Your Input On a 3.0 Engine Build

Every once in a while, I like to put together an engine, with a view to experimenting, adding to my experience and then hopefully moving it on... so it won't be happening in the immediate future. But I'm curious, in order to maximise appeal, what would a potential engine owner want? besides free.... - a stock standard 3.0sc with CIS etc? why? simplicity, budget. - very slightly modified eg cams, headers but still cis.. - increased diameter pistons/barrels/cams/headers - 3.2 short stroke? - more stroke and all the above? - efi? (adds $$$) or happy with CIS? The only issue I have with building an engine with more performance is the first thing the internet wants to know is "how much power does it make?" The problem with that, is I can build an engine with high HP but it's gonna need to spin real fast and might be a bit piggy on the street.. so I tend to build engines that perform WELL on the street and in the mountains, but the dyno might show average dyno hp... But hey, I'm open to ideas and suggestions... thanks for reading. Mike www.aircooledporsches.com.au

3.5 CIS - big street friendly torque. Headers could just be the newer big bore SSI or the 3.7 CIS mentioned in Bruce Anderson’s OG book - maybe an Andial build?

Thanks. the last 3.5 on CIS I built was quite a success. Single plug. 1&5/8 headers... custom pistons cams.... It was very quick and torquey ... When I had to put my boring 3.0 efi turbo back in, I swear it was a downgrade.... I miss the response of the 3.5 cis. I'm considering doing another 3.5 but maybe using a 3.2 Carrera intake and efi and some MUCH bigger cams...

Mike, I enjoy your builds so look forward to your next. As for your next, assuming you go aftermarket EFI: Twin plug Stroked 3.2 crank using SC rods with the smaller big end journals to provide 76.4mm stroke.  Custom 98mm pistons to suit. William Knight is experienced at this. A plastic 964 or 993 intake manifold instead of the crude and restrictive 3.2 item. As for cams for plenum intake engines, I'm still at a loss but John Dougherty reckons: " The 993-SS cam is popular for this type application.  3000-6000 type of cam. The Dc35x is more of a 3500-6500 rpm cam.   Not something I do for motronic but in your case you can tune it. Both will have good street manners. "

Torque...loads of it! HP numbers are for CnC posers 👍 😁

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Good ideas there... what do you think someone would pay for something like that? custom pistons 98mm barrels crankshaft twin plugging intake custom harness standalone ecu crank/cam trigger custom exhaust camshafts when you start to add up all the parts alone, it's gonna be 'up there'. That's the struggle for me: it has to be something I want to build but also something that someone would want at the end of the day. Most internet experts want "itbs" itbs itbs!!! that adds thousands again.. but does open up for more compression and real cams. totally agree!

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That's a far too difficult question to answer Mike!

I agree with Ryan Keep it simple. 3.5 CiS Cams that give linear power from 3k to 6k. Similar characteristics to a 2.2e or 2.4 e, but still fun, quick to rev etc. but will run (safely) on 95 or 98 fuel. The engine needs to be saleable and usable rather than having a whole lot of nice to have jewellery, that might look good but when you look at it don’t provide value. jr

I like this. As mentioned earlier, I already built a single plug CIS 3.5 and it was fantastic. This time I might try a 'bigger' cam and see how the cis copes. I think I'm happy to trade off a lumpy idle or maybe even a high idle speed, in order to have more grunt in the middle to upper rpm. We all know the 964 cam works fine on cis. I think we can go bigger. And with the compression I'm planning, around 10ish with single plug, the larger cam will help with the dynamic compression ratio.. and keep it away from the brink of detonation. Careful distributor timing might need to be dialed in. Or perhaps, even (more money more money!) a programmable cdi from electrofit... EVERY IMPROVEMENT on these engines is $$$... so need to be careful. I just wish I had a spare car that I could fit this engine to for test drives. Once you've driven one, you'll swear it's all you ever need on the street.