can't go above 60

[little_pete]

No I don't though it's times like these I wish I did, is there a specific way round for the manifold gasket, one side is rougher than the other, though not too much difference, hmm perhaps I shouldn't put the inlet manifold on yet so I can take it to the nut and bolt shop to get t he correct nuts, that angle grinding is hard work, thought it would take 10 minutes.

[bmcecosse]

I used a hacksaw....then tidied it up with the angle grinder.

[little_pete]

If I had a vice I might have been tempted but I was just holding it down on the floor with my foot, (very elf and safety, I wore googles though) I like my eyes the way they are. Turns out I need a new throttle and choke cable, just too short.

regarding the exhaust, I used fire gum stuff I hope it is leak free now, not too confident. But I was expecting an exhaust hanger towards the front to take some strain from that clamp, mine only seems to have 2 one forward one aft of the rear silencer (very precious rear silencer). I presume it's wise to add one towards the front? maybe I can utilise one of the seat mounting holes, what size thread should they be? for now I've left my trolley jack underneath and the exhaust is now well clear of the body.

How does one connect the breather from the the tappet cover to the hif carb? the tube from the breather is significantly larger than the one on the hif?

[bmcecosse]

Either a new tube - or a good Jubilee clip... I just extended the choke cable inner, and a good long 'easy sweeping' accelerator cable is wise anyway.

[little_pete]

OK a rather sad update....

Have now git a Hif38 on with alloy manifold no air filter sorted yet and the hole on the manifold for the servo (non existent) is now plugged with a temperature sender. Accelerator cable is quickly thrown on but needs setting up I only get about 80% throttle and there is no choke cable set up. Anyway I can start it and let it idle for 10 minutes engine feels warm enough but not as warm as on a full run:

Hooked up the compression tester and the results are not too promising:

Dry:
1 2 3 4
135 130 137 130

Wet:
1 2 3 4
145 140 140 135

Not too great? new piston rings? or would warming it up after a good ride show different readings... I need to sort out my choke and accelerator cables and get an air filter sorted.

I was hoping for valves as I had another cylinder head to put on anyway

[bmcecosse]

Not great readings - was the throttle held open ? The engine really needs to be in good condition before it's worth trying to improve the power output.

[little_pete]

Yes I know, biggest power increase I can do at the moment is to get my engine running closer to standard. throttle was open but as I say can only do about 80% until I finely adjust the cable, but I think it's open enough to let the air through.

So I have a relatively shiney looking 940 head (not fitted yet), whats the verdict. new piston rings (I know you say it's a home job but I think a little beyond me for now) or whole new refurbished short engine? again I'll be enlisting the aid of a garage to do the swap.

I just did the compression check with a couple of seconds, is this enough? surely it gets up to compression the first full revolution?
battery was seriously flagging by no.4 on the wet.

Was hoping for good readings to rule out any major work or point to the cylinderhead which i was to change anyway

Oh well better to know than be pulling my hair out trying to find those missing horses.

[bmcecosse]

Did you have ALL the spark plugs out? The battery needs to be good/fully charged - can you add jump leads from another vehicle for the test? You should crank it for a few seconds on each pot. And yes - throttle slightly open is fine. If the engine doesn't smoke/burn oil - there is really nothing to lose by trying the 940 head on it. Go for it!

[little_pete]

All spark plugs out, couple of seconds each cylinder throttle open. The engine doesn't really burn oil unless really revving so perhaps that is a yes? Adding the new head would probably solve a few gas leaks but really I want to do the best job for the long run. Which I guess is piston rings/possible rebore and then if I'm paying a garage to sort those out how much more would a decent short engine be to shove in?

[bmcecosse]

The readings hardly changed 'wet' - so I don't think there is too much wrong with the bores/pistons/rings. And all are 'similar'. Fit the 940 head!

[little_pete]

OK thanks for your advise and giving me a little more confidence, I'm away now for two weeks, but will look at getting the head skimmed and take on the project when I get back, not much to loose only time and a couple of gaskets right? While I'm there I guess I check for scoring on the bores and any excess play in the pistons? or anything obviously wrong.

[bmcecosse]

Why are you having the head skimmed - is it damaged on the face ? You do know about the need for 320 thou clearance on the ex valves? If you skim it - this will be more difficult to achieve without sinking the exhaust valves.......

[little_pete]

I have a scratch on it, I can see and feel with my nail, it goes across a water or oil hole and into one of the combustion chambers, was worried it would provide a track for water/oil. I was under the impression there should be no defects like this? perhaps I don't mean a skim just finished or dressed or whatever you would call the final step after skimming would be.

[bmcecosse]

Ok - well if it's just a finish grind of say 5 or 10 thou. The compression ratio with this head fitted will already be quite high - without any 'skimming' making it any higher. But do check for that ultra important 320 thou clearance.

[little_pete]

OK update, So I've added a new inlet manifold hif 38 carb, the hole for the servo brake take off on the manifold is actually plugged with a temperature sender, but it's plugged. (the part I ordered for it from minispares wouldn't fit, but I'm sure it's supposed to be the same thread looks very course compared with the temperature switch I've shoved in)

Anyway so I ran it, it goes OK up can get over 70 now which I'm happy with. But there are flat spots around 60 in 4th though the carb hasn't been fully adjusted yet (running AAA needle), see below.

First issue which is different from before the plugs, seem to have gone haywire, they used to be all a similar colour and a little on the lean side. I know new carb needs to be set up, Hence my plugs are sooty mainly from idling so much I would say it's running a bit lean now. The major problem is Plug 2&3 seem to be much richer than 1&4 with plug 3 look so sooty I thought there was no spark from the spark plug, so I swapped it with 1 and the plug in 3 immediately when sooty, no 1 plug started to get a lighter coloured tip, so the plug works. For the leads I plugged off no. 3 with my hand and it gave me a nice tingly feeling so I think every things fine on the sparking side.

(I put, new dizzy (with electronic ignition, new coil (just because it was cheap in a bundle) and new leads. Also renewed the cables a little around the dizzy, All tested before changing carb/manifold) Put a new fuse box and new fuses in as I was having electrical issues (fuel pump not on etc) which remedied themselves when wiggling the fuse box.

Anyway back to the plugs (looks of soot but it's been idling lots and on choke to heat the engine and then set up the carb)[frame][/frame]Plug 1 (it's very sooty as it was in 3 half a mile ago)

[frame][/frame]Plug 2 (I'd say very rich)

[frame][/frame]Plug 3 previously in plug 1 and was running lean half a mile before this image. I'd say very rich to no spark

[frame][/frame]Plug 4 too Lean but getting there


The only thing cylinders 2&3 share are an exhaust port, would a leak in this port cause what looks like rich running?

After the plugs there's the timing/rumble. Now the timing alters the rumble. If I turn the dizzy clockwise (I think this is advance) then the engine picks up revs, If I leave it at this picked up revs I get an awful rumble under load. If I back it off the revs drop and I can tune out the rumble, to make it very difficult to happen but the engine feels slightly less lively. Initially thought the rumble is the exhaust against the body but I can confirm it doesn't touch the body any more.

Still can't get the pinking, there is a little tinkle (which just sounds also like a rattle) under load but it doesn't seem to change volume/pitch or rhythm with the engine revs/more load.

Any advice appreciated. Supposed to drive to Germany at the end of July and want to get some miles on the car to get more confident with the engine. I have a 12g940 head waiting to go on but don't want to make too many changes at once.

[bmcecosse]

The carb is probably a bit too big until you fit the 940 head - and the AAA needle will be too rich as well right now - but will be better with the 940 head. . The 'black' looks like oil burning? The light rattle is very possibly pinking -the rumble needs to be investigated. What's the oil pressure at 40 mph in top gear after a good run?

[little_pete]

The black is sooty black, I thought that was petrol/rich or unburnt and wet black was oil? or is it the other way around or is it not a simple as that? What would you suggest another compression check? but I did one before the carb and manifold were put on? although not great they were all pretty similar.

Is anti clockwise on the dizzy retard? I don't have an oil gauge attached right now but the oil light doesn't come on on hot idle or with the clutch down (slows engine a little) and turns off very quickly on start up. My old mini used to have to rev a little on first starting to get the light off but then it never came on again.

[bmcecosse]

Oh well - if sooty it is richness. Mixture distribution on these engines is far from perfect..... It's what makes them slightly less efficient than F 1 engines - well that, and the lower rev limit........

[little_pete]

Oh well I hooked up the old oil pressure gauge straight away reading over 50 revving a little it gets to to 75 warmed up it idles at just below 50 (sitting for 10 minutes choke off and rad top hose hot). Was about to take it on a run when I felt below the oil gauge nut for leaks and there was a tiny little bit of oil, so I attempted to nip up the brass nut and in doing so stripped the thread (foolish boy) so now I've had to disconnect the pressure gauge again.

I tried to test with the oil light after a run turn off waited and then back on again light goes out instantly. Also went in 4th gear 'till 15mph with no throttle to really slow and labour the engine the light would not come on. (just going by my old minis light used to come on if you dropped the revs with the gears)

Other observations I pulled back the timing even more the rumble is very hard to hear and I wouldn't be able to have spotted it over the exhaust if I didn't know it was there, but too much lead foot just makes the car hesitate.

After idling on choke to heat up I revved the engine a few times alot of smoke was evident looked white with a slight hint of blue couldn't tell if it was unburnt fuel or oil. Once I'd been for a run and tried again there was no more of this smoke.

Should I be looking out for a new bottom end? any ideas? Not confident with this engine, might have to take it to someone who knows a bit better than I do.

Thanks for your help with my amateur mechanics

[bmcecosse]

Well it sounds like the oil pressure is ok - but a full gauge test would be a good idea. I doubt it needs a new bottom end. But the AAA needle is 'designed' for a modified engine and will be too rich for a standard engine.