High compression ratio piston with performance camshaft?

[43576]

I was wondering if is impossible to have both high compression ratio piston with performance camshaft at the same time? The camshaft lobes is high to push the valves further, would it have damaged the piston head?

I have a Fiat Panda 100HP which claim 99bhp but on the dyno is 95bhp, Later it becomes 119bhp when I fitted performance manifold 4-2-1 with sport CAT and remap (11bhp more)

I saw a Fiat 1400 Fire on Italy website, they sell forged pistonhead to increase compression ratio from 11.5 to 12.5, the performance camshaft it sells as well.

My opinion is better to get the camshaft only? Or compression piston is better?

Appreciate any answer.

[GreenV8S]

43576 said:

I was wondering if is impossible to have both high compression ratio piston with performance camshaft at the same time?

It depends entirely on the engine design. If you're changing the spec of the mechanical components then the person designing the change needs to understand how the various components will interact and perform.

[stevieturbo]

Up to the builder/installer to check for any PTV issues when putting it all together, and if necessary, cutouts may need cut into the pistons.

[Crudeoink]

43576 said:

I was wondering if is impossible to have both high compression ratio piston with performance camshaft at the same time? The camshaft lobes is high to push the valves further, would it have damaged the piston head?

I have a Fiat Panda 100HP which claim 99bhp but on the dyno is 95bhp, Later it becomes 119bhp when I fitted performance manifold 4-2-1 with sport CAT and remap (11bhp more)

I saw a Fiat 1400 Fire on Italy website, they sell forged pistonhead to increase compression ratio from 11.5 to 12.5, the performance camshaft it sells as well.

My opinion is better to get the camshaft only? Or compression piston is better?

Appreciate any answer.

If you have to ask this question, no offence but you should really leave the buying of parts and assembling of the engine to someone else.

[43576]

I am car mechanical for 23 years. I am asking a question.

[GreenV8S]

43576 said:

I am car mechanical for 23 years. I am asking a question.

If you have to ask this question, no offence but you should really leave the buying of parts and assembling of the engine to someone else.

[thebraketester]

You are going to be deeper in parts than the cost of the car.

[SturdyHSV]

Peak lift is largely irrelevant for Piston To Valve clearance, as the piston has long since left by the time the valve reaches peak lift.

The cam duration is what can mean it's opening in to / not closing away from the piston face.

I'd suggest asking the parts supplier if the two work together. Going to a performance cam will likely mean more duration and more overlap, so you'll likely lose some dynamic compression ratio, so upping the static compression ratio with the high compression pistons will help bring that back.

There is no way of us knowing without knowing the specs of it all and even then you'd have to measure the PTV clearance to be sure once the engine was assembled anyway. You could take some educated guesses, but you'd still need to double check anyway.

[43576]

Thanks for the info.

[Inline__engine]

people have been raising the static compression ratio for use with higher performance camshafts for probably 80years. Unless you have terrible fuel octane this is the way to go