Upcoming engine swap - 2.7 into a '70T.

[Rick Lee]

A friend of mine, who does not really participate in this online community, recently bought a nicely set up '70T which was made into an RS clone. It has a 2.2l engine, Dansk SSI's, Bursch muffler and looks pretty solid to me. My friend is hell bent on putting a 2.7 in there to keep it close to a real RS. I know, I know. So a local Pelicanhead is selling him a nicely sorted 2.7 CIS from a '77S that was bought from another local Pelicanhead. I'm sort of the consultant here and am afraid I may be tapped to lead this engine swap endeavor, as my friend is a very busy guy and takes far too much of my advice seriously. An engine swap is not really anything I haven't done before, but I was wondering what all we should plan for.

I told him to consider a new clutch, perhaps aluminum pp and/or lwf, the usual new seals and bolts, valvle adj. What issues might pop up here? I don't know what year it is, but I'm pretty sure this RS clone already has a 915 bolted onto the 2.2. Does that make sense? Will it mate up ok with a 2.7 CIS? Are case-tranny studs compatible? Are SSI (assumed thin) flanges compatible?

Please send your recommendations. Thanks.

[dd74]

From what I know, Richard, SSIs come in two sizes: one for 3.0s and below, and the other for 3.0s and above, so exhaust wise, he should be okay.

I don't know if the 70 T had the 915. It may have had the 901 transmission. Tell your friend to check the gear pattern, and advise accordingly.

As far as the 2.7 bolting to a 901, I "think" it can be done. Actually, it would be nice if this works, as the 2.7 is heavier than the 2.2, until your friend decides on some weight savings for the engine, i.e. taking off the CIS and installing Webers.

Good luck.

[Halm]

Otto is bolting a 2.7 RS type clone motor to my '70 with a 901 right now. I don't think that is a big deal at all.

BTW, here is an early pic when he started the long block.

[jpnovak]

Richard,

The 2.2 should have a 901 but that may have been changed as you mentioned. Look for R gear in the upper left corner of the shift pattern. This is the indicator for the 901.

The 901 will mate to the 2.7. I don't think any changes are necessary. the 1970 type 911 will have a 225mm clutch which is the same size as the 915. Just make sure the correct 901 clutch (pull type) is used. I prefer the 901 pattern, especially on the track. the lower gearing of the early 901 would be preferred over the later 915.

There are a few wiring issues to be dealt with for the CIS but it is straighforward. The SSI's should bolt on.

I am not sure why a late model CIS 2.7 would be an improvment over a 2.2. Does the 2.2 have issues? There is really no similarity between the low hp 2.7CIS and the MFI 2.7RS motor. If it were me I would just drive the crap outta the 2.2 until it gets tired and then build a 2.5 or so off that case.

Tell your friend to spend the $$ on seat time, brake cooling, and suspension, in that order.

[Rick Lee]

Actually, the 2.7 is an S version. He's got plenty of seat time (in his Ferraris) and this is sort of a project car that he's dreamed up and it has to have a 2.7. My guess is that it will get carbed at some point. What sort of wiring issues are there? And where is R on a 915 and where is it on a 901? I have driven both, but don't remember.

[jpnovak]

Is this the same friend that has the nice stable of Prancing Stallions? I will not fight the dreams of project cars. I am building my dream right now. Which now has doors and fenders attached, but that's about it.

on a 915, R is right then down, same as your ex-Carrera and 993(or is it 6speed?).

What induction does the 2.2 have now? I assume its a 2.2T with carbs. Why not just swap them over and rejet. Easy to do, easy to tune, lots of fun. That is unless the motor will be sold complete.

I am not completely sure about the 2.7, but my 3.0 conversion into the 71 requires the movement of 4 or 5 wires. Its just swapping pins in the 14-pin connector. You just need the two wiring diagrams and it is easy.

[Rick Lee]

Yes, this is the guy with the prancing stallions too. He'll be with me at the swap meet and we'll hash out his engine swap plans then. I'm sure it will get carbed, but don't know when. If I'm doing this swap, it's ain't getting carbed until it goes to the pro wrench for final tuning. If the shop does the swap, well then, they can have at it.

[Spud]

I happen to have a 2.2S MFI motor in my RS clone, and have looked into swapping for a 2.7 motor. I seem to recall hearing that the CIS cams are really only good for CIS, and you should think about putting in a hotter cam if your friend is even thinking about going to carbs.

This is the time to do it, while the engine is still out of the car. Of course once you're in there...

[Bobboloo]

Not much to add here.

The flywheels are the same whether you're using the 915 or the 911 (901) tranny. The mainshaft is smaller on the 911 tranny and requires the matching clutch and pressure plate. Either way you should have what you need already.

The electrical can be switched via the 14-pin as stated.

A couple things though.

You need a CIS fuel pump, an accumulator, and filter along with the appropriate fuel lines and fittings. You also need a return line to the gas tank. I'm not familiar with the lines on a 70T which has carbs (which don't normally have return lines) but I would think that since this car is a 70', and the other two models of that year had MFI, that the bodies came off the same assembly line therefore the return line was already built into the chassis and the gas tank. The spot to check for this would be at the center tunnel where the shift rod connects to the tranny and at the gas tank. If the car doesn't have the return line then I think your easiest solution is to take off the CIS and install the carbs.

Assuming that you go this route the carbs will have to be rejetted and the venturis will have to be swapped for larger ones.

I have a 72T with a 2.7CIS motor in it and it makes for a good street car. Better in my opinion than a "cammed" 2.2. The 2.7 CIS motor "pushes" the car much more effortlessly than the smaller displacement. It's called torque.

[Bobboloo]

I seem to recall hearing that the CIS cams are really only good for CIS, and you should think about putting in a hotter cam if your friend is even thinking about going to carbs.

Hotter cams require the appropriate piston as well.

The CIS cam is not much different than a T cam. It's just timed later for reasons associated with the CIS piston.

Carbs will work fine on this motor as is. The main downside is fuel economy.

To realize more potential from the motor would be to rebuild it as a 2.7RS. That's a lot more work than a motor swap.

[KTL]

I have nothing to add to the swap other than this:



One other thing. Why not swap in a 3.0 and just say it's a 2.7? The 3.0 and 2.7 CIS motors look the same to the untrained eye and he'll have the increased reliability of the alum. cased 3.0 engine. Just send him out for a ride in one of the Ferraris (why no 355 in the stable?) and substitute the 3.0 while he's away........... What he don't know won't hurt him/will benefit him!

[Rick Lee]

Hey Kevin, I was even suggesting a 3.2 or 3.6, but like I said, he's set on a 2.7 and I just happen to have a lead on a well-sorted, local one. As for the 355, I asked him that too and he says he's still waiting for them to depreciate a bit more before he grabs one. Right now his main concern is this 2.7 transplant and then more garage space. Next priority is a pristine pre-73S 911. Maybe a 355 will be come thereafter. Life is full of choices, no?

[KTL]

A 2.7 it is then! The NoVA clan should be able to knock that job out no problem.

Yeah, i'm waiting for the 355's to drop down to my level as well. My level is sub-308 territory............ Ha!

[Rick Lee]

355's will never be sub-308 level. And even if they were, the maint. costs would put you back into 993TT territory. My buddy is not much of a DIY'er, so I'm not sure who's gonna be doing this job. It might be more than I can tackle on my own and I don't know if this will turn into a NoVA gang gathering. I'll know this weekend.

[Jim Richards]

It might be more than I can tackle on my own and I don't know if this will turn into a NoVA gang gathering. I'll know this weekend.

Depends on how much seat time we get in them Furraree's.

[john_colasante]

So when you're friend asks you a question do you excuse yourself and immediately run to check this forum or do you evade the question and then thoroughly answer it the next day with an air of authority? Does your friend know about your secret "Cyrano"?

[zephog]

Ask your friend if he would care to sell his old motor to a fellow pelicanite down in NC? or better yet, a motor swapping clinic if I can push/pull my motorless bastardize targa that far north?

[chuckw951]

Originally posted by Richard LeSchander
Please send your recommendations. Thanks.

I may repeat what some of the others have mentioned....hear are my thoughts:

Transmission:
If it's a 1970 car I guess I would be surprised to see a 915 transmission installed. More likely it is a 911 transmission (the 70/71 version of the 901) with the 225mm clutch. The 2.7 will mate up to that transmission or the 915 for that matter just fine. While you're there inspect the clutch parts...you may want to install a new clutch package while you are there. For some reason the 70/71 clutch package is more expense than the rest.

Exhaust:
SSI's that were on a 2.2 will work just fine with the 2.7 motor. I do have a question though, on the SSI's I have on the left changer there is a tube that goes to the air take (pre heat maybe?) I 'm not sure if that's needed when going to CIS.

Wiring:
From my understanding the 70+ 911 models have the 14 pin connecter for the wiring harness. You need wiring diagrams for both years (70 and 75) to match up the wires. Will there be issues with the alternator and external voltage regulator...I'm not sure.

Guages: tach, fuel temp, fuel pressure, idiot light. I think the 2.7 tach is different than the early tach. On my swap I used an SC tach. On my swap the temp and pressure sensors were different...the idiot light sensor didn't need to be changed. Need to research these things.

Fuel system:
A CIS pump will be needed up front. As I recall the 70 911 had the fuel pump up front so that should make things easier. Other posters might know, but isn't the 70 fuel pump something special...new ones are very expensive so your buddy can sell the old one. Fuel lines: CIS runs on high pressure and you'll need a return line to the tank. The car may have the return line or it may not. From my understanding it is not easy to route new lines through the tunnel...installing carbs from the 2.2 motor would be easier. I also wonder about the 911T stock lines from the fuel pump to the motor. Are they beefy enough to handle the increased pressure? I don't know, but worth investigating.
Fuel tank: If the fuel tank is a 911T tank, would it have the inlet for the return line or would the tank need to be modified. The 73 1/2 911 had a different tank right? I 'm not sure. You'll need the fuel filter/fuel accumulator parts (which incidentally I have from my abandoned CIS swap...cheap, let me know).

Ignition: What type of ignition does the car have now. Seem like you should to the 6 pin CD right? Did the 70T have CD ignition (3pin?) I'm not sure.

Overall: With all due respect to your buddy...a 2.7 CIS motor isn't the same thing as the 2.7 motor that was in the original RS so getting stuck on the displacement doesn't make sense to me. Can't the 2.2 liter motor be modified...that might be easier and less expensive than doing the swap. Can one use 2.4S pistons in the 2.2 motor to bump up compression? Toss in some cams and S heads you'd have a higher revving powerful motor that would be truer to the spirit of the RS motor than a 2.7 CIS...
Another option would be to get the 2.7, ditch the CIS, change the piston and cams and install the carbs from the 2.2 motor (are they webers?) BTW, so the '77 2.7 motor have all of the bugs worked out of it. As I recall the 2.7 motors need some attention but once the studs are fixed they are good motors.

At the same time this sounds like a good project and sounds like it will be a fun car. I would just urge your buddy to think about all of the options that are available...engine swaps and engine modifications...and where he is trying to go with the project. Torque is great for an around town car...but at the same time there is something special about a small bore flat 6 at 6K++ RPMs.

Well that's my .02

[Rick Lee]

Ok, the fuel pump requirements make me nervous. I saw digital photos of what a shop had to do to my Carrera to replace a fuel line in the tunnel - scary stuff. Where can I find diagrams for the 14 pin connectors? Thanks for all the great info.

[jpnovak]

Don't worry about the pump. The return lines are there. Just swap the pump. In fact, I have a CIS pump if you need it. I will let it go for the $30 it will cost for a new one for my carbs.

Look under the Pelican main page for 911 wiring diagrams. They are even in color which makes it easy.

Another issue for keeping the 901 tranny is that you would not have to run wires for the electronic speedo. The 915 has no mechanical output.

Jamie