1242 8V Head to 16V Head

Hi There,

First....Happy New Year!!!


Is is possible to swap the 16V head to an 8V Under block from the 1242 8V punto engine.

Greetz Dennis

you might have some trouble with pulleys lining up, but thats minor. other than that, it should fit
i don't get why you'd want to though. the 16v's bottom end is stronger. why not just use the whole engine?

edit: just realised why you'd want to. your running custom pistons aint ya

Yup .

I'm just thinking about some far far away future plans. And i was wondering if this was a straight fit..the head only..the rest....o well probably there is a solution.

Head gasket is the same. Bolts are slightly different.

Problem is that that you either need the 16v pistons or pocket the 8v ones.

Cheaper to buy the whole engine. The 16v is much better block anyway.

There is some more things to change, which are not very expensive but time consuming. And why going for the inferior engine anyway?

My Pistons are 2mm lower than the original so I think the valves are not an isue.

Otherwise I gasflow the 8V head. Or put some bigger valves in it.

I would go rather this route.

The 75 head has got larger valves than the Mk2 MPI and the 1242 SPI engine.

But you can go even slightly larger on the valves in connection with a light weight valve train.

Hi,

Oldtopic up

Today I get a little start with my cylinderhead.

But i can't find the correct bigger valves for this head. I read that from a bravo bravo was an option but they are all 16v's

if possible I want to place 2mm bigger inlet and exhaust valves.
Original 31.5 so 33.5 and out 27.5 so 29.5mm

This will give a benefit of 6.5% on the inlet area and 7.3% on the exhaust valve area ( Pi (3,14) xValve diameter x valve diameter/4 x Valve lift (9mm)

And flow the head and stuff like multi-angle valves polishing the ports and burningchambers..

But it seems quite good for a original head Almost no bumps and sharp edges

Pics.








Intake


Exhaust

If you can't find what you need from a FIAT parts list, best bet is a trip with one each of the old valves to an engine reconditioner: it should be possible to find something which will either fit or can be machined to fit. You want something off a car designed to run on unleaded and definately not a deisel! Failing that, simply get some made up.

If you go down this route, just be careful the valves are compatible in every way - including the collets and spring caps. Last thing you want is poorly fitting collets so that it drops a valve on the first turn!

Cheers, John