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Most cost effective way to Increase performance in 76' 2.7 engine???
Hello Group
Thanx |
SSI headers/heat changers made a noticeable difference on my 1977 2.7.
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Cost efficiency
This is increased performance
80 3.0, 9.3/1 CR, easy 200 horses with more available. A couple more hours work needs to be done to finish http://forums.pelicanparts.com/uploa...1439147807.jpg 86 3.2 9.5 CR easy 230 HP with chip. Several more hours work to fine finish http://forums.pelicanparts.com/uploa...1439148007.jpg |
Backdated SSI exhaust,
CIS S camshafts if you have the standard camshafts. Left 911 105 143 00 Right 911 105 144 00 Plus the usual tune up, distributor check, CIS air leak, and fuel pressure checks. |
I'm interested too, I have a set of SC grind 3-bearing cams that I heard make a difference w/o messing with Ps & Cs.
My car is a 914 conversion that I'll run headers on (/6 HEs are too $$ for me to afford), but in a 911 the SSI backdated HEs should help produce the same results with heat. I'll probably end up having my engine guy take a look and give his 2-cents if it's a cam-swap or a full redo needed. If I do a full rebuild, I'll post up my cams for sale...but I have no ETA on when he'll get it in for a look. |
It's been mentioned here before so I'll throw it out there. The easiest and most effective way to get more out of your engine is to lose weight.
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Left 911 105 143 00 Right 911 105 144 00 this means??? newbie here sorry |
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weights in check! LOL |
RoguePorsche:
Esully provided you with the Porsche part numbers for the left/right S cams. I have a '75 with a almost-freshly rebuilt 2.7 in S trim, SSI's, well-tuned ignition and CIS, and some weight stripped out of the car. It revs great and I'm not wanting for power. (Maybe I don't know what I'm missing, but this config is more than enough engine to get into lots of trouble.) |
Your car may already be the S spec engine. I think they only offered that version in 1976.
Interesting that the 1974 S was rated at 175 hp, and the 1976 was 165 hp. I'm not sure what was done to detune the engine. There is an ID number on the engine, 911/xx, by the right side of the fan. Can you post yours? |
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Funny! I believe when he said to loose weight, he meant the car.
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While there are only so many horses on the table upgrading internals and it gets $pendy very quickly, there are plenty of threads here of users putting their cars on a diet, some losing quite a bit for free. I think the sound deadening in the tub and engine bay alone is close to 30 pounds. It gets harder as you start looking at lighter components like carbon fiber panels. Then there's the folks who like to drill out parts. I'm just pointing out, there certainly are some economical ways to increase your power/weight ratio by putting your car on a diet. |
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….would to hear your list on lowering cars weight thanx R |
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if doing a rebuild/refresh on a 2.7, is it difficult to bump up the displacement to 2.8/2.9/3.0 litres? is it a case of chucking in new pistons/barrels?
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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 |
If the engine has not been running lately, it is hard to tell from a compression test what is wrong. Rings could be sticking, carbon could prevent the valves from sealing. I would say the minimum should be 125 psi. A leak down test could give you a better idea of where the problem is.
With a leak down test, if you hear air coming from the intake or exhaust, then you know the valves are not sealing. If you hear air in the case, the rings are not sealing. Black plugs could be oil leaking past the valve guides or rings, or rich mixture. Worn valve guides won't show from a compression or leak down test. Mid year cars also had a problem with head studs pulling from running hot for emissions during that time period. Have you checked the torque on the head stud nuts? |
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. |
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This is my 1970 911/ 2.7L conv. project
http://img.auctiva.com/imgdata/1/6/3...51832469_o.jpg http://img.auctiva.com/imgdata/1/6/3...51832479_o.jpg http://img.auctiva.com/imgdata/1/6/3...51832486_o.jpg |
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 |
I'd '86 the smog pump pulley also....
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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 |
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 laborhttp://forums.pelicanparts.com/uploa...1440212526.jpg |
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 http://forums.pelicanparts.com/911-engine-rebuilding-forum/879894-2-7-engine-rebuild.html |
Your a newbie and own three 911's ??
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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. |
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Thanx casor! appreciate your help I own now 6 911 widebodys :) I learn better when I'm hands on |
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good info Sully how much $$ we talking here??? |
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 |
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. |
My fresh rebuilt 1976 2.7 195hp
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 http://forums.pelicanparts.com/uploa...1442022738.jpg http://forums.pelicanparts.com/uploa...1442022771.jpg http://forums.pelicanparts.com/uploa...1442022815.jpg I would call Henry Schmidt at Supertec Performance in Fallbrook, CA. |
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