[engine_work] I Forgot How Much I Missed It!

[TT205 42]

I haven't time to wade through the topic to look for the reason now but Sandys hillclimb engine pressurised when it was first started didn't it and that was a temporary mystery

[DrSarty 90 1 Cars]

MadScientist also had pressure issues but for different reasons, i.e. 'SuperSeal' rings (IIRC) and dry sumping plumbing. And he had an iron block and GTI6 head too.

 

Anyway: here's a pic of the new lifter packet.

 

 

Attached below are the 2 Emerald power run traces overlaid on a single graph showing what've I've explained above, i.e. the ITBs nicely filling in the torque hole, but the engine power and torque not lifting above previous values and diving off early, feeling strangled.

 

I would welcome anyone more knowledgeable than me explaining whether my current deduction of a massively pressurised block, probably combined with lifters somewhat starved of oil (or being crap lifters in the first place), would create enough pressure-based resistance within the engine to effectively strangle it from producing more torque and power when it should do, based on the modifications applicable (i.e. increased CR, cam timing optimised, new parts (lifters), ITBs, staged injectors and a 4-2-1 exhaust - we should've been seeing around 160lbft and 190+bhp).

nbu pug 205.pdf

Edited October 23, 2013 by DrSarty

[kyepan 291]

on the lifters, i bought a new set, they were prefilled, i drained and refilled, overfilled, and caused no compression on turn over - so lifters can misbehave in unexpected ways.

 

I also suffer from some crank case pressurisation and oil does get spurted out of my crank shaft oil seals on an ITB setup, i've gone for a more agricultural breather system that has improved it, but still, it's not ideal.

 

And on the rollers disaster, i share your pain.

 

Have you stripped the engine down to inspect the oil ways on the gasket yet? do you have a photo of the gasket pre installation we could use to compare?

 

The lifters should quieten within 15/20 mins.

 

How did you deal with cam timing on the dw8 pulley initially?

[brumster 135 1 Cars]

On lifters, when I recently installed my old faithful D6C after several years on the engine stand, it started up naturally 'clacky' (after some initial oil pressure priming, naturally). After a minute or two, no noticeable improvement, but then one quick brief rev up to 4k or so and it went quiet in an instant - literaly snap of the fingers stuff. So to have a noisy top end like that does imply something not right with the followers, or the oil feed to them. I'd only echo comments that the spray bars were installed correctly, no blockages, fully pressed home, etc.

 

On the gasket, I also installed a 3-layer MLS on a recent rebuild of my XU10J4 Longman lump. Despite only ~750 miles of use since original build by Longman, my trusted man-with-the-machining advised me that the head had suffered from the previous MLS that Longman had installed, and very light indentations were clearly visible in the head surface. He recommended an incredibly-marginal skim just to restore the surface, for fears of the new gasket not sealing.

 

To quote him :-

 

Head skimmed as lightly as possible (head height was 131.71-131.74 and is now 131.66-131.68) removed approx 0.07mm – still minor gasket witness mark but should seal up ok – monitor this with future engine rebuilds as you may need a thicker gasket to get more lives out of the head.

 

Could anything like this have happened? I presume you're happy that the head was not warped in any way and the block/head interface was straight and true - but had the previous gasket caused any issues (maybe it wasn't an MLS though....)?

Edited October 23, 2013 by brumster

[kyepan 291]

I also nearly went for an MLS gasket but decided against this on the basis that the head and deck were not freshly machined, the tolerance for deck flatness needs to be very very fine, iirc 10 times flatter than for a normal gasket, as they have virtually no squish, which is one of the reasons i opted for a standard gasket, that and being a little concerned over valve clearance.

 

When you said it went pop, what exactly happened?

[DrSarty 90 1 Cars]

Thanks Justin and 'Brum'.

 

Engine not out and stripped yet, but I will photo and document everything.

 

My breather set up is the same as the 2.2 engine that preceded this and it was fine.

 

We were expecting the lifters to clear in a short space of time, and a few high rpms were tried to assist matters but clearly to no avail.

 

The spray bars will be inspected again, but they were removed and refitted again within the hour effectively with zero changes or opportunities for damage, and I always take great care (and satisfaction) in the getting the nice click as each 'o' ring pops into each cam cap hole. Additionally the bars only fit one way round, and won't pop in properly if fitted the other way.

 

The HG is an issue of concern as stated, and we'll inspect things carefully upon disassembly. I don't have a photo prior to installation (if I had it would've been posted early and I'd have been shouting at the top of my voice if the difference was obvious), which is why I'll have to photo-document with verified time the removal of the head to show its pattern and condition.

 

I am quite prepared to inspect, find and show that I've made an error; it's always more proactive to admit when one's made a mistake, be that a badly fitted or blocked spray bar or some kind of breather problem. But I can't do anything about the lifters, as they should work straight of the packet IF they have an oil feed.

 

Similarly, the HG cannot be fitted incorrectly, can't be the wrong one as it fitted and the part number was thoroughly checked, but it can possibly slip (?) during fitment or be badly manufactured. I've recently pondered if the riveted tabs which join the 3 layers slipped during manufacture making the layers overlap slightly on fitment causing oilway restrictions and possibly piston scrape. As you can see, I've wracked my brains thoroughly on all logical possibilities as fundamentally everything went wrong when the lifters and HG were changed concurrently, indicating they or one of them was a key factor in the failure.

 

I take onboard the possibility of head surface damage or legacy marks, but would that be possible from an OE gasket? Also, the engine ran smoothly (despite the lifter clatter) which maybe wouldn't be the case if there was bad sealing between the liners, block deck and head. And finally, would a poor head to block seal cause the crank case pressures?

 

Removing the head will be educational, confusing or redeeming...

[DrSarty 90 1 Cars]

Oh yes, and on the DW8 pulley fitment.

 

It has a tang with a zero degree marking on it (but unfortunately no other marks to aid adjustment!), which has a hole which aligns perfectly with the OE no.2 pulley locking hole when the woodruff keyways are aligned; so when fitted, it was initially identical to the previously fitted OE pulley.

Edited October 23, 2013 by DrSarty

[welshpug 1,657]

I remember taking apart an XU5 which had been assembled with the gasket the wrong way, it is possible, the engine was very dead.

[wicked 103 3 Cars]

​

 

My cometic HG... Iirc it did fit if you swapped it...

[DrSarty 90 1 Cars]

Because of the dowels in the head, as I stated earlier, it was not possible to fit my MLS HG the wrong way round; and my friend Guy also checked, by taking it off and ensuring it was the correct way round, as it just wouldn't fit the other way and give any indication of water gallery holes lining up. In particular I'm referring to the teardrop shaped block and HG holes in diagonally opposite corners.

[wicked 103 3 Cars]

OK, then you can forget that one...

Btw this is the 'standard' HG, not the thinner one you used.

 

Don't forget the 'problem' could already be in the first setup, but did not show because of less bhp, torque, compression etc...

Edited October 23, 2013 by wicked

[DrSarty 90 1 Cars]

Hmmmm...trust me I've thought that too and that one or more of the changes exposed an original weakness. However it was a fresh engine, still with receipt from the engine builder, which ran for nearly 3 months without a hitch.

 

Torque and BHP at peak did not increase at all really (so negligible TBH), but of course anything can break after time and use. CR increased from 10.4 to 11:1, but I understand this is quite within tolerance, and some are running CRs the same and even higher (up to 13:1 on an iron block).

 

At some point, someone might say I'm being argumentative. Trust me I'm not, and I'm 110% grateful for people's input; but I'm using a diagnostic technique prevalent in the TV series House which uses a deductive reasoning process called 'differential diagnosis', as it will eventually lead to an area to focus on for testing whilst being mindful of outside (odd) possibilities.

[kyepan 291]

On the dw8 you said it had a line which said zero, zero to what though? unless it was dialled in with a vernier that could mean anything. when I initially set mine up I matched the key way and teeth to a number 4 pulley, then dialled in with a gauge from there. I don't remember seeing a zero on it, and was paranoid about it being out... You said later it was dialled in when the itbs went on,is that with a vernier? And how many mm lift did it need and in which direction?

 

Whilst its not probably the problem, if it was way out you could be listening to tappy valves, right from the start and not tappy lifters... As mine was. It ran, but lacked top end and was noisy. This is sounding all too similar.

 

Additionally, it ran fine with the initial dw8 setup, it was only when I later changed the timing onto the stage two cam, fitted it wrong, with some verniers that I bent valves... And that only ran for fifty miles in that tappy state.

Edited October 23, 2013 by kyepan

[DrSarty 90 1 Cars]

On any vernier pulley, the 'Zero' degree mark is going to be relative to a start position. The DW8 pulley mark could equally have been a red blob of paint; the point is, with the woodruff keyholes lined up and the belt teeth aligned too, the DW8 pulley was locked to the head with a pin through the hole/notch on the pulley hub which made it exactly the same as the no.2 OE pulley that was previously fitted.

 

Therefore, to start with, the DW8 pulley was a 1-for-1 replacement, initially identical to a no.2 OE pulley. Lift at TDC etc on either inlet or exhaust was not a specific issue, as cam timing was done on the basis of a no.4 inlet and a no.4 exhaust pulley as advised by PeterT and detailed in the last few pages.

 

With the Piper vernier, with one of the adjusting clamp screws removed, the resulting hole acted exactly like the locking hole on the OE no.4 pulley, and therefore both cam pulleys were locked as per the factory/Haynes specified head removal and fitment process. That said, anything's possible, although considerable care was taken to check this was done well.

 

Any swinging of inlet or exhaust pulleys was done in a kind of 'gently does it, let's see what happens basis'. It's not scientific nor ideal, but we moved inlet first 4-5 degrees retarded first, walked the road wheels round a bit to check for issues, then checked the results. We repeated this and stayed at 11deg retarded on the inlet as we made good gains. We then played with the exhaust cam doing the same and made better gains. At no point that I'm aware of did we ever encounter valve clash to piston or valve.

 

That said, I have considered this carefully and thought a little as you've done, but had to initially rule it out based on the fact that the engine performance was down and the tappets noisy before any changes to cam timing. At least initially then, to be clear, the pulley replacement was effectively a 1-for-1 or almost a non-event, providing I aligned the vernier pulleys to act as exact replacements on fitment, which I'm confident I did, as the car ran fine, if a little tappet/noisy from Cambridge to Peterborough, then from Peterborough to Emerald (over 100 miles), and then several hours on the rollers before failure.

 

You may be onto a contributing factor, but I can't see where as surely an error like this would've shown up much earlier, namely on the drive there or during the testing power runs. And you're alluding to tappy valves, but one has to ask how are they making that noise? Are inlet valves clashing with the piston or the exhaust valves, and if so, how long would this continue without a fairly terminal failure? Would it not be considerably before a thrashing, a 100mile road drive and well over an hour of hard runs on the rollers? I'm asking because I genuinely don't know, but I suspect clashing valves would stop play pretty quickly (?).

[petert 586]

It's hard to tell from your picture, but those lifters look suspiciously like the Piper ones. There's a picture on my website. They would take a long time to pump up if you put them in dry, maybe 20 mins, but should eventually come good. I can't see that any small error in cam timing would equate to the failure. With standard pulleys it could only be +/- a degree or two out. The thinner head gasket will retard the timing slightly if the belt tension isn't taken up equally on both sides. I know this, as I have to use offset keys when I deck blocks 1mm.

[kyepan 291]

When I bent mine, Ant said it could last 50 or a five hundred miles, as he has seen both. Many six engines with inexpertly changed cam belts tap for life, or at least until they drop a valve head and make a big mess, either way they can go on for a considerable time if not placed under undue stress. So it depends on the severity of the bend.

 

If the belt teeth and keyway lined up, you're not going to be a million miles out in both pulley cases, hopefully not enough to bend anything on an MI-16. I bent mine turning it over by hand, but had the inlet exhaust cam I was using as an inlet 180 deg out.

 

Based on the description of the pop, i would guess its dropped a valve, the head is in the combustion chamber, and there is a possible hole in the top of the piston leading to the oil smoke. Have you had the plugs out to look down the wells? if the engine was in a state to compression test that might be worth it?

 

That showed up the cylinder that was down on compression in my case. In fact eight valves were bent, so despite a good compression test on the other cylinders, it still had less than straight, and hence noisy valves.

 

Either way, i totally understand how you feel, a lot of work, effort and carefulness, still resulting in unexpected, unexplained and as yet undetermined failure. Soon to be rectified and enjoyed i might hopefully add.

[Miles 331 1 Cars]

Same here with aftermarket lifters, Issues. Sounds odd as they are a simple thing really but the only ones to use without going solid are Pug ones if you can still get them,

[petert 586]

I'd find some good 2nd hand lifters at the wreckers from an XU10J4R/RS and reco, rather than aftermarket.

[DrSarty 90 1 Cars]

I may well have clashed valves, but what's going to explain the pressurised block?

 

You can see (and if anyone's ever watched an episode of House), there's an idea that makes sense but it doesn't explain all the symptoms.

 

Engine out next week, pictures posted etc.

[brumster 135 1 Cars]

I think your soluitions rests on finding your best buddy, getting him drunk, throwing him to a load of prostitutes and doing some crack. You will then have a moment of epiphony and realise it's nothing like what you were looking at, but you unsettled a liner and an incredibly small rodent crawled into the crankcase breather, climbed up the oil gallerys and shat into your followers.

 

If you can shag the boss, a fit prozzer and a red-headed co-worker along the way, then all the better.

 

Good luck!

[DrSarty 90 1 Cars]

Yup! That's it. I'm on the case.

 

 

P.S. You didn't specify if the red-head had to be male or female; is that optional?

 

PeteT:

I was going to recon the lifters, however the set that were originally fitted I recon'd anyway. Therefore I figured that 1 was passed it, and as I wasn't sure which, and recon'ing another set could've yielded the same results I could've ended up chasing my tail, and I wanted the engine silent and perfect. Therefore the decision for new lifters was taken, i.e. get it done and know for sure they were good. Now look what's happened!

 

If Piper/Kent sell those lifters (pictured), then they're ripping everyone off. My set (from Lyndale Engines) cost me £6ea plus VAT, roughly half the price of a Piper set.

Edited October 24, 2013 by DrSarty

[cRaig 273 1 Cars]

More importantly, where is Olivia Wilde in all of this..?

 

Good luck getting to the bottom of the mystery!

[welshpug 1,657]

I don't think these are ever that quiet, especially if you start hitting them with lumpier sticks.

[kyepan 291]

best of luck rich, hope it goes well.

[DrSarty 90 1 Cars]

Would regrind count as lumpier? Lift isn't affected IIRC, only duration...

 

Anyway, they shouldn't be as noisy and for that long as they were.