Crank and rods to destroke a 2 litre to a 1.6??

[HrRACING]

I don't suppose anybody on here knows what crankshaft and rods you need to destroke a two litre engine to a 1.6.

We are really struggling to get power from our K4M now for the Super1600 class in European Rallycross, and thought that a destroked two litre is probably a better way to go.

Does anybody have any ideas on this?

I look forward to hearing anybodys thoughts.

Many thanks

 

[not normal dan]

I don't suppose anybody on here knows what crankshaft and rods you need to destroke a two litre engine to a 1.6.

We are really struggling to get power from our K4M now for the Super1600 class in European Rallycross, and thought that a destroked two litre is probably a better way to go.

Does anybody have any ideas on this?

I look forward to hearing anybodys thoughts.

Many thanks

Surely this would drop the compression ratio quite abit? In turn dropping the performance?

 

[HrRACING]

People in Europe are managing to get more power from doing it this way than trying to squeeze it from a 1.6 K4M.

 

[bozothenutter]

Surely this would drop the compression ratio quite abit? In turn dropping the performance?

shorter stroke , longer rods/higher piston...compression could stay the same

 

[not normal dan]

But surely the 1600 rods are shorter?

 

[Cupman29]

You wouldn't use 1600 rods then.

 

[jamesd1263]

Normal rods smaller pistons

 

[not normal dan]

Shorter pistons, you can decrease the bore of um

 

[HrRACING]

But does anyone know which rods and crank to put into a two litre bottom end?

 

[not normal dan]

I've just checked auto data to see ir it has the engine specifications e.g. rod length, stroke, piston details an crank details. It doesn't but i'll checI the Renault manual I have

 

[Oliver_K4M]

You can use parts of a F4P-engine to get 1.8l. But I don´t think it´s possible to destroke to 1.6l as the bore / stroke ratio becomes to bad for the cylinder head design of the F4R engine....

But the original Super1600 engine was good for 220HP, so I wonder why you think about this.....

 

[HrRACING]

It is possible to get to a 1.6l with the 2l engine being destroked. I know people who have done it but can't get hold of them.

I have done everything I can to get as much power from a k4m as possible, without going to Sodemo to buy an engine for 50k Euros.

If you have any ideas how to extract more power then im all ears!!

 

[keechy]

Which colour Clio is yours? was watching the Hungarian Rally Cross Last night, Saw a few Clios in the 1600 class.

 

[Oliver_K4M]

"Possible" is everything, you can destroke it to 1,2l if all your parts are custom, but then you are also at 50k euros.
What´s your power output with your current k4m-engine? And what do you want to destroke, a Renault 2l engine (Clio RS F4R), or any other 2l engine?!?

Because I don´t understand what´s the benefit of the F-block? Its cylinder spacing is 4mm bigger, the block is higher and so also heavier compared to the K-block.

But if you really want, I think there are no Renault OEM-parts that might fit. Based on a F4R´s bore of 82,7mm first have a look for crank shafts with a stroke of 74mm, cylinderspacing between 90mm and 88mm and bearing diameters that would fit without big mods....much luck...

It is possible to get to a 1.6l with the 2l engine being destroked. I know people who have done it but can't get hold of them.

I have done everything I can to get as much power from a k4m as possible, without going to Sodemo to buy an engine for 50k Euros.

If you have any ideas how to extract more power then im all ears!!

 

[Chip-mk1]

Should think arrow would be able to do you a shorter throw crank and long rods, but its likely to be very expensive as a one off. What is your budget like?
Would really sort out the terrible rod ratio on these engines though and would bring the piston speeds down to something sensible as well.
Should think it would be an epic little 10K screamer with the right supporting modifications, but you are going to need to invest quite a bit of money to find out.

 

[bengtt5]

wouldnt it be easier to destroke a 1.8 valver engine

 

[Oliver_K4M]

Why?

 

[Chip-mk1]

wouldnt it be easier to destroke a 1.8 valver engine

Almost no difference as the bore is practically the same (the majority of the CC difference between the F7P and F7R comes from the crank to begin with not the pistons) so you would need almost exactly the same crank to get down to 1.8 anyway. So no not really mate.

 

[HrRACING]

Should think arrow would be able to do you a shorter throw crank and long rods, but its likely to be very expensive as a one off. What is your budget like?
Would really sort out the terrible rod ratio on these engines though and would bring the piston speeds down to something sensible as well.
Should think it would be an epic little 10K screamer with the right supporting modifications, but you are going to need to invest quite a bit of money to find out.

Budget isnt huge, but will find what money is needed. Just cannot fine the 50 grand to buy a Renualt Sport engine from Sodemo.

Currently have spent about 6 grand on the K4M and havn't got only just got 190 bhp at the moment.

 

[Chip-mk1]

Budget isnt huge, but will find what money is needed. Just cannot fine the 50 grand to buy a Renualt Sport engine from Sodemo.

Currently have spent about 6 grand on the K4M and havn't got only just got 190 bhp at the moment.

Give Arrow a ring then and see if they can offer you a short enough crank to drop the capacity down low enough.

Based on an 83mm bore you need to be asking if they can do you a 73.9mm crank, and you will then want a set of rods probably just over 20mm longer than standard as well (assuming you get pistons made which move the pin up a little)

You'll want to be on solid lifters of course, and dry sump, so I would imagine you'll need a budget of 15-20K probably (pounds)


Lot of money to invest in something that *should* work well but you havent got a prior working example of to copy etc.


Have you considered just swapping to a more competitive car instead?

 

[HrRACING]

Swapping to a different make of car isn't really an option with the amount I have invested in this overall.

I have found out that a lad in Belgium races a clip in the same championship as me and he has 225bhp from a destroked F7R.

 

[HrRACING]

Anybody any fresh ideas?

 

[ian-speedy]

Hi
I have been speaking to these people about steel cranks and rods , maybe they could help you with a custom set up

www.xrallyparts.com

I have had parts made by Farndon a few years ago , they charged me about £2000 for a crank and rods were about £150 each

http://www.farndon.com/

Give these a try and see what they can offer you

Cheers Ian