Banksy82

Getting on with building up the engine and all was going well until I got to the oil pump - photos below. End float and outer rotor to body clearances all good but inner to outer rotor clearances are at 13 to 14 thou, book max is .010. I do have a second early iron body pump from a Herald 1300 which is well within all specifications (only 4 thou on the rotor to rotor clearance) but a couple of points are niggling me. The rotor length is shorter than the later aluminium bodied one. There is no strainer on the pickup. (I have seen sumps with a hole/filter combo built in but I don't have one of those. I am wondering what the best course of action here should be? I have read that some of the new pumps don't meet specification right out of the box so I am uninclined to spend £60+ on an aftermarket pump. I'm between fitting the Herald pump and risking the alloy repair kit here: https://www.jamespaddock.co.uk/oil-pump-repair-kit-alloy-body-pumps-3 As a reminder I am building up the 'best I can with what I have' to get the car back on the road so that I can enjoy it while I complete a full rebuild on a second block to a roughly MK3 standard spec so this is not a 'forever' solution - I understand the 1500 angled pumps to be preferable so I will probably look out for a good used one of these for the 'new' engine. Does anyone have any thoughts? Karl

Will do. I'll wait until it is back together and there are a few miles on the car before posting it here but I'll keep a record of part numbers and photos should it be successful! Karl

Very little to none, I will mic them up anyway but I'm calling the laygear good! This is exactly the plan, received some bearings and sleeves yesterday and turned up a dummy shaft. With the 19mm bearing and hardened sleeve the 'wobble' of the input shaft on the top is less than with the original bearing (all rollers still at dimension) on the worn shaft so the play will be better than before. It just comes down to how much weakness removing 0.7mm from the shaft diameter will cause, I will make sure there is a decent radius at the end of the tip and given the type of driving I am going to I'm happy to risk it!

I'm sure there is wear but the surface is smooth and unmarked so for now I'm going to settle for it. I will mock up some options with a dummy shaft to test possible repairs! How true this is! Good idea. Wish I had done that before putting them all back!😁

This sounds like the best repair to me as it replaces both bearing surfaces with new hardened races to correct tolerance. I don't suppose you remember the issue number off hand do you? I'm also considering a similar repair but maintaining the original input shaft bearing surface. I am very much trying to complete this on a budget and I can probably complete my fix with the machinery that I have whereas boring out the input shaft is beyond my capabilities and I would have to factor in machining costs. I have some bearings and races on order and I will be mocking up some options to decide viability! PM sent!

Gearbox assessment done; most things look good and all of the end play values are within tolerance. Layshaft and lay gear cluster inner races are both good. The only issues are the mainshaft tip (hopefully a passible solution found - if not new shaft from Canleys) and the reverse idler gear has damage to 3 of the teeth - image below - the straight cut teeth on the synchro hub and on the layshaft are thankfully all good. Which leads me to three questions: Plan is to replace the idler to prevent possible damage to the more expensive / unavailable parts that it meshes with - Paddocks have it in stock - are there any known issues with these parts? Main bearings are SKF units which seem to be unavailable, are the replacements from Paddocks or anywhere any good or am I better off reinstalling the ones I have taken out. They seem smooth enough under the kinds of pressure I can apply by hand but I know this doesn't always show up a bad bearing! Is it worth replacing the needle rollers in the layshaft even though everything looks good? With those sorted and some gaskets and gearlever balls/ washers I should be good to go! Thank you all!

Thank you both - good to know. Hopefully I can repair!

Good to know, it is the Main shaft for a 3 rail 4 synchro D type OD box I haven't called yet as I hope to fashion a repair and do not want to waste anyone's time unless I am likely to make a purchase. I should probably clarify that I am not suggesting that the quality is poor - I just don't know!

Canley Classics have the shaft available for about £190 (quality unknown) so more involved machining starts to become less economically viable...

Definitely the sensible choice!

There do exist drawn cup needle rollers in 16mm O/D that I suppose could be Loctited into the input shaft but their I/D is 12mm max and the diameter that the shaft would have to be turned to to fit a 12mm inner race on would be (in my mind) too small! On top of that I would be a little worried about alignment!

Fabulous! I was looking at inner races all of last night but didn't think to go larger and metric! I have just spent some time looking at these and it looks like the sleeves are available in 12.5mm an 16mm lengths (the 0.5/0.75 cage I have is 15.9mm in length and it can't be held tightly end for end or it wouldn't work. The caged bearings themselves are available in 13mm or 17mm lengths - I would guess that the 17 would be too long so would have to settle for the shorter 13mm All of these things are reasonable priced so I think I will order some in and ponder them on the bench. I can make up a mock shaft tip from mild steel just to check the fit in the input shaft. The next question is my cheap carbide tooling up to turning the shaft tip!!

Thanks - I'll do some forum digging!

Just been down to my local engineering firm (not engine / gearbox specialists) and they reckon they might be able to sleeve with something... It will probably cost me in the region of £90 and they are not really sure what to sleeve with. Do you have any idea what your friend used as a bush? Additionally does anyone know what the correct dimension for the mating bore in the input shaft should be? Mine measures .7512 (a thou and a bit over the - I assume 3/4 nominal) is this wear or normal running clearance? Thanks all.

Thank you. I’ll give him a ring!

BINGO! - Main shaft tip looks like it has been chewed by an angry beaver... Layshaft seems in surprisingly good condition - the fretting in the 'photos is where the shaft meets the casting of the box; where the rollers run is pleasantly clean. Shame really as the layshaft is £30 and the mainshaft is £200! Additionally - and it comes as no surprise - the drained oil was golden with synchro wear. Lots to mull over this evening...

Thanks all, I guess I am at least opening up for an inspection… It may be worth pointing out that the whine is only noticeable when stationary and in neutral. (Clutch out) Goes away with clutch in. As soon as the car is in motion it either isn’t there or unnoticeable over other general noise. I’ll open up and have a look. Getting to look at the main shaft tip looks to be straightforward. Karl

Noted! Just been out to the workshop - I have about 90thou movement in either direction when I 'waggle' the input shaft with moderate force by hand... I take it that it is the needle bearing that fails and takes out the mainshaft tip with it?

Good to know - I think I'll just turn up a 5/16 pin from stainless with a head small enough to fit down the main bore in the casting but bigger than the bore in the bronze bush just to prevent it ever falling through.

Thanks for all of the engine input - I am likely picking up a second short engine in the next few weeks. The plan is to build up the best of the two with minor replacements - bearings, thrust washers etc and get the car back on the road while I rebuild the other. Time then to turn my attention to the gearbox and O/D. It is a 3 rail with a D-type overdrive with two known issues before removal. Whining noise when out of gear - disappeared when clutch depressed. I put this down to release bearing - but I guess could be the excessive crank end float as someone mentioned previously. When first started overdrive takes some time to engage but this improves with time, after 10 mins of motoring it flicks in and out just fine. After separating the box from the engine I discovered that the clutch arm was flapping about in the breeze with no pin at all. Plan is to generally clean the unit and then to replace the throw-out bearing anyway as I already have a spare that came with a NOS clutch that I have and then replace the missing pin.... The Moss catalogue talks of a tolerance ring, I'm guessing this is the wrap of steel in the clutch arm itself and then the pin is simply prevented from falling out the bottom due to a friction fit / force of habit? Does anyone have any experience of this? It feels like a recipe for missing pins but I'm thinking Triumph must have had a reason for this arrangement. Along with this is there any other recommended work / tests / measurements. Thanks again Karl

Yes, I don't see why that wouldn't work. With the amount of wear in the bores I would feel apprehensive about moving any of the rings from their current location as they must have worn to the same shape as the bores - I feel like I could make thing worse (probably already have!)

That is interesting and might change things a little. I don't explore the rev range anywhere near that much (5500 from time to time) so if I can obtain a better block than mine quickly I may be better off installing that in the meantime and rebuilding mine with an improved cam, rebore and crank grind. The car would then end up with the 'correct' engine (Not that it matters much!) Thanks for all of the info - really helps narrow down some options!

I'll bear that in mind! Even with some extra to cover your work and the needles I imagine that would work out more reasonably than I've seen elsewhere. Thanks

Fantastic resource! Thank you! It looks like the Early and Late MKIV heads are very similar (the late one I have having a larger intake valve - bigger is better, correct? 😀). From the workshop manual it looks like the major differences between early and late are the valve timing (camshaft) and the advance curve on the dizzy? I'm feeling the start of a plan....

From what I can tell from reading various sources the MKIII (small journal) and Early MKIV (large journal) engines had similar power outputs (measured differently apparently) with the later MKIV Engines (mine) being down on power from the previous ones (does anyone know why? Head, cam?) Small journal Herald engines seem to be better value than the original MKIII spits, the question is can I put a MKIII profile cam into a herald 13/60 small journal and use my late MKIV head to achieve a similar free revving engine to the MKIII? I don't particularly want to spend extra cash on the first two letters on the block if I am going to have to rebuild it anyway??