"The best engine core" for a trackday car ?

[teveo]

OK, I searched the forums well, and found no clear answers..

I just wonder what is considered the best core for building a reliable 250-270 HP engine?

Looking for a better engine for my 74 Carrera, even though this car has a good running 2.7 (stock motor) but we want MORE!

Would be happy to hear from anyone with advice or knowledge, I have time to do this right and would like to get a good start.

This one is being retired.. -->>

[Craig 930 RS]

3.2 Motronics routinely get 213 RWHP with minor mods - go with that.
Right at 250 FWHP

[JeremyD]

Or look at the 3.6 that is in Jacks Car - BBII - lots of track miles - reliable.

of course I can't argue with a nicely done 3.2/3.4 - and they tend to be easier to mate up to a 915...

[azasadny]

I would go for this! Shipping would be pretty expensive, though...

Porsche 1981 911 Sc Engine 3.0

[teveo]

Originally posted by azasadny
I would go for this! Shipping would be pretty expensive, though...
Porsche 1981 911 Sc Engine 3.0

Yes, thanks, I actually looked very close at this one when it was posted,.. seems like this engine is clean, however I am looking for more displacement, bigger is better! 3.4 .. or 3.6 is interesting.

No worry about the distance, we do trans atlantic logistics (& systems), anything than can be shipped to NJ is close .. from there it is a free-ride into my garage.

I haven't built an engine for some years now, and just building it this coming winter would be half the fun. Have no 911 engine experience,.. but VW's, Porsche 356, V8's, various european engines, ..old jag's and a few motorcycle engines.

[PorscheGuy79]

I think a cheap 3.2 in need of a rebuild, then bump it up to a 3.4 with a bit more compression, ITBs with big air cleaners, some headers... I mean if price is no object that would be fun.

But then again, Matteo brought all new meaning to the word's "Price is no object".

- 3.9L CMW P&C
- Bore case to 109mm
- new head gaskets
- ARP rod bolts
- solid rockers
- Valve job (regrind intake and exhaust seats)
- new valve guides
- CMW 52mm in valves
- CMW 43mm ex valves
- CMW Chromolly drilled retainers
- CNC port heads to 45mm
- Jenvey 51mm tapered to 45mm Individual Throttle Bodies
- Jenvey horns, fuel rail, linkage etc
- DC62 Dougherty Racing cams
- Motec M600 ECU


The idea was to have a fun, happy revving engine with a decent torque and a good throttle response...

The 3.9L capacity should provide for a nice torque base... and the ITBs, Motec and cams should make it fun above 5,000 rpm.
The goal is to get 400HP at the flywheel.
All the components have been ordered...

3.9 RSR project --- my Carrera reborn

[Steve Marshall]

Cory Jump at Planet 911 in Oklahoma City has a very nice bone stock 3.0L Euro SC motor to sell. I think he wants around $ 6k for it.

I've got a 74 Carrera with a Euro SC motor and it it a blast to drive. Plus, if you ever decide to club race the car it will be a very competitive F class stock, whereas all the other hot rod motors will put you in an uncompetitive GT class.

[randywebb]

It all depends on the rules...

I'd grab a 3.2 if it was ok (in fact I did) - the heads flow well.

[Steve Marshall]

It also depends on how much money, effort and complication you want to get into.

[89911]

I've been involved in two rebuilds for track cars. Mine was originally a 3.2. I went with 3.4 p/c's, cam, and twin plugging. Theres more, but I'm being brief. My brother went with euro 3.2, and a cam and pretty much left every thing the same. His was much cheaper and at the last dyno it was putting 225 at the wheels. That is just about 260hp with the conversion. A lot of power with just going with higher compression pistons and a more aggresive cam. Both of our cars have been solid engines and take as much abuse as we can give them.

[Chuck Moreland]

All depends on what you want.

You have a nice lightweight 7R case. That motor in simple 2.7 "S" trim will probably pump out 240 hp, and close to 300 if you make it a screamer.

I opted to build a 2.7 for my 73 because I like the charactor of a peaky "S" engine. I like the rush of it coming on cam, the responsiveness and the sound of the independant throttle bodies. And it made for favorable racing classification.

[teveo]

Yes, I was playing with the idea of making it like an RS engine, I havent read up on this,.. so I dont really know what is neccessary..

We dont have much clubracing, so i dont have to adapt to many rules.. however we have a very nice track 35 km away, it was just chosen to be Norways "national racing facility" so in the future things get better an better..

Have to stick to open trackdays (and fast cornering at nighttime, all with a focus on safety )!

In my other 74, a Targa, the 2.7 pulls very well, the car is lightweight and I like the engine characteristics.. but the Carrera coupe needs something that keeps me in front from 0 to 100 (km/h) even when a hormone treated 3 litre Japanese challenge..

Trond

[Steve@Rennsport]

Trond:

FWIW,......a 2.8 litre, twin-plug, S-cammed motor with all the right stuff & close-ratio gears will dispatch all but the heavily turbocharged competitors (and give them a big scare up to 120 MPH).

The only other thing I'd do is intall a 3.6 Varioram motor from a 993 but that magnesium-cased 915 with the 7:31 R&P will be VERY unhappy about that solution.

[teveo]

Originally posted by Chuck Moreland
You have a nice lightweight 7R case. That motor in simple 2.7 "S" trim will probably pump out 240 hp, and close to 300 if you make it a screamer.

Originally posted by Steve@Rennsport
FWIW,......a 2.8 litre, twin-plug, S-cammed motor with all the right stuff & close-ratio gears will dispatch all but the heavily turbocharged competitors (and give them a big scare up to 120 MPH).

Thanks,.. both my 74's have this engine case I suppose...? (they have the original engine from what I can see.. ) Carrera 9114400434 & targa .. 9114112429.

Would it matter which engine I started out with if i was going the 2.8 liter path.. I mean, not buying a bigger engine is what.. an extra $6000 to spend on parts alone!

[Steve@Rennsport]

Your 74's have the same 7R case and both are fine candidates for a hot 2.7 or 2.8 as long as the requisite upgrades are done to the case.

One adds Case Savers, line hone, oil bypass modification, Carrera oil pump, shuffle-pin for a 2.8, decked, etc.

A 2.8 isn't cheap to do, but its a real good performer that belies its modest displacement,........

[teveo]

ok.. just for the curiousity, what are we looking at for a twinplu 2.8 enigne?
~ $4k P/C kit, Heads? Cams? machining.. etc .. ballpark will do..

Trond

[ael911]

$15K to $20K should do it

[911teo]

I'm afraid ael911 is right....

[teveo]

Yes, admittely more than I paid for the car! Maybe I am cheap, but that is halfways to a '76 Ferrari 308 I was drooling at .. opa, no swearing in the church!?

So based on this, for $10k my 2.7 can be massaged into a hot 2.7 RS spec engine? $15-20k -> 2.8 RSR twinplug 275 hp engine?

I like more the idea of a hot "original" or modified original engine, keeps the car more balanced as well I suppose. I guess it is important, I did some reading on 915 gearboxes here, and it made me rethink a little. (it is just fabulous how much info that is collected between the gigabytes here)

[randywebb]

What skills do you have - that can cut the $$ -- esp. if you have a nice set of Bridgeports tucked away in the barn on the back 40...