Small Port Swap

[Alex170984]

Hi,

I am going to be embarking upon a bigport to mongrel smallport swap.

I am using small port pistons, but bigport crank and rods, but also the smallport head and inlet manifold but retaining my bigport ECU.

I have read articles and threads about a flat spot occurring at 2k rpm when people swap to smallport from bigport and it's down to the TVIS being deleted.

I have jammed my TVIS open on my current engine because it is restrictive for my high lift cams, so in essence, i have deleted the TVIS but haven't physically removed the butterflies or plate.

I was under the impression due to my cam setup that this apparent flat spot would be there if I was running standard cams, but because I am not, i haven't noticed it...I thought this would be the same when I swap over to the small port head and inlet manifold.

Has anyone been victim of this flat spot?

Cheers

[Alex170984]

I have since seen conflicting threads saying it's a load of rubbish.