Where is everyone #5

OLDSKOOLERnWV · Sep 28, 2019

I guess we all want that perfect run.....

AModelCat · Sep 28, 2019

Lysdexis said: ↑

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Mechanic, when asked to work more than 12:

rank · Sep 28, 2019

MagnumaMoose said: ↑

The gas engines are doing that too. Conjecture on my part but it was a huge deal when the Mopar guys made the cross ram manifolds and it worked by giving lots of volume of air ready to get ingested once the intake valve opened, rather than having a pressure drop while the engine was trying to get a fresh charge.
Edit: the problem was that the tuning was only effective and efficient in a portion of the powerband. The Cross Ram was a big improvement over what they had before, but it was still a compromise, which is what engineering is all about. Getting the best and most efficient and effective operation out of a given piece of equipment, no matter what kind of equipment it is, not just engines.
The Cross Ram worked well in two ways, when the rpm's were low, inside the intake runners the speed of the air entering it was amplified by traveling so much faster than the engine could ingest it that it reached the end of the runner while the valves were still closed and " bounced back " went back to the intake/carb section and bounced again then provided a slight " supercharging effect " ( a slight air pressure spike ) at the intake valve end.
The second way was the large volume size of the air within the runner during high rpm operation. This kept the engine fed with air and prevented the air from trying to reverse itself and blow back out through the carb. Instead of the engine trying to suck through a small straw it was a huge straw, in effect. The air pressure spike was contained within the large intake runner. Shorter runners would have allowed the air pressure spike to escape through the carb ( or at least part of it. ) which is what is happening in an engine when it has a high speed stumble.
End Edit.

They have several tricks now that work and adapt at the different rpm's to compensate for the pressure drops that occur at the various rpms. Plus the amazing precision of the mapping of the fuel needs of the engine at all ranges, and what power level is being asked for at the exact moment.
The old carb engines were a lot more susceptible to all the different scenarios of what was going to be asked of the engine at all the various ranges and it was always a compromise between the different extremes.
The precision of the mapping like AModelCat said is responsible for a large part of the torque plateaus being so large and wide now. Also the variable geometry turbos like he said, are so precise and have done so much to eliminate the weaknesses of the airflow. Like the old two stroke motorcycle engines when they " got on the pipe " which was a small portion of the engines operating range, but extremely efficient while in that range. Now they have figured out how to manage the airflow throughout a much larger range and the results are unbelievable compared to the old carb engines.
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Isn’t there something in these new enginesccalled Variable Valve Timing that flattens the curves?

Lysdexis · Sep 28, 2019

OLDSKOOLERnWV said: ↑

I guess we all want that perfect run.....

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I think that guy posted the same thing a few days ago. Or someone else did.

Off to loves to get an oil change because I cant buy the oil and do it myself for cheaper than theyll do it.

Lysdexis · Sep 28, 2019

rank said: ↑

Isn’t there something in these new enginesccalled Variable Valve Timing that flattens the curves?
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They've also got variable intakes in them now. The mopars I know do on the pentastar and the eagle. Long runners for low rpm torque and above a certain rpm they shift the flow to a short runner to prevent a restriction on the longer path.

Yall ever see a nail head converted to suck through the exhaust ports and exhaust through the intake ports? Something about that design someone figured out you could make pretty good gains doing that.

Lysdexis · Sep 28, 2019

AModelCat · Sep 28, 2019

Got my Addidas track pants and fingerless gloves on. No I'm not going to drive a white Volvo. Weekly river run lol.

Lysdexis · Sep 28, 2019

AModelCat said: ↑

Got my Addidas track pants and fingerless gloves on. No I'm not going to drive a white Volvo. Weekly river run lol.
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AModelCat · Sep 28, 2019

Lysdexis said: ↑

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Actually quite catchy!

stwik · Sep 28, 2019

Gonna eat good this weekend in Birch Run Michigan

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