The Black Rat

[The American]

Run in and tune is done, with the filter cut and checked with a clean bill of health. I don’t know what it made yet, but it wasn’t having a re-tune so much as a check and retouch.

Apparently the VVT wasn’t working which he traced to the Haltech patch loom not passing current. That’s fixed which picked up 500rpm in response.

I can’t get there to collect until Monday (I’m a uni student tomorrow)

[Okibi]

Exciting!

[The American]

So what was up with the Black Rat’s engine?

TLDR: Valve not sealing properly and scratch or ripple in the crank seal surface resulting in persistent leak.

When the TBR came back after its initial run in and tune, it was producing healthy power and the oil filter was clean.
The valve train was noisier than I would have liked, but just about everything had been changed so I put it down to the heavy double valve springs and the shim-under-bucket lifter conversion. I checked this thinking with a mechanic and they agreed.

The other issue was a rear main seal leak.

If I’ve learned anything from this process, it is ‘get things resolved quickly’. In the time I’ve been trying to resolve this, the engine builder moved on, the tuner’s business model changed, and my own life circumstances have changed significantly (no workshop space at home).

The rear main seal was changed four times (actually, have lost count) and on the last attempt, the workshop advised me that there must be something else wrong, as they change many of these seals successfully, and there was no point putting another in without investigating further. They put a dial gauge on the crank seal surface which showed some inconsistency when rotated.

The original engine builder requested that a compression test be done, and wanted to understand engine health thinking that blow by might be the cause of the seal leak. He was of the view that the engine must have been hurt during the dyno run in and tune.

The compression test showed:
Low compression on one cylinder.
Leak down did not change with oil added to seal the rings (indicating top end as the issue not bottom end).

I spoke with the tuner about this and he called the diagnosis correctly: Oil leak is unrelated to the compression issue: Engine is probably fine if you can fix the seal and adjust valve clearances.

Summary:
Mechanic: I can’t fix the rear main, and I think it’s something else that’s wrong.
Engine builder: The engine is hurt and the Tuner probably did it.
Tuner: Engine is probably fine.

I mentioned earlier that the engine builder had moved on. The shop is still operating, but the person who built 4cl for them had left and was now working for one of the big V8 supercar engine builders. So, they were not the right choice for a tear down and inspection.

Another machine shop (John) was willing to do the work for me although they mostly focus on machine work.

When I had the engine built the first time, it was right before The Car Passion Channel ran the video in which his 500hp ‘Miata’ engine broke a main cap. On tear down, one of the observations John made was that OEM main caps were loose in their registers meaning that they were not as securely located as they could be.

The Car Passion video and the assessment of the existing main caps was enough to prompt me to order Mazworks main caps.

The second thing John pointed out was that the Supertech pistons were showing some scuffing, which he put down to the design of the piston in terms of the location of the wrist pins. He recommended CP pistons which I accepted.

The third item that John pointed out was that the speedy sleeve that had been installed as an attempt to solve the rear main seal leak, had been pushed too far on to the crank, and was contacting and had clearanced itself on the rear main cap, distributing metal into the engine. Thankfully, I had barely run the engine, and this had not caused damage.


The engine finally went back together with the billet main caps (new line hone required) and CP pistons. Allowing for Christmas and ordering parts, this all took about six months.

A few weeks ago, I dropped the shell back to the workshop that had all my parts, and they put it all back together for me and got it running.

The following Monday, I dropped it off to the tuner for a run in and retune. The oil filter was nice and clean.

The tuner noticed that the VVt was not working which he traced to the patch loom not passing power between the Haltech and the engine loom. Once fixed (replacement wire) the car picked up 500rpm in boost response.

I picked it up and still haven’t dríven it as I had to get on a plane the following morning, but initial impressions are that the engine is much quieter. The top end was quite noisy before and now it runs as quiet as the White Mouse with its standard valve train.
It also runs smoother than it did before. Previously at idle it had a persistent flutter (which I suspect now was the valve sealing issue). Now the idle is rock solid and clean with no flutter.

Now, if I’ve learning anything from all of this, I need to go and drive it a bit before too much time passes.

[ManiacLachy]

Quite the journey! I'm excited (though not as much as you must be) for your first blast, looking forward to hearing your impressions.

[greenMachine]

Blimey Charlie, what a saga! One lesson is to limit your cast of characters next time, I hate it when that sort of pass-the-parcel happens, a lot of people are reluctant to even think about accepting responsibility when there is some else they can point to.

Your description of the car sounds as if it just might be fixed, I certainly hope so. I await with interest to hear the Majic numbers the tuner found ...

[The American]

Blimey Charlie, what a saga! One lesson is to limit your cast of characters next time, I hate it when that sort of pass-the-parcel happens, a lot of people are reluctant to even think about accepting responsibility when there is some else they can point to.

Your description of the car sounds as if it just might be fixed, I certainly hope so. I await with interest to hear the Majic numbers the tuner found ...

Quite the journey! I'm excited (though not as much as you must be) for your first blast, looking forward to hearing your impressions.

Thanks Both!
On the topic of results, the tuner said it made 420hp, which is quite a bit less than last time (460hp). He told me that he’s got a new dynamometer and that the old one had ‘very happy’ days some days.

I could be disappointed that the number is lower….but…. It really doesn’t matter. It’s going to walk all over the diesel Hilux I’m used to driving!

[PaulF]

No point stressing on the numbers too much, it'll be a rocket ship!

What was the diagnosis for the valve leak? Damage to the valve itself or the seat?