Engine Tuning Choice

[cypriot]

Hi Guy,

I have Fiat 2.0 L Twincam complete engine which has 132 DB 2AO engine code printed on it.
it is disassembled now pistons, crank and rods are still standart. crank does not need regrinding

I also have Fiat 124 1.8l rally/race head see links ;
which needs new guides (I think to buy bronze type), GC triple race springs, and face skimming.

phpBB3/viewtopic.php?f=13&t=820

http://guy-croft.com/viewtopic.php?t=41 ... ht=4301155

what is the easier and cheaper choice to tune engine?

as I know I have two opportunities

1- rebuild and using Fiat 124 cylinder head with 132 DB 2A0 engine block, with using
a- 84.40 oversize oem pistons
b- H section good quality con rods

with Fiat 124 head cr will be arround 10.5


2- not using Fiat 124 head
a- completely port polish oem head,
b- standart valves with bronze guides
c- GC race triple springs
d- 84.40 oversize HC oem pistons

both of them will have 2 webber 40 side draught carbs, new oil and water pump, mocal oil cooler (Cyprus too hot).

I am thinking on favor of first choice but couldnt decide by myself.

thanx

Ali

[Guy Croft]

OK.

The best head will be the one with the late combustion chamber. If the chambers are the same pick the one with the biggest inlet ports.

GC

[cypriot]

Dear Guy,

Because of I want to finish my Fiat 131 Abarth Gr.IV Tarmac replica car project as soon as possible. I am only thinking to modify /tune main engine.

1- I am going to use high compression pistons for 84.40mm bore diameter(I coulnd get information about cr ratio from the seller yet)

2- good quality performance conrods with ARP bolts.

3- twin webber 40 DCOE sidedraft carburatters

4- Mocal engine oil cooler radiator

5- 4-2-1 exhaust header (it will be prepared according the Vassilis post )

6- and lightened flywheel

7- Facet Red Top fuel pump kit and Fuel Pressure Regulator

I am hope I can achieve 160hp with this set up.

In the future I 'll prepare cylinder head according to perfect information in this forum;

performance camshafts, lighter cam gears, bigger valves, performance valve springs, head port polish

and hope to have arround 190hp

my questions

1- which compression ratio will be better choice if piston seller come with several opportunity? as I know it should be arround 10.2 - 10.5

2- what is safe high rpm to set over rev limiter for oem HC pistons? 7,000 rpm?

3- is there high volume oil pump for TC engines? because I know that most of the Ford engines have aftermarket high volume oil pump opportunity. does TC engine need this type oil pump?

thanx

Ali

[cypriot]

Hi all,

I found 45mm Alfa performance inlet valves;

Valves dimensions are; Head 45mm, Stem 9mm O/A Length 105mm 45* Face Angle.

I couldnt find Fiat twincam engine valve length. if it is same (105mm)

Is it possible ream out the guide or use 9 mm guides and fit these 45mm Alfa valves?

waiting your opinions

thanx

Ali

[Guy Croft]

You've 'located' a big valve from a catalog and now you want to know if you can use it with a stem size bigger than the standard?

Look, Cypriot - if you want more power, this is what race_valves_are_for.

From time to time I stock them, something often forgotten because I run a forum. Sure, I have a business to run. But when I have them everyone complains about the cost. And they sit on the shelf for years and I wonder why I bothered.

Some folks, sure, like client and site member Slawomir from Poland, they do the research and find manufacturers who will make small batches of valves and yes you pay a premium if you want 4 not 40. And I help them.

Would I get involved in an enquiry like this where the idea is to get more flow from fitting a bigger valve with a thicker stem? Not in a million years.

For the benefit of all members. If you want to play shop_and_swap- please post enquiries like that in another section please, not GC Q&A.

I never play mix_and_match with standard components.

GC