787 fast boat help

[irish88]

the motor i just put in my 97 challenger came from a kid who claimed to be a x racer so anyway the crank is for sure something aftermarket the crankcase has been polished and port matched to the carburetors he intake also the carburetors are novi type r with an adjustable air filter it has a cone going down that ajust the air flow they have a external fuel pump anyone know anything about then like is the ajust the same as stock? anyway it has a twist head neptune pipe{which i was told was rare}jetnetics flywheel msd box

so the first thing i did thought how cool would this be in my bout so i :hurray:

i now have the motor in my boat i detuned kind-of i took off the neptune pipe< i couldn't stop that thing from leaking for the life of me> replaced with factory x pipe took off the twist head i mead who needs 210 psi? i dont like doing top end rebuilds every season took off the msd

do i have to run race gas? is it true that low octane gas causes piston failure?
do i have to take off my intake and carburetor because iam pushing to much gas with a stock head?do you have to fun race gas with a ported motor?
is there anything i need to watch for? thanks

 

[Gunsrunner]

The higher your compression the more octane rating needed, by going to your standard head you may have reduced the compression to the point where you dont need the high octane fuel anymore.
To low an octane fuel with to high compression causes detonation, this is what kills pistons.
You have changed the airflow through the motor by removing the aftermarket pipe, the carbies should have been set-up for the higher air flow, if so you will be putting to much fuel in for the reduced airflow so it will be running rich.

 

[irish88]

what ir i put the stock intake back on well it act like a restricter plate?

 

[timmyboy76]

need to rejet the carbs...