"R ltd" engine swap

Author
Discussion

Mr MXT

Original Poster:

7,711 posts

290 months

Monday 7th October 2019
quotequote all
Hi all

I have a MK1 1.8 needing a new engine. Is the engine from an 1.8 R limited a straight swap? I assume so as there are no power output differences but I do want to check that the ECU is the same? Lighter flywheel as standard which is a bonus.

Thanks

Neil Chambers

mrciarano

343 posts

68 months

Tuesday 8th October 2019
quotequote all
Really depends on year and market - is your 1.8 MX5/Eunos of the same year and domestic market? There's a chance.

Best thing to do really is to find the ECU p/n/model on the lid of it in the passenger footwell, and see if it matches the donor car. Between UK and Japanese motors they're not a straight swap as the ECU's and potentially the wiring loom would also need to be swapped.

Example:
ECU from a '94 1.8 MX5 without a factory immobiliser - BPF8
ECU from a '94 1.8 Eunos - BPF6

Neither will work with each engine out of the box as the BPF8 has wiring and specific tuning for the EGR controls to pass UK emissions, whilst this is not present on the Japanese Eunos.

There were also some changes made between cars from early '94 and '95 onwards, and then some from '96 onwards. Again, matching ECU is your simplest answer if you're looking for a straight up bolt-in; plug and play ordeal.

In real terms though, just swap the block you already had in - way easier and will have the same end result. If you want a lighter flywheel you may as well just fit one when you do an engine swap. Or transplant anything electrical from the old engine to the new engine. The first option is easier though!


Edited by mrciarano on Tuesday 8th October 21:35

tim-b

1,279 posts

217 months

Thursday 10th October 2019
quotequote all
biggrin
Mr MXT said:
Hi all

I have a MK1 1.8 needing a new engine. Is the engine from an 1.8 R limited a straight swap? I assume so as there are no power output differences but I do want to check that the ECU is the same? Lighter flywheel as standard which is a bonus.

Thanks

Neil Chambers
Can you also get the diff from the R-Ltd? I think they had the shorter final drive so better acceleration biggrin

Mr MXT

Original Poster:

7,711 posts

290 months

Thursday 10th October 2019
quotequote all
mrciarano said:
Really depends on year and market - is your 1.8 MX5/Eunos of the same year and domestic market? There's a chance.

Best thing to do really is to find the ECU p/n/model on the lid of it in the passenger footwell, and see if it matches the donor car. Between UK and Japanese motors they're not a straight swap as the ECU's and potentially the wiring loom would also need to be swapped.

Example:
ECU from a '94 1.8 MX5 without a factory immobiliser - BPF8
ECU from a '94 1.8 Eunos - BPF6

Neither will work with each engine out of the box as the BPF8 has wiring and specific tuning for the EGR controls to pass UK emissions, whilst this is not present on the Japanese Eunos.

There were also some changes made between cars from early '94 and '95 onwards, and then some from '96 onwards. Again, matching ECU is your simplest answer if you're looking for a straight up bolt-in; plug and play ordeal.

In real terms though, just swap the block you already had in - way easier and will have the same end result. If you want a lighter flywheel you may as well just fit one when you do an engine swap. Or transplant anything electrical from the old engine to the new engine. The first option is easier though!


Edited by mrciarano on Tuesday 8th October 21:35
Thanks for the detailed response, which I've read after I've picked up the engine. doh. Its not sounding great is it!

Transplanting the electricals seems the "easiest" way - I was tempted to do that anyway because I know it all works.

I'll update with how I get on.

I did get the lightened flywheel with it by the way - the diff had already gone.



Mr MXT

Original Poster:

7,711 posts

290 months

Monday 28th October 2019
quotequote all
It’s in....it runs (ish) see next thread on the mystery plug....

mrciarano

343 posts

68 months

Tuesday 29th October 2019
quotequote all
Great news, as they say fortune favors the brave! As I say the emissions equipment is the real question of difference so as long as that all marries up, then happy days.

I'm still waiting to get my car back; had to leave at a specialist to swap the motor for me as I didn't have the time to take it on myself. Fancy a trip to the south east and giving the garage a hand? biggrin

Mr MXT

Original Poster:

7,711 posts

290 months

Tuesday 29th October 2019
quotequote all
biggrin

absolutely not, got a built Duratec to swap into a Westfield shortly.

After working on kit cars, I’d forgotten what an absolutely pain 20+ year old Japanese machinery is!!

Good choice getting someone else to do it!