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Cam trigger wheel identification
Posted: Mon Sep 08, 2025 7:10 pm
by feraty
Hey,
Has anyone seen this kind of trigger, I know the 4 tooth big/small kind.
I've also been thinking about cutting it down to 1 tooth, but people online have noticed a general decrease in VVT stability.
this is from a Fiat FIRE EVO 1.2/1.4 8v engine, it has a 40 deg camphaser
55d2558b8cc234b0d7076efc38a78206.jpg
Thanks in advance,
Re: Cam trigger wheel identification
Posted: Mon Sep 08, 2025 7:25 pm
by AndreyB
"Fully Integrated Robotised Engine" what do they mean by that?
There is a chance that we do not support this trigger wheel (yet?)
Re: Cam trigger wheel identification
Posted: Mon Sep 08, 2025 7:42 pm
by feraty
thanks for the quick reply,
It means that the engine is fully build by robots, from casting to finished product.
these engines are known for their simplicity (inline OHC valve train, shimmed buckets etc)
makes them easy to work on and quite light even with closed deck iron block.
they were launched in the Fiat Panda FIRE in 1985 if I'm correct, 1000cc
but today you'll find them in 16v and 8v flavours, with turbo and NA.
ranging from 45hp(1l 8v) to 190hp(1.4 16v TB)
I had some stuff laying around and thought why not build an engine. grabbed some NOS oversized pistons/rods and a VVT head from the newer euro 5/6 engines (due bigger intake valves and ofc the added benefits of VVT)
I was afraid so, not a popular demand ofc
also couldn't find it on the wiki, or something comparible
Re: Cam trigger wheel identification
Posted: Mon Sep 08, 2025 7:44 pm
by AndreyB
there is a chance of this working as toyota 3 tooth - that toyota 3 tooth is one of the special triggers with extra flexibility
Re: Cam trigger wheel identification
Posted: Mon Sep 08, 2025 7:53 pm
by feraty
Does it allow for the unequal spacing?
the angles of the lobes looks like a hybrid between the 4-1 and the 3 tooth toyota.
Re: Cam trigger wheel identification
Posted: Mon Sep 08, 2025 7:54 pm
by AndreyB
Yes
Re: Cam trigger wheel identification
Posted: Mon Sep 08, 2025 8:01 pm
by feraty
Cool,
is it the VVT gap override function ?
filling in the various gap differences form tooth to tooth in tunerstudio?
Re: Cam trigger wheel identification
Posted: Mon Sep 08, 2025 10:50 pm
by AndreyB
Re: Cam trigger wheel identification
Posted: Tue Sep 09, 2025 6:39 pm
by feraty
Correct me if I'm wrong, first time for me using VVT and more than one cam tooth
- Offset is the actual offset compared to TDC, does it matter which of the three lobes is configured as TDC?
- Presicion, the expected range within the VVT angle? or just making up for the slop in the cam drive (belt stretching etc)?
and after configuring TDC to one lobe, does it use the others for intermediate synchronisation. just like a 60-2 tooth wheel on a crank?
thanks again!
Re: Cam trigger wheel identification
Posted: Tue Sep 09, 2025 6:50 pm
by feraty
sorry, first question is kinda stupid when i read it again. that will be determent by the cam phasing compared to the crank shaft