garybee

Andrew - yes that's exactly who I was thinking of  , fairly nearby for me also.  

Interesting to read your experience of them.  I don't like that people are jumped on for anything that isn't praise.  It does require people to be reasonable in what they post of course.  I've never seen anything other than that in what you've posted on here.

They can take a few attempts till you get the knack, the snap ring has a good grip.  Don't worry, you won't separate the jointeven though it does move a long way.

there's a snap ring on the end of the shaft, inside the diff.  You don't need to access it though, it just provides some extra resistance.  It will release with a sharp pull, pushing it all the way in first will help by giving you a bit of a run-up.

Gotcha, pretty conclusive for a leak between the cylinders and the water jacket then.  You say "coolant when you came to a stop", do you mean an overflowing header tank or something else?

There's always the possibility of another fault (cracked liner etc.) but realistically the chances are it's going to be the head gasket.  If that's the case and it was shut off quickly enough it can be DIY'd for <£100.  Do you do any spannering yourself or are you looking for recommendations? If the latter a location may help people suggest somewhere appropriate.

As long as you realised quickly and shut it down before the head got too hot it's an easy fix. That's assuming your head gasket has actually failed of course.  What are the symptoms?

edit: commiserations on the timing though, that is a real shame.

Well, that mod will have reduced the pressure at the big ends so certainly won't have helped (pressure being the result of restriction to flow and you would have had less restriction with the extra squirters).  Impossible to say what would have happened without them of course.

I make sure my camera keeps the OPG in shot when I do track days so that I can have a quick check afterwards as I know that I'm unlikely to notice at the time.  Did you see any reduced pressure displayed?

I think the rules have changed.  Although you still don't need one I believe that if you have one it now needs to be in date.  I'm sure a current competitor will be along to confirm but I think you'll either need to replace the cylinder or remove it.  

In which case they will be lowering the pressure and flow of fresh oil at the mains.  I wouldn't like that.

Many engines have a spray bar low down at the edge of the barrel.

I've never been a fan of the Gates flexible hoses having used the Vulcoflex type in the past (maybe new version is different?).  They tend to take a fair bit of force to form a curve.  Good for mocking up a system though.

There's great info for this on the DVA power website ('oilyhands' on here).  Oilyhands (Dave) has kindly put loads of info on the K-Series on there.  I believe it's a Payen gasket that he recommends.

That seems like a reasonable price and a good looking system.  The default option of Powerspeed has just got too expensive for me to consider it to be reasonable value.  I bet there would be a few interested in a group buy from Simpson.

Can't believe that is the cause.  Very glad to hear that you've found it though.

Going forward...don't just put it back together.  Take the opportunity to upgrade or improve something that requires the current level of strip.  That way it won't feel like a waste of effort.

Ta fellas, I had just read the OP again and forgotten the rest as it's been a while.  Watched the video and agree, extremely unlikely to be pinking.  I remember ruling that out before now 

It's not rhythmic enough to be a high pressure exhaust leak.  I remember expecting to see something light bouncing around when the cam cover was removed.

Your original description sounds like how I would describe pinking.  Does it happen mostly under load?

edit: forgot there was a video.

The bolt is not the problem, the threads have been stripped out on your radiator.  There is just a small section of thread remaining as the bolt has a plain, waisted portion near the head.  Therefore when the bolt was overtightened, and the threads were stripped, a small section of thread remained.  

You don't need to replace the bleed screw/bolt with a different type of plug.  You need to repair the damaged threads in the radiator so that the bolt can tighten the lower face of its head against the sealing washer/radiator.  That's what provides the seal.

Sounds like the thread has stripped out of the radiator.

I'd suggest making the leak tester and testing the rest of the system first.  If you slap a new pressure cap on it and it dumps its coolant without you noticing you could easily end up cooking the head.  Also worth checking for combustion gasses in the coolant.

Could be the classic header tank cap.  How long was there between stopping and noticing the leak.  Was it long enough for the coolant on the block to have evaporated off?

It's easy enough to make up a 'pressure test cap' from an old cap and a tyre valve.  Probably the most effective test you're likely to be able to carry out.

I'll take a couple of pictures of mine tomorrow and post them.  You can always check the angles of the straps yourself to ensure they fit within the required specs. 

If you have an opportunity to test one out before you commit I'd suggest doing so.  I had mine modified by Arch when I had the chassis repaired but found that I'm not HANS shaped.  It was so painful when I did the straps up I wouldn't manage a lap. 

No need to fret about running without the belt cover fitted, nothing's going to happen unless you start throwing gravel at the front of the engine (don't do that).

What makes you so sure the alternator/belt isn't the source, did you remove it?

I wouldn't expect there to be any appreciable slack between the two cam pulleys.  Maybe what you heard squeak when you did that was the belt tensioner.

Happy to have a listen although I wouldn't expect to be able to pinpoint the noise from a recording.  PM inbound.

It's yours Paul, please PM with address details and I'll get it sent.