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My blue C2 964 rebuild thread

Porsche964FP said:
ras62 said:
Why a 993 engine ? As for 3.8 it is a whole lot of cash for little benefit.

993 engine - cheaper than a rebuild. Has been done to great effect. Although it's another gamble on another engine. The car will no longer have matching numbers.

3.8 - torque values are higher. Which depending on preference can be preferable. If the OP needs new barrels and pistons the price jump between 3.6 and 3.8 is worth considering.

I personally would not consider 're-skimming' cams - I would replace. If the OP sticks with the intake manifold he has I would consider cup cams and a remap.

Possibly upgrade (if early 964) to the plastic manifold and consider a HotFilm/ MAF conversion.

Besides all these possible decisions are only worth considering once the full diagnosis is complete and the budget is considered...

I dont see any sense in putting another old engine in, who knows what condition it is in and loose originality? I dont understand the great effect comment, it is virtually the same engine, what am I missing?
If barrels are shot then 3.8 could be considered but I dont think you would notice any difference over a well sorted 3.6 The urban myth seems alive and well.
 
Not good news but at least you know where you stand and you know it will be sorted.

Hope your wife is understanding! :lock:
 
ras62 said:
I dont see any sense in putting another old engine in, who knows what condition it is in and loose originality?

993 Engine - Absolutely, as aforementioned - it can be a gamble. However if one does find one from a reputable specialist, where all the history etc is known - it may (and has for some) be viable.

As for the loss of originality - very true.

However it's a cheaper alternative for those with a tighter budget. Thus the option is worth considering.

ras62 said:
I dont understand the great effect comment, it is virtually the same engine, what am I missing?

The 993 engine is a more refined and reliable engine. The Varioram intake system is very effective. 993 engines also don't need valve adjustments as they have hydraulic lifters that self adjust.

ras62 said:
If barrels are shot then 3.8 could be considered but I dont think you would notice any difference over a well sorted 3.6 The urban myth seems alive and well.


3.8 - With all due respect, calling the difference between 3.6 and 3.8 a myth is unfounded. There are several very reputable sources that prove otherwise - documented. As said, there are torque increases to be had, that are noticeable - which may be preferable
 
Frank, the 993 is a fine engine but a better engine? Chase power and tell me hydraulic cams are a great idea. Much better to keep the original motor for so many reasons in a 964.
Ahh the 3.8. Well let me put it this way, you are correct, you should see more torque. However if you believe the extra 150cc of cubic capacity will make a noticeable difference over and above the 3600cc already there then I think you will be sorely disappointed. It's not rocket science when you look at the numbers. My 3.6 sits quite comfortably against a 3.8L. Rob :thumb:
 
ras62 said:
Frank, the 993 is a fine engine but a better engine? Chase power and tell me hydraulic cams are a great idea. Much better to keep the original motor for so many reasons in a 964.

Never said the 993 engine was 'better' - simply that there are logical reasons why one would decide on a 993 engine. Mainly cost.

The reason I stated the hydraulic lifters was to address your statement that the engines were 'virtually the same'. If we're talking power - that's a different point.

I agree keeping a 964 engine would in my mind be preferable. But again I was stating a 993 engine as a cost effective option - should budgets be tight.

ras62 said:
However if you believe the extra 150cc of cubic capacity will make a noticeable difference over and above the 3600cc already there then I think you will be sorely disappointed. It's not rocket science when you look at the numbers.

Thank you for pointing out that it's not rocket science - true it isn't.
 
I'm not sure a 993 engine would be cost effective tbh, 3-4k? for an unknown condition engine plus the fitting? Of no noticeable difference to the present owner and most potential new buyers would run a country mile. I know the differences between the engines and the advances of the 993 are not always advances at all. Cam timing anyone?
 
The 993 engine is far from being a direct replacement in the 964, labour costs alone would be much much higher if a 993 engine was used.
 
Good luck with the works, hope it's not too painful!
 
Chris W said:
Good luck with the works, hope it's not too painful!

Thanks.

I'll know more later today.

One option I won't be taking though is fitting a 993 engine.

It will be a heavy-hearted decision if it even has to be replacement 964 engine. I want to keep the car as original as possible, with all modifications being my chosen improvements, not forced upon me due to repairs.

I will just add though that I am keeping an open mind.

I expect that as it has so many faults that there will be a performance benefit when I get it back, sorted.
 
Once it's all been done you'll be left with a nice fresh engine.
Deep unbounded joy & driving pleasure - never mind the cost which will be forgotten in time :thumbs:
 
well put Frank, just suggesting another option as you say budget wise some of the rebuild numbers depending on options can be eyewatering plenty people went down the 993 route some on a reasonable budget if your decent with a spanner. :mechanic:
 
OK, went to see my engine in intensive care.

Its now dis-assembled.

The "noisy tappet" was the bolt that holds one of the rocker shafts in had broken (it had been welded previously too!).

The shaft had worked its way sideways and the rocker started to be at an angle as the shaft had moved. As to whether or not it has caused the rocker shaft casing to be oval or not we cannot tell at this time, until the head is stripped. Fingers crossed.

The angled rocker has damaged the camshaft.

Shims on the end of the camshaft were missing. The cam chain sprocket has marks were it has been moving, and there is a pin that was on its last legs.

It has had one new (or replacement, probably secondhand) barrel in the past. This barrel is in OK condition, but the other 5 have hatching marks and need replacing, so its 6 new (or good used) barrels and pistons.

I need a new (or used) camshaft.

Some of the nuts and washers in the engine are non standard and really bodged. some studs replaced, others not, wrong nuts fitted. It grieves me that someone has done a top end rebuild and not bothered to do it right. I will be going through the receipts for the last 10 years to see who might've done this, but as the car is 21 years old it may have been done a long time ago.

The bearing shells for the oil pump are worn through to the copper, but the indy says these can wear through at about 60,000 miles anyway.

The conrods look in good order, so new bolts, shells, polish crankshaft, and strip down the oil pump to check it but I am told these are normally pretty good so it should be OK.

The good news is that everything is fixable. I have decided against 3.8 barrels and pistons, as because my car was in such poor condition, just making it into a properly built engine will be a dramatic improvement anyway.

Timing chains look in excellend condition. I'm tempted to replace them anyway. I will wait for pricing. Any thoughts? Obviously its easy to say change them, but where do you draw the line?

Tim-ware is knackered, so will all be replaced. It has been welded, siliconed and had holes cut into it previously.

I will have more idea of costs when everything is priced up.

Thanks to SteveJC I now have a decat pipe to go with the existing G-pipe, and the primary silencer isn't standard either. My indy says he doesn't know what it is, but its a sports pipe of some description.

I reckon I will have to got through all this cars history records and find out what has really happened to it. However its going to have a better quality of life from now on.
 
Sorry to hear that so much is required on the top end. At least you know that when this job is finished you shouldn't have to touch the engine again for another 10 years.

MC
 
MisterCorn said:
Sorry to hear that so much is required on the top end. At least you know that when this job is finished you shouldn't have to touch the engine again for another 10 years.

MC

It'd better bloody well last longer than that!

It's being rebuilt to a higher spec than Porsche did when it was new, and as is only likely to be doing a maximum of 5,000 miles per year, and probably less, then I am expecting not to have to do it again in my lifetime.

(and I am expecting to live to 100)
 
Wow! What a nightmare!!

Good luck with the rebuild - as you say it will be better than new :thumb:
 

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