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  • CEF33Y
    replied
    ^^^Pics aren't working for me. And never been so keen to see a bunch of engine parts!

    Leave a comment:


  • PXL265
    replied
    I am watching with interest to see how it all goes and how big an adrelinan stain you get in the race suit after the first fast drive in it.....

    What you are doing is proper old school motorsport, answering the questions that don't necessarily need to be asked, but need to be answered and coming up with the solutions to answer those questions.

    Leave a comment:


  • Roy928tt
    replied
    A couple of people have made the observation that going to a short stroke motor with lower torque characteristics will make the car harder to drive. I'd suggest that they have less exposure to sub 500 kg vehicles.

    Considering that the vehicles I regularly compete against are powered by 4 cylinder motorbike engines of around 1300cc capacity and about 300kg, I don't think a V6 or V8 of 2.5 litres or even 2.65 litres is going to be comparatively lacking in torque.

    It all comes back to the weight being moved. Using the example of... myself, I'm around 78 kg so I add 16% to the weight of my car, I'd add 7.8% to the weight of a 1000 kg MX5 or 5.2% to something weighing 1500 kg......So realistically you could power a 500 kg car with a third of the torque of a 1500kg car and achieve the same performance, Remember of course that HP is just a product of torque and engine speed.

    Of course the only reason that a Cosworth DFX Indy car engine makes 800hp while the N.A. DFV makes 400, at the same engine speed and essentially the same engine, is that the turbocharged DFX makes more torque. I think the overall performance of the entire package is in good hands.

    At least, I bloody hope so.....

    Leave a comment:


  • Roy928tt
    replied
    ​​ ​​ ​​ ​​ ​​​​​​​Here are a few photos of what I've bought, Tony reckons that with another block there is enough to build 2 engines. Lets see if I can get 1 runner together first......I'm excited!

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  • Komdotkom
    replied
    Excellent!

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  • garvice
    replied
    Congrats on rewarding yourself with the purchase!

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  • Roy928tt
    replied
    Ah! Typical, my bloody email has been on the blink, only the last couple of days but enough to stop communication from Texas. I was getting a bit anxious, so I actually rang old mate in Texas, he was equally perplexed as his emails to me were bouncing back to him....

    Anyway he conveyed his bank account numbers over the phone and all is sorted,

    He also mentioned that he intended sending the engine in an ex Granatelli engine flight case, nice touch I thought. The extra parts to be packed in cardboard boxes rather than wood for out quarantine regime.

    I can scarcely believe I'm doing this, but there you go. One of the things about coming to motorsport, or perhaps returning to motorsport, would be a better way of putting it, after putting it on the shelf while I worked the FIFO life for 20 yrs. I'm able to wholeheartedly spend on my motorsport I don't need to worry about a mortgage or those expenses of establishing yourself, that is all done, now it's a reckless spendathon to the grave. I'm done with road cars, I've had a twin turbo Porsche, I've driven an F40, road thrills just don't cut it any longer ( the current car has a better power to weight than an F40 indeed is around Mclaren F1 stats)

    Now to step up to a properly serious 5 digit redline.

    I was discussing the care and maintenance of the Cosworth DF with my engine machinist, and really it SHOULD be a fairly reasonable thing to run, there will be quite some cost in getting it all together and fresh but the following few years should be reasonable...

    Here goes..

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  • Roy928tt
    replied
    A stinking hot day here in Adelaide, I'd like to be at The Bend for The Classic but I couldn't think of anywhere worse in this weather....

    So I spent a few hours in the shed this morning still dicking about spacing gears on the gearbox input shaft, it is consuming much time but is looking really good. The jig I made is invaluable, I'm pleased that I realised I'd be well rewarded by making one. When I'm finished this bit of work I will be able to utilise all six ratios, just another step on the way to getting the car suited to running on a circuit.

    I watched a new Motor Sport Magazine interview with Gordon Murray, in which he talks of the "virtuous circle of lightness" and of requiring an engineering argument for use of any bolt larger than 10 mm on the Mclaren F1. Interesting, there is a bolt of larger than 10mm diameter on my F1 back end, it has a hole drilled through it for lightness......

    No reply from Texas with banking details yet, I'll give him a few more days...meanwhile the package of Judd AV's is for sale in Canada, so that might be a fall back if the Cosworth falls through for whatever reason. I would rather go Cosworth, because the transaxle bellhousing is Cosworth pattern. It would be nice to have a couple of pieces that just fit together....

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  • Roy928tt
    replied
    Little steps, but starting to scratch the surface of Cosworth DF V8's the big end bearing is a Ford Kent 1600 but narrower (there are aftermarket cranks for the 1600 that use the Cossie size) The mains are the same size as the Austin Healy 3000 engine, DFV uses a 13/16 gudgeon, DFX a 15/16 gudgeon to deal with the extra stress of the 25 psi boost, DFV had I beam rods, the DFX H beams often Carrillo's.

    There are a handfull of bore and stroke combinations but it seems that through the competition life of the engine the limiting factor was the valve springs, Renault's pneumatic valve system really was the breakthrough in the search for more power.

    It seems that the biggest issue that Cosworth had was the timing gear breakages that blighted them till they came up with the quill drive for the cams, after that it was a matter of getting the valve train to live at ever higher revs.

    Leave a comment:


  • garvice
    replied
    Awesome read and completely understand the non logical /emotional purchase thought process. Sometimes you just need to do something that you enjoy /want. What's a few more weeks/months working hard to pay for it

    Leave a comment:


  • PXL265
    replied
    You've done so many things that shouldn't be done with this car, what's one more.....

    Leave a comment:


  • Roy928tt
    replied
    Bwahaha, whilst my lathe skills are improving, nobody makes cams on a lathe, I do have a mate with a cam grinder though.......I believe the go is to build the cams up with weld then grind the desired shape back into them, I've no idea how they are welded though.

    Besides all of that, there is gxxr, has a lead on a set of turbo cams, problem solvered.

    Nah, I might have to spring for an ignition upgrade but I think that is all the budget will support in the foreseeable future.

    Leave a comment:


  • PXL265
    replied
    Originally posted by Roy928tt View Post
    Yes, there certainly is no rush to swap over to Cosworth power, the Mazda still has much to give us.


    You'd have to wonder how the mazda would go with a more lively set of cams....
    Well there is the next job to task yourself with whilst waiting for the Cosworth to show up.

    Surely punching out some lumpy sticks would only be a matter of hours on the lathe for a man of your talents....

    Leave a comment:


  • Roy928tt
    replied
    Yes, there certainly is no rush to swap over to Cosworth power, the Mazda still has much to give us.

    I was just looking at the Mazda V Cosworth, among all of the figures in my head the 2 bores seemed to be similar. Indeed the Mazda is around 2 mm different, Mazda Bore: 84.5 Inlet Valve 32 Exhaust Valve 27.5 Cam lift 8.5 DFV Bore 85.67 Inlet valve 34.5 Exhaust Valve 29 Cam lift 10.4 .....

    You'd have to wonder how the mazda would go with a more lively set of cams....

    Leave a comment:


  • Guido
    replied
    Keep running this car as is while you put the motor together and then regroup your thoughts. Might even find that building a new chassis around this motor might be a good thing.

    Leave a comment:

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