MadaboutKitcars

Looking good, just one question. Where did you fit the kitchen? There is no room in my Marlin!

Looks very neat and tidy

Door and windscreen frame

I have been making slow progress albeit going a bit from one thing to another.
The windscreen frame has to be one of the Roadster's main features doubling up as a roll bar. However I was never very happy with it in the "raw" state. It is bent from a solid steel bar with a slot milled on the inside to take the screen. This left very sharp edges and some hollows in it from the bending process. So I have taken the angle grinder and P38 to it. Looks much more acceptable now.
windscreen_frame2 by Robin Martin, on Flickr
windscreen_frame1 by Robin Martin, on Flickr

I have also completed a prototype door. The plan is to use a solid plywood core as in the original Marlin supplied door. However decent plywood is sooooo expensive now I made the proof of concept door from MDF. I have now skinned it in alluminium (left over from the Pembleton build). I am pretty pleased with the result and now happy to take the saw and router to the final plywood version. The latch is from a landrover, modified by removing the outside handle and lock barrel. I was going to use a Morgan latch but they are now over GBP70 each whereas the landrover one is GBP30.
door_prototype1 by Robin Martin, on Flickr
door_prototype2 by Robin Martin, on Flickr

Cheers, Robin

Engine

Never buy an engine from ebay and someone you don't know were the words echoing in my head as I handed over my hard earned.....
Anyway the story is BMC 1800 engine (Marina, MGB etc.) for sale on Ebay. It had an almost unbelievable spec with a Vulcan gas flowed head, Piper camshaft etc etc and had never been run since its rebuild. Of course I smelt a rat particularly as it had had a quick blow over with black paint. Anyway - I persued it and the story had a certain ring of truth. Advertised by an older, and and possibly a bit naive, guy. He had purchased it for his MGB but then found it was originally from a Marina TC and wouldn't fit. The crankshaft spigot bearing is much smaller for a Marina. So he decided to sell it on Ebay and, not suprisingly as it wouldn't easily fit an MGB, hadn't had a lot of interest. So a bit of negotiation ending up in a price that was far less than what just the head was worth and the engine was mine. He even delivered it.
Today I couldn't resist any longer and started the checking process. The plan is to dismantle and re-assemble it anyway not trusing work that someone else has done. An engine built to this spec should have certain features, double valve springs, duplex timing chain etc. And I am pleased to say it all looks good so far!
The head has clearly had a lot of work - you can see the porting through intlet and exhaust ports.
engine4 by Robin Martin, on Flickr
engine3 by Robin Martin, on Flickr
And it has the requisite double valve springs and duplex timing chain.
engine2 by Robin Martin, on Flickr
engine1 by Robin Martin, on Flickr

The next step is to get it on to the engine stand and pull it apart a bit more. But so far looking good.....

Cheers, Robin

That reminds me of the first time I used Ebay...... We were moving 19 years ago, and I'd bought a TC engine from the scrappy a few years previously and gleaned the head and front pulley from it (all it needed was a slightly larger fan belt) to use on my MGB engine. Anyway, back to the story. In my Ebay nativity I started it off at 99p as I wanted it shifting as I didn't want to take it with us. Guy 'won' it for

That reminds me of the first time I used Ebay...... We were moving 19 years ago, and I'd bought a TC engine from the scrappy a few years previously and gleaned the head and front pulley from it (all it needed was a slightly larger fan belt) to use on my MGB engine. Anyway, back to the story. In my Ebay nativity I started it off at 99p as I wanted it shifting as I didn't want to take it with us. Guy 'won' it for 1.20. he turned up in a battered old car with all the family (Wife and 2 young kids) having driven from the Midlands to south Essex. he got out of the car saying "that was handy, I work at an engine reconditioners and have been looking for one for nearly a year - that will do nicely, can you give us a hand with getting it in the boot? Here's your 1.20, I raided the kids piggy bank"
I'd have at least given 10, having just made that statement, it probably had 5 scrap value! Anyway, off he went on the journey back, and I wondered if the floor of the old car would support the block all the way

Head Completed

I have now completed the dissassembly and reassembly of the head. It's now resplendant in MGB maroon which I understand would have been the original colour. Everything looked pretty good. The head has been gasflowed to what I suppose is stage 2. I am no expert but it looks pretty much as Peter Burgess describes in his MGB tuning book with the exception of hardened exhaust seats which it doesn't seem to have. Which leads me to think all the work on it was done many moons ago.
stripped_head by Robin Martin, on Flickr
reassembled_head by Robin Martin, on Flickr
During the strip and reassembly process I also cleared out all the waterways by blanking off the thermostat position and filling it with a solution of Rust Destructor and letting it soak for several days. It seems to have done the trick.
derusted by Robin Martin, on Flickr
While I was at it I also measured the combustion chamber volumes so I could work out the compression ratio.
combustion_chamber_vol by Robin Martin, on Flickr
Using the formula in Peter Burgess's book:

Engine size with +30 overbore = 1834cc. Cylinder swept area = 458.5cc
Combustion chamber volume as measured = 41cc
Clearance volume = 6.5 + 2 + 4.5 + 41 = 54cc
Compression ratio = (458.5 + 54) / 54 = 9.49

While I was at it I though it would be fun to work out the potential 0 to 60 time. Again using a formula from Peter Burgess.

0 to 60 = (2 x W / T) to the power of 0.6
W = weight – say 750 kgs = 1650 lb
T = torque – say 120 lb/ft (figure from Peter Burgess book for an engine with similar configuration)
0 – 60 = 7.3 seconds
So - no slouch then....

Cheers, Robin

Nice, like the colour. Sonuds like it'll be pretty peppy.

Yes, that does look nice and it has cleaned up well.
Looks like that engine you bought was a really good find.

I have been looking for ideas that would help to bring the exhaust out of the side of the car as Marlin intended. Marlin supplied a special exhaust downpipe which allowed this but it was a very tortured design and probably not good for gas flow. And of course it's long since you could obtain it. I even tracked down the manufacturer (Double S) and they confirmed that had binned the pattern. But after a lot of Googling and general phaffing about I have purchased this exhaust manifold - currently on its way from the USA.

patriot h4800 exhaust by Robin Martin, on Flickr

It's a 3 into 1 design, ending in a 2" pipe, that hugs the block. I reckon with a bit of luck I should be able to bring the exhaust out the side either under or over the chassis rail.
So the next question is does anyone have any experience of silencers? There are loads for sale on Ebay, most of which I guess are from China and of dubious quality. I am looking for something that is not outrageuosly loud, but not too quiet either.....

Cheers, Robin,

exhaust

Didn't SS also make the original silencer?

Yes I think SS made the complete system. But, although they remember making it, they no longer have any of the patterns. Or so they told me.

Cheers, Robin

I have pretty much finished the engine build now other than the water pump and sump.
The sump I have to swap from the original engine as the one that came with the replacement had been buchered somewhat. A bit of a pain as it means I will need both engines in the air at the same time in order to do the swap.
The water pump hmmm... the one I purchased from a well known MGB parts specialist was rubbish - the casting looking like a copy of a copy of a copy... But I think I have located something better now.
You can see from the pictures that I forked out on a vernier timing wheel. Reground camshafts (so I am told) frequently need the timing tweaking to get it 100% correct. Certainly true in my case as when I had selected the specified advance it was nowhere near where it would have been if I used the two dots on the original chain wheels.
And finally I couldn't resist trial fitting the exhaust manifold I purchased from the states. The hope is that this will help me get a side exit for the exhaust without too many tortuous turns or any cutting and shutting of the exhaust system.
timing1 by Robin Martin, on Flickr
engine6 by Robin Martin, on Flickr
engine7 by Robin Martin, on Flickr
engine5 by Robin Martin, on Flickr

And finally - purchased these from Ebay. Already a bit of a bargain, the guy that makes them reduced the width so they would fit the Roadster - FOR FREE!
seats by Robin Martin, on Flickr

Engine build now complete. Been a bit delayed with problems caused by poor quality parts. As the MGB is so popular you wouldn't think it would be a problem but there is pretty much nothing available from the "normal" aftermarket and everything seems to come from China. Having said that some of it is very good, but some of it absolute rubbish...
I have fitted a fancy rocker cover as the original was a bit bent, but in fact it is not a great fit so may go back to the original. And a new distributor which has an advance curve (allegedly) tweaked for stage 2. Was rather cheap though, although it looks made well enough, but it will be another 12 months or so before I can verify its operation. In the meantime I will have a go a stripping and rebuilding the original.
Some pictures.
engine10 by Robin Martin, on Flickr
engine11 by Robin Martin, on Flickr
The observant may notice the non-standard engine mounting rubbers. The original Marina ones are like rocking horse poo and so I have used Land Rover ones as suggested by the original Marlin build manual. These have the added advantage of lowering the engine slightly which I hope will give enough clearance for the fron carb to fit under the bonnet. The original bonnet had a couple of unslightly bulges.

Virtually zero progress on the Marlin recently due to holidays and having to catch up with some DIY stuff round the house. Oh - and I managed a freak accident and very nearly cut the tip of my thumb off. Arghh. But I have made these. Any guesses as to what they are. Hint - nothing to do with cars.
tubes by Robin Martin, on Flickr

Tea and coffee cadies for your new kitchen

Pair of Monty Python 'Black Knight' helmets for Halloween costumes?

Bit of a giveaway now as to what they will be...
first_fit by Robin Martin, on Flickr

Trunions....

After several months of DIY I finally have some time to spend on the Marlin. I really should be completing the resto of the chassis but I fancied something a bit more interesting so decided to trial fit the front suspension. The Marina uses an odd setup for the front suspension using torsion bars and trunions, based on that used by the Morris Minor but, unfortunately, having no common parts. Parts are as rare as hens teeth....

The standard problem with the upright is lack of maintenance causes the lower thread on the upright to deteriorate. Ultimately the trunion can part company with the upright. Mine were no exception.

upright rusted thread 2 by Robin Martin, on Flickr

I was able to track down, thanks to the Marina Owners Club, some new old stock of "Walford Trunions" which were a period fix for the problem. Basically a new threaded sleeve is screwed on to the old damaged thread and a new oversize trunion fits to that.

original and walford trunion by Robin Martin, on Flickr

You are supposed to fit the new threaded sleeve using the supplied threadlock but that was a bit suspect being 30+ years old so instead I bonded it using an industrial Araldite. Jobs a good-un. I should say that it is also tightened up to 100 Lb/ft as well!

inner component of walford trunion by Robin Martin, on Flickr

walford trunion fitted by Robin Martin, on Flickr

Finally I fitted all the bits up to the car. The Marina uses a lever arm damber but on the Marlin this is replaced by a Mini upper suspension arm and a conventional damper (not fitted yet)

front suspension trial fit by Robin Martin, on Flickr

The critical point is that the torsion bar should pass through a hole, on the chassis where it is finally fixed, without any lateral or vertical tension. This is also the rubbish part about Marina front suspension as it makes it pretty much impossible to play with the castor or camber. Anyway after a bit of fettling it's a great fit.

torsion bar position by Robin Martin, on Flickr

Now that I am happy it fits, and I am not missing any major bits, I can take it all off again and complete the cleaning up of the chassis!

Cheers, Robin

Trunnions

I fitted those 'over trunnions' to both my Marina saloon and Ital estate back in the 80s. Great bits of kit!

Regards, Mick

Nice work, Robin.
Was there a reason for the bottom trunion being threaded? It seems an odd thing to do?
How do you keep the new thread lubricated, maybe some waterproof marine grease?

The upright rotates in the trunion using the thread. It effectively un-screws and screws-up a little every time you turn the steering wheel. It's ancient technology inherited from the Morris Minor. Quite why they didn't fit a balljoint instead I will never know. There is a massive balljoint at the top of the upright where it joins to the top arm. They could have put similar at the bottom.
The thread is lubricated using one of the 2 grease nipples on the trunion. The original design only had a single grease nipple which is why not much grease ever reached the thread. And made worse by lack of regular maintenance.
My guess is that the majority of Marinas still out there have worn threads on the upright. I think as long as you fill them full of grease before the MOT the tester doesn't notice.

Cheers, Robin

Thanks for the explanation, Robin.
I guess it was probably a cost thing?
I had an Austin Healey Sprite (aka Midget) that had threaded fulcrum pins that wore out the lower wishbones in the same way. We lived in a terraced house then and I can remember changing the wishbones in the gutter outside the house.

Trunnion Lubricant

My ex-REME tester threw up his arms in horror when he discovered I'd greased my trunnions. He insisted that Hypoy should be used, so I mended my ways, bowing to his superior knowledge.

Regards, Mick

Morris Minor /Marina trunnions should be greased. Certain Triumphs eg TR6 and Reliant Scimitar which use TR trunnions should be gear oil. that said its always been a bone of contention within the Triumph group.