Urq project

[diesel des]

So my working theory is that there was knock on cylinder 4. This blew the gasket into cylinder 3 and 5. That melted the head, block, burnt the pistons slightly and damaged some valves. The bores actually look ok, with only the odd light mark and I would run it ok. This issue is the deck is damaged and burnt and due to how I have it skimmed to get the squish I wanted I can't skim it further.

Obviously the head is scrap, which is unfortunate as it's a jnl race spec head with oversized super tech valves etc. A few pistons are damaged from having molten metal blowing about on them. Also the turbo is finished as the turbine wheel is damaged. That's not strictly replaceable, so I need another gt35 billet. Totaling it up it could easily be 5k damage.

On a better note the oil came out clean, with no metal on the magnetic sump plug, so I think the crank and rods could be ok.

I will get the injectors tested to see if cylinder 4 was lean. Is cylinder 4 the weak one on these engines? The engine never ran lean on the wideband and my timing looks conservative, so I really don't know.

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[4WDrifter]

Bummer mate!

[david1980]

Damn

How hard is it to source the damaged bits and would you get JNL racing to do anymore work after the comments on here lately about substandard work?

Might be worth looking into a newer 07k if you are having to go back to the starting point or just doing a quick/cheap build and enjoying the car so you don't lose heart.

[diesel des]

I would definitely use jnl again as I have had no issues with his work. I also thought 07k but that would need so much work. I just need to build this again with a new block and head and it all fits. I have a spare stock head. Hopefully a TDI block isn't to hard to find. Need to price up some bits next week.

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[david1980]

What was the final spec of this engine before tragedy happened?

Would you go full spec head straight away?

[S2central.net]

Yikes - that is an expensive gasket failure... would be very interesting to know if a lean running injector in #4 was the root cause.

[diesel des]

What was the final spec of this engine before tragedy happened?

Would you go full spec head straight away?

The engine was a:
2.5 stroker
x beam 159mm rifle drilled rods,
forged pistons,
8.15:1 Compression ratio,
1200cc injectors,
3 fuel pumps with surge tanks,
baffeled sump with an accusump,
oversized valves and "race spec" head work,
7a cams
Tube exhaust manifold
GT35R with 84mm Billet compressor,
Large intercooler,
Seperate exhausts for the turbo and wastgate,
Vems etc

Im not sure in what direction to go at the moment. I do have a bone stock head in storage, but would at least change the exhaust valves to supertech or similar.

A few folks have asked about my maps. Im happy to show these. Remember this was a starting point i felt was safe, and i intended on tweeking from there.

Lambda target.


VE map


Timing Map

[diesel des]

No map comments? Anyone specialise in mapping vems in the UK?

Anyhow I had the injectors tested while I watched at holeshot racing. This guy is properly mental in such a good way. He builds bike engines, generally but not always with a turbo or even 2 attached. Proper turbos. Efr9180. Gt42. 910 bhp at the rear wheel mental. He holds a world wheelie record and build bikes for that ghost rider fella.

Anyhow the injectors are perfect...

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[Airwolf]

Why are you using 3 fuel pumps instead of 1 big one?

[diesel des]

Why are you using 3 fuel pumps instead of 1 big one?

One pump is high flow low pressure and it pumps fuel from the foam filled fuel cell to a surge tank. This pump keeps the surge tank filled, and it overflows back into the main tank. The surge tank has the 2x walbro 450 e85 pumps in parallel that deliver the high pressure to the fuel rail. The return from the fuel rail goes back to the surge tank. I went with 2 high pressure pumps so I would have plenty of fuel for e85 or even methanol at my desired power rating.

I know of no single pump system that would be able to match the performance of this setup.

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[diesel des]

Oh and the 3 pumps I have can draw up to 50 amps so it isn't a small setup.

This is the guy who tested the injectors.

https://www.holeshotracing.online

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[Error404]

Your VE table is virtually flat - for example your VE figure at 100 (kPa?) 800rpm is the same as 250 (kPa?) 6000rpm - VE should be an air mass model. These numbers alone cannot be correct, unless there is something else to the equation - to be honest I have never even looked at VEMS though - how is the fuelling calculated using the VE table? Is there more overlay tables or variables? I am sure some of the VEMS experts will be along shortly.
Timing looks pretty sensible in my opinion, of course depends entirely on other factors.

[Airwolf]

One pump is high flow low pressure and it pumps fuel from the foam filled fuel cell to a surge tank. This pump keeps the surge tank filled, and it overflows back into the main tank. The surge tank has the 2x walbro 450 e85 pumps in parallel that deliver the high pressure to the fuel rail. The return from the fuel rail goes back to the surge tank. I went with 2 high pressure pumps so I would have plenty of fuel for e85 or even methanol at my desired power rating.

I know of no single pump system that would be able to match the performance of this setup.

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I see, so if one of your pumps fail your engine can Lean out for the lack of fuel instead of having one pump that stops your engine if fails.

Weldon delieveres big fuel pump that have the ability to do sugetion and pumping

[S2central.net]

This is the guy who tested the injectors.

https://www.holeshotracing.online

Bikers are just nuts - especially Irish bikers - leather clad organ donors.

Anyway... getting back to the plot, if your injectors are perfect then it begs the bigger question of what caused that cylinder to melt down and cause damage to its neighbours - are both pumps at full health ?
If you have one that is underperforming you would expect to see some lean running under high load across all cylinders - and you said the WB02 readings were consistently good - scratching my head why one cylinder would be so adversely affected.

[Error404]

Quoting Dmitri - Cyl 4 always knocks first.