2.0S MFI on 2.7 Engine
 

I want to fit a 2.7 engine with DC40 cams and 9.5:1 C.R to my 69S, using the 69S MFI system(005) pump. Am I likely to be able to get the engine to run properly without having to modify the MFI pump so that I can eventually put a correct 2.0S engine back in the car?

Rob

Call a good MFI shop
 

Since you plan to keep the option to go back to OEM for resale. IMHO Look for clean pumps & stacks for sale here and modifying them to fit your specific engine needs. A good MFI shop can do many things with an MFI system so ask them what to buy. MFI can be very engine specific. RS 2.7 pumps are expensive. Best of luck. :)

I would give Mark Jung a call and get his input on the 2.0S pump. The stacks and throttle bodies will be fine.. they are the same specs as those on a 2.7RS engine but I'm not sure the 2.0S pump will deliver enough fuel.

I have a 2.7RS spec pump that was checked and calibrated by Mark. You can find it on the for sale section if you decide to go that route.

jbell959 has a nice pump
 

I thought jbell959 had sold the 2.7 RS pump or I would have sent you a link. On the Left Coast Mark June is up in the Pac NW and Aaron at Burnham is in Camarillo, CA.

You will need a set of stacks matched to your head ports/application. Look for a set already machined & rebuilt if possible. Usually a set of E or T 2.4 stacks can be machined/rebuilt for the larger motors. Be careful because a lot of crusty junk 2.4 stacks are showing up. There are limits to stack repair so be picky.

I did have a factory 2.7RS (019) pump for sale a while back and I did sell that, but I also have an aluminum 2.4T pump that was converted to an RS pump with a factory space cam and it was calibrated and sealed my Mark

http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/965963-aluminum-mfi-pump-2-7-rs-recently-serviced.html

Thanks for the info. I will only convert the 2.7 to MFI if I can use all of my 2.0S MFI parts. If not, I will leave it on carbs in the meantime.

Rob

You can use all of your MFI parts but Mark Jung will have to put the proper 2.7 space cam in your 2.0 pump. I'm also doing a 2.7 MFI motor with 69S MFI.

I don't think there is a 2.7 space cam available for the 2.0 pump, only for the later 72-73 pump? - but perhaps the 2.0 pump can be calibrated to a different "map" to better suit the 2.7l motor.

Yes, it may be correct that just a recalibration is necessary since a 69s engine cam profile is very similar to 73rs cam profile (essentially both have an S cam). Therefore, it seems that the space cam in a 69s injection pump could be similar to a 73rs space cam in theory but I would also be interested to know what the MFI specialists like Mark think.

So that 2.7 has clearance for the injectors in the intake runner?

After talking with him, I sent Mark a 69S pump to be converted. It was found to have frozen plungers so I bought another pump, I think it was a 2.2 E and sent it to him.

Matt Blast said that 69S stacks were a good choice for a 2.7RS build and he's redoing those for me.

Matt Blast does great work. He completely refurbished (to like new) the MFI stacks, throttle bodies, and linkage for me when I built a 2.7RS-spec engine for my old 73E.

Agreed, Matt is a real gift to the 911 community.

Had a talk today with the local race car guru who has built many hi powered race car MFI engines. He is confident that he can get my 2.0S MFI set up working properly on my 2.7 motor with S cams without having to send the pump out for rework.
I will probably go in this direction and post the results as a matter of interest. Unfortunately it will not be in a hurry as I have got to learn that in the Porsche world, good work takes time.

Rob