Ultimate 3.0l CIS to MFI conversion thread

[j911brick]

Mallory makes some nice pumps for drag racing that should work, bu would have to be regulated and they cheap, but still cheaper than Bosch.

[kiwiokie]

Just went to the PMO site to look at their pressure regulators and saw they also offer MFI throttle bodies that appear to have the MFI injector in the throttle body which would avoid having to get the injector hole drilled in the heads. Am I right in assuming this? Would save some $'s if that is true. Here is a pic from the PMO site:

[Rick Cabell]

Hello everyone.
Kiwiokie just invited me onto this thread because he spotted a 77 3.0 Carrera on another thread that I converted to MFI.
First Kiwiokie, that set up you just posted from the PMO set up is a completely differant ball game. I think the idea is to deal with Porsche parts to duplicate the 74 3.0 RS.
After reading the thread, Jeff Higgins has pretty much covered it. And yes, 69-73 MFI parts are becoming harder to find. There are out there, but the price is higher than the old days.
My only disagreement with Jeff is the possible use of CIS pistons. I wouldn't even try it.
My approach was to copy the MFI system from a 71-73 MFI car and build it into my engine. I started by installing J&E 9.5:1 pistons the 69-73 911S MFI cams. I used the 69-73 cams housings so in would be less hassle down the road. I 'd hate to be stuck looking for a custom seal if needed. I saw a set of mag housing throttle bodies and stacks from a 69-71 car here on Pelican. They were already bored for a abandoned 3.0 RS project. I sent them to Eurometrix to be rebuilt and double checked. The bore matched the port size of the 3.0 carrera. (same as early SC). I then sent a used 2.4 liter pump to Gus and told him to build me a 3.0 RS pump.($1600). I think I used a distributor from a 2.7 RS. To make it simple, I built a 2.7 RS engine onto a 3.0 aluminum case. (original engine to the car.) SSI heater boxes and stock muffler. The most important issue was drivability. I didn't want a high strung finiky running engine. The engine came out better that expected. No bugs to work out, and it ran stronger that anything I've ever driven in the same class. It had to have 250 HP. I forgot the heads. I build a jig to bolt the head to, and bored and threaded a MFI port into the head. I didn't weld up the cut out for the old CIS injector.
If you want Kiwiokie, you can paste a photo of the engine from the other thread. It's beyond my capability. As far as cold start, I used the 69-71 air cleaner with the squirter tubes built into the top of it. Except for the J&E pistons,every part is from a 69-73 MFI car.

[EmeraldE]

I've now got Rick's '77 C3.0, with the engine that he describes above, shown in the picture below. He did a beautiful job on it, cosmetically and mechanically.

It only had about 1,000km on it when I bought it, so I'm still kinda running it in at 5,000km now. I expect to dyno tune it soon, and will report results here. The engine pulls very smoothly, and seat of the pants says the engine is more than 11% stronger (capacity differential) than my rebuilt 2.7RS-spec MFI, 9.8 compression Mahle P/C engine. We can't quite get the 3.0 to idle as smooth as the 2.7, however. Given that Rick did everything fresh and right - Matt Blast on the t-bodies and stacks, Gus on the pump, S cams, etc. - it's not clear to me why we can't get it quite as smooth yet. The A/F readout on the dyno will be helpful there.

Also, in trying to better understand the original Porsche 3.0RS set-up for comparison, I've corresponded with Matt Blast at Eurometrix and Aaron Hatz at Flat 6 (he has rebuilt at least one original 3.0RS). Both believe that the 3.0RS intake set-up was pure 2.7RS - 36mm intake ports, 312 plastic stacks, S/RS T-body specs, S cams, RS space-cam, etc. Porsche reported the 3.0 hp at 230 at 9.8 compression, vs. 210 and 8.5 for the 2.7. I have to believe there is more than +20hp, however.

Having been disappointed with the leak issues of a magnesium case (even with all the case work done), and experienced the power and torque differential, I'm a real fan of the 3.0MFI. But I still have a stock '78SC 3.0 in a DE car, so am interested in hearing about others' experiences with more aggressive 3.0MFI engines.

Best,

Bob

[Rick Cabell]

Bob, I thought that car idled like a kitten.

[giovanni86]

so am interested in hearing about others' experiences with more aggressive 3.0MFI engines.

I think I'm building an "aggressive" engine set up, with rsr cams and modified metallic stacks.....


question:

My mechanic ask 5K euros (more or less 6.5K usd) to use the rsr cams instead of the s ones and for use the modified stacks instead of the plastic ones...

do you think the price differencial is "fair"?

I'm planning to use my car both in track days events and for "compatible" road use(compatible=country road..), do you think that upgrades are worth for me?

thanks

[giovanni86]

what is the fair price for a pair of plastic stacks and for a pair of s cams?

[EmeraldE]

Rick, it seems to idle a little low and hunts moderately, and is a little rougher cold than the 2.7. We're at about 1,000 feet here, and honestly I can't tell you if my mechanic here (well versed in MFI) set it up much differently in the tune up than you - I know he tried a click leaner but put it back where you had it on the pump. It appears to idle richer than the 2.7RS - Gus redid that pump as well - but I haven't tested the A/F on either yet. I've got one of Henry Schmidt's manual MFI enrichment controls on the 2.7MFI, and always lower it as quickly as possible - I'm thinking of putting one on the 3.0 to see if that makes a difference.

But once I get above 3,000 rpm, there's no question which engine is in the back!

BTW, do you recall if Gus used the 2.7RS MFI pump space cam, or something different? I know it's marked 3.0RS by hand on the pump.

Are you still finishing the Talbot car, or on to something else? Need a place to stay on your way to Savannah this year?

Bob

[EmeraldE]

Giovanni, others will know better but $6,500 seems quite a bit for different cams and bored stacks vs. S equipment. Lots of different, high quality aftermarket cams to choose from, I think mostly in the $1,000 +/- range. Plastic S stacks are $600-$1,000 I believe, based on condition.

[kiwiokie]

Thanks Bob and Rick, very useful info. That engine is beautiful.

[Rick Cabell]

That's Gus's writing on the pump. I'm sure he used a 2.7 space cam. Still on the talbot car. Should be done it April.

[giovanni86]

thanks EmeraldE

[giovanni86]

does anyone knows if it is possible to convert an early bosch pump to a 019 type?

thanks

[YTNUKLR]

Any 2.4 pump can be converted to 019 specs. exactly - 015 911T, 014 911E, 013/021 911S

The others can be made to that spec. but a 2.4 L pump is recommended to start with

[giovanni86]

Any 2.4 pump can be converted to 019 specs. exactly - 015 911T, 014 911E, 013/021 911S

The others can be made to that spec. but a 2.4 L pump is recommended to start with

thanks thanks... exactly what I need to know!

[sluk]

a pics of engine reassembly of a real 3.0 engine

[kiwiokie]

Great pics sluk. Do you have the details of the pump - model number and space cam?