Over Square mk6/mk7 performances

[winterheating]

Could anyone guess how a 2.4 mk7 would perform with 2.2 crank and rods in it?
Or are they the same crank and rods allready?

If so it would be interesting to see, a mk6 2.0 crank and rods into a 2.4 would definitely make an oversquare 2.2.

[dumper]

If possible I’d think that you would have to start with a new or rebored block as the wear pattern in a used block would be different due different Stroke

[winterheating]

That’s a a good point. Fitting a shorter stroke what was longer May not be as bad as the other way round.

[Mike]

Short stroke, revs. Long stroke, torque.

[winterheating]

Yes but it’s also something to do with the combustion characteristics of diesel too, I’m sure.
So that’s one reason they build the engines that way.....

Or the peak torque and power drops right after a certain rev point... as in there is a max point, as they do have a lower redline.

So it’s what determines what.
Just the fact the crank stroke is longer produces more Newton’s per metre as it physically does.

I’m very very curious

[Mike]

Cam has an influence too.

[JustJames]

you would have no compression
short stoke in a long stroke block means the piston will not get to the top of the chamber
deck the block or fit taller pistons but then you have either lost integrity in the deck
or
you have made a heavy piston that will cause you more issues than you gain from a short stroke

[bambi mk 1]

you would have no compression
short stoke in a long stroke block means the piston will not get to the top of the chamber
deck the block or fit taller pistons but then you have either lost integrity in the deck
or
you have made a heavy piston that will cause you more issues than you gain from a short stroke

You would have to go and spoil it ,nice bit of comedy while it lasted Morecum and not so Wise

[Jim Archer]

The usual trick is suitable length conrods, longer the better really.

Jim

[JustJames]

as the opener was to use an existing crank from another ford product

yes, longer rods is the way to do it, but that would mean getting custom rods made from the ground up and that's not cheap at around £2k for some by Arrow
taller pistons can be easily achieved by finding a near match at nearer £400
correct diameter or a plus size and machine the bores
correct size on gudeon pin
and machine to suit the height

its all hypothetical as I doubt the crank would fit, haven't looked but are the journals different?

[bambi mk 1]

as the opener was to use an existing crank from another ford product

yes, longer rods is the way to do it, but that would mean getting custom rods made from the ground up and that's not cheap at around £2k for some by Arrow
taller pistons can be easily achieved by finding a near match at nearer £400
correct diameter or a plus size and machine the bores
correct size on gudeon pin
and machine to suit the height

its all hypothetical as I doubt the crank would fit, haven't looked but are the journals different?

James I am fairly certain the cranks are the same across the board

[JustJames]

Hi
I'm pretty sure that they are not as the original post talks about a 2.0 mk6 crank and the 2.2 and 2.4 mk7's which is 2 different gens of engines
I think the 2.2mk7 was the psa engine? and not the earlier 2.2 mondeo/jag tddi - please correct me if I am wrong

"Could anyone guess how a 2.4 mk7 would perform with 2.2 crank and rods in it?
Or are they the same crank and rods allready?

If so it would be interesting to see, a mk6 2.0 crank and rods into a 2.4 would definitely make an oversquare 2.2."

this is when the engine changed from the Ford to the PSA engines
The PSA unit is all a 85mm bore (I think but stand to be corrected), so you wont get oversquare as 85x85 =1929cc
The mk6 Ford referred to would probably be the 86 x 86 tdci ZSD ford
The 2.4 was also the earlier gen ZSD engine at 89.9 x 94.6
The early 2.2 as used in jags etc was a 86 x 94.6 - so a 2.4 crank stroke on a 2.0 bore
mixing the 2.4 and 2.0 would give you 89.9 x 86 = 2183cc


So the mix you have...
more time than me to figure it out!!!

[Airthies]

Wouldn't you be able to cross reference cranks and Conrods on 7zap or catcar?

Sent from my A55ho11 using Crapatalk

[JustJames]

wikipedia has it all

what you need to do is work out the goal and the reason and then engineer to that with what is off the shelf
I dont see the point in an oversquare diesel as you have no need for the high revs because the diesel molecular structure is a long chain it requires more time to breakdown and combust, thats the main reason for not having high revving road diesels you need a clean complete combustion
We used the vw 1.9tdi blocks to build high revving petrol turbo engines for the strength the crank, rods and bottom end caps had (using the 16v petrol head and large turbos to make in the region of 1000hp grenades (pull the pin 10 seconds later run away) that really only worked on the strip

We are about to do a transit jumbo 10 second challenge on a diesel street legal, were up at the drag on Friday 7th for the stock runs

[Jim Archer]

You assume Ford haven't already thought of this already. Much quicker and easier to tool and make cranks and rods than blocks

Changing crown height of pistons is fraught with issues, just a couple of mm can change the wear rate by 200% in high speed automotive diesels.

Jim