[engine_work] I Forgot How Much I Missed It!

[DrSarty 90 1 Cars]

(I'm biting my lip here Justin):

You can't just say I DO have bent valves. I've already said that only 3 valves in cyl 3 were bent or broken. As for ALL the others, currently it doesn't look like it or feel like it when fitted to the guides. I've done a table rolling test and will also do a final check, but please don't be pedantic concerning cyl 3, or anything else for that matter as it isn't helping.

 

I'll check the spray bars completely tomorrow. As to whether they're a vital component or not I don't know; however THEY DOWSE THE JOURNALS NOT THE LOBES!

(My engine - cam caps fitted 1>5 right to left i.e. correctly):

 

IF they were blocked at the feed end, then that's potentially no oil getting anywhere in the head other than up to the interface in cam bearing cap #5 (and then going no further).

 

It's pretty damn clear (pics will follow) that the cams are scored where they reside in their bearings under the cam caps. As Wicked proposed and I (and I suspect Guy) will agree, lube starvation seems to have caused something in the valve gear to lock up or snatch causing the valve contact/failure, not the other way round.

 

I'll still inspect and test the valves further for trueness and impact/clip marks, but I'm pretty positive that they're all OK (less cyl 3). Should you be right I'll freely admit it.

 

Should the spray bars prove to be completely clear, then I'm afraid I'll have to look into the block supply and pump area.

 

I'm also totally positive on the MLS HG being fitted correctly now, as there are witness marks on the MLS HG that show the 3 coolant holes on the exhaust side of each combustion chamber are in the right place. Pics below:

Edited November 12, 2013 by DrSarty

[welshpug 1,657]

The spray bar is fed from the journal, it doesn't feed the journals.

[petert 586]

The spray bars supply oil to each journal. Only the inlet side sprays the lobes. There are no spray holes on the exhaust side. If using thin oil and left standing for a while, your head will appear dry. Mine was the same when I pulled the cover off recently.

 

Additionally, if there was no oil up the top the cam lobes would look very different. They still look perfect.

Edited November 12, 2013 by petert

[DrSarty 90 1 Cars]

I'll put pics up tomorrow of the cams where they sit in the journals. I'll also post pics of the tops of the lifters.

 

Again: we're not proposing 'no' oil to the head, but a restricted supply or distribution.

 

Currently we've not clarified or confirmed if the noisy head was lifters (bad parts), lifters (not much oil) - or both of these together, AND/OR some type of valve noise based on valve(s) touching what they shouldn't.

 

I'd really like to find out.

 

Meanwhile (yes Meirion), I am planning to prep, install and enjoy the '6; but I have to chase the Mi16 issue as far as I can.

[Miles 331 1 Cars]

Luck, I have had a Mi of all things run with zero oil pressure for around 15 to 20 miles, the oil pump chain snapped as the engine was removed from a rolled car, replaced the pump and chain, yes it rattled it **** off for 30 to 45 mins then ran fine for the next 2 years so with good oil it can protect cam bearings etc.

 

As said normally if the valve head snaps off the liners crack as well,

[DrSarty 90 1 Cars]

Cam journal pics (showing pretty clear):






VERSUS cams (showing what I would call scoring - please advise me if it is or that's normal):

^ Also note shim in above picture for fitting of DW8 pulley (cheap vernier option) ^







Please note on the last picture (including the cam pulleys), scoring on both cams where they rotate in the journals/under the cam cap #5, and also the angled hole on the centreline of the head where cam cap#5 would be bolted down, in between the 4 central cam bearing cap bolt holes. This is the single oil feed to the head from the hole on the face of the block nearest the alternator. Cam cap #5 bolts down here which has a rebate to accept the oil from this head feed and feed oil through the oil spray bars.

 

And finally, the attachment shows the comparison of the OE cam pulleys versus the replacement verniers, specifically regarding the orientation of OE locking holes with alternatives on the verniers.

 

The pictures are representative, but clearly show that generally speaking, with the woodruff key at 12 0'clock, the OE locking hole is at 4.30 on both the no.4 (inlet) and no.2 (exhaust) OE pulleys. When overlayed very accurately onto the replacement verniers:

 

> Inlet: one of the four Piper pulley locking/adjuster bolts as marked can be removed, leaving a locking hole in exactly the same place of the locking hole on the no.4 OE pulley - that's how the inlet was locked

 

> Exhaust: the tang with a '0deg' marking on which is notched lines up exactly with the no.2 OE pulley - this notch is the same size as a cam locking hole and ideally located - that's how the exhaust was locked

 

So in summary, I'm also totally confident, that as these pulleys were overlayed in terms of woodruff key and teeth alignement extremely accurately providing alternative cam pulley locking holes to match the OE items, therefore cam timing was suitable for cambelt fitting.

OE vs Vernier Pulleys.pdf

Edited November 13, 2013 by DrSarty

[DrSarty 90 1 Cars]

Well, after having a decent chat with the folks at Lyndale engines, I'm gonna have to eat some humble pie and begin to side with Anthony and Justin's opinion.

 

Guy's a bit baffled as I was, with there being apparent/assumed evidence*** of oil feed issues, especially when considered in conjunction with the block starting to pressurise. But as Anthony said re the HG - but which can be applied to the oil supply as well - they were both 'red herring'.

 

*** - This would be not much oil in the head before draining, noisy lifters, scored lifters, seemingly scored cam shafts and excessive block pressure.

 

Upon placing the valves in Lyndale's valve facing machine, which spins the valves up like a drill would've but in a more professional way, 3 or 4 valves were then visibly bent. As Anthony and Justin said, without doing this it's very hard to see, plus it's also very confusing how it's happened as one is confident of their procedures, and therefore red herring are much more attractive solutions. I believe the real problem was my bad camshaft and timing belt procedures causing several valves to clip and bend.

 

A few bullet points then:

> No oil feed problem; all a red herring

> Lifters did fill, and even tried to cope with the over-extension when valves weren't behaving properly in the guides

> Lifter-to-valve-and-to-cam gaps was the cause of the noise, plus the bent valves themselves

> The block pressure is a separate issue I can't quite explain, despite the suggestion that shifting to ITBs can cause it, because the breather system was successful before

> The head may be repairable providing the broken valve head didn't do sufficient damage to the combustion chamber to breach a coolant gallery - would then need metal work, a skim if it has any life left in it and 2 new valve seats (plus new valves obviously)

> I will probably never take on any cambelt work on an Mi16 with the engine in the car, and maybe even leave cambelt and timing work to a pro, as it's really risky

 

And the last bit is the lesson for me, and seems to have been a lesson to many others, including professional engine builders; even Lyndale's team have done it twice!

 

The Mi16's large valves are great, but their proximity makes it very easy to clip valves (inlet to exhaust) upon assembly when rotating cams to lock them on the bench and also in the car, during cambelt fitting and tensioning, and also during additional cam timing operations.

 

These operations should be done extremely carefully, being very confident of the process and necessary checks, and also potentially just left to a pro who knows Mi engine's well (and possibly GTI6/XU10J4RS lumps too).

 

Lyndale said it took them a while to figure it out, after doing the same as me only not going quite as far as breaking the engine. They had noisy lifters and replaced them only to get the same lifter noise that wouldn't shut up. What bugs them to this day - and me too - is how the car can almost behave normally, idling fine and smoothly as mine did, provide decent power although down and power, and seem to deliver good compression.

 

For my engine and subsequent disaster, personally I don't think the valves clipped on the bench whilst rotating them to lock the cam pulleys, but in the subsequent cambelt fitting and tensioning process in the car, which is made particularly difficult given the space available.

 

I'll take this on the chin, and thank J and A and everyone else for their time and consideration. In fact I'm going to prep the GTI6 lump right up to and including water pump replacement, and then have Lyndale fit the new cambelt kit and demonstrate to me how it's done and prove it's to OE spec. I'm not going anywhere near it until I've learnt more about it.

 

Just as a note: Lyndale said that they 'evacuate' lifters on fitment, thus allowing them to be clear of any type of contaminant and be ready to be filled via the engine's normal procedures. Yes it's noisy for a bit, but they will pump up and don't recommend pre-filling. In fact they even said my lifters would be fine to be used again once evacuated.

 

Finally, I always acknowledge when I've messed up and treat it as part of learning.

Edited November 13, 2013 by DrSarty

[Anthony 1,003]

Glad that you found the issue in the end

 

(and possibly GTI6/XU10J4RS lumps too).

GTi-6's are considerably worse in many ways, as valve-piston clearance is very tight compared to Mi16 and S16 engines to the point that all but the mildest of cams realistically need valve pocket cutouts enlarging.

 

They're not difficult to do the cambelt on, but it's certainly not one to do if you're not confident in what you're doing, and it's absolutely critical to ensure that the bottom pulley hasn't slipped - if it has, the timing hole will be in the wrong place and it'll all go horribly wrong when you turn the engine over.

 

"Tapping" GTi-6 engines are all too common unfortunately thanks to bodged cambelt changes and incorrectly repaired engines following cambelt failures (which they're prone to doing prematurely). They're a ticking timebomb that might last 50 miles or might last 50k miles.

[welshpug 1,657]

Glad to hear you have finally nailed a cause, and learned from it, quite often in engine failures you can't nail a single specific root.

 

 

I think it is wise to be cautious, but really anyone can do a belt with the correct precautions taken.

 

Adding adjustable pulleys and higher lift cams just adds to the peril, unfortunate that a valve did drop really, many do live on for tens of thousands of miles before causing issue.

 

 

Regarding the the RFS engine - Remember as I mentioned about the harmonic balancer they can separate and place the timing pin out of sync, and that you can use an 8 valve pulley in its place to confirm the timing is 100% spot on.

 

There is another way which is to use a Solid alloy pulley from Miles.

 

The exhaust valves on these are even larger, and the cutouts VERY minimal, the Mi guys should count themselves lucky with the 7mm stems and deep valve relief's, only oil control to worry about in mild tuning!

[DrSarty 90 1 Cars]

I remember what you said WP about the crank pulley on the '6.

 

Does anyone have an 8v (I guess you mean XU5/9JA i.e. 1.6 or 1.9 GTI) crank pulley I can borrow or buy? (Miles' solid '6 pulley is nice, but f*%king expensive!).

Edited November 13, 2013 by DrSarty

[welshpug 1,657]

I will send you one Rich

[kyepan 291]

I'm glad you've found the problem and know how it feels to dink valves, utterly gutting, so easily done, barely perceptible when it happens. Despite all the precautions.

The only other thing i can say is don't give up, build it again, make sure it's done properly (get a dti), and then enjoy it.

 

Second time round i was even more cautious, plugs out to make sure compression wasn't confused with valves, making sure the standard pulleys matched, holding cams in place with spanners and mole grips, almost locking the cams before the pulleys went on. getting help when I got stuck, which i did, got in a right muddle.

 

J

[dcc 855]

Hey Rich - a bit off topic, ensure the crank pulley hasn't slipped on the rubber with your gti6 engine.

[welshpug 1,657]

very much on topic and mentioned several times already Dan, keep up

[DrSarty 90 1 Cars]

***CHAPTER 3***

 

Recap (for any late joiners):

Chapter 1 - XU9J4 in

Chapter 2 - XU9J4 goes bang (silly me!)

Chapter 3 - Enter the GTI6

 

***

Below a few pics of the engine with some initial queries. Apologies if the question re the cam pulleys has been asked before, but as you'll see from the pics from different sites there are confusing differences.

 

The engine came from a W reg 306 Cabriolet. The first question is why does it have a GTI6 / XU10J4RS / RFS engine in it? That's not normal is it?

 

 

Here it is after initial strip:

 

There'll be a For Sale add soon for:

> Cam belt covers complete (originally said 'cam covers' - oops)

> Coil On Plug set (4off)

> Engine management loom

 

The exhaust manifold is going exchange with Miles for a reangled version with modified downpipe on front section.

 

I can confirm the head is definitely an RS due to the cast-in letters on the side of the head:

 

I'll check the block casting or stamping today, which I believe will identify the bottom end; however I'm starting to wonder if it's a J4R engine with an RS head. If that's the case, are there any major differences between the blocks which will effectively not make this a GTI6? Specifically, I thought a J4R was 10.4:1 and an RS 10.8:1 (?) EDIT: Just found these 2 useful links: http://forum.205gtidrivers.com/index.php?showtopic=137577 and http://forum.205gtidrivers.com/index.php?showtopic=99389

 

The next question concerns the cam pulleys, which appear to be J4R items as they don't appear to be adjustable/vernier-type pulleys (with the 3 bolts to rotate the outer part separately to the hub:

(My engine)

 

The confusion enters because on several other pics I've found of GTI6 lumps, some have the verniers and some have pulleys like mine:

(Cameron's GTI6)

(Others)

(Definitely a J4R from a PeterT for sale ad)

(Different pulleys again!)

 

Surely verniers aren't essential for the GTI6 cambelt timing operation, i.e. it has to be possible with solids (?).

 

Therefore, regardless of the pulleys, I'll need to ID the camshafts fitted. Is there a marking/identifier visible without removing the twin cam covers?

 

Then a few general questions pop up, such as why was the '6 lump in the cabrio? Why the non-vernier pulleys (and what cams are on this RS head)? Why the 'In' and 'Out' pen/paint markings on the pulleys, which indicates this engine has a history?

 

The good news is that the timing is all spot on, namely with the crank locked both cam sprocket holes line up with the locking holes in the head, despite it being obvious that the crank pulley outer part has slipped (as they often do) due to the rubber (harmonic) damper bush.

(My finger shows the position of the locking slot on the block - compare to hole in crank pulley which should align)

(However crank pulley woodruff keyway lines up where it should - my engine compared to a reference picture)

(Ref)

 

Flywheel locked:

(And pistons all checked to be level/midway by measuring down spark plug holes)

 

It's never easy is it? Your help appreciated, i.e. why the non-vernier pulleys, are they essential to timing and how do I identify the cams?

Edited November 15, 2013 by DrSarty

[welshpug 1,657]

you have the later type of adjustable pulley Rich, you need to slacken the centre bolt and give the pulley a tap, it'll be free from the central hub.

 

markings are from possible a HG job, though they probably did not realise that they are identical look for any rivets visible on the gasket at the front and rear or either end of the gasket.

 

looks like it is a mid year engine, as it has a manual tensioner but the later type of cam pulley.

 

 

why was the RFS in a cab?

 

because its a straight bolt in conversion which gives 32bhp more than the original RFV engine.

 

 

 

 

why will you be selling the cam covers?

[DrSarty 90 1 Cars]

Aaah. All great answers thanks Mei.

 

For Sale list edited to say 'cam belt covers complete'; that's what I meant, not the cam covers themselves.

 

So they are verniers, but clamped up using the central sprocket belt; simple and clever.

 

And ref the HG, you're saying that if they're are rivets present on the HG tabs, then that would imply a HG change (as factory HGs don't have rivets)???

 

Now gonna go and check the block identifier to see if it's RFV (10.4:1) or RFS (10.8:1) based on the non-dished pistons on the RFS.

Edited November 15, 2013 by DrSarty

[welshpug 1,657]

spot on ref the gasket not an issue in itself, however it does mean that future cam upgrades will be more sketchy.

 

blocks are the same between RFS and RFV, its the piston that differs, the RFS has a dish its just not pronounced, the RFV one is like a small bowl in the middle of the piston.

Edited November 15, 2013 by welshpug

[welshpug 1,657]

RFV pistons -

 

 

 

 

 

RFS pistons, with +1mm valve cutouts...

 

 

[DrSarty 90 1 Cars]

Yay!

 

Got a bore scope and we have RFS pistons/bottom end. The casting of 'NS J4R' in the rear of the block apparently is inconclusive as that's not different between the RFV or RFS (or other 2.0L) bottom ends. Mine are flat as pictured above and definitely NOT dished as obviously as the RFVs.

 

Additionally, I have a vacuum pump running off the exhaust cam, and apparently the RFV doesn't have one which means my cams must RS cams with the appropriate cam tang to run the pump.

 

Finally, on triple-checking the crank pulley and cam sprocket locking alignments as I bought the engine, everything is perfectly timed up.

 

So, I have a good '6 lump it seems. 10.8:1 with hopefully good compression, ITBs, staged injectors and GTI6 exhaust manifold and I hope we'll be well over 180bhp on the next trip to Emerald.

 

Cambelt kit and water pump kit will be bought and fitted tomorrow following extremely accurately the fitting and timing process which I've compared in several documents and am confident with (despite the slightly different vernier pulley arrangement). I'll also check for rivets on the HG.

 

Block will be cleaned and painted, exh and inlet head faces also cleaned, Aerolock exh studs fitted (ready for the new re-angled manifold from Miles due next week), cam cover gaskets checked and probably replaced, and the whole thing generally tarted up ready for fitment. But I'll put oil in and do a compression test before it goes in.

 

I may also purchase a replacement Bosch phase II fuel pump in case mine shows any sign of weakness and swap it on the rollers if needed.

 

Connections etc as per below diagram will be followed:

 

Comments, advice welcome.

[welshpug 1,657]

Beware of the cam cover seals, they are bonded on and not replaceable, adding a careful line of RTV sealant is a wise move, if the oil filler cap seal is dubious they are well under a tenner from a Dealer.

 

The Plastic covers with replaceable seals from the later RVY and LFY engines unfortunately have a different bolt pattern.

[DrSarty 90 1 Cars]

Thanks (yet) again.

 

a ) OIL

Below pics show my plans on the oil catch tank/breather system. Comments welcome.

 

Pic 1 (purple lines) shows standard main block hose routing, i.e. 2 outlets on block joined, then going to head:

 

Pic 2 (orange lines) shows plan to create loop, making large bottom outlet link only to head {no longer connected to higher, smaller block outlet} then to head, then back out from head to breather tank which vents to atmosphere and also feeds back to the block):

 

b ) COOLANT

I also need to review the coolant pipe set up, as the GTI6 rear distribution union (rear bottom of block above intermediate driveshaft bearing housing) is totally different. Does anyone know if the Mi16 union is a straight swap, as that'd be the simplest solution?

 

I am thinking that a swap for the Mi one fixes things instantly, i.e plumbs straight into the existing hosing still in the car, to the heater matrix and expansion tank.

 

If it doesn't, I'll have to use hose adapters such as Y or T pieces to take the single large hose outlet on the rear union to deal with the expansion tank and matrix. The other matrix outlet currently goes to the Mi head coolant union but it's on the side, entering right to left, whereas the GTI6 head union has a connector at the rear.

 

The larger GTI6 front connector on the head union should be able to go straight to my rad, or I'll have to modify the GTI6 hose that comes off it.

Edited November 15, 2013 by DrSarty

[welshpug 1,657]

Main reasoning behind the different water pump union is the large exhaust manifold, BBM do a specific heater pipe for this engine.

 

Not sure if the alloy block union will fit.

 

BBM also do a thermostat housing adapter to accept the standard 205 alloy thermostat cover instead of the plastic cover and clip in top hose connection, these allow you to do away with the heat exchanger pipe that exits the top radiator hose by using the normal 205 top hose.

 

 

 

 

I think other than the front lower radiator hose they are all different to the Mi16 kit, that's not to say you cannot adapt your current hoses with a T-piece or two.

[Mad Scientist 106]

Do you know you are missing the metal coolant pipe, that routes the output from the union across the back of the block? You will be able to make your existing hoses fit to that I think. Got one here if you need one.

[DrSarty 90 1 Cars]

Pipe's not missing, just removed before pic taken. Already sussed upon removal I might need to use it and 't' off it.