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Nobody
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me got dumb question: how to determine if a case is good?
looks like i am moving forward on a deal for a serial number 68S mag case. engine was dissembled and the case is not being re-used by the current owner cause he wanted to replace with more "correct" 67S case for, well...his 67S. story is solid and i have no reason to not believe him...thus far solid guy.
anyhow, what are some things i need to examine or clarify? he is willing to send me pics of any area i request and answer any questions to the best of his ability. thanks in advance! |
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Licensed User
Join Date: Feb 2003
Location: ....down Highway 61
Posts: 6,505
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I dont know if this will help or not, but I had everything that was even remotely questionable on my engine checked out by a good machine shop. I would never trust myself to make a decision on something like how straight a mag case was.
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Author of "101 Projects"
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Get a copy of the Engine Rebuild Book. In there, I explain why this case is very undesireable and will cost $$$ to bring it back into spec.
Briefly, the intermediate shaft ran in an aluminum channel in the early Al cases. When they went to Mag, they kept that design, but the case material isn't strong enough to support it. Basically, nearly 100% of these cases become egg-shaped in this area and need to be machined to accept the later-style bearings that they installing in 1970 to fix the problem. This applies to the 1969 mag cases, and the late 1968 mag cases. Unless the serial number of this case is *the* one for your engine, then it won't matter if you use a 68 or a 70, or a 67. The key for numbers matching is to have the numbers match - the year matching is not really a good 2nd place, particularly when these cases were a bit troublesome... -Wayne
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Wayne R. Dempsey, Founder, Pelican Parts Inc., and Author of: 101 Projects for Your BMW 3-Series • 101 Projects for Your Porsche 911 • How to Rebuild & Modify Porsche 911 Engines • 101 Projects for Your Porsche Boxster & Cayman • 101 Projects for Your Porsche 996 / 997 • SPEED READ: Porsche 911 Check out our new site: Dempsey Motorsports |
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Registered
Join Date: Mar 2004
Location: City of Seattle, WA
Posts: 3,374
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So really bob, you should go with a replica 3.0 RS MFI motor instead.
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Andy |
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Author of "101 Projects"
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Quote:
![]() -Wayne
__________________
Wayne R. Dempsey, Founder, Pelican Parts Inc., and Author of: 101 Projects for Your BMW 3-Series • 101 Projects for Your Porsche 911 • How to Rebuild & Modify Porsche 911 Engines • 101 Projects for Your Porsche Boxster & Cayman • 101 Projects for Your Porsche 996 / 997 • SPEED READ: Porsche 911 Check out our new site: Dempsey Motorsports |
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Nobody
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thanks for the replies. actually i have both your books wayne. just hadn't read that section until tonight. an additional $750 for machine work would be expensive. i was not aware of this necessary upgrade. gonna have to take that into consideration.
my plan is/was to build a 2.2S, a cult classic, from the 2.0 68S case. thought it would be unique to have a serial number 68S (although non-matching) in my 68L. sort of a T/R car of sorts like the 68 T/R autofarm car recently featured in octane which also has a 68S engine. the seller is going to take pics for me so maybe this expensive machine work has been done from a previous rebuild. probably should mention that my car currently has a carbed 2.2T. looking at your top engine picks wayne - maybe the build the 2.2 S spec engine you mention. |
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Author of "101 Projects"
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A 2.7RS spec engine with higher compression pistons is probably the most powerful engine you can build out of that case economically. In other words, all the rebuilds will cost the same, why not maximize your power?
-Wayne
__________________
Wayne R. Dempsey, Founder, Pelican Parts Inc., and Author of: 101 Projects for Your BMW 3-Series • 101 Projects for Your Porsche 911 • How to Rebuild & Modify Porsche 911 Engines • 101 Projects for Your Porsche Boxster & Cayman • 101 Projects for Your Porsche 996 / 997 • SPEED READ: Porsche 911 Check out our new site: Dempsey Motorsports |
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Nobody
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damn it wayne - that makes sense. why would you go and do that to me
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Registered
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Really you should go with the biggest MFI motor you can build
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Registered
Join Date: Mar 2004
Location: City of Seattle, WA
Posts: 3,374
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For Example, supertec 3.5:
![]() we're here to help, bob, really ![]()
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Andy |
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Nobody
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oh man andy...if only my pockets were deep. that engine would be the path to divorce
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Registered
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Everyone who races 2.0s this side of the pond says that the aluminium cases are the ones to go for.
I am just about to reassemble a mag-cased 68S that only needed big end shells and a timsert for the gearbox bolt. Everything else was perfect and the cases had never been split before (the odo shows 83,000 Km). I will also have a complete 67S motor for sale next month if that's of any use. |
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Nobody
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thanks for the input nick!
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Nobody
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the seller sent pics:
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Registered
Join Date: Mar 2004
Location: City of Seattle, WA
Posts: 3,374
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Quote:
It's all about ... balance ![]()
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Andy |
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Author of "101 Projects"
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Are those bearing shells in the case? Looks sortof like it to me (on the Intermediate shaft). If so, the update has been already done (a good sign).
-Wayne
__________________
Wayne R. Dempsey, Founder, Pelican Parts Inc., and Author of: 101 Projects for Your BMW 3-Series • 101 Projects for Your Porsche 911 • How to Rebuild & Modify Porsche 911 Engines • 101 Projects for Your Porsche Boxster & Cayman • 101 Projects for Your Porsche 996 / 997 • SPEED READ: Porsche 911 Check out our new site: Dempsey Motorsports |
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Nobody
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thanks wayne - time to start collecting parts!
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