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Hi everyone — I’m restoring my Dad’s old 1929 Invicta 4.5 litre high chassis, and we’re in the process of replacing the old 8-hour clock with a smiths rev counter. Since there’s never been one on the car before, we will need to add a rev counter drive to get the count.
On good advice, we’ve heard that “you can take a drive off the rear of the dynamo I think – I have a feeling some Lagondas are done that way? In which case, you would need the little drive gearbox that bolts to the rear of the dynamo in order to achieve this, if your dynamo does not have that. You may need to ask the Lagonda Club about that option?”
So, does anyone out there have one of these drive gearboxes that goes on the end of a dynamo? Here’s a blurry shot of the end of our dynamo (showing the shaft end, and also 3 mounting bolt holes).
Maybe it’s like the one in post 1155 ?
Also, here’s a shot attached of one off a CAV dynamo being restored at CDRC Ltd (the nice shiny-looking one on a bench)
If you can send pictures or give us a lead on buying or building one, I’d really appreciate it!!
I may be wrong but I do not believe the Meadows engine, as fitted to Lagonda 4.5 Litre cars, used a dynamo driven rev counter.
However, I believe Speedograph Richfield in Nottingham can supply a dynamo mounted gearbox for a rev counter. Worth giving them a call.
Hope this helps
Regards
MarkThanks Mark! I actually have been in touch with them, and they don’t have anything “off the shelf” for the application. So, I think we need to put something together (?!). The other possibility mentioned by Jo Moss Kitcher was getting the rev count “…from the back of the crankcase on the right hand side – in which case it takes its drive from the oil pump drive (so in other words, the gear on the camshaft that drives the oil pump also has a shaft going upwards – which mates with a slot to drive the rev counter) Have a look and see if there is a ‘blank’ plug screwed into the top face right at the rear of the crankcase close to the edge of the cylinder block, or whether there is a brass screw thread attached to the blank – if there is, then the drive is already there.”
Does anyone out there have a rev counter set up this way, and would be willing to share photos? Thanks —
If you send me a personal message thru the forum I will send you photos of the installation to which you refer.
What Jo describes is how Lagonda drive the rev counter in the Meadows engine. It is part of the crankcase on the rear right hand side.
If you are not already a member joining the Lagonda Club could be a good move. They have a significant spares stock for the Meadows engine and you could advertise for the parts you need to drive the rev counter.
Regards
MarkHi Ted, as well as joining the Lagonda Club (which I also strongly recommend) there is a healthy Facebook Group (if you do Facebook) where you can also ask for advice and assistance. Look for the Lagonda Owners Group. Is it a closed group which means you have to request to join but with 376 members there’s lots of well informed people to offer advice.
Thanks Rich! I actually did join the Lagonda Club last year (at the suggestion of a couple of Invicta Car Club members), and so far I’ve been positively impressed both by the website’s resources and the member’s commitment to the marque (love reading about all those trips through Spain, Australia, etc)… While I hope someday to bring the car back to England for a grand tour, I’m also hoping that I can drive around Japan — my wife’s home — for a while too: good thing it’s RHD! But before that, I need her roadworthy, and the rev counter is really to help in understanding the shift points, engine behavior, and give my soon-to-drive 15 year old son a visual reference point for shifting.
Hello Ted,
I know someone with an Invicta local to me here in Australia I’m happy to give him a call to ask about how the rev counter on his car is arranged. Following that, perhaps I can put him in contact with you directly.
All the best, MikeHi Mike — yes, that would be quite helpful since unfortunately the Invicta Club doesn’t have a site online yet for sharing ideas, and there’s only a few owners here in the US that I know of (one out East, and one in BC Canada, and I’m stuck in the middle here in Detroit!).
Hi — I’m still trying to find the right setup for getting the mechanical rev counter reading off the engine. Here are some photos from the rear of the engine under the firewall. Does any of this look like the place to install a hook up a cable or install a drive?
first I have a shot of the firewall, showing where the hole for the rev counter drive cable is next to the speedo cable
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second I have a photo of the driver side rear of engine. Is that round plug where it might go in?
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then I posted a photo with the layout under the firewall behind the engine, showing all the connections available.
finally, I took a shot of a mystery connection on the passenger side next to a supplementary oil supply tube. Might this be the mystery connection?
On our later M45 the mystery fitting isn’t present and our drive is located in the round plug shown in your picture.
Here’s a pic of ours whilst on a dyno after the rebuild
Thanks Adrian — what a beautiful engine! I’ve never had a chance to see ours exposed in all its glory. Is the black oval hatch panel held on by two bolts the place for adding gear oil (something I need to do as well)? Also, does that rev counter drive come out of the housing? On our picture, we’d like to somehow pull it out and open it up but we’re not sure we’d be opening Pandora’s Box instead. Quite a thing to behold, and I hope sometime to visit your shop if/when we ever get the car over to the UK
Hi – – That oval plate gives access to the timing marks on the flywheel. Not knowing your version of the engine, I can’t say whether it would be an issue to open it up, but I doubt it would be. Heres a photo taken before the bits were installed.
And a closer shot
Hi Ted,
Just to add confirmation. My version of this engine is the sanction 4 type, in my LG6, so even more recent! The large threaded hole in Adrian’s final photo is also where my rev counter drive emerges; your photos show that you have a circular plug with four dimples for removal by a pin-drive spanner in that location. Note that on Adrian’s and my engine, there is a threaded boss for a bolt to presumably lock the brass drive adaptor in place.
Your mystery component appears to include a tap handle. I would opine that it is for a water take-off, perhaps for a heater? Is this engine original to your car? If not, be aware that these Meadows engines were used in many other applications, eg buses, tanks, marine. Whilst the basic engine would be the same, there would be differences incorporated specific to the intended application. Such engines were available, sometimes still unused and crated, until fairly recently, and were a ready and cheap alternative to rebuilding an original engine. Alternatively, parts from such engines could be incorporated as part of a rebuild. or example, I’ve discovered that the water pump on my engine is actually the marine version, with a bronze cover plate.Laurence
Thanks Laurence and Adrian… it helps to see how other engines are outfitted to get a sense of what we might be able to do. As far as I know this is the original engine to the chassis, at least according to the number plate on the crankcase cover (it’s engine No. 7223 for reference). As for the water cock, if it can supply heated water that would be a nice option to have for any kind of future heater. Seeing as how the car spent most of its pre and post war years in Nigeria, I’m sure heating was not really a consideration, but it would be nice here in Michigan. My next step is to find a kind of spanner or wrench that can take off that lid, and see what’s down there… anything I should be looking for?
Hi Ted,
You need a pin spanner/wrench for that. You might get away with using a hammer and punch, provided you accept there’s a fair possibility of damage to that “plug”. That said, if you are replacing the plug with a rev counter drive, damage to the plug is less of a concern. A suitable pin spanner could be made fairly easily with basic equipment. Find four screws that fit snugly in the holes in the plug, make a template accurately transferring the hole position in the plug. Then find a suitable piece of steel of adequate thickness and length, drill and tap for those screws, using your template to accurately match the plug hole positions, screw the screws in so that they protrude slightly more than the depth of the holes in the plug … and voila! You have your pin spanner. It’s not something you are likely to be able to buy ready made. All this said, if it’s really tight, bearing in mind it has probably never been undone since 1930 odd, you might need to at least get it started with that hammer and punch.
Laurence
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