1.6 to 1.7 engine swap

[PVB507]

Hi guys!

I own a Puma 1.6, but the engine is on it's way to certain death. The big end bearings are on their way out... So right now, it's sitting on my driveway, while I recently purchased a (really fantastic) Clio RS 197.

I have done a bit of thinking and came up with an idea... why not change the complete engine? I know, it's better to sell the car for scrap, engine swap is a lot of work, costs a lot of money, blabla. But I have some free time and I like to get my hands dirty, so why not change the 1.6 for the 1.7?

But before I embark on such a project I want to ask a few things. First and foremost, I'm not a mechanic, and I have never done an engine swap myself. However, I know my way around an egine, know how to use tools, am eager to learn, and will not simply back down after a failure. Also, I have some friends which know their way around cars. So, how much of an expert job is it? Can it be pulled off by a unexperienced bloke with a wide arrangement of tools, surrounded by a couple of skilful friends?

Furthermore, I have some specific questions:

• Does a 1.7 fit easily on the 1.6 engine mounts?

• Is the 1.6 gearbox the same and does it fit on a 1.7?

• I assume I will need a 1.7 ECU, is it plug and play?

• Cooling components: are they the same?

I am really looking forward to your responses! I am eager to start, so fire away! :grin:

 

[siju]

The zetec-se engines are all physically the same. The one difference of the 1.7 is the RHD (as you sit in the car) mount. The other two (gearbox mount and torque link). Cooling circuit is the same. Gearboxes are also the same regarding mounting but there are difference in ratios between 1.6 and 1.7.

You will need the 1.7 driver's side engine mount, 1.7 ecu and engine loom (1.7 has vct so there a couple more plugs that htere aren't in 1.6). You need a 1.7 maf, 1.7 airbox with the hose to the throttle body. MAF is slightly larger creating a slight difference in the airbox and hose to throttle body.

Pretty straightforward. I did a swap from 1.4 to 1.7.

Alex

 

[PVB507]

Thanks Alex! This helps a lot!

I've got some more questions...

• It turns out there are two variants of the 1.7, MHA and MHB. I have a 2001 Puma. Which one will I need, or are they interchangeable?

• What about the exhaust manifold, can I simply transfer the 1.6 one to the 1.7? I see no difference when I compare the drawings from Ford's parts catalog, but the part numbers are different

• And last but not least, a bit of a technical question. If I leave the 1.6 'box on, how will this affect the 1.7's performance?

 

[st220kyle]

- interchangeable I believe

- Yes they are essentially the same and a direct swap. however, some have 1x lambda sensor and some have 2x lambda sensor. You will need to select whichever one depending on how many lambda sensors your new wiring loom has.

- I've not used the 1.6 box on a 1.7 engine, but have driven fiesta with 1.6 and 1.7 engines. The 1.6 reved alot lower at motorway speeds with slower acceleration. But the 1.7 is revving it's tits off at 80-85mph but quicker on the acceleration.

Hope this helps

 

[siju]

Both MHA and MHB do the job. However you need to get the right engine loom. If you have digital speedo you need the digital loom and of you have analogue speedo you need the analogue loom.

My brother's puma had initially a MHB and then swapped it for a MHA without problems.

The manifold should be interchangeable as a 4-2-1 aftermarket is the same for all zetec SEs. My custom manifold was from a 1.6 I installed it in my 1.4 and then swapped for 1.7 with the same manifold.

The 1.7 gearbox empirically has longer 1st and 2nd the same 3rd and shorter 4th and 5th. So for twisty roads the 1.7 box is the best.

Cheers
Alex

 

[PVB507]

Many thanks for your replies, I have a good overview right now of what needs to be done.

Sourcing the engine and the parts won't be a problem. However, the ECU and engine loom give me some worries. There are quite a bit of ECUs for sale on ebay, but which one to get? How do I know it's been on a MHB? Is there a certain code on the sticker? Furthermore, I stumbled upon a couple of ECUs where the key and lock are included. Does this mean that every ECU comes with its own key, which means I will have to change the locks?

And then there's the engine loom, of which there is only one on ebay right now, and I can't find it on any other websites. Do you guys know somebody with a MHB loom? Or a good place to look?

 

[st220kyle]

Every ECU comes with its own key to an extent, it's the chip inside the key that is coded to the ECU. (Which is inside the fob part of the key)
So no you don't have to change any locks, you can swap the fob over from the new ECU onto your original key and that will be fine.

Have you considered buying a scrap1.7 puma for the conversion?
Its surprising how expensive all the little bits will mount up to when buying individually.
When I fitted a 1.7 in my fiesta I bought a complete car and made most of my money back selling off what was left. I also knew I had all the right bits that were compatible.

 

[PVB507]

Ok, that clears things up a bit

Have you considered buying a scrap1.7 puma for the conversion?

I was just considering that... a quick calculation shows that I will need at least 700-800 euros for parts. And it turns out there's a scrap Puma for sale here in The Netherlands for 600...

 

[siju]

Basically you need a digital loom if you have digital clocks and analogue loom if you have analogue clocks. A dive or tape ecu work 100% for digital cars. For analogue ones I am not sure.

One place to look is Ian (puma bits). I bought the whole conversion from him. By whole I mean engine-geaebox-loom-ecu-engine mount-maf-airbox.

 

[PVB507]

Quick update: I went for the donor car idea. Bought a Puma 1.7 with major rust but a good engine (100k miles). I will create a seperate topic to keep you guys updated and post questions.

Thanks again for all the help!

 

[st220kyle]

That's the best way to go , good luck!

 

[PVB507]

So guys, a quick question about the engine loom... What exactly do I need to pull out and swap over to the other car? There is a big bundle of cables coming out of the ECU going behind the dashboard, I hope I won't need to get this out :?

 

[CherryVimto]

The loom from the ecu goes up the side/end of the dash and through the rubber grommet at the bottom corner of the windscreen.
But, there is also a very small piece of wiring/loom that goes through the interior of the car. If my memory servers me correctly, that goes to the rear ABS loom.

Basically for the engine, you want the ECU and ALL of the wiring associated/connected to it including that large bundle of wires!

 

[PVB507]

Thnx for the info. I dug a little deeper and I can see the loom from the ECU going through the metal next to the firewall. But how do I remove the rubber grommet and pull the cables through the hole? I'm a bit of a newbie, so I'm scared to damage the cables...

 

[CherryVimto]

The big grommet should just pull out. From the outside try and squash the grommet edge in one place so you can see the inner edge of it. There is a groove around the outer edge of it which holds it on to the bulkhead. Work your way around the grommet, slowly pulling it out around the edges until it is free.
Once it is free from the hole, pull the wiring through making sure you don't snag/drag the wiring against the edge of the hole. Would be a good idea to put your hand in the hole and pull the wiring through your hand... using your hand to protect the wiring from the hole edges.

 

[alerno]

Both MHA and MHB do the job. However you need to get the right engine loom. If you have digital speedo you need the digital loom and of you have analogue speedo you need the analogue loom.

My brother's puma had initially a MHB and then swapped it for a MHA without problems.

The manifold should be interchangeable as a 4-2-1 aftermarket is the same for all zetec SEs. My custom manifold was from a 1.6 I installed it in my 1.4 and then swapped for 1.7 with the same manifold.

The 1.7 gearbox empirically has longer 1st and 2nd the same 3rd and shorter 4th and 5th. So for twisty roads the 1.7 box is the best.

Cheers
Alex

How can you tell a MHB apart from a MHA?. I have conflicting information of when this transition was implemented in every country. My car is German, I live in Barcelona. In case my car were MHA: do you happen to know if I can convert it to MHB by adding a lambda sonde?

Any info is MASSIVELY appreciated since only Euro III cars are now allowed to circulate in traffic now. So it depends on this whether I can drive my car or not.

 

[siju]

I don't know when the transition was made. You can check under the inlet manifold and beside the starter motor is the engine code engraved on the block. It starts either with MHA or MHB.

I guess that you can add a 2nd lamda sensor but you have to change also the engine loom for it to work. But I don't know how the government defines which cars can be driven in the cities. E.g. of they say that only >Euro3 are allowed then if the car originally was a Euro2 I don't think it will be eligible for Euro3 if you just add a 2nd lamda sensor. I'm not sure about that though so better to check it for yourself.