? Then in time (presuming I enjoy driving the car as much as I expect to!) I might look to build up a tuned up engine using my spare engine parts as a basis.

If this is not possible, for example if I find the bores are damaged in my eBay engine too, then Plan B is to jump right to a moderately tuned engine. I don't really want to start spending lots of money on standard parts, when performance parts cost essentially the same! I'd be thinking something like a 540cc build (or 595cc depending on the price of having the cases machined) with a cam, bit of porting, exhaust and carb change?

Fingers crossed for the cheap option A though, as ultimately that way I'm more likely to get chance to get out and driver the car sooner I'm hoping to start investigating the coming week so should have a clearer plan soon!