Advice on engine to use for 2.7L RS rebuild

[ckissick]

I have a 1970 911E with a 1974 911 2.7L engine. I'd like to create a 2.7L RS-spec engine. My current engine would be a good candidate, but it runs fine, and I'd like to be able to drive my car during the rebuild. My plan would be to buy a blown engine for cheap, and build a new one while still driving my car. Why buy a running engine for more money, if I'm going to take it apart and replace parts, anyway? After the rebuild, I'd make the switch and sell my current engine.

What would be the best engine for such a project? Or if not the best, what years and displacements would be a good starting point? Should I avoid the mid-70's engines with the case stud problems, or do the case-savers do the job? Also, should I not use my 901 tranny?

Charlie

[Bobboloo]

This is a tough one.

The cheap blown motors often turn out to be the most expensive ones, unless your in the parts business, buyer beware.

Building up a 2.7RS from a blown motor can get really expensive. The machine work needed to bring back a blown 2.7 can get out of control real fast.

It's seems to me that your 74' 2.7 is one of the better starting points for a 2.7RS because it didn't spend most of it's life being cooked by thermal reactors like the 75' to 77' motors did. To me the smarting money would be building on your present motor than starting with a 75' to 77' motor.

Probably the best starting point, however, would be a good 73'S motor with a 7R case. You would have virtually everything you need minus P+C's, MFI space cam and 97mm spigots. The buy in would be higher but you would probably come out ahead compared to the cost of trying to build a 2.7RS from a 2.7CIS motor.

I'm building a 2.8RS motor ground up from a 74' 7R case, 2.4 donor motor,S MFI and JE pistons. I'm not sure that it'll be the best route when I tally up the end costs though.

As far as the 901 is concerned it should have no trouble handling the power. I think you should go for the tranny with the shift pattern you prefer be it dogleg or H.

[ckissick]

Thanks, Bobboloo;

My engine would be a good starting point, but with two small kids and everything else going on it will take me a long time to rebuild. My engine already has Webers, which I'd use on the new motor. I want to do the work myself, as I love that sort of thing. But it may take up to a year. I'll probably also buy parts as pay checks come in. I have family connections that allow me to buy parts wholesale, so I'm lucky there. I could buy a working engine to put in my car during the rebuild then take it back out when I'm done.

What about earlier, smaller engines, if I can't find a nice 7R? Anyone?

Charlie

[Chuck Miller]

Charlie,

Unfortunately the early case you want (the 'late/early' 2 liter sand-cast aluminum case) is MUCH harder to find and MORE expensive than the 7R case you already have…

Just tried finding one for our own Membership/Boutique Chairman Mike Hammond for his 67-S rebuild with almost no results…

That case is THE case du jour for most under 3 liter build ups…

Sorry Charlie,

[rst73]

You might want to try Ollie's in Santa Ana 714 558-7334, George
sometimes has spare engine cases ready to go. Give him a call.

All the best!

Roger Grago
R Gruppe #27
73 RS-T
70 2.4 MFI VW Bus