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Thread: What exactly was done to Odin's Warhorse?

  1. #1
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    What exactly was done to Odin's Warhorse?

    Andrew,

    I know you have some inside info. The article gave some hints, but nothing too specific.

    1) According to the article, the crank is stock, so that implies it hasn't been stroked.

    2) The pistons in the picture have a significantly bigger bore than stock, but I thought the S62 was already bored to the maximum and that BMW has to use a special gasket because of the small amount of space between cylinders (I think I read this on the S62 wikipedia)

    3) bigger valves?

    4) Ported heads?

    5) Schrick cams?

    It's clear from the pictures, that there are no MAF sensors and no cats. Since those are gone, it's a pretty safe bet that the ECU programming is also targeted for max HP rather than cleanliness.

    really curious, John

  2. #2
    This is really for GM to answer, as it is his masterpiece, and also a work in progress.

    The story was written almost exactly two years ago this month, and I know that the car has made at least one lengthy return trip to Dinan for more mods, so it is far from where it was when I wrote that piece. Also memory isn't my strong point, things go in one ear and out the other, thats a big part of the reason I started the site, as a way to retain what I can't!
    Andrew Macpherson

    Expert Z8 Inspections, with full support for both Z8 sale and purchases.

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    I didn't realize that was Grease Monkey's car. So, Grease Monkey...care to share any details?

    thanks and regards, John

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    As you already know, the engine in my Z8 is based upon the S62 motors Steve Dinan builds for the Daytona Prototype class in the Grand Am series. The crankshafts used in those motors are stock because of displacement limits in the series. The piston diameters are also stock for that same reason. Because I wanted to be able to take advantage of Steve's ongoing development work, I decided to use those same parts. The pistons shown in the article are actually the same diameter. It's just an optical illusion which makes them appear to be different sizes. The latest pistons installed in my engine are a newer generation based upon Steve's latest research and have increased valve relief due to the radical cam lift now being used. Also, compression ratio has been increased to help compensate for the altitude where I live. The latest cams were designed by Dinan and have extremely radical profiles designed to maximize performance at higher RPMs. Because we decided to keep the VANOS system on my engine, midrange torque remains adequate, but from 4000 RPM to the 7900 RPM redline, the engine just keeps getting stronger and stronger the higher you rev it. Quite intoxicating! The valves are light weight, large diameter race designs and the heads have been thoroughly ported and polished in traditional racer style. The OE hydraulic lifters have been replaced with solid ones. The connecting rods are as pictured in the article. The spark coils are borrowed from the M3 race motors. The velocity stacks are Dinan designed units which maximize airflow at high RPMs. The MAFs were removed because there are more efficient ways to monitor engine performance and the carbon fiber replacements are larger in diameter for better flow. The air intakes in the nose of the car have also been replaced with large diameter carbon fiber tubes. The water/oil heat exchanger has been eliminated under the intake plenum to reduce heat soak in this critical area and an external oil cooler added. Lightweight valve covers are used along with an extremely light weight racing alternator. The header port mating configuration has been chosen to optimize high RPM performance and utilizes very large diameter pipes all the way to the Dinan designed mufflers which offer virtually no restriction to the exhaust flow. The cats were eliminated because they always restrict exhaust gas flow and my State does not have smog inspections. An underdrive pulley system has been added to reduce parasitic drag which frees up a few more ponies and keeps the auxiliary drives from over-revving. The current flywheel is a 12 lb. aluminum unit with a light weight clutch package capable of handling 550+ lb/ft of torque. Of course, there are a few other things Steve has done to the motor(like ECU tuning) but like all good racers, he is reluctant to give away all of his secrets. Suffice it to say, the current motor is producing in excess of 550 hp at the crank and is considerably light than the stock motor. The one major component on the race motors that I am not using is the dry sump system. While there are advantages to such a set-up on a race car, including the ability to lower the engine in the car, most don't translate well to street use. The biggest drawback for me is the need to eliminate the air conditioning system in order to provide space for the dry sump's pumps. I have also modified the rest of my Z8 considerably, mostly to remove excess weight, and the latest weighing session has the car at 3410 curb weight, which is 275 lbs less than the stock curb weight of a Z8! That's like adding another 25 horsepower to the motor. Coupled with 3.91 gearing, the car is scary fast. Hope this answers your questions.

  5. #5
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    Quote Originally Posted by Grease Monkey View Post
    Hope this answers your questions.
    Thanks a lot. It is excessively cool!