Nick Jones

I don’t believe this is correct. There is a separate drilling at the top of the adapter that carries the selector rod in the single rail application, which is redundant when fitted to the 3 rail casing, but iirc has no internal link to anything else and can be ignored. I have the parts in question loose at home and can check this evening if you like? Edit: note to self..... read whole thread before replying. Glad its resolved Colin. Yes, parts are getting very pricey...... Think I paid £170 a couple of years back for a D type mainshaft with larger spigot...... Does perhaps mean that the box of oily scrap in the corner is actually of some value. Trying to get an MX5 box into my GT6 at present....... not a match made in heaven...... lots of mods (to the box, trying to minimise car mods) are needed, involving machine tools and TIG welders....

No. Only if you are trying to make a J type box that is the same length as the D type. For that you also need the ( now rare and expensive) OD adapter from an early 3 rail Dolly 1850 box. The mainshaft needed was never a factory but is available from Mike Papworth Nick

Colin, it should be possible to transfer the internals from a single rail to 3 rail casing (any 4 synchro one) and pop any 4 synchro top housing/selector mech on it. You do use the single rail mainshaft. The single rail OD adapter (the long one) is quite tall where takes the selector rod in its original application and this part of it sits above the 3 rail casing split line. You might need to relieve the edge of the top housing to miss it but nothing more that I recall. It’s been 30 years since I did one mind, although I do have most of the parts to do another to hand. Nick

Use the flanged nuts from Minispares - I’ve not found anything else modern that will hold the torque reliability. 46 is really on the edge for 3/8” UNF. Torque wrench check is a good call also though. Nick

Alloy nuts are the devils work..... just imagine how they fair in the hands of your average rattler-gun-toting tyre fitter Nick

Valve heads should stand proud from the chamber roof, not flush and certainly not recessed. And you raise an important point. Valve heights have a significant effect on chamber volume and thus CR. This does mean that direct measurement of volume with a burette or syringe is much the safest way. CR on a Mk2 2L is already marginal for modern fuel and doesn’t want to go up unless using an “interesting” cam with lower dynamic compression. Injection, giving more even fuel distribution, and electronic management of fuel and ignition help the margins. Nick

Question is..... do you need a cylinder head that has had a 2mm skim? Might have some purpose if you are wanting to run a wild cam and need the compression ratio bumped way up to get the best from it. Otherwise, keep looking..... they are out there. Not directly related but on the Mk2 heads, there are various thicknesses from the factory, the 2.5 ones being at least 2.5mm thicker than the (early) 2L ones. For reasons that seemed good at the time I modified a 2500S head, which is a whopping 4mm thicker than the early Mk2 2L head, for use on my flat piston 2L, plus I wanted higher CR. That was a BIG skim. I got away with it, though it’s scary thin under the spark plugs. However, I know others who were less fortunate and found water. One as an immediate hole at the outer edge of the squish area and another that showed as head gasket failure when the same area collapsed. Nick

2L cars go pretty well. The Vitesse (and GT6) Mk2 engine is the best of them. If set on a 2.5 be aware that they really need longer gearing (as Clive already said) and that the standard transmission, gearbox especially, is already on (or beyond) its torque limit with the 2L and doesn’t last very well behind a 2.5. That black one looks nice but £15k..... Nick

Me too...... Not sure how the outgoing oilway can be misaligned. The flat covers pretty much the whole width and the groove is elliptical..... Looking at your video, I would also say that assuming starter cranking speed with plugs out, the oil delivery is fine. Nick

The oil way that feeds the rear cam journal reduces to around 3mm where it enters the cam way. The path on up to the head is further “obstructed” (metered even) by the flat on the cam and spiral groove in the cam journal. This by design...... so suggesting that the flow to the head is restricted....... by intent? My mileage on Triumph engines using this rocker feed arrangement is well into 6 figures and virtually all with only the standard feed. A short interlude with an external feed on a 1500 (in a Herald) was notable for its smokiness. Turned out the reason the front few rockers were getting no oil was that the back ones were so worn the whole of the metered volume was escaping within the first four. Fitting the external feed practically filled the rocker box with oil........ The penny dropped and I fitted a less knackered rocker assembly. The flooding stopped. But then I didn’t need the external feed either...... Nick

It’s not hard to clean the oil galleries on these. Just means removing some threaded plugs and the oil pump/distributor drive bush. Also very easy and direct access to the rear cam bearing if the core plug is removed. I would do this whenever an engine is dismantled for refurb and with especial care when there has been an oiling related mishap. I’d be amazed if your engine guy has not already done this. I can see problems occurring with the front bearings if the oil pump/relief valve are compromised as low oil pressure would lead to reduced flow at the end of the line. However I’d reckon that would involve pressures of less that 20psi (as measured in the usual spot) at higher revs. Nick

Oil pressure gauge take off is T’d off from the factory switch position. It’s still blanked off in the pic above which is no doubt why you are puzzled. The gauge itself is in the dash..... combined in the temp gauge. The ring main feed is taken from the large (3/4” UNF IIRC) blanking plug in the main filter outlet gallery to make sure it’s not robbing anything else. Nick

So I plagiarised my own post from Sideways. This is relevant because it illustrates that path from the main filter outlet gallery (which is HUGE) to the rear main and rear cam journal, is short and not shared by anything else, apart from the rocker gear, which is fed from the rear cam bearing. These areas have the best oil supply in the house..... Quote The pic shows the block side on. I believe the critical area to be the longitudinal oil gallery shown by the green line. It's 11mm diameter all the way along, except where the shaft bushing passes through, where it's actually bigger due to being able to go both ways round the bush. More specifically it is the shorter section of this, indicated by the white line, between the point where it is fed from the oil filter (other green line joining) and the shaft bushing which has to feed 3 main bearings, 5 big ends and 4 cam bearings through one 11mm gallery. While it's adequate for road service with decent bearing clearances, at high rpm and/or when bearing clearances are bigger I reckon this is the real bottleneck. What the octopus does is bypass this. In fact, I suspect that the octopus is probably overkill. I reckon that connecting a single external line (purple dotted line) from the feed gallery just above the oil filter to the front main feed giving a ring-main effect would be enough - if only you could get a big enough connection into the block at that point. The octopus still scores in that by taking oil to each main feed point, you don't need to worry about individual flows so much. Another approach, and I seem to remember Steve that you did do quite a bit of work on this a while back, was to enlarge the longitudinal oil gallery by drilling it out a bit. Challenging due to the length. However, I'd say that you'd win a large part of the benefit simply by drilling the rear section up to the bush. If you could push that a bit further, just up to the next cam feed or even just chamfer the entrance to the next section, then you'd gain a little more. The front section doesn't matter nearly so much as it's feeding much less. Now I'm basing this on 30 minutes poking around the oilways, vs. years of hard, real-world trial by racing, so feel free to shoot my theory full of holes..... What I'm wondering now is whether I can be bothered (and be brave enough to risk hurting what is a pretty much fully prepared block) to drill that first section bigger. This is only a road engine and while it'll doubtless get a good ragging, the old one has withstood the same treatment for years....." What I actually did, rather than than drill any oil galleries was to take turn my suggested purple dotted line above into an actual pipe..... Octopus lite..... if you like. almost 20k miles in and it hasn't blown yet. There are some tough miles among them, including over 200 on track. That has led to some low oil pressures, but now I have an oil temperature gauge I know why...... Nick

Just to clarify...... your failed bearings were at the timing chain end of the engine? Nick

I give zero credence to the crack theory I’m afraid. Just get hold of another standard, used rocker assembly preferably from a known runner and try it on to see what comes through. Alternatively, have the oil-gallery plug out of the back of the head with the engine running and see what comes out. Should be a steady trickle rather than a gush. Nick

+1 for the flanged nuts from Minispares. I’d consider those essential. The studs should go again unless obviously damaged. Does it seem that the head might have been off recently? What symptoms other than white smoke? Header tank like a jacuzzi and smelling of fumes? Water loss? Loss of compression? Does the car have a brake servo fitted? Nick

Best deal available I think. Nick

1 & 2 are the front two cylinders and furthest from the pump in circulation terms. All pumps should be measured before fitting. New might mean unused, sadly does not guarantee fitness for purpose. Measuring is quick and easy and involves only feeler gauges and a steel rule. Excessive gear end float can be corrected by lapping the housing. Excessive clearance between gears means bin food. Nick

Strange. 5 and 6 are fed from different main bearings and both of those are early in the feed path. I have heard of others having problems with no.5 but we never really got to the bottom of why. It was a competition car and surge was one suspect. The other was that the oil was not hot enough (hillclimber). Are the crank journals ok? Be aware that quality control on the new pumps is patchy. They need careful measuring before installing and sometimes some of the casting flash removed from the internal passages. Hope all goes well tomorrow Nick

As above, or no foil coating at all. To answer you question though, I’d have the foil facing the manifolds as I think the other side is more likely to stick and by doing it this way you just might get more than one fitting out of it. Nick

You do know that there isn’t meant to be much oil flow to the rocker gear don’t you? The other irony is that when your rockers and rocker shaft are good, even less oil is visible as the close tolerances limit the flow at the exit points. Nick

New ones are different to the originals with no parts interchange. Sealed for life, non-repairable. Dunno if they are any good.....

Beware that the 5.5” Wheels come in at least two different offsets. The set I have would cause problems one the front of a GT6 or Spitfire with 175/70 tyres or least be extremely close. This means they’d probably also be really close at the rear on a swingle axle, long shaft car. They are perfect for the rear of a short-shaft or rotoflex car so I’m using them on the rear of our GT6 and Spit (both Roto rears) with 5” on the front. In the OPs case I’d suggest sticking to the 5” which are easier to find, more reasonably priced and will fit.

Oh yeah, one of the weirdest seat/pedal/wheel alignments out there. I don’t notice as I’ve been driving them forever but whenever anyone new gets in the Vitesse, there is always comment passed.

Provided you don’t heat it to more than 100 C you won’t hurt the seal. The tap it on with a dead-blow, or at least soft-faced hammer. Maybe worth just checking the splines (male and female) for burrs and dressing any found with a fine file. These shouldn’t take much force to fit.