2.4T engine into 2.4S Car

[Mountaingoat]

Hello

I'm just about to drop in a 2.4T engine on Zeniths into my 2.4S car. Does
anyone have any idea if I will need to change anything on the fuel side. Currently
I'm running S fuel pump and filter. I'm guessing the fuel pressure will be different.

Thanks heaps, amazing forum!!!!!!

[daepp]

I belive the S has return fuel lines to the tank for the MFI that will need to be dealt with. And I imagine the fuel pressure for the dual carb setup will most likely be different than that for MFI.

[svandamme]

what's wrong with the current 2.4S engine???

[Bobboloo]

The fuel pressures are different so a pump that works with carbs should be fitted. Be sure to hang on to the MFI fuel pump. They are very expensive to replace should you want to go back to MFI. There is a proper procedure for storage that you should look into to avoid the pump from seizing.

Since you have a return fuel line you can hook up a loop setup with a regulator in the circuit. This will keep cool fuel supplied to the carbs on hot days when cavitation is most likely. Also taker the opportunity to relocate the pump to the front of the car next to the gas tank. They work easier pushing the fuel rather than having to suction the fuel.

[911pcars]

I also suggest using a fuel pump more in line with carb requirements.

However, how much different is the output pressure of MFI and CIS pumps? If approx. the same, an alternate plan is to use a FPR to regulate line pressure to the carbs. There are many CIS owners who have done just this.

Sherwood

[Bobboloo]

Sherwood makes a good point. For some reason I was thinking that the MFI fuel pump put out less pressure than the carb fuel pump but I looked it up in the factory manuals.

Here' the pressures for the fuel pumps from 70/71' motors.

911T (carb) 4.3 psi 80 liters per hour.

911E/S (MFI) 14.3 psi 125 liters per hour.

So you should be able to keep the MFI fuel pump and regulate the pressure down to feed the carbs 4.3 psi. The additional flow will just return to the fuel tank via the return line.

[Mountaingoat]

Hey guys

Thanks for that, I bought the car without the S engine. The plan is to use
the T for a while as is, to get the car fit for the road etc as its just been renovated and then slowly work towards either sourcing an S or rebuilding the T up to S spec. Although sorcing MFI kit seems a tad difficult and costly so I might just go for Webers or PMO's.

I like the idea of regulating the pressure down to suit the carbs so I can keep as is. this seems like a really simple option. I guess fitting the regulator on the mfi line feed will do the trick.

Has anyone ever tried this??

Thanks heaps