2.7L cis lump or dual webers? Help!, Converting to dash six - need advice Options

[startsw/p]

Hey all. Who wants to donate their two cents worth on this... I am converting to six cyinder, and I have two engines.... a 2.2T with webers and a 2.7S with CIS.
I thought the CIS would be nice for everyday driving, and would be less troublesome overall, especially if the car sits for a long period of time. However, I heard there are some clearance issues on the rear firewall. Has anyone overcome this? Or would it be better to use the carb setup on the 2.7 and change the cams???? Either way I have pieces left over... and pieces to buy. Thanks. -Kris

[iamchappy]

I say go with the CIS far less work than keeping those carbs in tune and as far as a daily driver very smooth and better gas millage. No problems with the fitment with the firewall but without it, it makes things a bit easier to service the thermostat,oil pressure sender, coldstart valve, oil breather, not to mention the top transmission bolt, and removing the oilcooler. Personally I dont see a problem with trimming the firewall in the rear but some do. (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

[ArtechnikA]

if you had a 2,2S it'd be a hard question, but with a T, it's easier. use the 2,7.

you don't *have to* change cams in the 2,7 -- i don't have the lift & timing in front of me, but a CIS cam is not *that* different from T cams. so you won't be giving up anything.

the easy thing is to put the Webers on the 2,7, update the venturiis and jetting, and call it good. drive it like that for a while, enjoy the car, work out the other bugs. keep your eye open for a nice set of uprated cams. when you find it, pull the motor and swap the cams.

[Root_Werks]

Stick with the CIS if that 2.7 is in decent shape. I have put a few CIS engines in 914'4 before. Just a couple of things you might have to do:

Relocate the lid latch to the "other side". As in mirror it and simply lengthen the pull cable.

On both of the ones I did, I had to rotate the fuel dist. to the fittings wouldn't hit the firewall.

That's it. The rest you can figure out (Plumbing, wiring) using a Haynes manual.

(IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[startsw/p]

Thanks a bunch, guys. (IMG:http://www.914world.com/bbs2/html/emoticons/pray.gif)
But, which gives the most usable power?
Is there an ideal setup in a 914, if it's not strictly a track car, and drives to the track instead of trailering...
What's good for devouring 911's? (Besides my sawzall of course) (IMG:http://www.914world.com/bbs2/html/emoticons/sawzall-smiley.gif)

[seanery]

I hate CIS! My 2.7 has webers, E cams, RS Pistons...CIS should fit if you use a factory style engine mount. If you use one of the "Quick 6" type bars you may have clearance issues with the rear of the engine bay/trunk. My first 2.7 was a CIS motor and we had to cut it out.

Anyway, the CIS cam makes for a very mild motor :yawn:

[iamchappy]

"What's good for devouring 911's?"

Answer - 3.0 914 turbo carrera. (IMG:http://www.914world.com/bbs2/html/emoticons/rolleyes.gif)

[Root_Werks]

Well, because of the wieght difference in the cars, it depends. A 125hp 2.2T motor will keep up with most 911SC's on the road. A 180hp 2.7 will probably beat most stock 3.2 Carerra's.

Do the math:

180hp 2300lb 914-6
180hp 2800lb 911SC
214hp 3100lb Carerra
204hp 3000lb Carerra

I am just guessing on my numbers, they are probably off a little, but you get the idea.

[seanery]

IIRC, the 2.7 CIS motors were rated at 165 hp (IMG:http://www.914world.com/bbs2/html/emoticons/barf.gif) We're guestimating my 2.7 at 210. (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[startsw/p]

I think I'll try to get it running with the CIS 2.7 first, and I'll dink around with the carbs later if I find cams cheap enough. Pulled the plugs on the 2.7 and the burn looks really consistent, so I'm optomistic. Just need heaterboxes.....

[airsix]

Sammy, you left out one thing. It's petty, but still worth noting - with carbs the engine will sound better. (by the way, I HATE carbs, but I do like the sound).

-Ben M.

[startsw/p]

But the cost per HP .... is it really worth the big bucks for the cams, pistons and overhaul bits to gain the 40 or so HP? The carbs are rare enough, who still stocks euro pistons? Sometimes I think it would be better to just go with a 3.2 to start with.... (IMG:http://www.914world.com/bbs2/html/emoticons/headbang.gif) but how much is too much... I don't want to flare the fenders, and I already have a carrera front end in with 16" fuchs and 205/55's all round. Too much HP will be lost on those skinny little rubbers. If I don't use the carbs I have a whole 'nuther engine to use in maybe a 550 kit... (IMG:http://www.914world.com/bbs2/html/emoticons/idea.gif)

[Trekkor]

finish the conversion, with the webers.
If it is not to your liking, search for a bigger motor deal.

All the hard stuff will be out of the way.
I'm running a 2.0-6 and loving it.

KT

[morgan_harwell]

There is a lengthy discussion of CIS 914s on the Pelican BBS. Look for thread "CIS on a 914/6".

If you "just have to have Webers" install the 2.2T(130HP?).
If you want about 40 more HP, and twice the gas milage install the 2.7L, CIS intact.

With gas at $2.50/gallon Webers don't make sense. A friend's 914/6 with 2.7L CIS engine, Webers installed, gets 165 miles/tank of gas. My 914/6 2.4L CIS, CIS installed, gets 300 miles/tank city, 425+ miles/tank highway.

Without changing the cams & pistons, Webers won't deliever more horsepower. Just poor gas miliage and c***py exhaust emissions. Something to consider if you street drive your 914 a lot like I do(12K-15K miles/year). The BAR refferre(sp) commented that my sixer CIS engine was one of the "cleanest" he had ever tested.

> IIRC, the 2.7 CIS motors were rated at 165 hp
Its reasonable to assume that by removing the 911's 2.7L restrictive exhaust (remember thermo reactors?) and using 914/6 tuned length headers, a few extra HP is to be had with just that one bolt on.

[Dr Evil]

I'll be using my CIS on my 2.7. Dan, how do you move the fuel distributor?

[J P Stein]

I was just reading a blurb by B. Anderson in the latest Excellence. With a otherwise stock 3.0L , they got 210 hp *on the dyno* with a pair of Webers & 914/6 heat exchangers.

More HP is always a slam dunk for me, but it is a double edged sword.... milage, adaquate tires, ...yada. It's all in whatever rings your bells.(IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

BTW, carbs are simple devices, much easier to deal with than a
30 year old FI system......after one has climbed the learning curve. I haven't had to change any of my settings in 2 years.
2-3 plugged idle jets in that time, tho.....a 5 minute fix.
To be blunt,most of the stuff I read about carb problems are opperator induced.

[sixnotfour]

Depends also on what you do with the car , weekend warrior every day driver ?
All my -6 have carbs but everyday driver CIS, especially early mornig leaving to work,
nice warm up, 3.2 with motronic even better.

I love carbs but get tired of rainy morning grouchy warm up.

[Howard]

QUOTE (startsw/p @ Mar 13 2005, 08:03 AM)

If I don't use the carbs I have a whole 'nuther engine to use in maybe a 550 kit... (IMG:http://www.914world.com/bbs2/html/emoticons/idea.gif)

Funny you should mention it. Club members alerted me to a Craig's list 2.7 on the cheap. Got that, a tail shifter, 911 front and 5 lug rear adapters and a bunch of other stuff as the guy was just cleaning up his garage. Got a nice looking CIS.

So the whole mess has been cleaned up and set aside for a 'someday' project. Would love to do a 904 or 718, but wonder if I will get to it in this life (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[Downunderman]

I would have said Webers until a few weeks ago. I completely rebuilt mine a few years ago and 25k km later they start popping and farting for no apparent reason. I suppose I should be grateful that it only took me a day to fix them. Turns out that the teflon throttle shaft bushings were worn which was what I suspected, but I had to eliminate everything else first. Now its pulling like a train again. I was lucky that the local Weber importer had the bushes or I was f....d. He told me that Weber went into liquidation about 5 months ago and spare will run out pretty soon. I think I might invest in some PMO's.

[startsw/p]

Is there not a larger throttle body for the CIS engine?
I'm leaning toward the CIS, as I drove a bone stock 1.7L '72 for years with no complaints.... loved the gas mileage, just had trouble getting out of its own way is all. That and does anybody fog their carbs when they store for the winter? CIS is a sealed system, so I guess you just run fuel stabilizer through it before parking.....