Started on Head Gasket Replacement

[adam quantrill]

One side is on and torqued down - one side to go... but I need 4 new pushrods.

---

Decided to take a break tonight as I'm fuackered and don't want to start making mistakes.
Besides I am borrowing a dial gauge tomorrow so I can dial in TDC so I want to leave the odd side for now. Plus my pushrods hopefully come tomorrow and an extra nut for bolting down the extra bracket.

Edited by adam quantrill on Wednesday 15th May 20:17

[adam quantrill]

Right - kitchen plumbing done, so I can get back to the wedge at last.

Offered up the other cylinder head today and got all the studs in place but not torqued down yet.

So I have a dilemma - this bleeding extra bracket hanging off the stud on No 1 cylinder.

As far as I can make out, it's the waterway at the "front" of the No. 1 cylinder that was being leaked into. This end of the cylinder head is what the supercharger bracket is bolted onto.

According to Jasper, it's not uncommon for these cars to 'burp' fluid, which is starting to suggest to me that this is (another) design problem with the mounting of the supercharger - it couples vibrations into whatever it's bolted onto - leading in this case to head gasket failure. For example the water pump - it's bolted onto one of those bolts and I have seen the water pump casing fracture at that point (so I have now reinforced it).

Sooo... what to do? With the stud left protruding there isn't enough thread left above the head nut to get a bracket on there anyway, unless it was much thinner (i.e. steel instead of aly).

[adam quantrill]

Some progress today at last - I identified a lug hanging off the block next to the LHS engine mount - what is that for? Anyhow it's quite substantial and has a 10mm hole through it, so I've made up a bracket to replace the ally one that went onto the cylinder head bolt.

It's quite convoluted but when bolted in place seems really sturdy. Apologies for the iffy welding - not pretty but effective.... anyhow you won't be able to see the bracket with the blower back in place.





So - instead of transmitting force and vibration to the cylinder head, the force should be transmitted to the block instead - hopefully reducing the tendency to knacker the cylinder head gasket.

Here it is bolted in place, the white cardboard is a template representing the end of the supercharger bracket/air collector box so I can see how it will fit together:

Edited by adam quantrill on Monday 27th May 22:17

[adam quantrill]

Some progress over the weekend - have got both heads on now. Spent some time calibrating my big torque wrench which seems to be about 20lbf too low. I thought it was easy torquing to 80lbf - as it was really 60lbf!

Spent a few hours fettling the new bracket and deciding how to assemble it - turns out it can quite happily be mounted fairly permanently on the air box/bracket as the lower bolt slides on and off the block.

I also took lots of piccies of all the brackets to help document it all.

Finally, reconnected the earths and took her for a spin - well spun up the engine for a compression test - seems reasonable in all 8 cylinders.

Has anyone installed a composite valley gasket before - are there any things to watch out for or is it fairly straightforward?

Edited by adam quantrill on Monday 27th May 23:08

[adam quantrill]

Good progress tonight - inlet and exhaust manifolds all on. Plugs in. Hoses mostly on. The collection of nuts and bolts in the seed tray compartments has depleted to the rocker cover screws so I must be close....

[adam quantrill]

Another good stint - water in, oil levels checked, block airways sealed, all the hoses installed, alternator and supercharger on (latter a bit fiddly).

Only got left to do: air meter, throttle cable, exhaust olives and start 'er up!

[adam quantrill]

Well the Beast Lives Again!

I expected only an hour's work and a nice drive but that hour turned into three.

At first it wouldn't start - no spark - then I worked out I had put the leads onto the ignition amp the wrong way around - luckily I have a spare wedge to refer to!

So got it started - so far so good. After burning off the crap on the exhaust manifolds there was still a lot of smoke/steam and in fact a water leak which was a bit worrying - had I put the valley gasket in properly? Luckily it turned out to be a couple of hose clips on the fiddly heater type hoses just behind the water pump.

So - water tight and running, revving OK and idling nicely. Gave the underside a bit of TLC with the wire brush and anti rust paint in a couple of spots and finished painting the manifolds. Cleaned up all the tools (I now know where the _all_ are ;^) wanged them in the boot and off for a spin - after a wash!

It's running great - only took it up to 4k RPM at the moment but it's certainly pulling better.

I can finally admit I was in a bit of a race with Delilah to see if I could get back on the road first - made it - just...

[mrzigazaga]

adam quantrill said:

I can finally admit I was in a bit of a race with Delilah to see if I could get back on the road first - made it - just...

Hey Adam thats not fair..I have been waiting on parts that have been delayed by thoughtful but non-constructive interference by the parts suppliers!..i:e they thought they would hold the order back to put it with some stuff that was ordered the following day even though they said it had been sent..Their excuse was they were saving the garage £7 postage!!!!...FFS..Still all will be resumed tomorrow...But well done for getting yours sorted..Delilah was a bit slow..It must be her age..Bless...But she should be a bit more spritely soon..Cheers...Ziga

[rev-erend]

Well done Adam.

Will you be retorquing the heads down after a few miles ?

[Oz2]

Well done Adam good work, ill be on the blower ;-) when i have the need for advice on this procedure.
Zig have you thought........
Maybe Adam Q bunged the postman a few quid to loose your parts for a couple days while he went on to win the sx race dick darstedly style (muttly laugh)

Edited by Oz2 on Friday 31st May 14:40

[adam quantrill]

Hi Alan - I hadn't considered this, nor did RPI suggest it when I asked them about the installation procedure. Given that the s/c is in the way of the odd bank it would be a few hours work. But at least I won't have to remove the exhaust manifolds as all the proper studs are visible anyway. And I am now on rubber gaskets on the rocker covers, which makes things easier.

I might try it on the even bank first, and if there is no movement, trust to luck on the other side.

Cheers Adam, maybe there is a small market for my alternative bracket, if it turns out to work better. But with only 15 V8 SX's made, and most in unknown locations, maybe not.... I too had to wait for parts btw (just look for the gaps in the story dates).

[Oz2]

Perhaps zig has been thwarting also????

Yes I've been looking at mine to see how it is attached and trying to see how the bracket fits, now I'm waiting for a head gasket failure....
Very interesting thread Adam.
Cheers

[adam quantrill]

Danny Hoffman said:

Could you see any sign of your leak?

Just realised I didn't answer this - well there was a small breakup of the old composite gasket - but you could hardly tell it apart from where it had ripped because bits of it stuck to one face or the other.

Also there was a little corrosion on the metal ring in the gasket around the front edge of No. 1 cylinder.

To be honest - it wasn't really conclusive, just looking at it.

However, now it's all back together there is no sign of bubbling from the header tank overflow pipe any more, so I guess it must be fixed!

Well it was a long job all in all, much longer than with a normally aspirated engine, but on the other hand there were a few jobs jobbed along the way:

Fixed a big crack in the nearside exhaust manifold and reinforced the flange.
Repainted both manifolds (my tin of heat resistant pain has almost run out after 10+ years...)
Made a new bracket for the supercharger.
Rustproofed some chassis tubes.
Documented and photographed all the supercharger brackets and bits.

[mrzigazaga]

Oz2 said:

Zig have you thought........
Maybe Adam Q bunged the postman a few quid to loose your parts for a couple days while he went on to win the sx race dick darstedly style (muttly laugh)

......

Oz2 said:

Perhaps zig has been thwarting also????

............

[adam quantrill]

rev-erend said:

Will you be retorquing the heads down after a few miles ?

Yes.

I looked into it and it seems it's not an uncommon procedure. Also (unlike bolts) studs are fine for re-torquing.

First side done tonight - and they took about a 1/2 turn to return to 80lbf so I shall be doing the other side soon (difficult as I have to move the blower again, but at least I now know how to do it relatively easily.)

[adam quantrill]

A quick update - the coolant started bubbling again. After trying running with various injectors disconnected (another great bonus of EFi over carbs) I narrowed it down to cylinder number 4. Phew - at least it's not under the blower again!

So I whipped off the rocker cover once more and found the end nuts needed torquing _again_.

This time I undid them all, then torqued them back up again in the recommended sequence. A quick spin and it seems to have stopped bubbling. So fingers crossed!Especially this time of year - can't be doing with the coolant bubbling out.