131mirafiori forum

Something i never dared to do, because i don't know if it's possible... Is therte anybody who has ever fitted a 2 litre cilinder head to a third serie 1600 engine? Does the head fit immediatly to the engine? Or will there be a problem with the pistons and valves?

Do you mean a tc head on a sohc block .

Yes, that's what i mean. I have a third series 1600 sohc engine in my CL and i am wondering if it's possible to fit a TC engine without having to change pistons or valve timing.

Pistons are definately diferent as have cutouts for valves on twin cams. I have taken both engines apart but can't remember much about the 1600 single cam engine but I do have a cylinder head off a 1600 single cam somwhere and could check it with twin cam head if you like but you would have to wait untill the end of the week as the twin cam heads are at a different property to the single cam head.

Thanks David. I can wait for a few days more. No problem, for i have no inlet manifold for double Webers yet. I do have an abarth 4-2-1 exhaust.

Pistons are flat ,as i recall. So i guess the valves will touch the pistons when fully opened. Yes?
I could change the whole engine by a complete 2-litre, but i have no way to haul the complete old block from the engine bay. Left alone to put in the heavier 2 litre. So that's why i thought it would be an idea to just change the cilinder head and make a 1600 TC.
Anybody else who has an idea?

Hi there,  i remember the info from a friend, that the block is the same, so if pistons changed, the head should fit. A bit bigger overhaul, but then you have a new engine without changing the bottom.

Isn't the twincam based on the pushrod block? The auxillary shaft simply replaced the block mounted cam. I haven't seen a pushrod block in over twenty years, but I'd be surprised if it can't be done.

The push rod was based on the twin cam block.
But i don't have a push rod engine. I have the sohc from1981 and on. Why Fiat desifned this terrible cilinder head is still a mystery to me... :-\

That engine was used in the regata 85 as well with mods for front wheel drive also the 1900 regata turbo diesel head was based on it but was a stronger block and was used in tipo diesel (and others) as well, so I wonder if they were making prototypes of the diesel engine and thought they could update the old pushrod petrol engine ?

diesel version in regata-

Yes, yes, yes, but can i fit a twin cam head to it without having to change the pistons?

I don't think so for reason stated earlier about valve cut out in piston but I suppose there is no reason why you can't machine out your own in the pistons ? as long as you get it right but the other problem is you will end up with a low compression 1600 twin cam as all the 1600 t/c engine had high top pistons unlike the 2000 t/c

I never "opened" this type of engine, but i suppose the pistons are flat. Right?
Bore is all the same. Stroke is different. So, no questions about the size of the combustion chamber. If the 2000 had flat pistons, why should there be a problem with a 1600?

As I remember your engine has flat pistons but its a long time since I looked at that engine.
The 2000 is longer stroke so probably gets away without having high compression pistons although you can fit 1600 pistons into 2000 and up it more.
If as you say you don't have a hoist I suppose you could remove front crossmember after blocking car up and remove sump to get pistons out not forgetting to first fit engine brace to hold engine up and the engine wouldn't be as heavy as you would have removed head.

Yes, i know the pistons from the 2000, or 1995 cc are flat. One of the main reasons why the engine only produces a minor 113/115 bhp.
I have the pistons from a 1600 in my Racing engine. Together with double Webers it delivers about 142 bhp.

So, does anybody else know this? Is the cilinder head 1981-on flat or has it a combustion chamber?

I Always took these worthless engines out to change them for 2-litre engines without ever looking at the inside. Wish i had, then i knew what to do now  ;) :D :D

Here you go, your head at the top and twin cam below.

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You have to admit Fiat put big valves in that single cam head.

I might have to do it the other way round !! ;D
 have a 1995 block and single cam head on , make it look standard  ;D ;D ;D
 will that go together ?

Just a question and sorry for hijacking the thread, What kind of horsepower are you expecting if you put the 1600cc pistons to the 2lt one, without the 2 double carburetors?

with 115 standard i would expect around 122-125bhp

For me, it's not about more horsepower. It's about a worn carburator and an exhaust that is at the end of it's life. I have this TC head and Abarth exhaust. Also double carburators.
All i need is an inlet manifold and the information about fitting the head to the engine.

Hi comp pistons from 16tc with twin 40s jetted correctly is easy 130 bhp plus.

I really miss twin carbs on a twin cam, heard a 124 Abarth on twin 44's and 4 branch fire up and it all came back. The growl a twin cam makes is music backed with the right exhaust.

David,

Do you have pictures from the pistons of the sohc engine?

No, I only kept the head of it.

So i am back to the beginning  :-[