Race Engine Forum UK

Dear Friends,

We have a Fiat131 with a Tipo/Tempra 16v engine in the workshop. Although I have built some Fiat ohv pushrod and Sohc engines, I have not built a Fiat 16v engine before. Therefore, I need some general build advice and also specific information regarding the performance camshafts for this particular engine type.

Currently, I have not fully dismantled the engine and the owner does not know what is inside. The engine was running on twin 45 DCOEs.

So far, I have noticed that there are 2 Colombo Bariani camshafts in the engine but unfortunately I could not find the technical information of these profiles which I will need during the blueprint and the build. ( or I will have to find the Lobe Centerline by measuring but I still need the cam data at least for the correct clearances )

Inlet cam part nr. 16.109.276 S ( 10.9 mm lift and 276 degrees )

Exhaust cam part nr. 16.101.262 S (10.1 mm lift and 262 degrees )

One simple question here is; do these engines ever have exhaust cam timing @ TDC more than the inlet side ? ( I guess not but the current cams timed like that !! )

My other findings are; the exhaust cam has an adjustable vernier but the inlet cam doesn’t have one.

The engine normally has 2 balance shafts but this particular engine doesn’t have the balance shafts fitted. So, the timing belt runs thru a cylinder head mounted belt tensioner only. The belt width is 17.30 mm

Shall I be able succesfully built this engine without the balance shafts as I have found.

As I have mentioned, I don’t know what I am going to see in the engine. Cylinder head’s inlet ports give me a clue that the head might have been worked.

Regards,

Kerem

Kerem hi

you should use the production Fiat cambelt!

The cams are street version. Don't worry about the actual open/close degrees just time them up with full lift eg:

full 110 deg both
or
108 inlet 110 ex
or
106 inlet 108 ex

you need to be careful with valve to piston clearances. 110 will give the most clearance.

Set the running clearances cold at 0.016" inlet and 0.018 ex cold +/- 0.002"

If you want a cam timing data sheet written by me send me an email to guy@gcre.uk

G

Guy Croft wrote: ↑July 1st, 2020, 2:16 pm Kerem hi

you should use the production Fiat cambelt!

The cams are street version. Don't worry about the actual open/close degrees just time them up with full lift eg:

full 110 deg both
or
108 inlet 110 ex
or
106 inlet 108 ex

you need to be careful with valve to piston clearances. 110 will give the most clearance.

Set the running clearances cold at 0.016" inlet and 0.018 ex cold +/- 0.002"

If you want a cam timing data sheet written by me send me an email to guy@gcre.uk

G

Guy hi,

Many many thanks !!!

I would very much appreciate if you can advice the CR with these CB cams.

Best regards

Kerem

anything from 9/1 up depending on fuel - they are a very modest profile...

The higher the CR the better..

G

Guy Croft wrote: ↑July 7th, 2020, 4:07 pm anything from 9/1 up depending on fuel - they are a very modest profile...

The higher the CR the better..

G

Many many thanks Guy once more.
I have received your e-mail as well.

All the best

Kerem

Hi Karem,

Hope you are well :-)
How did it work out, do you have any results you can post?

Best regards,
Martin

M Faulks wrote: ↑July 13th, 2021, 10:08 am Hi Karem,

Hope you are well :-)
How did it work out, do you have any results you can post?

Best regards,
Martin

Hi Martin,

Thank you very much, I am well. I hope you are well too.

I have completed the built and the engine is on the car now. It has got a trigger wheel set up which I have to finalize the ignition mapping and I have to change the inlet manifold. The one which came with the engine is for TBs and the angle is too steep for the DCOEs.
Since I have built this engine ( customer preference for the time being ) with standard but modified pistons ( for slightly higher CR ) I couldn’t get 11:1 CR. And may be 11:1 CR with 95-97 octane with these cams would not be suitable anyway.

I will share further when I have results but it will certainly be a tame engine with its current specs.

Best regards

Kerem

Hi Kerem,

I'm good thanks, glad to hear you are doing well, and hopefully keeping clear of covid. Life changes, wish I had made time and changed priorities to get over...

Sounds like a project for throttle bodies? Do you have any pictures you can post, sounds great.

Best regards,
Martin

M Faulks wrote: ↑August 10th, 2021, 7:00 pm Hi Kerem,

I'm good thanks, glad to hear you are doing well, and hopefully keeping clear of covid. Life changes, wish I had made time and changed priorities to get over...

Sounds like a project for throttle bodies? Do you have any pictures you can post, sounds great.

Best regards,
Martin

Hi Martin,

Certainly, keeping clear of covid is the main challenge in today's rather strange world. It is extremely annoying and adaptation very difficult. I hope we will be able to get over with it.

We were discussing about the TBs with the owner of the car. It can be very nice with the TBs. The main issue is I have to decide about the ECU brand which I can get hold of someone reliable for the mapping.

I will post some pictures of the car and the engine bay within next week.

Best regards

Kerem

M Faulks wrote: ↑August 10th, 2021, 7:00 pm Hi Kerem,

I'm good thanks, glad to hear you are doing well, and hopefully keeping clear of covid. Life changes, wish I had made time and changed priorities to get over...

Sounds like a project for throttle bodies? Do you have any pictures you can post, sounds great.

Best regards,
Martin

Hi Martin,

I have posted some photos here above regarding the Fiat 131 with our 2.0lt 16v build with std pistons 10.65:1 CR.

Best regards

Kerem