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SC engine removal


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Called GCR at 4pm today and it was ready. Quite excited obviously but with the new lockdown looming I thought I’d better collect it quickly.  Carrpet (930-owning neighbour) gave a lift at very short n

I went round Birmingham in one day, keeping below 4k rpm with lots of hills and engine braking, then changed the oil at 500 miles, then did another 500 miles before going back to Chris. Just do whatev

Awake at 0100hrs this morning after three hours sleep.  Why?  My car is being collected between 0630-0645 to go to GCR where they will refit the engine and gearbox today.  I’m quite excited.  It's a g

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Output flange seals are easy to replace Ian. may as well change them while you have such easy access with the box off the car. Still easy on the car but not so pleasant having to removed the drive shafts and laying on your back.

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2 minutes ago, proporsche said:

one is holding the clutch cable and the other is holding Omega spring.Also put those on after the trans and engine are in the car

 

Ivan

Ah I see what you mean, good advice, thanks Ivan

45 minutes ago, Ian Comerford said:

Thanks Les, I’ve got them on the list

All ordered from Matthew.

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On 28/11/2020 at 08:43, Ian Comerford said:

I’m not spending anything on cosmetics, I’m more bothered about internals so wonder, apart from the 964 cams and a bit of polishing, what else is worth doing?

Forgive me if you've already considered these and I've missed it, but: 964 oil pump and Dilavar head studs?

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SC oil pumps are by pretty robust.  If it needs changing then the 964 is a good shout (& probably the SC variant is NLA)

 

(Only) if P&C are toast, then going 3.2SS with Wossner 10.5CR pistons is similar cost to standard.

 

With the ally rather than mag cases, not sure that the dilivar & their chemical intolerance is worth it.  I went steel. However, given the mileage that engines have lasted before headstud failures, whatever you use will probably outlast us.

Edited by PeterK
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I’ve got the gearbox pretty clean now and wanted to finish this before I started to replace seals.  I’ve also got the clutch fork assembly stripped and have compared the fork with the new one. The one fitted is barely worn at all.  Measuring old vs new reveals 74.66mm across faces and new is 74.30mm but measured through the plastic bag.  Other than wear between the faces how else do these fail as it seems I might have a clutch fork to sell?

5828A752-BDF8-4996-84D8-312A1D652913.jpeg

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Had a call from Chris at GCR today about the engine. All seems good.  He’s tripped the engine fully and started to rebuild the bottom end with new shells etc.  He thinks the pistons and barrels are ok and will only need new rings.  ARP bolts are going in and the heads are being skimmed slightly.  We agreed some minor cosmetics such as the fan being refurbished and some media blasting of cases but all within the original quote.  The 964 cams are good. He reckons two weeks as long as nothing bad shows up.  Happy day!

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Exciting ! 

What static cam timing is Chris going to use for your 964 cams Ian ? 

Apparently there's some options for moving the torque curve up or down the rev range according to how the cams are timed. 

 

 

Edited by GaryH
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2 hours ago, Ian Comerford said:

Good question, thanks Gary, I wasn’t aware of that.  How were yours done, can you recall?  Also what differences did you experience?

Hmmm - that's why I'm asking what Chris is suggesting ? ;)

My 3.0 makes 232.1bhp but it's higher up the rev range than with the stock SC cams and I seem to have inadvertently traded some 'area under the curve' torque to achieve the higher hp 😕

Since I now have more hp than a stock 3.2 ;) I'm interested in trading some headline power to regain some of the lost torque,  possibly by retiming the cams 👍 

(All this is detailed in various old threads)

Other than the lightened valve train (and the head porting) your engine will be the same spec as mine so I'm interested to see what shape your dyno curves are. 

I've got my pre/post rebuild dyno graphs somewhere I can dig out if you're interested ? 

Edited by GaryH
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IIRC, 1.26 is the standard 964 cam setting and popular opinion seems to suggest 1.4 as the sensible move to increase mod-range torque at the expense of top end.

 

That said, I'd really like to hear from someone who has done it for real on their own motor here in the UK, rather than a bunch of keyboard warriors in the US who might just have heard it from somewhere.  Soon would be good, like next week, before I time my cams to check piston to valve clearance 😜

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IIRC there wasn't a Porsche specified range of cam timing values for the 964 cam (like there is for the stock SC cams), there was just a single value ? (1.26 does sound familiar, even after all these years !) 

55 minutes ago, proporsche said:

if you like to have more power at the top let`s say timing is 1,2-1,5 set it at 1,2...If you like to have torque from 1000-5000 rpm set it at 1,4  as an example..

Ivan

Ivan, would the cam timing alter the actual 'amount' of torque produced or just 'where' in the rev range it's produced ? 

The torque curve on my 3.0 with 964 cams was moved up the rev range but I also lost torque in the lower rev range (compared to my previous stock SC cams). 

Edited by GaryH
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well the amount does not change but the kick in does ..so most likely yours has been set up in the lower limit....Personally i like to upper settings, because i do not really go for the 6K rpm for regular driving;-)

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Hmmmm - so a loss of torque is more likely down to something else ? Could 'over' porting the heads be responsible ? 

Mine was primarily a trackday car so peak power at 6850rpm wasn't a problem :)

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6 minutes ago, GaryH said:

Hmmmm - so a loss of torque is more likely down to something else ? Could 'over' porting the heads be responsible ? 

Mine was primarily a trackday car so peak power at 6850rpm wasn't a problem :)

I’m sure I’ve read something on here about over-porting costing power.  It might have been a 9M reply.

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12 minutes ago, Ian Comerford said:

I’m sure I’ve read something on here about over-porting costing power.  It might have been a 9M reply.

I read something similar. Sounds like another possible answer. 

I spoke to John Dougherty (CamGrinder) and he reckoned the 964 cams should not have caused a loss of torque (quite the opposite in fact), just moved it up the rev range. 

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