Most cost effective way to Increase performance in 76' 2.7 engine???

[casor]

Originally Posted by RoguePorsche

Hello Gang,

70' 911t/ 76 2.7l engine

did a compression test ;(

left
42 psi, 115psi, 90psi,
right
117 psi, 117 psi, 115 psi

…going to put oil in to the"42psi" cylinder to see if its pistons or valves.

PS: Car sitting for a long time, changed oil & spark plugs (spark plugs BLACK) hence us

doing a compression test.

ANY ADVICE on what to do next???

Thanx
R

Take it apart.

[RoguePorsche]

Originally Posted by casor

SSI's add a decent amount of thrust. I have these going into a 2 to 2 Dansk muffler on my SC. A little too loud for me but this helps the more efficient headers breath. Plus, you get rid of the heavy CAT and the header crossover which just adds heat and more back pressure. My 2.7 has SSI to a 2 in 1 out muffler arrangement which sounds better (quieter) but probably less performance.

One of my hot shoe mechanics - John Butz from CB, was mad at me for not installing the alum pressure plate on the clutch. $871 from our host but you lose about 5-6 pounds exactly where you need to and the eng will spin up faster. I was too cheap.

There are alot ways to trim weight off the engine. You can hack off the bosses on the intake runners that aren't used. You can use alum and ti fasteners all over the place, alum fan strap, hole the aft eng mount, make a lighter bellcrank plate, use alum rod for the throttle pushrods, a lighter cooling shroud etc etc.

Unless you want to spend alot of money, the exhaust will give you the most bang. But you must do the Raceware studs and the case counter bore and Time Certs otherwise they will pull out.

thanx casor!

[RoguePorsche]

This is my 1970 911/ 2.7L conv. project

[casor]

Rogue - I wasn't really kidding before about the eng. I would not bother with a leak down or whatever. The numbers say take it apart. Plus you have to do the Racewares/counterbore on a mag eng anyway. A must.

I also see that you need the fan w/ more blades. There's a guy that restores the fans and rings but I had mine glass beaded and I painted this stuff with epoxy.

It all depends how far you want to go and how much you want to spend. I want something reliable and that looks nice when I open the lid. For you to get there on what I see just with the eng, if you have somebody else do the rebuild, you're looking at $15K these days and that may even be optimistic.
Rob

[casor]

I'd '86 the smog pump pulley also....

[RoguePorsche]

Originally Posted by casor

Rogue - I wasn't really kidding before about the eng. I would not bother with a leak down or whatever. The numbers say take it apart. Plus you have to do the Racewares/counterbore on a mag eng anyway. A must.

I also see that you need the fan w/ more blades. There's a guy that restores the fans and rings but I had mine glass beaded and I painted this stuff with epoxy.

It all depends how far you want to go and how much you want to spend. I want something reliable and that looks nice when I open the lid. For you to get there on what I see just with the eng, if you have somebody else do the rebuild, you're looking at $15K these days and that may even be optimistic.
Rob

MY GOAL IS TOO GET HER STRAIGHT AS A DAILY DRIVER & SELL.

My friend who is a decent mechanic says its the valves. He did the "oil in piston test". Im going to take her in to get a look. Anyone know of a good porsche mechanic with "Valves"??? In Los Angeles??

"do the Racewares/counterbore on a mag eng anyway"
…will do on the smog pump

This means?? sorry I'm a newbie

Thanx Casor

[casor]

How many miles on this thing? Do you know the history by chance.

If you have a magnesium case engine - this means the "engine block", where the crankshaft is - then you run the risk of one or more of the 24 head studs pulling out of the magnesium because it's a bad material for this application, previous overheating, and just plain age. You can see the silver head studs in the attd pic on my recently rebuilt engine - they are exposed to the elements. On top of all this, the older "dilavar" would tend to rust and fracture if they were scratched or old. If you have dilavars, you have to get rid of them anyway.

To greatly reduce the chance of the new head studs from pulling out of the magnesium, the engine case has to be bored where each one of the threaded holes are that anchor the studs. Then a thing called a "Time Cert" is threaded in ea hole and the new studs thread into that. The TC's greatly increase the surface area in the magnesium case that the studs are pulling against, thus greatly reducing the chance of them pulling out when the six cylinder heads are torqued down by the 24 head studs.

So, the point is that the cam towers, heads and cylinders have to come off do all this. You have to already take the heads off to do the valves, so you are not that far away. You don't need to disassemble the entire engine block - only all the stuff down to it. I recently had all this done and it's expensive. The new studs, nuts and washers are almost $1K alone - plus the labor

[casor]

Rogue - I read your post again and you said you want to fix it up and sell. I hope you got this thing cheap. Just to open up the engine is $3-4k in labor. And nobody who knows anything (ex me!) is going to buy it w/o the above mentioned work being done. And the above assumes you are going to pull the engine, pull off and pile on all the crap on top and then stick it all back in. And then if you don't do anything with the stuff on top, the thing will still look like hell. Bad for marketing.

See my rebuild at link below

2.7 Engine Rebuild

[Dpmulvan]

Your a newbie and own three 911's ??

[casor]

Originally Posted by Dpmulvan

Your a newbie and own three 911's ??

Ha ha - no, I'm not a newbie! It all started in HS when my friend and I used to steal his dad's red 356 coupe which didn't have a single pc of straight sheet metal on it and never ran until we got it going ea time. I have owned 911's since '92, mostly aircooled, one watercooled. Have two 911's now, the other Porsche is a Cayman S. Plus all the motorcycles....I'm a glutton for punishment.

[E Sully]

Originally Posted by casor

One of my hot shoe mechanics - John Butz from CB, was mad at me for not installing the alum pressure plate on the clutch. $871 from our host but you lose about 5-6 pounds exactly where you need to and the eng will spin up faster. I was too cheap.

Unless you want to spend alot of money, the exhaust will give you the most bang. But you must do the Raceware studs and the case counter bore and Time Certs otherwise they will pull out.

I have read quite a few threads where the owners find the aluminum plate makes the car difficult to drive in everyday street driving. Good for track, not so much for regular street.
I have also read case savers work better than time certs.
Best bank for buck is probably getting rid of smog equipment, 11 blade fan, case savers for studs, back date exhaust with SSI's, valves and guides if needed.

[RoguePorsche]

Originally Posted by casor

Rogue - I read your post again and you said you want to fix it up and sell. I hope you got this thing cheap. Just to open up the engine is $3-4k in labor. And nobody who knows anything (ex me!) is going to buy it w/o the above mentioned work being done. And the above assumes you are going to pull the engine, pull off and pile on all the crap on top and then stick it all back in. And then if you don't do anything with the stuff on top, the thing will still look like hell. Bad for marketing.

See my rebuild at link below

2.7 Engine Rebuild

Thanx casor! appreciate your help

I own now 6 911 widebodys

I learn better when I'm hands on

[RoguePorsche]

Originally Posted by E Sully

I have read quite a few threads where the owners find the aluminum plate makes the car difficult to drive in everyday street driving. Good for track, not so much for regular street.
I have also read case savers work better than time certs.
Best bank for buck is probably getting rid of smog equipment, 11 blade fan, case savers for studs, back date exhaust with SSI's, valves and guides if needed.

good info Sully

how much $$ we talking here???

[casor]

Sully is probably right with the drivability issues on a car w/ a lightened pressure plate - w/o the spinning mass, you have to rev the hell out of it and dump the clutch in to get it moving. And then the revs increase and fall off quickly. Same issue with a lightened flywheel.

I do remember BMW twins m/c guys using lightened stuff, but only with the centers lightened and careful additional lightening around the perimeter - all this to reduce the "clutch dump" issue. This was usually done to the flywheel only. From having both vehicles in my shop and from having done clutches on each, it is easy to see that the clutch set ups on the old 911/BMW twins are almost identical.

Still, they are different animals with different power curves - the 911's like to rev, the BMW's, no so much.

If it were up to me since I am so cheap, I would keep it simple and predictable. Just the lighter starter probably took off 3-4 lbs and if it doesn't work, it's easy to replace with the orig.

Rob

[E Sully]

Price would depend on a few factors. Parts you can look up on Pelican. Labor you would have to ask the shop that is doing the work. I take everything apart, clean, and assembly myself, so if you are paying someone else costs go up quite a bit. I only pay for the machine work and parts.
Things like a good used 11 blade fan can be $2-300. Used SSI's can save a few bucks over new. I always buy new exhaust valves, but will re-use intake if measured in spec. I bought new rings, but was lucky to have good Nikasil and not Alusil cylinders.

[JOHN21BLACK]

J&E PISTONS 9:5.1
964 GRIND ON CAMS SET 1.26
PORT & POLISHED HEADS 40IN./32EX.
TALL PMO MANIFOLDS MATCH PORT TO HEADS
40TIN ZENITH CARBS LARGER VENTURIS
3 ANGLE VALVE GRIND
FIDANZA HIGH PERFORMANCE ALUMINUM FLYWHEEL
SACHS HIGH PERFORMANCE ALUMINUM PRESSURE PLATE
BACK DATED SSI STYLE EXHAUST HEADERS
M&K MUFFLER
MSD IGNITION
FRONT 9 ROW OIL COOLER
CASE SAVERS
7:31 R&P IN 915 TRANS


I would call Henry Schmidt at Supertec Performance in Fallbrook, CA.