Head gasket gone

[islandbloke]

Hi Guys,

Took Lottie in for a number of jobs after she failed her 'Manx MOT' test in December - one of the fails was excessive engine oil leaks.

So my local mechanic set to over Xmas to replace oil seals and stuff - and when I called in to check on progress he told me he suspected the head gasket had gone - lots of yuk in the sump evidently, and she HAD been using water regularly and smoking on start up a couple of days beforehand.

Question is, what's the book labour time for a head gasket job (engine in place). He's also doing the valve shims and timing belt etc. while he has her in bits - but what would you consider a reasonable number of hours for this from an expert spanner man? Just so I know when I get the bill...

[islandbloke]

No thoughts on this guys?

[Vulcan Grey]

No thoughts on this guys?

I've done it in place. No idea's on book rate... as I'm not a pro.

There are a few things that you really need to watch out for.

I would seriously consider that you DO NOT have the head machined unless absolutely positively necessary, as it is very possible, and likely, that any machinist will distort and taper the head.

Check the head for distortion relative to Lotu's spec in the shop manual, inspect the surface for flatness, look for indentatioins due to the head gasket sealing surfaces.

ONLY after all that, if it does not meet Lotus' spec, then you could take it to a machinisht, but they must realize that the relationship between the head-block mating surface, and the cam tower surface must be maintained (over the whole head length) so that the belt does not run off the end of the pullies when it is all reassembled.

The machinists (both of them) screwed up my head this way, even after telling the second not to machine anything, and that I only wanted him to verify that there was a taper.

Other than that, order the new composite Goetze gasket from a Lotus parts supplier, and torque it down with the proper specs, and don't them them machine anything in the head withou asking you to buy the proper parts from a lotus parts place (i.e. sintered valve seats, sodium filled exhaust valves, silicon bronze valve guides, etc...)

Yes at the same time you should reseal the water pump, shim the valves, change the timing belt, inspect and or replace the tensioner bearing.

All can be done with the engine in the car.

OH and NEVE EVER turn the crank when the head is off the block, without first using cylinder liner clamps to hold the cylinders in...!!!!!

Edited January 19, 2007 by Vulcan Grey

[islandbloke]

Thanks Travis - I was beginning to think nobody had a head gasket blow before!

All comments duly noted - but I'm useless with spanners so need to trust the job to someone more skilled...which is why I could do with an idea of the amount of time that would seem fair to do it.

[Bibs]

Call Lotus on the number below and they will happily tell you exactly how long the work wil take Stu

[islandbloke]

Thanks Bibs - will do on Monday!

Stu

[Bibs]

They have the warranty guide books right next to them which will have exactly, to the minute, what the job will take

Let me know if you have any problems

[Guest glyn.harper]

Hey Stuart.. How goes it fellow Isle of Man Lotus owner!

I had to rebuild my engine.. twice!! Not longer I had it, the head gasket went. It was rebuilt and it went again within about 1000 miles because the head had been skimmed and raised the compression ratio too much. That causes the head to spit the gasket out.

Second time, myself and Dean rebuilt the engine in my garage.

You can take the head off and do it with the engine in situ, but in my experience it's easier to just take the engine out!

While the heads off, you'll need to check the condition of the nikasil liners. Mine were shagged, so I had to fit new pistons and liners.

I'd guess about 16 hours for a job like this.. and that's garage time doing it with all their tools and experience.

As you've already been advised, don't get the head skimmed unless you can make the difference up with a gasket because an increase in compression ratio isn't good..

Think you've still got my mobile number if you want to give me a shout? If not, Cleator has it..

cheers,

Glyn.

[Artie]

Hey Stuart.. How goes it fellow Isle of Man Lotus owner!

I had to rebuild my engine.. twice!! Not longer I had it, the head gasket went. It was rebuilt and it went again within about 1000 miles because the head had been skimmed and raised the compression ratio too much. That causes the head to spit the gasket out.

Second time, myself and Dean rebuilt the engine in my garage.

You can take the head off and do it with the engine in situ, but in my experience it's easier to just take the engine out!

While the heads off, you'll need to check the condition of the nikasil liners. Mine were shagged, so I had to fit new pistons and liners.

I'd guess about 16 hours for a job like this.. and that's garage time doing it with all their tools and experience.

As you've already been advised, don't get the head skimmed unless you can make the difference up with a gasket because an increase in compression ratio isn't good..

Think you've still got my mobile number if you want to give me a shout? If not, Cleator has it..

cheers,

Glyn.

Glyn,

When you did the head gasket did you clamp the liners in place or just replace the gasket and put everything back in place and bolt it together?

Artie

[islandbloke]

Hi Glyn,

Thanks for that. I'd have been in touch for a mini-hoon except that mine's been up on ramps more than she's been on the road since I bought her back!

According to the PO she's running up to 1.25 bar boost from a S300 turbo, has been ported and flowed and has/had a custom solid copper gasket, so I expect that may have something to do with it (if raising boost raises cylinder pressure, as I guess it must). Memo to self: use right foot less to control boost better in future...

Will be in touch once she's on Manx plates and we'll go for a blart while the roads here are still unlimited!

Stu

[Glyn Harper]

Hi Artie/Stuart..

the liners were clamped in place, and they were bonded in with the correct Loctite the first time the engine was rebuilt. So, when I had to work on it the second time they didn't need touching. We did check the heights though to make sure they were correct, and they were.

Frustratingly, because the compression had been too high, when the head gasket had gone it had super heater the water creeping into the cylinder and putted the top of my new nikasil liner! Fortunately, that was also within tolerance but it was touch and go whether my new 1000 mile old liner was scrap.. taking the piston with it! (you couldn't get them seperately at the time).

But.. 5 years and about 6000 miles later, it's still good!

Interestingly, we used a different head bolt tightening sequence. Rather than torque the bolts up to a certain amount then do quarter turns, we worked out what the final torque would be and then tightened it up about 10 lbs of pressure at a time all round. Took a lot longer, but by using the same tightening sequence we ensured the new head gasket was uniformly squashed into place. As I say, 6000 miles and 5 years later it still runs like a dream!

Stuart.. mine is in being repainted at the moment at Classy Chassis at the White Hoe industrial estate. Pop down and have a look sometime if you like. It's going to be metallic Black!!