Engine Build Plan 2.4/2.5/2.7
 

I split my first Porsche engine and had a look at what I'd bought. There was no history on it. Its a '73 911/57 2.4 Euro w/Zeniths and w/7R case! I'm looking to build a street rod without going crazy with the $$$ but you never know :) I did have a similar post but have done some research since http://forums.pelicanparts.com/porsche-911-technical-forum/744635-2-4t-engine-upgrade-options.html

Any more suggestions?

• all journals look good and are std
• bearings look good with almost no scoring and very minor wear
• #1 thrust bearing looks good but has copper showing on one side (didn't check end play yet)
• cams and rockers are very good - one shaft was backing out
• chain tensioners look good (black) but I found chunks of chain ramps from the inner (?) ramps but the center pieces was still on their studs. I just bought a low mile hydraulic tensioner kit anyway
• pistons, cylinders and pins looked pretty good but one piston had small chunks out of the edges (damage from before rebuild?) Cast cylinders
• oil pump has crystallized crap in it but it looks like it happened while in storage
• heads look great too. They have 32mm intake ports.
• one carb is in pieces and are of unknown condition (Zenith)

Tentative Plan

• Clean (of course) and check clearances
• Probably just change bearings anyway
• Polish crank (maybe - it looks pretty darn nice)
• Disassemble and clean heads and check valve job and guides; repair as required
• New pistons
• Upgrade cams
• recurve distributor
• Reuse hardware

Options

• put it back together and have a 130 hp motor (boring)
• above with 2.2T pistons - cheap but maybe a little shy on hp
• get a 3.2 - not that interested on a used engine
• find a used '70/71 2.2E complete engine and go for originality (core+rebuild of engine and MFI pump could be very expensive)
• hone cylinders and get JE 9.5 pistons or bore and upgrade to 85mm QSC cylinders with JE pistons
• Mod Solex cams. I guess I could regrind to E too
• upgrade to 2.7 p&c but add $2000+ for case machining, upgraded hardware and freight from/to Canada; perhaps the heads will be the bottleneck then?
• rebuild Zeniths ($2k-I'm not fooling around with carb rebuilds again), PMOs or EFI which I would ultimately prefer
• twin plug and 10.5 compression - I would rather spend the money on EFI

- After writing the above my main area of uncertainty is around the piston and cylinders choices
- Will cast cylinders be okay for this type of build?
- Do I need ARP rod bolts?

Thanks!

2.4 t
 

Looking at your questions, I had some of my own. Have you taken this apart yet? If so have you measured your heads for intake, exhaust sizes? Are they 32 or 34 or 35 mm intakes? Is this a counter weight crank?. Have you considered going to a 2.7 with your 70.4 crank. I have a 71 mag case bored for 90mm pistons with bored heads but they are 32 mm. You could get 2.7 with solex cams, 9.5 JEs, weber 40s your exhaust for 210 hp. Anything more is pushing the mag cases. best Henry

Bumping this because I am curious what you wound up doing.

parted it out and bought a 2.2E which will become a 2.45E MFI