All Spark and No Bark

[FridgeFreezer]

13 hours ago, ThreePointFive said:

What else can I look at (or is that a huge question and I just need to keep reading on here)?

Honestly it's not a big problem at this stage, if your timing is still fairly unknown and you haven't touched the fuelling (which you shouldn't until the timing is right) it may well hunt.

Once things are further along you can prevent hunting by a little tilt of the fuel &/or spark tables, someone better versed in tuning can probably explain it better but even fuel-only a small tweak can give a rock solid idle;

Basically you slope the "idle" corner so that if the revs drop or the load increases, it goes slightly lean, which will tend to make the revs pick up, and it will kind of self-stabilise. Go too far, or not enough, and it will bounce around "hunting" like yours is. Mind you, 1300rpm isn't idle so you need to wind the idle/bypass screw down until it idles about the right sort of RPM even if it does hunt.

[ThreePointFive]

Small steps towards progress, thank you.

Took the stepper motor out and it was partially open (because of course it was). I took a rubber bush I had lying around, sanded it to size and slid the stepper shaft through it, now seems to seal up the hole and it can't get sucked into the engine as it's held around the shaft.

Revs are now 500-ish and while starting is more of an issue, it does start and I dare say it's no worse than the carbs with the choke. I don't think I'll need a PWM. Hunting is now +/- 100RPM and the rev counter/MS agree, it's also smoking a hell of a lot less though it's working half as hard so that's no surprise. That meant I could run it for long enough to get some heat into it and the temp gauge was working all along, it seems.

However, as always on this build it's three steps forward and one back, so I have a loud clicking which seems to be coming from the top of the engine, passenger side rear. It's linked to revs. I took a short video but it sounds like cam to me.

 

Total top-end rebuild required?

[Bowie69]

Sounds far too like an exhaust manifold leak to me.

Assuming the lifters have oil, they rarely get noisy in these engines, no matter how worn the cam has got.

[FridgeFreezer]

5 hours ago, ThreePointFive said:

Total top-end rebuild required?

Crikey you're an optimist aren't you?

I'm with Bowie, and my personal experience is the exhaust manifolds and downpipes are an utter PITFA for ticking and pinhole leaks.

[garrycol]

Always look for the easy things first - 80% of the time it will be easy.

So I am with the others - check exhaust manifold first.

If still there, I would be thinking sticky lifters - first put in sticky lifter additive into the oil.

If still there, rocker covers off and check clearances

And then on and one - do the easy stuff first - starting with the exhaust because like the others it sounds like exhaust pop to me.

Garry

 

 

 

 

[Bowie69]

Yep, listening again, with better speakers, definitely sounds like exhaust.

 

[FridgeFreezer]

3 hours ago, garrycol said:

If still there, I would be thinking sticky lifters - first put in sticky lifter additive into the oil.

Before adding magic goop I'd just wait until the thing's driving and give it a rag - when I rebuilt mine a couple of lifters didn't pump up, sounded absolutely awful until I gave it a couple of blips to ~4krpm at which point they pumped up and it all ran like a sewing machine.

[garrycol]

Yes good point 🙂

[Chazza]

Lifters need at least 2000rpm to get filled anyway,

Cheers Charlie

[ThreePointFive]

Welp, it's not the exhaust manifold so that's sorted.

Up for ragging it as long as it's not a choice between it freeing up or self destructing across the garage floor.

[keeley75]

On 7/17/2020 at 5:23 PM, ThreePointFive said:

However, as always on this build it's three steps forward and one back

You’re actually at a really good stage..

It runs, you have scratch built a wiring loom and made an oddity of components work together.

Tapping noise aside.

Im sure it’s been said already. Check the timing using Tunerstudio and a timing light. Once you know that’s bang on and correctly calibrated in the ECU move on.

Don't do what I did and try and tune it all at once. Also ensure when the engine is running and trying to tune it. Make sure everything is switched off in Tunerstudio.

For instance I was trying to tune the fuel and things like MAT or WUE compensations were also trying to do their bit. 
It’s taken me almost a year to fully get a feel for Tunerstudio and what stuff does. There are so many settings that can be tweaked you can easily lose yourself.

Just get it timed right. Stable idle and keep things simple it will all slowly come together.

 

If it helps. Our build are very similar except I have a H180 camshaft fitted. I can send you screen shots from tuner studio to get you close’ish. 
 

If it really needs a top end refresh that won’t take long maybe an afternoon. enjoy....

 

[ThreePointFive]

I am unsure what to do next, so screenshots would be really helpful, thank you.

I'm having an enthusiasm slump with the whole thing at the moment. I know it'll be short lived but I don't know what course of action is correct.

I have still got two weeping core plugs which are a lot better now I've put some heat through everything but not completely solved. The tappet noise is even worse after a 5 minute run with some very reasonable blipping of the throttle (it's very loud, I didn't want loud...) and the exhaust on the passenger is so tight up to the chassis leg that it's worn through the exhaust wrap already.

I'm at a good point now to take a look at the top end, make sure there's no glittery bits appearing and replace anything if I need to. To do that, I need to drain the coolant and if I do that, I might as well do the core plugs. If I'm doing the two weeping ones, I might as well do the other three on the driver side.

I really need to get it on an engine stand to sort everything (which I don't own), £20 in brand new coolant lost and taking apart a lot of what I've put together over recent months but then everything should be sorted. Struggling for room in the garage so this is far from ideal.

Or I can keep building things up, get it ready for an MOT and give it proper runs to get everything hot, which may solve the tappet and core plug issues without any need for work. However, if that doesn't sort them and it turns out I do need to take the thing apart, I then have a lot more stuff to remove including bodywork which will inevitably get scratched and damaged.

I hate the idea of taking apart what I've already done, but I hate the idea of taking part a finished car even more.

Oh and my bottom oil cooler outlet on the engine will not seal. Risking the threads if I tighten any further and I've used O rings, so this is a problem.

Not the biggest dilemma to ever be faced by humanity, but a gigantic pain in the arse.

[FridgeFreezer]

Been there done all of that, and more than once!

It's disheartening as hell when freshly built stuff has to come apart or doesn't work right but there's no alternative if you're doing it right (which so far you very much are) - you've just got to "embrace the suck" as they say and crack on with it. But, don't beat yourself up about walking away for a few days, or doing something else like tidying the workshop and generally re-aligning your chakras as you can get to a point of "all work, no progress" and that's no good for you or the truck.

Sometimes just downing tools and tidying the workshop lets your brain relax and a solution to a problem will suddenly pop into your head purely because you stopped staring at it. Just like many of the best ideas happen in the shower or sat on the crapper

These days I never fill coolant until I've run everything up with straight cheap water to check for leaks, but I learned that the same way you did... also I buy coolant (and oil etc.) in 20L drums now, it's often only slightly more money than a 5L jug and it hurts less when you don't have to go out and buy more every time.

Not sure what your oil cooler outlet looks like but is it possible it's got a little debris, a pinched O-ring, scored fitting or somesuch? When I blanked mine off I had to turn down the blanking plugs by a couple of mm to get them to sit in the hole & seal and not just bottom out in the threads.

Exhaust-wise, is it possible you've got the engine/box canted over or across slightly on the mounts? They've all got adjustment in (Land Rover tolerances) and it's easy to end up with everything sat over whichever side plopped in first while you were wrestling with the engine crane. We've used large thick spacer washers before now to bring stuff to a better level on standard mounts, there's no law against it

[ThreePointFive]

Bah, I hate knowing the answer deep down and then having that answer confirmed. I think that does it, engine needs to come out and have a proper sort-out.

In a week's time I'll pull it out, leaving the gearbox in place and stick it on a stand, I was going to buy one anyway so that I can rebuild the original 3.5. If I'm not struggling for access I will have a better chance of getting the plugs properly seated, which I am sure they were but this time I will do some surface prep to make sure there's no gouges causing the weeping. 

Other fun issues that have cropped up is the resistance on turning the engine over by hand is not uniform throughout the 360 degrees of rotation and I'm getting a rhythmic clunk when running it on the starter, so I need to look at that urgently. Should I be able to inspect the bottom end just by taking off the sump?

Yesterday I also saw that I'm getting a release of compressed gas up through the inlet manifold on number 3 just turning it over, so I'm guessing that's a valve or cam wear issue. This was with everything disconnected so it was only air and I hadn't seen or heard anything prior to now.

This is no longer an MS issue so I'll update elsewhere once I get going, but I will do all the research on this stuff so I'm not spamming the forum.

 

[Chazza]

I take it that this is an engine new to you?

If the tappet noise is getting worse as it gets hot, then suspect that the liners have come loose. In any case I agree with you that it is time to investigate the tight-spot. Did you try turning the crankshaft with the spark plugs out?

The gas in the inlet manifold has to be a; burnt valve or seat; or incorrect valve timing; or something wrong with the rockers and rocker pedestals.

If you need to strip and reassemble the engine, have a really good read of this, best advice I have ever found on the net, and buy your parts from Turner Engineering.

Cheers Charlie

  

[FridgeFreezer]

I had assumed given how thorough you're being that you'd had the engine apart and checked/freshened stuff up as appropriate.

The issues could all be linked - a lifter or two or three not pumped up so not lifting makes a nasty noise and would lead to rough running and uneven resistance when turning it over.

Whatever, once you've pulled the engine out you can have a proper look, pulling the rocker covers is an easy 1st step to see if everything's moving as it should, next step is inlet manifold which is just one big lump and gives you access to the cam & lifters, TBH there's not much more to a Rover V8. I'd be surprised if you've damaged your bottom end, especially if all was fine before you started.

I can recommend V8-Tuner for parts, I think the chap who ran it died recently but I believe the business may be carried on by his partner.

Real Steel are OK for parts too.

20 hours ago, ThreePointFive said:

but I will do all the research on this stuff so I'm not spamming the forum.

The forum's here for research posts, I say spam away!

[ThreePointFive]

Chazza, correct - engine completely unknown to me. Can't recall if I did try with spark plugs out, I suspect not but did have the exhaust manifolds off. 

Fridge - The engine was always the bit I took the biggest gamble on, never had a look beyond under the rocker covers and the valley. I got it as an alternative to the 3.5 that definitely needs a rebuild so it was always a risk, but I didn't (and still don't) have a clue about the procedures for taking engines apart/rebuilding them.

Are there any manuals that would be worth obtaining?

To properly inspect it will I need to buy all new gaskets?

If I'm looking at slipped liners, I take it the engine is junk at that point. £5k for a rebuilt Turner one is both extortionate and very reasonable depending on if you account for how much it won't increase the value of the car.

 

[FridgeFreezer]

Rover V8's are incredibly simple and easy to spanner on, they're a 1940's engine and honestly not much harder than faffing with axles etc. - just keep stuff clean, keep dirt out, use gallons of brake cleaner on everything and mark what came from where. The RAVE overhaul manual on the Rover V8 is pretty good (PDF attached), honestly there's very little to them at all - correct sequence of tightening bolts and correct torques on head bolts is about it.

If you have rubber rocker cover gaskets you can re-use them, if not, buy them they're great

If you take the intake manifold off you need a new valley gasket.

People are quick to claim slipped liners on any 4.0 or 4.6 block but honestly it's overblown, and there's people out there re-linering blocks for reasonable prices... although given the price of crusty 4.6 P38's with electrical issues it's hardly worth it and I'd be surprised if the awful racket yours is making is a slipped liner, they're not that noisy.

If you have to take the heads off, new composite head gaskets, exhaust gaskets, and I'd really recommend ARP head studs, they're hardly more than stock head bolts and so much nicer.

v8-46v3e.pdf

[ThreePointFive]

Thanks for that, I am ordering parts now. I have ordered an engine stand that was a bit too cheap, a compression tester that I can use before I take everything apart and engine assembly gloop. Speccing up what I need on Turner's Engineering I'm up to £500 so I want to make sure I'm looking at the right quantities and spending on the right things. Views/opinions welcome:

16x new lifters

16x push rods (not sure if I need these...)

8x Inlet Valves

8x Exhaust Valves

16x valve springs

1x Valley Gasket (replaced 2 months ago but never mind)

1x Camshaft (tempted to get a performance one but had not considered this before)

5x Camshaft bearings

All the core plugs

1x Top gasket set

1x Bottom gasket set

1x Front cover gasket

1x Head bolt set

1x Timing chain

I don't want to do piston rings or anything bottom-end unless I see a problem as the cam is going to be far enough outside my skillset. I'm hoping the compression tester will tell me if there's a problem with those. I just want to be able to inspect things from the sump end and seal it back up if it's all ok.

I also haven't added anything rocker related, should this be a priority part in a top-end refresh?

 

[Bowie69]

Simply, you don't need any of that apart from gaskets.

Disassemble, assess, order parts, otherwise you are throwing money away.

E.g. valves, springs, pushrods all normally fine unless really abused.

Also, often better just to buy the gaskets individually, otherwise you always end up with lots of bits left over you didn't need. Plus, it allows you select what head gasket you want, and get the rubber rocker seals rather than cork, and the later valley gasket, rather than the early nasty tin thing.

When you have it apart, I am sure we all be only to happy to pick over the carnage you bring to us 

[FridgeFreezer]

^ What Bowie said, you're leaping about 10 steps ahead to the worst possible outcome!

Get the rocker covers off (8 screws) and have a look for anything obvious. That'll cost you a pair of rubber rocker cover gaskets.

Then the inlet manifold, which will cost you a valley gasket.

Once you're in there, post pictures and we can all throw buns at each other over what the problem might be.

You don't need to touch the front cover, cam, or bottom end at all at this point.

 

Oh, and calm down!

[Chazza]

I agree with the others.

Do a compression check wet and dry and if it comes up to specifications, leave the bottom end alone for now, unless you can prove that the tight-spot is down there somewhere.

If the camshaft bearings need replacing, then it is best done at an engine re-conditioners,

 

Cheers Charlie

[ThreePointFive]

I am jumping the gun but it's because I want to get it right first time; very bored of putting things on then having to take it apart because I missed something or just bad luck. I also don't want to skimp on a vehicle I am trying to make reliable.

I would have thought a cam refresh was a good idea in any case but will hold off. I've been reading this website, but I do so knowing people hate RPI and they're trying to sell parts for a living so everything is doom and gloom.

Everyone likes a bit of engine gore, so when the stand arrives I will take lots of photos for the entertainment of all.

Worst case, my engine cost me the exact same amount as the exchange unit price for a Turner engine... almost as if it is meant to be.

[ThreePointFive]

The stripdown begins. Taking off the exhaust wrap told a story in itself that I wasn't expecting. The manifolds have gone a pretty nice bronze colour except for rear passenger (cyl. 7) which looks like it's never fired. Spark plug told the same story.

Checked for spark and it was getting it, so checked injector and found a pin had pushed out of the connector. It looks like it never had fuel the whole time it was running but not once did I hear a misfire. I know that sounds stupid but it was running fairly well. I'm not convinced this is the source of my tapping noise though, that was definitely in the valley area.

Photos below, edited out some "persuasion" marks in trying to make it clear the chassis leg - not pretty but it did work...…….

Compression test was done stone cold which I know is not optimal, but I wanted a comparison rather than to achieve top-end figures. I've got half on 125, another 2 on 130 and 2 at 135. Not very even and not very high but I have always considered +/- 10 to be about tolerable, is that the correct approach?

While doing the compression test I started to get some interesting behaviour. The starter sounded like it freed up in some way and went from the normal whirr-whirr-whirr noise to a smooth whiiiiiiiirrrrr (scientific, I know). Turning the engine over by hand, it feels much smoother except one specific point where the resistance is very high and number 3 starts making a hissing noise. Even I can work out the resistance is air compressing and then releasing slowly rather than via the normal exit in the accepted manner. What I can't work out is why the rest of rotation now feels so much smoother, and what is going on with the valves for 3 - they appear to be operating normally.

Hopefully the engine will be out in the next two days and I can start proper disassembly.

[Bowie69]

15 minutes ago, ThreePointFive said:

Compression test was done stone cold which I know is not optimal, but I wanted a comparison rather than to achieve top-end figures. I've got half on 125, another 2 on 130 and 2 at 135. Not very even and not very high but I have always considered +/- 10 to be about tolerable, is that the correct approach?

That all sounds pretty normal, and fine.

Don't worry about not hearing a misfire on a V8, easily done, it is why having an IR thermometer in the garage is very handy.

What does it show under the valve covers? It may be as simple as a broken rocker, for example. From your symptoms, I'd say the exhaust valve is stuck shut. That way you get compression still, but never a release until the inlet valve opens (so back into the inlet....).