DanMi

Water needs to be moving even before the thermostat opens to prevent boiling at the hottest places, so there must be a route for the circulation, which this hole would allow. Not all Triumphs have heated manifolds and the heater can be off, yet this is a common design/part.

Don't forget that early cars such as MK1 spitfire don't have a heated manifold and the heater was an optional extra, so that hole is definitely needed then to get the water moving before the thermostat opens.

If the engine number is fh4940HE that suggests it is an early MK4 engine up to FH25000HE, thus it SHOULD have the MK3 cam in it (but who knows) so slightly more power than the later but should have twin SUs (easy upgrade). I personally prefer the smaller capacity revvy engine but hen mine is 1147cc. Buy on condition, neither will beat even a bottom end modern

Trouble with that is the gearbox number only tells us what the gearbox case had in in it when it left the factory not what is in it today!

mk1 block here https://www.ebay.co.uk/itm/353989878629 mk2 here https://www.youtube.com/watch?app=desktop&v=mXhRqwTrPUM note at 8.29 the curved water channel by the end cylinder not present in the early block With this channel missing in the early head, I doubt that a mk2 block would work wit a mk1 head or it could cause overheating/leaks

Do you mean polish the exterior to make it look nice and shiny or polish the inside to aid airflow? If the exterior then just a progressively finer abrasive and finally metal polish, interior as Pete says

I found that bonnet catches coming open was best cured with new catches, I happened to find some new old stock ones (still with green wax) replaced and they have never come open since.

lets face it very few of our cars are as they left the factory after 50 years plus of use, abuse and rebuilds, engine numbers etc really aren't a guide to what you have, as anything could have been changed, just because you have a 2500 saloon block, doesn't mean that it is of that spec, it could easily have been built to GT6 spec. I have a spare Herald 1147cc block which was built by the factory as a recon to mk2 spit standard (bar no cam bearings). Bodies shells get replaced etc etc.

Wasn't it only the late GT6s ie the non rotoflex ones that had the domed pistons. Of course any block could have been fitted with any pistons, crank and cylinder head over the years.

Wow a 10 year wait!!!

I use 2 dial gauges rather than measure the gap. So I would close the gap then zero the gauges with the exhaust and inlet fully closed. Then when no1 is at TDC at the end of the exhaust stroke the exhaust will be closing and the inlet opening but at TDC both gauges need to be at exactly the same lift the actual value does not matter. There is quite a bit of adjustment just by moving the sprocket on the cam as the holes are slightly larger than the bolts.

I always split the exhaust from the manifold, Actually on mine remove the manifolds as it is a mk2 spit with a single piece 4-2-1, then you can raise the back of the engine enough for the box to clear the prop and fit to the engine. i support the engine under the sump with a piece of wood toward the rear with a second plank of the correct thickens to fit between the first one and the bottom of the back plate, then raise the engine and slide the gearbox on the planks. The engine needs to be jacked up quite a long way

actually it will be only spit mk4. MK1-3 used 5/16 bolts. But agree it is not worth selling as replacing the UJ and then a balance would be not much cheaper than a new one

OK from the US but shows weber can be done https://www.ebay.co.uk/itm/273037916435. I have also heard of people using Mikuni motorcycle carbs

you are correct it looks like it has 1 wire from the coil -ve that then joins to 2, 1 to dizzi and the other to tacho. Odd but functional

and does the tachometer work? as there should be 2 wires from the coil -ve one to the distributer and one to the tachometer (white/slate)

for the extra wire you could use one of these piggy back connectors on the new wire https://www.amazon.co.uk/Insulated-Piggyback-Crimp-Terminal-Connector/dp/B00XWDEJEU/ref=asc_df_B00XWDEJEU/?tag=googshopuk-21&linkCode=df0&hvadid=232042431268&hvpos=&hvnetw=g&hvrand=2188618408675908135&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006906&hvtargid=pla-1930529947110&psc=1&mcid=3d2564d342243458b2288cb8d8a9ab46

spit mk2 and 3 cams are the same, they have the same part number though some sources say that mk3 has higher lift, they will fit the herald engine, though it will run direct in the block rather than running in cam bearings. I have a factory recon mk2 spec block which is actually a herald block so no cam bearings (that block is not used just acquired for spares). I think when they decided to not use cam bearings in about 1972 it was more cost effective to use a bigger journal cam as they had got rid of the tooling for boring for the small diameter non bearing blocks. Couple the mk2-3 cam with twin 1.25 SUs and a 4-2-1 manifold will give you the 67 HP of the mk2 spit. The only other major difference is the valves of the spit use collets rather than the fig 8 attachment plate and of course the spiral rear oil seal of the early cars and the diameter of the cam followers. Just be aware that the mk2 spit engine is very rev happy, which is fab in a sports car

very similar, just that the early spits (1147cc) had a 6 port head so a slightly different arrangement

no choice on my car as the mk2 spit has a 1 piece 4-2-1 manifold which is too long to raise the rear of the engine without removing from the cylinder head.

The difficulty with rebuilding a gearbox yourself, is parts and getting the best fit more than the work. A specialist will have a collection of synchro rings and will try many to get a good fit with your existing parts a kit will just give you 4 random repros, they also have a collection of used parts and old stock that they can source from, which may well be better than new repro stuff. I had mine done by Mike Papworth but it did cost north of 1000 for box and OD but it does work well!

it looks like an aftermarket radio interference suppressor. Can be ignored if you don't have an AM radio

Ah the fun of new pattern parts!

just appeared on ebay if intersted https://www.ebay.co.uk/itm/325859133382?hash=item4bdeb7c7c6:g:M~YAAOSwkV1lNnBs&amdata=enc%3AAQAIAAAA8LOdr8ZGEiT8eqi76k00yBVozSJ%2Flqub%2BaJCX2klC8actgAGDmMPd50Ng8qLHtaCTuPV5ynedjR1Fuqbbc3EL6mcThKLNtpw%2Fysyd1mj%2FErpprA%2F%2BahifOzFm%2BajyO31S%2B662mtxLOTMAoUg0GTU%2Fhx%2FANdLe9kwGj1Sfc51FBtdZur9qkt54R7nkYaARFIem1qxwG1LGIQEtdcPA9AUxcjVoiCm0vWvRfeh4bBsAoCXaXhjFCARi0NgNRCP8PpMeVt9UrCcCsFboDEbdn7aEcM4ZcEz7nq%2BYhe9X2lqyK9sFvIhm8VPV9UWWDJLVg3Buw%3D%3D|tkp%3ABk9SR_q3-LzsYg

The other (and very important) thing to think about is brakes, if you are making the car go faster than originally designed then it really also needs to stop better! I have no knowledge of Standard 8 brakes but guess that they would be weedy drums all round.