Old Ears too
Super Member
@grillebilly - Sorry for the detour.
What are you running motor wise in your hot rod?
What are you running motor wise in your hot rod?
Finally got the race car dialed in
- Thread starter grillebilly
- Start date
grillebilly
Empty Head
The biggest change occurs when the sun starts to set. First off, you see the tree lights differently. They appear to light sooner. The track surface cools a bit, which can either help or hurt, depending on air temps. The dew settles on the track sometimes too.
As far as the engine power, it changes with altitude, and barometric pressure affects altitude. Sometimes altitude gets below sea level and the cars are running faster. High pressure causes the reverse. Some racers have weather stations (computers) that they use to re-dial the car as needed.
grillebilly
Empty Head
It's a 540 cubic inch Chevrolet engine with a single 4BBL running on methanol. Alky is cheaper than gasoline, doesn't detonate, runs cooler and is less affected by high temps.
Old Ears too
Super Member
540!!!!
Yeah, Engine Master's did a show on that stuff recently. Really interesting to see how the engine reacted to differing mixture levels.
Yeah, Engine Master's did a show on that stuff recently. Really interesting to see how the engine reacted to differing mixture levels.
grillebilly
Empty Head
It was a 489, which was the exact same engine with a 4.280 bore instead of a 4.50 bore in the 540. I needed to freshen it up with new pistons so I bought an aftermarket block since pistons were a necessity. The displacement increase made it almost 2 tenths faster in the quarter, the power coming from the valves being unshrouded by the larger bore. Everything else from the old engine went into the new one.
Old Ears too
Super Member
The valves were one of the items they discussed on the Hemi vs 440 show. Combustion chamber shape, squish area, all that good kind of stuff makes a difference.
That's always a good way to save money re-using the old parts in the new engine.
That's always a good way to save money re-using the old parts in the new engine.
grillebilly
Empty Head
It often dictates how much of the intake ports actually gets used.
Old Ears too
Super Member
It all comes down to how much air the engine can pump.
My old 912 was a 'conglomeration' of parts my brother came up with and assembled by an ex-racer who was a well known 912 engine builder (who was also a good friend of ours too).
Heads modified with big valves, a cam, pistons with higher compression ratio, balancing, it all added up to a very nice motor.
My old 912 was a 'conglomeration' of parts my brother came up with and assembled by an ex-racer who was a well known 912 engine builder (who was also a good friend of ours too).
Heads modified with big valves, a cam, pistons with higher compression ratio, balancing, it all added up to a very nice motor.
grillebilly
Empty Head
Little brother took a cell phone video of a qualifying pass last weekend if anyone wants to see it.
https://www.youtube.com/shorts/jXBr-YnXcbA
https://www.youtube.com/shorts/jXBr-YnXcbA
Old Ears too
Super Member
Enjoyed seeing that @grillebilly. Looks like your car really gets down the track well.
Not quite a bumper dragger- but saw a little air under the front tires there...
Good job staying in it, and letting it settle on its own.
Regards,
Gordon.
