d.p.n.s

d.p.n.s mk3 discussion

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25 minutes ago, RUNAMUCK said:

Only need a mk one, a mk four, and a Hyundai Stella to complete the set!

hmmmm hyundai......intresting.

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19 minutes ago, Nominal said:

Pretty sure seedy al would sell his mk1 project.

i dont need the full set......unless a mk1 or a mk4 crossed my path .cheap or cheaper

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2 hours ago, RUNAMUCK said:

Only need a mk one, a mk four, and a Hyundai Stella to complete the set!

Mk4 and mk 5 are pretty much the same anyway

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On ‎10‎/‎28‎/‎2017 at 21:40, d.p.n.s said:

 a xf alloy head 4.1 with 200 bottom end (strokes it out...but unsure of how much).

200 has a shorter stroke so if its a 250 block, it will be smaller

I seem to remember reading an article about the bore/stroke/rod length of a 250 being a bit of a cock up for high rpm use- so it would add up to use a shorter stroke crank, and a longer rod if you wanted to rev it harder

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6 hours ago, cletus said:

200 has a shorter stroke so if its a 250 block, it will be smaller

I seem to remember reading an article about the bore/stroke/rod length of a 250 being a bit of a cock up for high rpm use- so it would add up to use a shorter stroke crank, and a longer rod if you wanted to rev it harder

When I first spoke to the guy that I bought it off  I thought he was trying to explain the way the motor is stroked using 200 bottom end . But now after doing some researh this is how I see it

It gives a longer rod to stroke ratio. Meaning the piston moves faster in the middle of the stroke .it' supposed to free up torque around the 7krpm range

 

 

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#cletus I just copied this from a Ford page on using 200 rods and pistons in a 250.

Yeah those numbers are spot on Dave, as you said it makes a better angle on the crank as the longer rods makes the piston dwell at TDC longer so the crank can be further rotated around before the piston moves down the bore giving it a better angle to push on the crank offset if you can understand all that. Its like haveing longer arms on the crank of your pushie, while you try and push down when the peddle is directly above the crank it gets significantly easier to push the peddle down the further you rotate that crank around.
Also because the piston dwells at TDC and BDC for longer it also means the the piston speed is increased because it has less time to move down the bore if that makes sense lol.
But like dave said its not really going to make any more hp if you fitted it into a stocker or even a mild xflow, its only the big reving top end xflows that will see the benefits.
Take a look at the stroker windsors, a 351 clevo will make HP and not much torque, thats the nature of cubes, but the 347W will make a little less HP but more torque and thats because of the longer stroke to bore ratio.
Plus the pistons are almost half as light as they are a lot shorter so your rotating assembly gets a lot lighter too.

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I might be way off,

But I'm 99% sure that the aussie  Corty diffs were the BW75 (25 spline) and the AU is a BW78 (28 spline)  I'm not even sure if the 78 lsd nugget can be fitted into the 75 housing. The 78 spline is the same as the Ford Nine inch. You can buy cut the length axles which have a long length of splined section. Easiest way out of.jail would be to shorten up an AU ute housing (already leaf sprung) and throw in some cut to length axles. 

You may be able to fit a 78 lsd to a 75 housing by changing the side bearings. @Valiant might know)  but the 75 & and the 78 refer to inches of crown wheel diameter (if I understand correctly) so getting your AU gearset into Karls spare Corty housing might not.be achievable? 

 

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47 minutes ago, RUNAMUCK said:

I might be way off,

But I'm 99% sure that the aussie  Corty diffs were the BW75 (25 spline) and the AU is a BW78 (28 spline)  I'm not even sure if the 78 lsd nugget can be fitted into the 75 housing. The 78 spline is the same as the Ford Nine inch. You can buy cut the length axles which have a long length of splined section. Easiest way out of.jail would be to shorten up an AU ute housing (already leaf sprung) and throw in some cut to length axles. 

You may be able to fit a 78 lsd to a 75 housing by changing the side bearings. @Valiant might know)  but the 75 & and the 78 refer to inches of crown wheel diameter (if I understand correctly) so getting your AU gearset into Karls spare Corty housing might not.be achievable? 

 

This could be true mate.   And I will find out 1 way or another if the info I've been given is true or not....wouldnt be the 1st time I was wrong.

And the mk3 4 and 5 cortinas didn't have leaf springs man..

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As per usual guys and girls any info on the 25 / 28 spline diff swaps  would be awesome.. 

Cheers

I think worse case I still have Pete's jig for welding diffs nice and straight so I could cut and make something work.

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