2.7RS pecs what do I need.
 

I have a 2.4t WITH 7R case and would like to make a good street and track engine out of it. What will I need to make it into a 2.7RS spec engine with a 9.1 comp. or so. Help please. Would like to have it ready for next summer.

My winter project as well. Are you staying with MFI, wyno?

NO. I am running Webers now. And are planning on keeping them on. What do you think?

I think you'll spend a lot to convert to MFI, so it's probably not worth it. I have MFI and I'll stay with it. I'm still learning all about this but I think other things you'll need are a number of case mods (oil pump, oil bypass, bore out the spigots for 2.7 p&c's, shuffle pinning ,etc.), 2.7RS p&c's (either Mahle's or you can go with other brands such as JE's), S cams, port the heads (36mm?)...I'm sure there's more to it but that's what I can recall off the top of my head.

Wyno, I'm doing the same project with MFI. Just completed disassembly of the engine and will begin sending stuff out for machine work in the next month or so. There's a couple of good threads to start with. Begin by searching "2.4 2.7" and throw in a few other terms as you see fit. Is your 7R the 2.4 mag or a 2.7 aluminum?

Im just finishing up on my engine as well. It's the 7R mag. caes, I did not know there was two kinds of 7R cases. Which do you have?

wyno, if you search with the button in the upper right for "2.7RS" in the engine rebuilding forum, you will get lots of information.

What you really should do though, is get Wayne's book, How to rebuild and modify porsche 911 engines. it is available here on pelican. It will show you everything you need.

I have the 2.4 7R mag case, which was available in late 73. The 2.7's had an aluminum 7R case.

Definitely get Wayne's engine book. There' just so much info out there, and Wayne's book is a good spring board with lots of great info.

Uhhh -- no. The 2.7's 7R case was mag also. I believe that it was the Carrera 3.0 and the early 930's that used an aluminum case.

John, you're right. I misread the BA book. Oops!

Yup. Already have most of the the books out there. I just need to know what stuff I will need to get them soon, so when the part return from the shop I will be ready to go. I can't wait to get started.

Wyno, have you already looked into places for the case and head work, cam regrind, pistons, etc? Have you already worked through piston to valve clearances for the higher compression pistons? Are you going to upgrade oil pumps? Have you already sourced your cylinders? Decided on what machine waork you are going to do? Where exactly are you at in the process? It would be easier for people to offer their advice if there was more of a specific starting point.

I will be getting case saver put in and shuffle pinning along with the stuff need for the RS spec and will be getting my heads port and polished and having the RS spec valve size done to it. but everything else is up in the air. Have not found a place to get the RS C/P at. Any ideas were I can get them at a good deal. The Webers have been done six month ago.

EBS has JE pistons with re-nikasilled cylinders. Talk to Jon over there who's a very helpful guy. I believe there are a bunch of other places that offer similar products. Hopefully others with experience will chime in. As far as the shuffle pinning goes, I've been told that there's no need to do it unless you're over 250hp. I don't know what the consensus is on this, though.

The RS valve size is just like all of the others: 46/40. Are you talking about RSR valves?

Jon at EBS uses time serts exclusively. There's a lot of back and forth on the board on case savers v. time serts, so I don't know. It's going to be he!! when I actually have to commit to some of these decisions since there's so many options.

Sorry, I meant porting the heads to RS specs.

I have just completed a 2.7 RS engine that began with a 2.7CIS base. Basically a lot of easy machining will get you where you want to be. Heads need to be ported to 36mm (don't forget manifolds), cam shafts reground to S, RS P&C, case needs time-certs & updated bypass and a carrera oil pump if you can manage it, in your case the spigots need to come out to 2.7 size. I don't think you need to shuffle pin (I didn't), but others might have an opinion on that. Remember to factor in a potential problem with mag cases in relation to warpage... this will require align boring and oversize bearings.

You'll also need to re-jet carbies and go to 34 venturies.

I got my RS P&C from Pelican for $1499 on special... this turned out to be a very good price for genuine Mahle RS pots and plugs... perhaps they have another set. The think to remember with the genuine RS P&C was that compression was only 8.5:1 but you can bump this using a variety of methods.

Fishcop, did you go to a higher compression? If so what route did you take--shaving the heads or off-center boring the rod bushings? I was going to buy the high compression JE's, but if I could get Mahles at that price, I'd jump on it! When did you buy those from PP?

ok then wyno, I will change my recommendation to reading wayne's book ;) It really does have a lot of information about what you will need. If you have specific questions not covered by the book, lots of people will certainly be happy to help!

Bill, I got the P&Cs from Pelican in January this year. Because of the standard machining required to clean the case up, the spigot surfaces were fly-cut as a matter of corse about .25 of a millimeter, so when rebuilding I simply did not "add" any extra copper gaskets. But you must carefully check deck-height as per Waynes book. I'm guessing that this bumped compression up to around 9:1.

Have you found the S cams yet??

Camgrinder, I'm starting with T cams and having them welded and reground to S-spec. Any thoughts on this?

Hi Bill,
Its a fine process.
I was curious since I have an extra set of original cams.
I will just list them on ebay :)

Can I safely assume that the originals cost more than a cam regrind? ;)

That depends on the price of welding and regrind.
And who has the original cams for sale.

Well, it sounds like you may be the place for both! Elgin was on my list of cam experts to call. If you can, shoot me an email on prices for both the weld and regrind route and the original cams. As with most people, budget dictates the route I typically go.