Engine mod (BJ 1991)

[Jack-Lee]

Head is ready, Pistons should lathe down about 1mm so i could install a smaler headgasket (0,3mm instead of 1,5mm) to increase the combustion from 9,3 to 11,2.

[Jack-Lee]

In progress.
At this time i had problems with the hydros. They "push up" my valves because the realy high oilpressure at cold start (about 6bar).
Buy other hydros and would test it tomorrow.

But when the engine is warm, "the power flows through!"
Fuel consumption about 3,5-4l/100km at this time.

Yesterday i start to build my own EFI.

[Jack-Lee]

Hi,

now the engine is almost finished (only the aircleanerbox is not in place)

I lathe the valves so i cut it about 2mm (i musst lathe a new notch for the cones). The reason : I would use light 50g hydraulic valve lifter from a BWM. These dont push my valves "half open" when the oil pressure rise above 2bar.

After that i weld the new intake Manifold. 0,82l Plenum, 190mm tube-length, 28mm tube-diameter, 150mm throttlebodylength,58mm throttle diameter.
I worked until 7am.. (about 20h without a break )

And now : The engine is like it should. Diesel-like but gasoline driven.
(PS. the performance-chart was driven with AFR 16,2 !)

[Jack-Lee]

The engine runs about 2 Weeks. No problems appears, i only update the ignition table. It looks like the original engine, lesser problems with the "TÜV"

[renault_megane_dci]

All this is mighty impressive !

Would you benefit a gearswap ?

[renault_megane_dci]

What's the length of the the valve ?

I have a Mini and I Wonder if I could use those smaller stem valves for improved airflow ...

70 HP out of an 8 valve 1.0 liter engine has quite some appeal ...

[Jack-Lee]

Hi,

i build the enginie completly new.
Now 1.4l (79mm Stroke now instead 72mm) with a forged crankshaft.
I used new Pistons from a Honda D15 Engine and H-Rods. The Rods guided over the Piston to reduce friction loss. The Head was changed to newer Model from the "6n Polo",with much better port geometrie. I optimize the ports and the valveseat. The valves lathe down to 6mm shaft and better valveplategeometrie.
Compression are now 12,2:1.
And i build in a oel"heater". This little thing heat up the oil via the coolingwater. At full throttle this heat exchanger cools the oil to max. 100-105°C.

[Stubby79]

You do good work. Waaay above my mechanical level on that engine.