I love my Chevy Chevette!
Posted: 04/04/15 03:27 PM
I would like to see a more in-depth write up of the Hancock & Lane drag cars that are featured in the Straight Line Spotlight. Both have badass small blocks. I bet the motor in that Competition Eliminator Cobalt turns some serious RPM's (I have heard close to 11,000). How can you make a motor survive at that RPM? What RPM does it launch at? The car looks pretty stock except the hood scoop, what is it like underneath? What is the ET and MPH? I think that it would be pretty cool to see.
My first time was in a Chevy
Posted: 04/04/15 09:52 PM
fully counter weighted cranks.. so the center of the crank is NOT balanced by offset balances on the end of the crank .. reduces the crank whipping in the middle when the harmonic frequency is reached.
thicker bulkheads above the main saddles. so the main saddles are NOT ripped out of the block.. this has to be done at the block design level.. when the patterns for the sand cores are designed. adds weight to the block..
better strut designs for the piston bottoms..
titanium connecting rods..
modifications to the oil system to increase flow rates. perhaps even removing the oil redirecting plug that is 8.5 inches down from the top of the block but an inch and a half or so above the rear main cap.. so the oil flow from the pump is directed out to the filter and then back to the same passage.. removing the plug shortens the oil flow from the pump to the main galleys by almost 26 inches and removes several 90 degree bends from the oil flow . actually Four 90 degree bends and a 10 degree bend.. the multiple bends above are hard to bypass. without external plumbing.
one might even want to create some custom designed main bearings.. that instead of having a half groove.. or a full groove.. are partially grooved.. somewhere around 60 to 66 percent grooved.. but with a tapered groove.. this could even be offset to one side for additional oiling.. the lower bearing that fits in the cap have tapered grooves that end only part way into the bearing.. this leaves you more thrust surface on the bottom 45 degrees or so.. but the tapered oil groove causes the rotation of the crank to push the last of the oil into the oil passage..
its debatable but it probably would be a good idea to have a fully cross drilled crank.. since the centripetal force of the oil in the crank oil galleys increases pressure to the rod bearings. but it can also empty the passage when the oiling groove is NOT flowing to to the main journal oil passage opening.
one also needs to look carefully at the oil pump pickup screen design and clearance to the pan.. and the screen shape to keep a reservoir of oil under the screen area.. i would love to have a camera and strobe light mounted in the oil pan on the GM tilting dyno.. http://youtu.be/LvVK6neQ4q4 to see how the oil reacts..
i have seen people weld either 1/4-20 or 5/16-18 nuts in three locations to their oil pickup screen to keep the proper clearance to the pan.. to prevent it from being blocked... what the heck am i talking about.. do you have a wet or dry shop vacuum.. clean it out and set it up to vacuum up clear water .. with a small bucket of water.. start vacuuming. look at the pattern of the water as the water level drops and gets sucked in with the nozzle held at different distances from the bottom of the pan.. after you have emptied the vacuum into the bucket a few times and retried.. rig up your oil pump pickup to the vacuum. and try again.. or rig the oil pump with the gears removed and the shaft bore plugged.. and attach that to the vacuum.. try different levels with water.. it would be very interesting to set up an oil pump dyno to test this oil pump pickup effect at high engine rpms. i don't like the flat bottom screens personally. i like a concave screen.. i also don't like the perforated metal over the ends of the pump.. i feel it blocks too much of the flow.. the perforated metal sheet is designed for percentage of open area.. by varying the hole size.. pump manufacturers may not be taking that info effect when they select a certain size hole for the screen.. to get smaller holes they have more area between them.. where the holes should be closer together.. that changes the strength of the metal..
this is if you intend to build a HIGH RPM motor. or want one to last at 7,500 RPMs for a few hundred miles or more..