General 1.2 swap questions

[TheAutopsy]

I do belive that I am overtinking this and should just jump into the swap, but I have a few last questions.
I was looking at the specs for the Punto engines and saw that the 1.1 and 1.2 SPI have a compression ratio of 9.6:1 but the Punto 75 has 9.8:1. Why is there a diference?
I pretend to use my head with the 75 block. Should I use a stock Punto 75 headgasket? Does it matter the thickness of the gasket on relation to the seicento one so that you dont have piston to valve contact?
What head bolts should you use? New Punto ones, or new seicento ones, or can you reuse the old seicento ones?
Is it necessary to machine the block and head always? Because they are aluminium?
And in case that you use the 866 cam should you instal it with Punto head specs or seicento specs?
And what about tune? Can you tune the original seicento ecu to optimize the new modifications or the adjustmens that the ecu does is enough?
Any help is much appreciated!!

 

[purf]

My answers to your questions below:

I do belive that I am overtinking this and should just jump into the swap, but I have a few last questions.
I was looking at the specs for the Punto engines and saw that the 1.1 and 1.2 SPI have a compression ratio of 9.6:1 but the Punto 75 has 9.8:1. Why is there a diference?

- I don't know - could be gaskets, pistons or heads? Someone should know?

I pretend to use my head with the 75 block. Should I use a stock Punto 75 headgasket? Does it matter the thickness of the gasket on relation to the seicento one so that you dont have piston to valve contact?

- The 8 valve fire are 'safe' engines so no risk of valve contact.

What head bolts should you use? New Punto ones, or new seicento ones, or can you reuse the old seicento ones?

- Dont re-use the head volts as they stretch to maintain pressure. Only use new ones. Punto 8v and seicento 8v bolts should be the same and I would expect same torque sequence.


Is it necessary to machine the block and head always? Because they are aluminium?

- in my opinion only if the head has overheated badly or is badly corroded. Some people will always get them skimmed. It's not a 16 hour job to renew like some engines!


And in case that you use the 866 cam should you instal it with Punto head specs or seicento specs?

- The cam shim clearances should be for punto 75 when using 866 cam.

And what about tune? Can you tune the original seicento ecu to optimize the new modifications or the adjustmens that the ecu does is enough?

- The ecu sorts itself out. But if you want maximum potential a chip would help a bit - if you have a right earlier (non micro) ECU.

Hope that helps

Main faff with 1242 swap is exhaust. Punto 1242 sports manifolds are cheap now so I'd use one of those. Might not be easy to get forever?

 

[TheAutopsy]

Thank you so much purf for taking the time to answer.
I can get 4-2-1 or 4-1 stainless steel ebay headers for quite cheap, but in portugal we have the equivelent of the MOT, and gases are strick also. So to use a aftermarket I would have to keep the original 1.1 one to put on and modify it to use to go to the inspection. I think I'm going to try the spacer metod and see what it works. Its not a big deal if I can't drive the car for a few days. Also have a punto GT that hasn't been driven in a long time
And how do I know what tipe of ECU I have? Its a left hand drive portuguese registred 1999 seicento sport abarth.

 

[purf]

Do you mean you need to keep a catalytic converter? If that is what you mean you can fit a 'sports cat' or earlier type cat under the car. Presume your car has the earlier type underneath rather than a close coupled - 'manicat'. A new 1242 Punto manicat is probably not too expensive on ebay. They do make access to the front of the engine (coolant tube) awkward and use up lots of space though.

The ecu is probably the older style in a larger metal case. The newer micro ecu is tiny in comparison. You can tell by looking at it. My sei is 2000 and has the 'micro ecu'.

 

[TheAutopsy]

So I finally bougth the engine. 1.2 with the 866 cam. I was planing to only put my 1.1 head on the block. But the oil pan is mangled quite a bit. So I will put a new one in. Is it worth to take everything out and put new bearings, caps, rings, Core plugs, valve stems, etc to make a rebuil engine? I dont have the gauges to measure tolerances so dont know ir its worth it. And if I take them out and they look good can I place them back in?
Also if I buy a 1.2 4-2-1 manifold (eBay ones that say that it fits1.1, 1.2 60 and 75 engines) it will bolt on my 1.1 head, and Will it have the extra inch that the block requires and Will it Bolt to my stock exaust?

 

[TheAutopsy]

On the last leg of the swap. Cleaned the block and pistons and everything. Will assemble everything.
My question os about the timming sistem.
I havent seen anything about this online, only on the Miller corner vídeo of his 1.2 swap. He had to use the seicento crank pulley, seicento water pump, and cam pulley. But had to use a 1.2 MK2/b MPI timming belt. He has a 1.1 mpi.
Is this also true for the 1.1 spi? Do I have to use my seicento parts with a diferent belt or does the complete Timing from my 1.1 spi Will work?

 

[TheAutopsy]

If anyone can help. I have the pulleys from the 1.1 SPI and the pulleys from the Punto 75 MPI. They dont look the same. Witch ones should I use?

 

[Jamieboy]

I'm not sure if this is your issue, but perhaps worth a look.