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Registered
Join Date: Oct 2007
Location: Mountain Home, AR
Posts: 39
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Perfomance question on future 2.7 build
Hi Guys, Just bought a 1975 911S with a 2.7. I previously had a 951 with the Lindsey 300hp upgrades. I have always loved the look and "feel" of the 911, but am really missing the in your gut power of the 951!
I know that it is comparing apples to oranges, but here is my question, What is the easiest and least expensive way to rebuild my 2.7 to match the raw power of my old 951. I am not a rich guy, nor a technical genius, but willing to learn and get my hands dirty. I would enjoy the education an experience of building my own motor. Not above an engine swap if that is the best reccomendation, but sure would like to keep the 2.7. It seems to me that the 911 could match the 951 with a lot less than 300 hp (I am guessing). Is inexpensive an oxymoron for what I am wanting to do? I hate to ask newbie questions, and have spent days searching the archives, and the internet, and have been unable to find a comparison of the two as a starting point. ![]()
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1988 951 turbo S 1973 Fully restored Big Block Charger (show car 1 of 1) Had it since I was 16! 2003 Chevy Avalanche, Yellow Z71 2000 Toyota minivan |
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Registered
Join Date: Jul 2001
Location: Portland Oregon
Posts: 7,007
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Hi,
You will not be able to match the power of your 951 using the 2.7 unless you spend well north of $25K, and you'll wind up with a peaky motor with little or no power below 5000 RPM. 2.7's can make anywhere from 200-250 HP, but its not particularly cheap to get good reliable performance from these engines. I think your budget will determine what avenue you choose for improved performance,... ![]() ![]()
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Steve Weiner Rennsport Systems Portland Oregon (503) 244-0990 porsche@rennsportsystems.com www.rennsportsystems.com |
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Banned
Join Date: May 2005
Location: Earth
Posts: 31,744
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I am kind of in the same boat.
I am looking at having my 2.7 rebuilt soon. I have a mechanic, but have not asked him any particulars. I mentioned to him, I would like to build the rs spec engine, he said O.K. I would need cams, pistons and carbs. The whole reason I am getting into this rebuild is because I want the PMOs. My understanding is, it is silly to just put the carbs on a stock 2.7. As I do more research I am wondering if I can just get my cams reground to early S profile. I also am wondering if I can have my cylinders honed or bored out and just have to buy pistons. Maybe 2.8 if my cylinders can be bored? These are cost saving ideas and I don't know if they are possible or not. I don't mind buying the PMOs, because that is what I really want. I understand that I would need the different cams and pistons to make them work properly. Can I do these things? The engine was rebuilt at 130,000 with the original owner. I am the second owner and now the car has 130,000 on the rebuild. I only put a few thousand miles on the car per year. No track, only weekend hotrod stuff. It will probably be the last engine I have to put in this thing. I hope. What do you guys think? |
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120 HP/Liter is all I ask
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I would try to source a good 3.6 engine and do a conversion.
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Registered
Join Date: Nov 2007
Posts: 24
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I have a 75 911s, 130,000 miles on original engine. Just had it rebuilt.
2.9L p&c Web Cam 05-262 10.5-1 cr Twin plugged Electromotive Crank fire Ignition SSI'S PMO.S Dansk two in two out 287hp Most fun you can have not cheap but well worth it. ![]() |
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abit off center
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Mark,
What PMO's did you use?
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______________________ Craig G2Performance Twinplug, head work, case savers, rockers arms, etc. |
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Registered
Join Date: Nov 2007
Posts: 24
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40mm Pmo's, They have a tendency to run very rich. Rocket like acceleration.
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Banned
Join Date: May 2005
Location: Earth
Posts: 31,744
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looks good, but I don't know if I can spend that much.
How much did it cost? Approximately. |
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Registered
Join Date: Oct 2005
Location: Idaho
Posts: 2,356
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Mark -
That's a cool engine, did you build it yourself? I've got a '77 2.7 that I'd love to do something similar to. WOuld you be willing to share some expense info? Thanks, Tom
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'74 911 Red Sunroof Coupe, 3.6L, etc... '76 912 Yellow SPEC 911/911CUP |
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Registered
Join Date: Nov 2007
Posts: 24
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Thanks for the nice comments, the engine was built by Rob King at S-Car-Go in San Rafael CA. Lots of internal mods done by Ollies in LA. Parts and Labor---------$40,000. What can I say?, While your in There.
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Banned
Join Date: May 2005
Location: Earth
Posts: 31,744
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There goes that idea.
My budget could only build a third of that engine. |
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Join Date: Mar 1999
Location: Vancouver,Wa.
Posts: 4,457
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I have about 7K in my 2.7L.....kinda hard to pin it down exactly as I just rebuilt again last winter. I do good shoppin'.
![]() 10.5:1 Mahles, Solex cams, 40mm Webers, single plug on race gas. 225-230 hp @ 6200 & 215ish ft/lbs between 3800-5000. A nice tractable motor with no rocket science thrown in but a I did a couple things to get the torque where I wanted it. I was pleasently surprised by the dyno graph.
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JPIII Early Boxster |
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While nothing is cheap, I think a swap to a 3.0/3.2 would be your best bet $$ wise. Then sell your engine to recoup some costs.
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John Snodgrass 1973 Porsche 911 "Barney" (race car for sale) 2008 Nissan Maxima - Daily Driver 1999 F350 Diesel Crew Cab - Tow Beast 1990 Airstream 36' Land Yacht - Home Away From Home |
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Registered
Join Date: Oct 2005
Location: Idaho
Posts: 2,356
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Quote:
Tom
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'74 911 Red Sunroof Coupe, 3.6L, etc... '76 912 Yellow SPEC 911/911CUP |
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120 HP/Liter is all I ask
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Quote:
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