Blown Head

[hot_c210]

Congrats on following through and getting the car back together hope it all works for you.

I have been lead to believe, although right now it may seem a bit impossible, that the L series motors when built the heads were over engineered (??) meaning they are meant to be near bullet proof. when it comes to gas on these cars its not too far from true, the 2.8 lost its rings before the head gave in and the first 2.4 lost the rings. both on gas and on 400,000km's the 2.4 didn't have a modified head either. dont know how true this is but it seems so from my experience.

But good luck with your cylinder head hope it all works out :-)

[coupe72001]

Actually, apparently the head being aluminium makes it a little vunerable to heat and abuse. You've certainly had a good run with yours though.

Can anyone help me out. I have never set the timing of the car while static before. Before I turn the key can someone tell me if Im on the right track?

- number one piston should be at TDC on the compression stroke.

- the rotor button should be pointing at number one on the distributor cap

- the crank pulley timing mark should be vertical (or lined up with something on the block maybe?)

- the timing-chain sprocket slips onto a dowl on the camshaft. That dowl should be at 12 o'clock.

- something else I dont know about..?

At this stage I feel like it'll be nothing short of a miracle if I get the car running again without if hemoraging from somewhere. Interesting lesson to pull so much of my car apart though.

D

[Vince66au]

Thanks for the support fellas.

I have decided to replace the head all by myself. First time, so this should be hilarious. If anyone has some tips for me I'd love to hear them.

Importantly I'd like to know; will a standard aftermarket head gasket suffice, or should I be shelling out for a pricier copper gasket, or something else altogether? Its an L26 by the way.

Also, if the head is really cracked/warped nastily, I may be in the market for another head. I know its been touched on before, but can anyone remind me of the finest of all the naturally aspirated heads that will suit? (Mines a ported E88 from memory)

Thanks.

dude if it was me..i would have burned the car by now...but the more this things happen the more ull know the next time..cheers..keep it up

[wardie]

coupe72001

From my experience fault finding the water in the oil issue that I had

- number one piston should be at TDC on the compression stroke. - YES

- the rotor button should be pointing at number one on the distributor cap - YES (the flat piece on dizzy drive shaft should be at about 10min to 11 if you looked at a clock) Can look right but if the car does not run properly you may be 1 tooth off with the dizzy drive shaft.

- the crank pulley timing mark should be vertical (or lined up with something on the block maybe?) - Should be lined up with the 0 mark on the timing gauge attached to the block

- the timing-chain sprocket slips onto a dowel on the camshaft. That dowel should be at 12 o'clock. - Not quite. On the timing chain is two marks. One lines up with the mark on the crank sprocket and the other lines up with the #1 mark on the cam sprocket. Adjust the cam so the dowel slips into the sprocket hole. Sometimes you will have to gently persuade the sprocket onto the dowel by slowly tightening the bolt. Make sure that the cam lobes for #1 are not pushing down on the valves.

- something else I dont know about..?Once it fires it will run crappily until you get the timing set right 10degree BTDC at 900 RPM

Good Luck

Wardie

[coupe72001]

Cheers Wardie,

I finally got there in the end and got it running. I was very confused because the timing gauge attached to the block was missing!

Unfortunately the sump promptly filled up with coolant again. I mashed the head gasket a tiny bit getting the head back on (it's really not a one man job I have decided), so that is probably the cause of my woes. The block is holding coolant, so I dont think there is a crack in the block anywhere. Ill try a new head gasket tomorrow, this time with a mate to help lower the head onto the block gently!

Fingers crossed that it works this time.

D

[coupe72001]

Ok... so I reassembled my engine, refilled it with oil and coolant, got her started, and the sump filled up with coolant again.

Having assumed that I had damaged the head gasket getting the head on, I removed the head, cleaned and polished everything really well, and then replaced the head gasket very, very carefully. The head bolts got tightened in three stages, in the correct order. I fired her up again and the sump filled up with coolant. Again. In fact with the engine off you can pour water into the radiator, and watch it drip back out of the oil sump drain hole almost as quickly.

I decided that maybe the intake manifold had a hole in it, so I blocked it off at both ends and filled the radiator again... no go.

When I had the water pump out there was no obvious damage or holes underneath on the block, and with the head off there appeared to be coolant down in the water jackets, so I dont think that the block has cracked.

Can anyone think of what I may have missed?

Better still, does anyone have a spare L28 block? Ill pay money for it. No joke; swapping the engine is going to be faster, cheaper and easier than trying to sort this mess.

I think my L26 has been hexed. Possibly voodoo. Im not sure.

Drew

[wardie]

Hey Drew,

If you have had your head tested and they say it's OK then I would suspect the back of the water pump in the timing cover. When I had my issues all the "L" series guys that I spoke to after I had my head skimmed and I replaced the head gasket only to have the engine fill with coolant as soon as it warmed up assured me that the Lxx blocks were almost bullet proof and "never" cracked. When I checked my timing cover I couldn't see anything wrong, there was a bit of erosion up to wards the top of the rear but I didn't see holes, but the guy who tested my head again for me insisted on checking the timing cover by shining a bright torch from the back and there it was two small pinholes. I had it welded up and away I went but later it happened again but in a bigger way as the erosion was weakened by the welding. I ended up getting a 2nd hand timing cover that looked like new.

I cheated and replaced the cover "carefully" without having to remove the head. I just took out the bolts that attached to the timing cover top and bottom as well as the ones around the side. Tapped it loose with a nylon hammer and then gently put the new one in top first with the sump loose to give me a little room.

Good Luck

Wardie

[coupe72001]

But I only just got the timing cover and bits back on! Arrrrgh!!!! (sobs into keyboard)

Oh well... guess dont have a choice. Thanks Wardie for the tip on the sneaky way to remove the cover - at least that will save me many bloody-knuckled hours.

I think I already know the answer, but are the timing covers identical for all the L6's? There are dozens to choose from at the local wreckers.

[coupe72001]

Hey Drew,

If you have had your head tested and they say it's OK then I would suspect the back of the water pump in the timing cover. When I had my issues all the "L" series guys that I spoke to after I had my head skimmed and I replaced the head gasket only to have the engine fill with coolant as soon as it warmed up assured me that the Lxx blocks were almost bullet proof and "never" cracked. When I checked my timing cover I couldn't see anything wrong, there was a bit of erosion up to wards the top of the rear but I didn't see holes, but the guy who tested my head again for me insisted on checking the timing cover by shining a bright torch from the back and there it was two small pinholes. I had it welded up and away I went but later it happened again but in a bigger way as the erosion was weakened by the welding. I ended up getting a 2nd hand timing cover that looked like new.

I cheated and replaced the cover "carefully" without having to remove the head. I just took out the bolts that attached to the timing cover top and bottom as well as the ones around the side. Tapped it loose with a nylon hammer and then gently put the new one in top first with the sump loose to give me a little room.

Good Luck

Wardie

You were spot on Wardie. Pulled the timing cover held it up into the sun and... er... saw the light as the saying goes. Pin hole behind the water pump. Your keep-the-head-on strategy worked a treat too. Ill dig up another cover tomorrow morn and should be on the road again for the weekend.

Thanks again to everyone who helped me out with this one.

[Factory 5]

You were spot on Wardie. Pulled the timing cover held it up into the sun and... er... saw the light as the saying goes. Pin hole behind the water pump. Your keep-the-head-on strategy worked a treat too. Ill dig up another cover tomorrow morn and should be on the road again for the weekend.

Thanks again to everyone who helped me out with this one.

hey i checked the L20et i have sitting in my carport too, same lil holes!

i sure hope the L24et doesnt!

[coupe72001]

So I pulled a timing cover off a wreck, cleaned scrubbed and sprayed that sucker with a rust-proof paint (and held it up in the light just in case).

Then I bolted it onto the car using the wardie technique - all good. In fact I was feeling so confident that I had reassembled 99% of the car before I filled it with water and filled up the sump. Again.

Err... WTF? I had to swear for like 20 minutes.

The old timing cover clearly had a hole. Does this mean that the new cover also has a hole, but somewhere that I couldn't see it? Has the cancer spread in the MONTH that the car has been on blocks?

Perhaps I have offended the god of Skyline and he wants me to buy a Commodore.

[Factory 5]

just get a new engine.....

start from scratch mate!

[coupe72001]

just get a new engine.....

start from scratch mate!

Hold the phone - the dripping has stopped!!! Call me optimistic but maybe I was just seeing the dregs of the last failed experiment leaking from the car. The radiator has stayed full all weekend and first thing I am going to see how she holds up under steam. You never know...

D

[coupe72001]

Yep... looks like the leak has been sorted. Flushed the engine this morning without the coolant level dropping, which is great news.

However... the sump is leaking noticably from where I tore the gasket. Has anyone ever changed a sump gasket without pulling the engine the whole way out of the car? For example by loosening the engine mounts and jacking from the gearbox. I would try to patch it with instant copper gasket, but my fingers are too big too get between the sump and the block properly.

[wardie]

Dude you back on the road again?

Wardie

[coupe72001]

Dude you back on the road again?

Wardie

Certainly am mate... except that I am letting the gang at Z spares tune the carbies for me (again!). Ill pick her up first thing Monday and hopefully nothing else will blow up until the weekend. Bad karma, bad luck or bad driving aside, the car may actually be close to... well... being basically sorted.

Something else odd happened. I replaced the rear disk brake pads (its a 280zx series 2 rear end) but immediately after one of the calipers/disks heated up and smelt bad. Anyone know what's gone wrong? The caliper only just fit over the disk - but I didn't have to force it on or anything. The pads are a US brand called "Rayspestos"...

D

[coupe72001]

Z spares gave me back the car after a couple of weeks. They barely had time to touch it - and their carby guy has gone travelling. They did however bill be $45 for a missing brakepad anti-rattle spring (not including labour to fit it), something I feel... somewhat raw about.

So, I took the car straight to a carby specialist in Richmond and he was grossly unimpressed with the state of the recently rebuilt SU's. His theory is that they were put together shabbily with inferior rebuild kits and that the car will never stay in tune for more than its three-week average... Recommended course of action; a complete re-rebuild with genuine SU parts and 3 hours on a dyno-tuner for adjustment, jetting, tuning etc. Estimated cost: 1G.

Sad panda. Im never going to pay off my bloody credit card.