what's in a 74 carerra motor?

[ssoar]

I've got a dead 2.7 to rebuild and i'm wondering if there is anything good to do while I've got it apart?

In particular what made the euro carerra make 210hp? I'm guessing hi compression pistons, radical cams and MFI (vs CIS) but I'm only guessing.

I did notice that Stoddard would sell a set of euro P&C for only $5000 (probably more now, was a 5 yr old catalog.... )

But if I knew what was so magic about those pistons, i could probably have JE make a set for a good deal less than $5K.

thanks for any ideas,

[TRE Cup]

The USA spec 74-75 Carreras had cis 2.7 motors, while the europeans got the 210 hp mfi motors. The mfi motor has different heads, cams, the injection, pistons, and all came with the 74 style heat exchangers, dual inlet muffler.
To make your dead motor into one of the 210 hp units will cost you a lot of money. If you want good horsepower for relatively cheap outlay, then install a used 3.2 or , if some more $$ are available, a 3.6. Granted you are not installing a freshly rebuilt engine, but the $$ /performance ratio is much better than converting/rebuilding yours.
If you must have that screaming mfi 2.7 wail, then Pelican and other suppliers can help you with pistons/cylinders and all the rest at reasonable prices
Good luck

[mr914]

What is the difference in 2.7 vs 2.7S heads?

Can the non s heads be converted to s heads?

If so, what is involved?

[TRE Cup]

2.7 mfi heads have threaded ports on the intake side for the mechanical injectors. The cis heads have notches in the intake side to clear the injectors mounted on the intake tubes above. It would take some welding and machining to convert the cis into mfi heads. There are other minor differences but that is the important part (about $800 last time we had it done professionally!)

[Bobboloo]

You can get the 2.7 RS P/C's for $1650 from EBS.

There is nothing magical about the pistons. It's the MFI system with the "S" cams and your exhaust that is magical.

The MFI setup for the motor will set you back major bucks as well as machining the case in a rebuild.

To rebuild your motor as a 2.7RS will cost roughly the same as a 3.6 transplant when labor is figured in. Both will put you close to the $10K region.

Bobby

[ssoar]

Are they a different CR?, or the same 8.5:1?

the reason I ask, is that in scca soloII SP rules, i can update and backdate assemblies, but intake and exhaust are free....so I don't have to use the $$$$$$$MFI.

So, if there is anything magic about the RS motor (internally, don't care about the MFI), then can I duplicate it with my pair of beat up 2.7s? ( I know, I'll build a 5.4 )

Looks like the main difference internally is the cams, which are too radical to use with CIS. What about if you just raise the idle up to 1500rpm? Or used a speed-density programmable EFI ?(which I was thinking about anyway, as I know CIS limits top end power)

just wondering....

[TRE Cup]

Rick Clewett, a Electramotive dealer and engineer, installed electronic injection on a 2.7 and it really woke up. With the original cis pistons,cams, and heads, I think he achieved over 200 hp! I can imagine that using T cams (more radical than CIS S cams) , a little head work and you might be able to eclipse the 210 hp easily.
I am sure you can do the same with a Motec, Autronic, or other similar system. The problem is cost- The last I checked, the complete system with manifolds, etc came in around $4500
Carb conversion on a stock 2.7 will yield you a mild increase of 15-20 hp, and that costs about $3,000
Looks like the 3.6 is a better idea, eh?
Speed costs money- how fast do you want to go?

[Bobboloo]

So, if I understand you correctly, carbs would be legal(scca)? Why not build a 2.7RS replica with Webers, per Bruce Andersons book.

He used the 2.7RS P+C's, E cams+Webers. You can get used Webers for around $1000.

Of course the motor probably wouldn't be street legal though.

Bobby

[ssoar]

Glad to know that electromotive on stock 2.7 gave 200hp. It doesn't have to cost $4K. I see Accel DFIs on ebay for $500-700, and I can either machine myself or farm out adding bosch injector bosses to the CIS stubs. I'd just rip the guts out of the CIS stuff to make a plenum intake, using the CIS throttle body or a bigger one out of a junkyard.

Clarification on scca's odd rules for SP:
Engine/tranny can be updated/backdated AS A UNIT (ie, no mixing and matching), but intakes and exhaust is free. So I can add any intake/ex system to any 2.7, 3.0, or 3.2 (not 3.6, it's from a different series of car, as the scca sees it)

So its very reassuring that the base 2.7 will respond to intake mods.

another option is there is a guy here at work who has a side business modifying CIS to go onto VW sand buggies. He has a lot of experience with moding CIS AFMs for higher flows, so that might be an option as well.

As for carbs, yeah that is a quick and dirty way to go, but after fighting dual webers on my fiats, I aint going there again. Poor economy, always going out of sync, poor cold driveablilty, inevitable stumbles off idle, and bogs off corners due to fuel slosh in the well.

A carb is just a poor bastard cousin of a proper AFM, with bandaids pasted all over it

(whew)

and did I mention that every time you think you might want to try a jet change, it'll cost you 6 X $4.50 for mains and idles, much worse for Etubes A pumps, or aux vents?

[TRE Cup]

Go with a 3.2 intake- the air flow is much better than the cis set up and it falls within the scca rules. Now you're in business at a reasonable price. If rules allow- Think about getting the JE high compression pistons for it, and you can change cams to take advantage of it- I can see you getting close to 250-260 all dialed in