Technical  First drive and a problem

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Technical  First drive and a problem

Nothing wrong with offering #bugsmike;) and in the sense of engineering I should and will find and fit an inner washer on what I class as a very poor initial design bit I'm sure it won't improve it.
Another thought for you or anyone that cares to throw into the ring, I've managed to trace the camshafts to be Colombo and Bariani race medium profiled camshafts ,
1 x FB.114.300C.A
1 x FB.114.294C.S
my question is do you think this will put extra stress to the standard cambelt 🤔
I've never heard of Colombo and Bariani , although Giacomo Colombo was a very famous (Ferrari?) engine designer. Maybe someone on one of the other forums might know of these cams?

The 124 Sport 1438 and 1608cc (your engine?) had the sportiest cams i.e. 26/66 66/26* (IO, IC, EO, EC)., so duration = 272*.
All subsequent twin cam engines had much softer cams fitted, especially U.S. models required to comply with SMOG regs.

Your cams, going by the numbers, seem to have :- Intake valve duration of 300* and Exhaust valve duration of 294* (std 124BC = 272* for both in. & ex.).

I'm not sure, but the 114 on both cams might refer to what is called lobe angle centres, i.e. the angle between the in. and ex. cam lobe peaks (= max. lift)

A = Aspirazioni, Italian for Intake; S = Scarico, Italian for exhaust.

Here's a diagram showing the valve timing figures on a 124 BC engine (26/66 66/26*, = 272* duration, 52* overlap):-

Scan_20260606.png


It's quite likely that your cams also have increased valve lift, this will likely increase the stress on the timing belt. However, the standard belt has been used, afaik, without any problem on modified engines.

I have seen a wider 'performance' belt advertised on the Autoricambi w/site, c. 25mm wide (iirc the standard belt is c. 19?mm wide), but there was a warning that this wider belt should only be used with flangeless pulleys.

There was also listed a 'performance' tensioner bearing made by SKF. but I think the standard bearing is quite adequate (unless you're going racing?).
 
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Interesting that the microfiche parts illustration kindly provided by @s130 above shows 2 washers fitted, one each side of the spacer that is fitted inside the tensioner spring. I compared this illustration with one in an original Fiat parts manual for the 124Bc engine - this manual only shows one 'penny' washer fitted under the bolt head bearing against the spacer and spring - the list of parts also lists quantity = 1, and the part no. was the same = 4180206.
The pic. I posted in post #45, clearly shows 2 washers and this is what I've found on every older Fiat twin cam engine I've worked on, so I'd use 2 washers.

Random thoughts (late at night!) -
Are 'penny' washers still being made after Decimalization occurred? :unsure:
Another term for such large washers with small holes used to be 'Mudguard' washers, but mudguards haven't been used on cars in a very long time, so I don't know if these are still available. :unsure:
It is a strange anomaly we come across from time to time. There are still many penny washers to be found of different size and bore, I've always called them "Wing" washers which I would imagine is the more modern term for "Mudguard" washer ;)
 
I've never heard of Colombo and Bariani , although Giacomo Colombo was a very famous (Ferrari?) engine designer. Maybe someone on one of the other forums might know of these cams?

The 124 Sport 1438 and 1608cc (your engine?) had the sportiest cams i.e. 26/66 66/26* (IO, IC, EO, EC)., so duration = 272*.
All subsequent twin cam engines had much softer cams fitted, especially U.S. models required to comply with SMOG regs.

Your cams, going by the numbers, seem to have :- Intake valve duration of 300* and Exhaust valve duration of 294* (std 124BC = 272* for both in. & ex.).

I'm not sure, but the 114 on both cams might refer to what is called lobe angle centres, i.e. the angle between the in. and ex. cam lobe peaks (= max. lift)

A = Aspirazioni, Italian for Intake; S = Scarico, Italian for exhaust.

Here's a diagram showing the valve timing figures on a 124 BC engine (26/66 66/26*, = 272* duration, 52* overlap):-

View attachment 488594

It's quite likely that your cams also have increased valve lift, this will likely increase the stress on the timing belt. However, the standard belt has been used, afaik, without any problem on modified engines.

I have seen a wider 'performance' belt advertised on the Autoricambi w/site, c. 25mm wide (iirc the standard belt is c. 19?mm wide), but there was a warning that this wider belt should only be used with flangeless pulleys.

There was also listed a 'performance' tensioner bearing made by SKF. but I think the standard bearing is quite adequate (unless you're going racing?).
After a foolish f'up I had to reset my valve timing and I used a different way with my dial indicator on #4 tappet caps using the given settings of 3.9mm to the exhaust and 4.0mm to the inlet and firing on #1 with both its the lobes facing upwards and the crank set at TDC, and all is a success🤞😁.
 
After a foolish f'up I had to reset my valve timing and I used a different way with my dial indicator on #4 tappet caps using the given settings of 3.9mm to the exhaust and 4.0mm to the inlet and firing on #1 with both its the lobes facing upwards and the crank set at TDC, and all is a success🤞😁.
Back to basics as taught at college, although as long as a engine turned over by hand for several revolutions before firing up eh!:):):)
 
I've never heard of Colombo and Bariani , although Giacomo Colombo was a very famous (Ferrari?) engine designer. Maybe someone on one of the other forums might know of these cams?

The 124 Sport 1438 and 1608cc (your engine?) had the sportiest cams i.e. 26/66 66/26* (IO, IC, EO, EC)., so duration = 272*.
All subsequent twin cam engines had much softer cams fitted, especially U.S. models required to comply with SMOG regs.

Your cams, going by the numbers, seem to have :- Intake valve duration of 300* and Exhaust valve duration of 294* (std 124BC = 272* for both in. & ex.).

I'm not sure, but the 114 on both cams might refer to what is called lobe angle centres, i.e. the angle between the in. and ex. cam lobe peaks (= max. lift)

A = Aspirazioni, Italian for Intake; S = Scarico, Italian for exhaust.

Here's a diagram showing the valve timing figures on a 124 BC engine (26/66 66/26*, = 272* duration, 52* overlap):-

View attachment 488594

It's quite likely that your cams also have increased valve lift, this will likely increase the stress on the timing belt. However, the standard belt has been used, afaik, without any problem on modified engines.

I have seen a wider 'performance' belt advertised on the Autoricambi w/site, c. 25mm wide (iirc the standard belt is c. 19?mm wide), but there was a warning that this wider belt should only be used with flangeless pulleys.

There was also listed a 'performance' tensioner bearing made by SKF. but I think the standard bearing is quite adequate (unless you're going racing?).
Different subject please, do you or anyone else happen to have a wiring diagram for the twin headlight CC 🤔 🤞
 
After further thought, I now think the figure of 114 in your cams specs. is Not the Lobe Angle Centres figure as I suggested in post #61 but is in fact the angle at which max valve lift is achieved i.e. 114* ATDC for the inlet valve and 114*BTDC for the exhaust valve. If this thinking is correct, then by my calculations, your valve timing figures are IO 36*BTDC, IC 84*ABDC, EO 81*BBDC, EC 33*ATDC.

By way of comparison, Vick Auto list Street Performance cams with valve timing of 40/80 80/40 and Racing cams with valve timing of 42/82 82/42.
 
Different subject please, do you or anyone else happen to have a wiring diagram for the twin headlight CC 🤔 🤞
Here's a 2 part wiring diagram from the Haynes Manual for the later U.K. (rhd) spec 124 Coupe:-

Scan_20260608 (4).png
Scan_20260608 (5).png
Scan_20260608 (6).png

--------------------------------------------------------------------------------------------------------------------------------------------------------------------

And here's another Haynes wiring diagram for the U.S. (lhd) spec 124 Coupe:-

Scan_20260608.png
Scan_20260608 (3).png
 
After further thought, I now think the figure of 114 in your cams specs. is Not the Lobe Angle Centres figure as I suggested in post #61 but is in fact the angle at which max valve lift is achieved i.e. 114* ATDC for the inlet valve and 114*BTDC for the exhaust valve. If this thinking is correct, then by my calculations, your valve timing figures are IO 36*BTDC, IC 84*ABDC, EO 81*BBDC, EC 33*ATDC.

By way of comparison, Vick Auto list Street Performance cams with valve timing of 40/80 80/40 and Racing cams with valve timing of 42/82 82/42.
I think the maximum lift is 11.4mm but I will stand corrected as all this technical stuff is beyond my pay grade 🤔 ;)
 
Here's a 2 part wiring diagram from the Haynes Manual for the later U.K. (rhd) spec 124 Coupe:-

View attachment 488606View attachment 488607View attachment 488608
--------------------------------------------------------------------------------------------------------------------------------------------------------------------

And here's another Haynes wiring diagram for the U.S. (lhd) spec 124 Coupe:-

View attachment 488609View attachment 488610
Fantastic and thank you. My Haynes should be with me this coming Sunday so hopefully me troubling you should be much limited 😁
 
11.4mm lift, that's a lot, standard lift on the 1608cc BC is approx. 9.5mm, VickAuto performance cams have 10.02mm and their Racing cams have 10.6mm.
 
11.4mm lift, that's a lot, standard lift on the 1608cc BC is approx. 9.5mm, VickAuto performance cams have 10.02mm and their Racing cams have 10.6mm.
I have a new tensioner bearing coming so when I'm doing this I will measure just for fun. We have to bear in mind that I haven't a clue if the head has ever been skimmed by necessity or to raise compression, or, if it has different or modified pistons. The only information I got was that the engine had been rebuilt with these camshafts and hopefully I never need to find out what its internals are 🤔 😂
 
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