I think crossing the line and hitting the limiter in 4th at 135mph is what's to blame for all this.

I think it's had valve float when the limiter has kicked in and I've had a bit of valve to valve contact. It's around 3-4 months since I did that and I think they've fatigued over time and finally let go the other day.

There's no other explanation as there is no sign of any contact on any other valves or pistons.

I think had I used Ferrea valves and had a limiter set at 8500 rpm I wouldn't be in this mess.

I need to see if the block is salvageable first. it's already at 100mm so if I cant hone out the marks this has left without going oversize then it's game over for the block which is a shame as its sleeved and is spot on.

 

Good job I was planning that winter refresh on the engine. Pity the dropped valve beat me to it.

I've stripped the block down this morning. Bearings were on their way out. Rear thrust bearing, both halves were cracked!!

I've had zero mechanical sympathy for this engine so for almost 18,000m I think its held up pretty well but it was certainly ready for a refresh.

Piston skirts were in great condition. Bore of the dropped valve cylinder is damaged but I'm hoping an oversize rebore will sort that. I'll see what my local engineering shop has to say about that.

The current plan if the block is salvageable is for a set of CP 100.5mm pistons (purely because of the sleeved block), new heads, Ferrea valves and currentGTX35R turbo fixed by AET Turbos.

If the block is goosed then I'll have to bite the bullet and go the 2.35 route but I really can't afford one of the blocks at the mo so it will have to wait a few months.

 

So it looks like my engine failure was just down to the valves failing. Every single inlet valve has the beginnings of a stress fracture in exactly the same place that the others failed.

Just to clarify unlike last time that there are no signs of impact damage on either the valves or the pistons so it's just a simple materials failure.

 

A simple, yet costly failure. At least you've found route cause with the failure, but it sadly doesn't help the situation.

 

What valves did you use Darren?

 

Supertech Stainless Niterided inlets and Supertech Inconel exhaust.

Supertech Double valve springs and Valve clearances were all set to cam manufacturers specs (Cosworth)

 

Heard of a few failures with super tech and they’re supposed to be the best

 

Did you check for coil binding on full lift ?

 

Haven't got the equipment to do it Paul, such as life for a home built engine.

It all came as a kit from the same manufacturer so you would think it would all work together. Heads were low mileage and I used stock guides and valve seats which were in good order and all checked prior to assembly.

 

You can easily visually check for coil binding, get one of those dentist small angled mirrors & put the cam on full lift, you should as least have 1.5mm gap at the centre coils, they will closer towards the top & bottom.


Did you have thicker of the 2 options of spring platform, TS/SUB-4, if so they will be very close to binding, depending on your actual cam lift.

 

Yes I do, Cosworth 10.8mm lift inlet cams.

 

To be honest Daz, I would mock up your valve train & measure it, with those platforms 2.85mm thick, & cam lift, you will be surprised how little error there is, valves don't stress themselves on there own, something under lying usually does.

 

Thanks Paul, I'll do exactly that.

 

Thanks to a tip from Paul Finch (thank you Paul) I have managed to check for coil bind and I think I've ruled it out.

I measured the springs fitted into the head. Installed height with seat and retainer is 38mm.

I then put the spring assembly (again with seat and retainer) into a vice and compressed the spring to 27mm (cams are 10.8mm lift). Although it looked tight I could compress the spring another 2-3mm after this point.

Installed height (38mm).




Simulated full cam lift 10.8mm




So I'm assuming that rules out coil bind being the issue.

 

I can't help, but this is a really interesting thread.
Good luck with the re-build.

 

Hi Daz, did you ever get the car back together and get to the bottom of the issues? Been nearly a year now.

 

Haven't touched it yet. It's sat in the garage gathering dust.

Had an accident in June which has put me out of action for a few months.
Will hopefully make a start on it in the spring.

 

Sorry to hear that. At least you've still got it and it's a project with great potential when you get back on it again.

Happy new year!

 

Hey all,

Thought I'd better update as it's been a while.

A fair bit has happened since the engine shat itself due to the valve issue. Not much of that was on the car.

After the failure I lost complete interest in the bloody thing and just parked it in the garage and forgot about it.

18 months ago I moved house and put the car in the garage in the new house and continued to ignore its existence.

I contemplated starting work on it and then had a fairly major accident whilst building some stables at the new house for the wife. I fell off a roof and shattered both of my shoulders. I'm now equipped with some upgrades
Left




Right


12 months on and lots of surgery and lots of physio later I'm now just about fully recovered although my days of playing tennis/squash are numbered not that i did much of that anyway.

So now I'm able to again I thought I better make a start on the car.
The new house came with a triple garage but for some reason the previous owner only concreted half of the floor so that was the first thing to be addressed.




I then needed to put some lighting in and a few coats of paint to make it a suitable work space.


With the garage sorted it was time to make a start on the car.



Now as you know I don't do things by halves and this is no exception.



What's the plan I hear you ask?

Well now the car is not my daily anymore I can approach things a little differently this time round. One thing is for sure... This will be the best car I've ever built.

It won't be a quick moving project this time round but everything will be done meticulously and to the best of my ability.

Watch this space!

 

Looking forward to this having read your previous project treads

 

Me too. Always interesting and in-depth.

 

Blimey mate, you've been through the wars recently. Glad you're on the mend now though and glad you're able to complete the car!

 

What a project!! good to see your sticking with it. Must of been very frustrating with the valve issue!!

 

You still working on this Daz? People like us never grow up from wasting cash on cars

 

Aye still here mate. I've seriously considered getting rid but the dilema is what to replace it with.
The fact is unless I'm spending 6 figures I won't get anything anywhere near as capable or fun.

So, here we go again!

 

Wowzers, glad you’re on the mend and look forward to more updates

 

stick with it daz, not many good projects on here anymore so will enjoy reading your updates when they get posted. bloody sore one you had there as well but at least you will have fun setting off scanners etc at airports with all that metal lol.

 

Cheers fellas,

As said it will be more of a slow burner this one but hopefully it'll be a good read.

Yabba you're not wrong mate it hurt like a b4stard and recovery was a bitch. The worst thing about it was the fact it was both at once.
Never mind I'm the other side of it all now.

 

Quick update.

Engine bay is primed.


Next job is unfortunately a necessary one. I want to completely seal the underneath of the car. Many reasons for this but the primary one is to protect it from all the ****e they put on the roads here during the winter months.

As it's an Aussie car it has very little underseal on so I want to rectify that. Also the car is having a full colour change so I want the underside to match the rest of the car. Big job as all the running gear and fuel tank have to come off to do it properly.

It get's a layer of this stuff and a layer of 2K colour afterwards:


I've done this on cars previously and it always looks good once finished.

 

wish i could do all that to my bug its rusting like hell underneath, good to see your able to protect yours properly m8.