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Thread: Cross drilled and slotted engine ;)

  1. #1
    Throbbing Member scheistermeister's Avatar
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    Talking Cross drilled and slotted engine ;)

    Found this on another board, yes it is a joke.

    "Took out my engine for a 383 rebuild and look what I found! Turns out I have a rare factory performance engine complete with drilled pistons for decreased weight and slotted block for extra cooling.

    Close up of a cross drilled piston. Looks like GM left a little work to be done. A nice port and polish should clean all that mess up and improve flow as well...I think I'm going to send my new pistons in to Total Engine Airflow. They did good work on my heads, so I'm hoping that they can increase some air flow for the pistons as well to match the rest of my ported components. I'm going to make sure to use forged cross drilled pistons though because I've heard that the stock cross drilled ones aren't very stong and tend to produce minor stress cracks....you definately don't want cracks in your piston. The reason being because the air will build up in the cracks and lower your air flow and drag coefficient.

    A nice shot of a deep dish piston....yummy! These deep dishes increase the cylinder volume for more horsepower. Pretty self-explanitory if you ask me.

    Good shot of the slotted block. These precision slots create a ram-air type effect cooling the block internals.

    Some people think that the slotted ram-air blocks were a GM gimick....I actually experienced negative (-) engine performance with this block...but I completely belive it's because my headers increased the under-the-hood temperatures. Therefore,..only hot air was entering the engine...thus actually heating the rods. And we all know hot metal expands. A longer rod length obviously means the stroke is shorter which cuts my displacement down. Through advanced calculations I've come to conclude that this decreased my displacement from 350 to 346. Know I know why my friend's 347 Mustang can beat me. I was actually in the process of fabbing some dyer ducting to run under my car to pick up some cool air. Remember to go under the car...if you go above the car you'll only grab hot air because hot air rises. But I decided instead of messing with all the logistics involved in that I'll just go with a 383....that way when my headers heat my rods I'll still have somewhere around 379ci... which is bigger than my friends 347...so I should win then.

    Special GM coated racing runners. WARNING!!! If you happen to have these runners...DO NOT PORT THEM! By porting these runners you will remove the special coating inside which helps maintain good back pressure. This coating also helps to create air flow turbulance. Air flow turbulance is very powerful...no NOS needed there. For a perspecitve think of how powerful the turbulance is that can shake those heavy airplanes in the sky up and down. Now imagine that same power shaking your pistons up and down. I know what you are saying. Vortec heads use a similar pattern to make the incoming air vortex or twist into the clyinder. This harnesses the power of a tornado or cyclone. So you might be thinking that a vortec port would work best...but that's plain pure ole' . Let's put this into perpective for ya. A tornado only has enough power to lift something and throw it into the air. Once thrown into the air an object in motion will remain in motion unless acted upon by another force. But air turbulance has the power to overcome the power produced by the flung torando objects because air turbulance can actually move objects that are already in the air. Let's see that vortec air do that! Let me tell you...with this coating, my engine reved like a motha! The astute reader will notice that one of my runners was ported. I did this and then I listened to my exhaust (with no headers on) afterwards. I had to retard the timing about 30 degrees to slow down the engine to where I could determine which clyinders were firing when. (Use a clear distributor car if you have one) The cylinders that had the turbulance coating were definately louder than the ported runners. And we all know louder=faster!

    Notice that even the manifold has this coating. When I get my 383 I will definately look into getting my ported superram and base coated with this awesome material. I will post dyno results from desktop dyno. Also, notice the pool of coolant fluid. That is no accident my friends. There are special holes drilled in the manifold that let coolant puddle ontop of the manifold. This cools the manifold and lowers the temperature of the air going into the combustion chamber. Notice the clever desgn places the coolant puddle near the injectors too. This also cools them so that the gas temperature goes down. (The gas gets heated by the muffler and exhaust under the car. Trust me...hot gas is NOT what you want on a performance car, because more energy is required to burn cool gas than the gas that is already heated. For every reaction there is an opposite and equal reaction. So the more power that it takes to burn the gas, then the more power the gas will produce.) I have my Autometer gas temperature guage duct-taped to my A piller and have noticed a 1degree drop in temperature since I've had manifold drilled. Well worth the money, time, and effort IMHO. Remember every 1 degree is worth like 1hp. If you are making 1hp/ci then every 1 degree cooler the gas is is 1 more cubic inch your engine will increse (as long as you have ample hood clearance for the additional cubic inches. If this is a problem either cut holes in your hood or buy a plastic scoop of Ebay) With my new setup, I will actually be using an intercooler to further cool the radiator fluid....but I need to find a place to mount it. I will also add ice into the radiator and intercooler. Make sure to use crushed ice if you care about your water pump though. The ice normally would freeze the coolant, but as long as the liquid is constnatly moving, it should not freeze. So coolant temperatures below freezing should be attainable. This should drop my gasoline temperature about 6degrees. This is good because it makes up for the increased rod length from the header/ram air block setup. Here's an insider hint straight from the TPIS Insider Hints book.... After creating the coolant puddles on the manifold, heavy braking is recommended in order to constantly coat the entire manifold in this cool coolant. The coolant puddle is a good idea as long as you don't plan to flip your car...because you don't want coolant on the underside of your hood..."


  2. #2
    RIP Sangrun Hunter's Avatar
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    Ouch!

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