2.7 Rebuild.... Advice?
 

Hello Gents

I finally splashed out on a 1974 2.7 CIS engine (currently very ugly). I've read all of Wayne's book as well as B.A's. Assuming I have Alusil barrels and the CIS pistons (and that I keep them for the time being), what is my best bet for extracting some power?

On my list are S cams (BA recommends E cams). Can I use them with CIS pistons?. Webers, headers/sports exhaust (don't need heat here in Australia), and a dialed in distributor recurve. Will add hydraulic tensioners.

What else is a good idea?

Thanks

http://forums.pelicanparts.com/uploa...1068004609.jpg

That's great picture, John....to illustrate why *not* to paint the fan. They all look like that sooner or later.

Have good close look and see what the ham fisted morons did to get the motor out.... GAS AXE! They cut through the tinware and front mount :o

fishcop,
there's not enough clearance in the CIS pistons to clear S cams. If the engine is running ok then I might be tempted to run it as it is(with the new tensioners) and when the extra $$ is in hand swap pistons and cams and switch to webers.

Thanks Tim. I have a 2.0 in the car at the moment, so I won't bother putting it in the car until it's *right*. I have the webers, and a set of S cams, but you have cleared up my question on the P&Cs. Depending on whether I have Alusil or Nikasil, I will think about getting new pistons and rings right away (or should I re-use the current rings?). Do I have anything to gain from porting the heads whilst having the valves done at the shop?

I know there has been endless debate on the reuse of Alusil/rings and changing pistons, but until I pull the heads off I won't know what I have.

Thanks

Looks like they cut off the 14 pin connector and some of those pesky injector lines too. That's the first motor I've seen that was actually worse than the "mint" one PartWerks sent me once.
-Chris

Insert the head studs and helicoil the studs the studs in the case (but not the perimeter studs).

I just pulled three studs when I re-assembled my case, now I have to dis-assemble, heli-coil, and re-clean. :(

7R - German for two steps forward, one step back.

Yes Chris but did you notice the distributor cap looks really good!

Troy

Given that I was really only chasing the long block, I'm not too concerned with the bolt-ons or injection system. Incidently I've found that the distributor is brand new... I guess that's one good score.

I've found only one pulled stud, but I do intend to time-cert the case on the rebuild.

Fishcop,

Like everyone said, forget either the E or S cams with CIS pistons. It will never work. Totally inadequate valve to piston clearance. Hopefully you have Nikasil cylinders, but don't count on it.

If the 2.7 engine was running when it was removed, you might want to try the webers on the long block as it is for a little while. It's a fun combination and will be an improvement over the CIS. It will have a ton more torque than your 2.0, but will not quite come alive over 4K RPM, like the S-cam engine will. Cracking the long block is a big commitment. You can always go back and do the full rebuild when the CIS core is used up. That's what I did, and I'm glad I did.

Is your 2.7 from a 74-77 911S? If not, you will definitely want to port the heads, since the regular 74-77 911 heads have very small ports.

Thanks,

Thanks for the advice JP. The engine did not come from a running car (arrived in a crate ex-Japan). But the crank and pistons turn over fine. Preliminary compression figures indicate it's sound. The main problem is that it was obviously subject to weather whilst stored, and when I shine a torch into the valve area a couple of the exhaust and intale valves appear to have light corrosion. So I think I'll have to have the top end done no matter what. Given that I don't know if the case leaks or not, I thought it might be best to just "start from scratch" as my car is running well on the 2.0

The engine is from a 1974 Japan delivery, so I'm guessing I have the small ports.

Oh, I'm pretty sure it will ....

Is it from an "S"
 

Based on the color of the shroud, I don't think its an "S" engine. The "S" had a green shroud.

My $0.02.

Troy

I always thought "S" motors had red shrouds.... All the S motors I have seen are red.... maybe just the pre 2.7 liter shrouds are red????

I'm pretty sure that from 74 onwards, the colour of the shroud didn't tell you anything... I've measured my ports and I have the smallest made 30/33. Definitely need a head job.....

I think the "S is red, E is green" rule is only true up to '73. My '76 911S had a black shroud. What is the engine type number? 911/92 or 93? Might be hard to see with the AC comprssor still on. I thought all of the ROW 2.7 engines had the larger 35mm ports. Guess not.

I found an actual reference to my engine in Wayne's book (spec. sheets at the back). I think the quote is "sometimes found with 30/33 ports"... Well I found them! I think I've found an engine with the most-least desirable parts :D With Alusil cylinders, 30/33 ports, 8.0:1 compression ratio, and CIS injection this motor is screaming to be masculated!

Well, all I can say then is my 75 is an "S" and it has a green shroud.

Troy

my '77 911s Calif smogged had a green shroud......Ron

Definitely can use some work here. I would suggest:

- Replate and use 2.7 JEs
- S Cams
- Valve job (maybe slight enlargement of ports)
- Webers

-Wayne

Thanks Wayne, that's just what I intend to do. I'm just having a bit of trouble locating someone who can re-Nikasil barrels here in Australia.

Plating isn't cheap and I wouldn't plate the 2.7 Alusils cylinders unless they were like new. The cylinders tend to wear in an oval pattern. If they show wear I would bore them out to 92mm and then plate them and get a set of 92mm JE's to give you a 2.8L motor. Plating is about $1200 for the set and the pistons are $1000 for a total of about $2200. You might also consider a new set of 2.9L Mahle P+C's for a few hundred more.

The cheapest alternative is a new set of Mahle 2.7RS P+C's. You can pick these up for about $1400.

The cheapest alternative is a new set of Mahle 2.7RS P+C's. You can pick these up for about $1400.

DO IT JOHN! The exchange rate is your friend right now...

The 2.7 RS are forged, not cast pistons.......Ron

That's a good point Ron. Are the 2.7 Euro sets that are forsale these days from people like EBS forged like the original ones?

I can only imagine that they are.

I bought my 2.7 RS forged from EBS in '98 for about $1600US

I'm sure we can beat their price easily on any available piston and cylinder sets...

-Wayne

I've noticed a couple of sets on Ebay for around $1700 USD, is this good price, or can I do better?

You're right Cam, 71.43 today :p

You were too fast for me Wayne! Okay I'll test you... What can you do a set of RS P&Cs for?

Cheers

I'm having Tom check this right now...

-Wayne

I mentioned the info as a data point.. I always give PP the 1st shot at my parts, except the wierd ones. I didn't know PP existed in '98..
no dis-respect intended.......Ron

For the BBS, we can offer them on special for $1599. This is brand new, and applies only to the two sets that I have in stock. If you want them, then give Tom a call at 1-888-280-7799x221. This is a below-normal-margin thank you deal to people who have contributed to this forum. This is the forged, Mahle, 1973 911RS 2.7 Piston and Cylinder set.

-Wayne

John
What happened with the 2.4t uprated to S specs and Webers that was for sale? Did you get to look at or drive that motor. I believe that it still for sale.

I don't believe there was anything wrong with the 2.4, It was just that I found a complete 2.7 for half the asking price of the 2.4

ber911????

Wayne, thanks for getting back to me on the RS pistons. I will make some enquiries in relation to additional import costs. What do you think the shipping weight/price would be to Australia? I'd phone you but you lot are asleep when I'm awake!

Nope, I'm awake. I'm not sure of the shipping costs - where are you located? Probably about $100 or so - we won't ship this Internationally without insuring it...

-Wayne

John

I had a set of P&C DHL'd from California for slightly more than what Wayne quoted (US$128). They arrived in only a few days.

(disclosure: bought before Wayne started stocking the P&C - I would have bought from him, of course)

I was using the 2.7 RS 8.5:1 with stock CIS.
and not a problem with getting a good mixture and smog numbers were great.......Ron

John - Some encouragement for you: I dyno'd my new race motor on Wednesday, the base specs are:

2.7 litre 7R case - hpc coated
Carrera RS ports/valves (with some massaging) (36/38 I think?)
10.5:1 ARIAS pistons - short skirt, hpc coated
GE80 cams
Early heat exch's
Single big outlet monty exh
40mm Webers

Made 228hp basically untuned and running rich.

Now just have to sort out the MFI pump, finish the dual distr and connect up the second set of plugs...hoping for 250hp

Cheers - Ryan

ps: the GE80 cams are great - no probs at all driving on the street

Ryan

Your engine sounds quite similar to what I'm building:

7R case
S cams
Webers (34 venturis)
RS P&Cs (8.5:1)... or something similar
Early exhaust (with the heat exchangers removed)
Big Mili Miglia silencer (single out)
Heads are standard 2.7 with some mild porting

I'm chasing 200 (reliable) hp

What's the story with the HPC coatings and what sort of cost?