Casting intake ports

[HenrikGM]

Hi Jens.

I took some cam specs from the actual valve lifts.

LSA 109
intake@1,27mm 213 degree
exhaust at 1,27mm 205 degree.
Maximum lift intake 11,55mm
Maximum lift exhaust 11,35mm
Intake more than 9mm lift over 112 degrees
exhaust more than 9mm lift over 102 degrees.

flows 300cfm at 7mm
360cfm at 11mm,
Exhaust not flowed yet.

Stock ignition timing says maximum 50BTDC exhaust side plug, and 45 degrees intake side plugs.

I have this one running as much as 48 degrees advance both plugs simultaneously.
Even at 225kpa abs pressure ignition advance is 40-44 degrees.
Engine will cause burn-back into the intake if ignition is less than 30degrees.

Power level on a turbo charged stock meteor is interesting. We had ours on the dyno last year, taking load measurements from the waterbrake directly into a custom written MS1 code(the whole engine, including the brake is operated with MS1).
A scatter plot of all logs with more than 20% throttle shows a linear relation ship between manifold pressure and produced torque. The factor is quite accurately 18, and confirmed liniear or extremly close to linear between 1500 and 3200rpm.
As such we know the power level the engine is producing on the tractor, just by reading the datalog.(roughly speaking)

Previously we ran large HX60s, but the engine was impossible to run with those turbos. Massive burn back issues into the intake.
Increased to HC5As with #52 housings, and the turbos still spools instantly, but gave a more free engine(cant explain it better, but the engine is more free in the feel of it, remember these engines makes the whole sorroundings vibrate if its not completely right..)

Really interesting to hear what you could suggest.

Cam specs.
Lift
Intake flow path
intake manifold

Above 4 is in my focus as urgent, however if you do it right, the engine will make in the range of 2000hp on pump gas in its stock form only with the add-ons. But its tricky to prevent the engine from burning back into the intake. Many many examples of these engines making very serious backfires, especially on methanol injection, flying toilet type.

[Jens Gustavsson]

hur stora är HC5As with #52 housings? typ HX80 eller?

[Kadett4wd]

Kunde man inte inte borra hål rakt mot varje ventil i topplocket och pressa i ett rör, alternativt skruva fast i en fläns.
Som styr luften till varje ventil.
Strunta i att kanalerna läcker lite inbördes i topplocket, bara luften blir styrd på ett mera korrekt vis ned mot ventilen.
skulle nog göra stora förbättringar i gashastighet ned i cylindern.

Lite som porsche hade keramikinsatser i topplocken för avgaskanalerna.

[HenrikGM]

hur stora är HC5As with #52 housings? typ HX80 eller?

Yep, HX80 size.
Up to 1,5kg/sek

I can find the wheel diameters if needed.

[HenrikGM]

Yeah, it has been done before. It gives 24 intake ports, and the problem is still the short side turn.

I flowed one made like that for another DK pulling team, running bigger valves, better seats, better everything.
It yielded 5-10cfm more that the rough ported test port, from 6-9mm after that it overall lost flow, especially high lift flow.

I thought about inserting a short lenght of pipe with a ~25degree bend on the end, however it doesent really fiit good, and alot of individual adjustment is needed to get the pipe to sit correctly.
Thoughts was that if i could cast the head full, then mill a new round port and hand port the short side radius to make that turn. I would then get only one port pr cylinder to build manifold on.

But what gas speed to aim for? The engine is doing 3-4000rpm. Im thinking 300fps is too high, we will loose power on that.
Just a wild gut feeling guess gets me to 240fps target airspeed.

[Jens Gustavsson]

jag ska försöka göra några simuleringar i kväll om jag hinner.

mvh jens