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Registered User
Join Date: Dec 2012
Posts: 31
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Budget help: 2.7 7R Engine rebuild
I'm about to start a rebuild of a 1974 2.7L S (7R) engine that I picked up complete recently. The decisions I make on parts will make a massive difference in budget, so that where I could do with some help.
It was already out of the car, so the only real test I could do was a cold leakdown test. All cylinders were around 10psi loss. I don't know how accurate the equipment is, but at least wear is similar across all cylinders. It's going into a 1971 911. It will be used mostly as a fun road car, with a few track days thrown in. I've definitely decided that CIS will be swapped out for carbies. Everything else I could use some help with. There are no emission concerns where I am. And no cold weather. The stock 2.7 S heads are currently: valve (46 intake / 40 exhaust) & ports (35/35). What would you recommend as a well matched combination? I've read Bruce Anderson, but he doesn't really take larger capacity into consideration for the 2.7CIS. Option 1 (increase capacity to 2.86L engine) Pistons & Cylinders = 93mm Nickies 9.5:1 Camshafts = maybe S or GE40 Heads = what valve/port work would be required? Swap heads out? Option 2 (2.7L engine) P & C = 90mm Nickies 9.5:1 Camshafts = ? Heads = should I stick with stock valve/ports? Option 3 Surprise me? Thanks everyone. Looking forward to hearing some suggestions. Last edited by kinsja; 11-01-2016 at 10:49 PM.. |
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abides.
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Are your cylinders shot? Why not stock cylinders and J&E pistons?
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Graham 1984 Carrera Targa |
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Registered User
Join Date: Dec 2012
Posts: 31
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Registered
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There are lots of options but none of them are very kind to budgets. Anything been done to the case like time serts on the head studs? Your quest for reliability and power on a budget may start with a 3.0 with an aluminum block.
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72 911T 2.4 MFI 2017 Escape SE 2.0 turbo 2020 Honda Civic Touring Sport 1.6 turbo 10' Madone 5.2/17' Lynskey ProCross |
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Registered
Join Date: Jul 2001
Location: Portland Oregon
Posts: 7,007
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How long do you expect your engine to last?
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Steve Weiner Rennsport Systems Portland Oregon (503) 244-0990 porsche@rennsportsystems.com www.rennsportsystems.com |
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Registered User
Join Date: Dec 2012
Posts: 31
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Hi Steve, it's not a forever engine. I just want something fun for a few years. Once it's installed in my car I will be able to do a rebuild on the matching numbers engine I've removed.
So, it's going to be a value for money build rather than lifetime build. That's what I'm thinking at this stage. |
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Registered
Join Date: Dec 2014
Posts: 13,840
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Sell it and buy a 3.0
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Under the radar
Join Date: May 2007
Location: Fortuna, CA. On the Lost Coast near the Emerald Triangle
Posts: 7,129
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I would be temped to put carbs on it and see how it runs.
OR Pull the heads, inspect the cylinders, check for case savers, and do a valve job. OR Do a complete disassembly, have the cases repaired for $$$$, hope the crank is good, spend $4000 on 93mm P&C, $1000 on cams and have a great motor. Yea, I would love to have a 2,9, twin plugged rocket, but I decided to buy a 3,0 and start there.
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Gordon ___________________________________ '71 911 Coupe 3,0L outlawed #56 PCA Redwood Region, GGR, NASA, Speed SF Trackrash's Garage :: My Garage |
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