2.4/2.8 engine build advice needed

[TH71T]

Hello all, new to the forum and creating first post so appologies in advance for any transgression of the rules or asking a question thats been asked and answered. Recently aquired my first 911, a slick roof 71t with 470 appearance group and a non numbers matching 1972 2.4t engine.

Car is currently on a rotisserie while i repair the rust issues in the suspension pan and parcel shelf/rear seat area. My goal is to have a stock looking F body with a hotrod engine and fast road suspension for occasional road rally use.

The engine was rebuilt approximately 15k miles ago, and turns over by hand, but suffered water infiltration into the chokes due to the negligence of a mechanic during previous ownership. Ollies will be doing the machine work on the engine. EBS overhauling cylinders and supplying pistons and assembly parts.

What I have:

Existing engine
Case: 901.101.101.5r (will have reinforcments welded in mains, shuffle pinned, ect...)
SN: 6130023
Type: 911/51
Heads: 901.104.302.0R k1819n
Cam Towers: 901.105.111.0R
Hydraulic tensioner
11 blade fan
Cams: unknown (probably E)
SSI Heat exchangers

Parts I own for upgrade:

Heads: 901.101.342.2R (2.7S)
Cylinders: 90mm Mahle nickasil (used)
PMO 40mm EFI throttle bodies
Crank fire pully and VR sensor mount.
MS3 PRO engine managment computer.

It has been suggested to me that a great engine would be a 2.8 10.5 (92mm JE) twin plug EFI wasted spark. My questions are:

1. Camshaft recomendations. Want lots of torque and midrange for fast road use, but dont want an engine that goes flat too early on the top end.

2. Can i get away with a fender mounted oil cooler with this engine. I would prefer not to have a RS front bumper and oil cooler.

3. Any advice

Many Thanks

[Longballa]

You should be just fine with just a fender cooler but even better if you remove the passenger side battery box. Then you can install a fan for the cooler. Look to LN engineering for the 2.8 Malhe pistons and cylinders. Carillo can custom make the 92MM pistons also. You don't have to twin plug but it's a nice upgrade so you can go higher on the compression.

[TH71T]

Thanks for the advice. Im glad to hear that a fender cooler is probably sufficent. I plan to use Elephant Racing finned brass lines to supply and return the oil cooler. I suppose I could cut the box out and add a fan if I have issues. I did look at LN and know they make a great product. I would probably go all Mahle if I was building a track engine. Unfortunantly budget concerns have me leaning towards boring my 90mm to 92mm, replating, and custom JE pistons. I planned on twin plugging the heads regardless of what I built due to the relatively low cost of the machine work to do so. Since Im running a distributorless ignition anyway I was advised to go ahead and go 10.5 to 1, use both plugs, and up the displacement.

[Longballa]

I like the factory oil lines. Easier to fit and they're black. The finned lines won't lower the heat much. Cutting the battery box out adds the air flow you want. A fan makes all the sense in the world because when do you need cooling? In traffic on a hot day, right? I use a lot of Elephant products but the finned lines are large and ugly. I've painted them black and it's a pain. Go factory.

[TH71T]

Good to know. Will the factory lines fit outside of the rocker panels? Pardon my ignorance, this is my first 911. In fact its my first German car period. My history is with all maner of English cars. Hence my earlier camshaft question. I was told an E cam was great but ran out of steam at about 5500. I know that increasing compression and displacement will naturally add to the low end grunt and I can get a little more sporty with my cam selection. I dont want to do something stupid and select a lopey race cam that comes on at 5k. Im used to cars that blow up if you turn them much more than 5k.

[davep]

Existing engine non numbers matching 1972 2.4t engine
Case: 901.101.101.5r
SN: 6130023
Type: 911/51

Actually that is a 1973 2.4T engine serial and should have case halves 901.101.101.5R & 901.101.102.4R
6130023 is very early, my data suggests that the production engines started at 6130021, so this should be the third in the series.

[TH71T]

I will check the other case half to see if the engine is still original. If this case matches anyones car I will be more than happy to help reunite it with its chassis. All I would be interested in exchange is a case that is in similar shape to build my engine. The previous owner had a 20 plus year ownership history. Their recolection was that the car had come from California before making its way to the East coast.

[66S]

Boring 90mm cylinders to 92mm leaves a pretty thin wall on the inside of the head gasket and is not recommended. A lot of people do it anyway.

[TH71T]

Good to know. Im not interested in buying problems. If my cylinders are in spec, or can be reconditioned, im happy with running a stock 90mm bore and building a 2.7. Or for that matter if pistons are avaiable going to the first overbore size if that makes sense. Im not looking to get the last availabe horsepower out of the engine. What i really want is a nice torquey street engine that can withstand the miles. Thanks again for the advice. As you can imagine I have recieved a lot of conflicting advice over this. Basically everyting from leave it stock to build a 962 engine. The first I dont want, the second I cant afford. Trying to find the happy place in the middle of the two.

[Longballa]

If you buy new pistons and cylinders from LN Engineering the 92mm cylinders aren't thin. They're made new and aren't bored thin. Yes, the oil lines go on the out side of the car. You'll need to weld on the oil line brackets in 3 places for the screws to mount on the oil lines. A lot of people just screw right into the car body without the brackets but that's a cheese ball way to do it. 2.7L engine is a great engine to build but In my mind if you're buying new pistons and cylinders why not go 2.8L. That's the hot rod brain in my head. And, why not twin plug and run high compression pistons and why not short gears and so on and so on.......