Which way to go...2.5, 2.9 , 3.0, 3.2

[deoxford]

Hi,
I currently have a 72 T with the 2.4 MFI.. I love the MFI
But I am tired of getting pasted in the streights by higher HP cars.

SO do I go with the 3.2 swap like I was thinking?

Or do I do something cool like a Hot 3.0

Or rebuilt /(find) my engine to a 2.5 or 2.7, 2.9 MFI

I was reading about the 3.0 the is able to make about 220 hp
That is really All I am looking for the 220 to 240 range/


It would be great to keep the MFI then I would not be limited to what I race in because I put to much engine in.


Please let me know what you think , and what it take to do it, and the cost.

This is kind of a sunday car ,but mainly a track car.

Thanks

[deoxford]

One more Question, can my 2.4 MFI be changed to a 2.7 MFI
using my MFI and new larger P/C's?

[A Quiet Boom]

FWIW, My otherwise stock '81 3.0 with Zenith's and early exhaust made 174 at the wheels, doing the math that's 205 HP at the flywheel and I've still got some tuning to do. I've got to believe with 964 or webcam 20/21 cams I'd be right around your 220 target. Just a thought.

[MBEngineering]

HI are you feeling lucky,really lucky, if so check the crankcase casting No' near the oil return tubes, you may have 7R cases, you will require the cylinder spigots bored out to fit the 2.7 cylinders, send the pump to the repairs to change the space cam for the 2.7 one and then watch the bank acc' empty, WHILE WE ARE HEAR WE MIGHT AS WELL!!!!!!!!!!!! good luck and post some pic' of the strip/build.

regards mike

[304065]

None of the above.

23/31 TB's and Smart Racing Bars and Elephant Bushings and Revalved Bilsteins.

Anyone can go fast in a straight line.

[deoxford]

John,
Thanks for the help I do have bars, and 22/30 and HD Bilsteins, with poly bushing

[Henry Schmidt]

IMO: Short stroke, twin plug, MFI, 3.2.
Fast, powerful, reliable and period correct.

[davidppp]

Mmmmm..

What Henry said, for me..

Kind regards
David

[jbell959]

I saw this engine when I was at Henry's shop a few weeks ago and it looks even better in person.. This would be a great choice.

Henry - What is that hose you have connected to the breather cover?

[Henry Schmidt]

That hose is a drain for the oil tank breather.
In the picture the breather (from a 91 Turbo) is on the right behind the air filter.

[kenikh]

If you want FAST, Henry's suggested engine is the way to go. With the right work, 300HP is very doable. Not cheap, but bulletproof and FAST. What's not to love about a 70.4mm crank on 98mm pistons with MFI? You could spin it to over 7500 RPM and not break a sweat.

[Henry Schmidt]

300 RWHP. If this engine only makes 300 @ the crank I would be disappointed.

Yes, it runs on street gas.

[davidppp]

Ooohhh..Henry..

Please...You must tell what you did inside to make that?

Kind regards
David

[rswannabe]

I'll second that. Please post the specs to that 3.2SS when you get a chance.

[Henry Schmidt]

98 mm QSC cylinders and JE pistons 10.3:1
930 Turbo oil pump w/ internal mod for max flow
911SC crank with knife edged flyweights 70.4 mm stroke
lightened 911SC rods with ARP rod bolts and 928 nuts
All rotating parts balanced to 0+or- .5 grams
Supertec head stud kit
911SC heads (porting, twin plug and MFI injector port machining in house)
41 mm intake ports
39 mm exhaust ports
Supertec MFI pump mods
Supertec MFI Polymid fuel lines
Supertec mag stacks 52 mm top 41.5 mm bottom. (52 mm velocity stacks and PMO air filters)
Throttle housing rebuilt by Supertec 41.5 butterflies 40 mm ports.
Supertec valve springs
Tytanium valve spring retainers
DC62 cams (thanks John)
Taylor wires w/ Bosch connectors made in house
Supertec RSR plug wire holders
RSR spark plug connector holders
BurnBros cast aluminum sump plate
Supertec Gen II Twin plug distributor
Getty Design amber shroud
1 5/8 headers.
Sport muffler.
MSD 6AL only one
Two Blaster II coils
Bosch CIS fuel pump

[jpnovak]

Wow!

[rswannabe]

Henry - What is your preferred MFI pump to use as a base for a motor like this? 2.2S, 2.4S, RS?

Deoxford - Thanks for starting the thread. I have a strong 2.2S in my car now and I absolutely LOVE the charactoer and sound of it, but I want more. I've been accumulating parts for a 2.6SS, but I am now thinking about a 2.8SS or 3.2SS. They all cost roughly the same to build I believe, with the 3.2 being slightly cheaper becasue the core costws less and doesn't need all the machining of an early sand cast aluminum case. I'm curious to see what other people's opinions are.

Brooke

[Henry Schmidt]

Originally posted by rswannabe
Henry - What is your preferred MFI pump to use as a base for a motor like this? 2.2S, 2.4S, RS?.................
Brooke

The best pump to start with is an RS 019 pump.
That said we can make any pump work.

I used to race a 3.0 twin plug, hi butterfly engine that made over 300 hp on a stock 2.0E 010 pump.

All MFI pumps move enough fuel to make 700-800 hp. Now the only question is how drivable will the engine be.
MFI pumps have very little flexibility so when you tune them for power you loose fuel mileage. If you tune them to idle within a given CO range you might loose throttle response. The whole thing is a compromise.
As with any performance modification when you gain in one area you loose in another. The prime example of this give and take is camshafts. A cam that gives you great top end will probably offer poor mid range transition.

We are working on a version of the Falconer governor for application on the 911 engine. When completed it will offer a far greater range of adjustabilty. In fact it should be fully tunable throughout the rpm range.
Don't hold your breath however, I have been playing with this for close to 20 years. It seems the Falconer governor has limited access to the front burner.

[rvanderpyl]

Henry can you PM me your cost to (re)build a 2.4T MFI to work on a 2.7RS style motor. 10:3 CR. S heads, S Cam, twin plug, for street/DE use. The MFI is on a running motor

Oh , and how long you need.

Thanks

[confused]

I just saw that 3.2 SS at the Dana Point Concours event, I didn't know Henry built it until I read this but that engine really caught my eye. Looks like one hell of a powerplant for an early car.

Would be great in my 914-6 #200.