R26 RS250 engine conversion

@ianplymouth

 

If you get a complete engine from a donor car then I imagine the fuel rail etc will be there. I'm sure all you'll need is a different in tank fuel pump and a relief valve?

 

Nothing has really changed on a swap, you need the 250 fuel rail, then fit a DW65c pump into the fuel tank unit, but you will need a 5bar regulator to replace the 3.5 on fitted(it also needs a bit of modifying).

As for the throttle body, use the R26 one, you will need to make an adapter plate but it isn't a big deal.

You also need to use your original wiring loom, this will reduce any problems with the connections into the fuse box, a R26 and 250 looms are so different, you won't get the VVT to work because the ECU isn't setup for that.
But you will need to keep your sensors from your old engine, saying that you need to keep the 250 map sensors even if your not going to get a big map upgrade, R26 map sensors are good for 1.7bar, 250 map sensors are good for 2.5bar.

 

Don't bother with the 250 pump, it won't fit.

AS said above, you just need a 5bar regulator and a dw65c pump, the pump is almost a straight swap, you need to trim a very small piece of plastic off of the R26 fuel housing.

 

Yes you can drill the 225/R26 manifold but why if you have the 250 one fitted, the 250 manifold has a bigger bore not that it makes any difference

 

I wonder if the bigger bore intake manifold would be beneficial for a big turbo build? I see the 225 is tiny really!

 

Apparently the 225/R26 throttle body is good for 500hp so i doubt its an issue for that manifold either

 

the pressure relief valve you need to replace is the one in the fuel tank.

https://www.ebay.co.uk/itm/5-0-5-BA...686468?hash=item234a512204:g:xtQAAOSwd0BV5gFg

this is the one i bought.

for the modification, you need to turn down the end where the small green "O" ring is, i think its 8mm and needs to be 5.7mm from memory, but check the one you take out.

 

The top engine cover that covers the cambelt on the R26 has to be used, then you use the the original engine mount, think i had to drill and tap a vertical hole at the front of the cover to add an extra bolt for security.

You can still use the original dog bone mounts, i just added yellow powerflex inserts.

I don't have the car anymore, after the second hybrid went bang i put the car back to almost standard and sold it, then sold all of the parts that came off (mistake ) I think its still going.

 

Have you seen this thread ???

https://rsmegane.com/threads/225-inferno-getting-a-250-engine.13083/

 

if you need any other information i will try and help

 

I'm not that good with anything like a 3d printer, i just used a piece of 8mm thick aluminium and shaped it, i used one of the holes in the 225/R26 throttle body, drilled and tapped the others, didn't look pretty but worked.

 

I ran the 250 Throttle body, without any problems on my 250 engine Clio, but as Ian has said 225 one is easier, with less problems.

 

Car is now sold, running my sons car now. Stick with the 225 one, less hassle.

 

It will all depend on what you have done to it, don't put the 630 injectors in, if you are running a hybrid turbo then just don't boot it, if you drive it steady you should be okay.

You might get the spanner light come on (mine didn't) but it should still drive okay.

As for the throttle body fit that, there good for 500hp and the ecu will like it, i did fit a 250 one to mine but every so often it would just stop working, had to stop turn the engine off and then on again to reset it, bit of an inconvenience when your on the motorway.
So much easier to make an adapter.

 

It might be worth swapping them to the 225/R26 injectors as im sure the 250 injectors are bigger as in flow more, not as bad as 630's but they will over fuel

 

Hi Chawkie
Yes i know there is a problem, i didn't realise this was a problem till i took my fuel unit out, the only experience i had was with the 225 i did a good few years ago.

I have bought a 225 phase one fuel tank unit, i didn't pay a lot for it as there are a few being stripped, but i would get in quick as soon they will start becoming a must have item like the 250 fuel rails.

I am machining one for someone else, i can do one for you if you want.

There is another way around this, but its expensive, buy a 250/265/275 fuel unit as the FPR is the same size but 5.5 bar, saw that when i fitted the better fuel pump.

 

I am not sure if the 225 phase 2 unit is the same as the phase one unit, but i know the R26 is different.

 

Yes the phase one unit is the same except for that relief valve, i have fitted a DW65c pump to my phase 1 unit already its so easy on these.

The Pipe can be left or broken off, it doesn't matter as long as its not blocked.
I think if you brake it off it does that quite easy.

I am going to try and sort the FPR valves out this weekend and i will get some pics for you early next week.

Ahh okay, didn't realise you were out there, the dimeter you need to get the nib down too is 7.4 mm, you will also need keep the "O" ring from the old relief valve.

 

I bought one of them, it came up as the same part number, but its different.
the body is smaller in diameter, so that the reservoir wont hold as much fuel, its some kind of swirl pot design to aid in the corners.
Mine was an aftermarket one and was £48 new delivered.

 

Thats where mine came from

 

It all depends on what you want in the end, my 265 toped out on the standard pump at a fraction under 400hp, i don't think the 225/R26 pump is quite that good, but i am unsure of there limit.

Also the pumps are getting old now, i changed the 225 one as a mater of course as i had the unit out to do the valve as i wanted to run the rising rate fuel system and it seemed silly not to fit a new pump at the same time.

The R26 is going to have the 250 fuel setup, just in case another big turbo turns up

After speaking to Chris at EFI, with what i have fitted to mine now, 265 turbo, 250 injectors and fuel rail, 250 map sensors and the rising rate fuel system, he is saying we will be looking at 340hp, that i think i will be happy with (for a while)

I would get a Phase 1 fuel unit just in case, while you can at a reasonable price, i think its going to be a cheaper option than going for a swirl pot with a return setup, just my opinion.