M96 Engine Rebuild time

Jamesx19 · 4 Jul 2018

Hi Ian,

Thanks

Screwdriver is to stop the engine spinnng when it comes time to fitting the flywheel and clutch to the crankshaft.

Manifolds are Direnza. Will pop up on ebay for around £150. Most ads don't say they are Direnza, but they are I think..

Yes, cost was £9,400. inc VAT. plus another £400 for manifolds Air Oil seperator and other parts inc a high lift jack! .... and Oil / Coolant etc.

Just under my 10K budget for a very comprehensive rebuild. I was lucky as no damage to the crankshaft, and no rubbish through the engine or damage to the oil pump. An actual failure of IMS bearing or a thrown big end would be more money. Plus of course I've saved on stripping and fitting. Figure near £12K for Hartech to do everything that mine has? :dont know:

Cheers

Jamesx19 · 4 Jul 2018

Good luck Armagreddon.

Grant great to deal with. makes time for you and treats questions (which he must have to answer the same ones constantly) seriously and gives a considered answer.

Hope its not too bad

maldren · 5 Jul 2018

Manifold pipes are tighter bends but they look as though they have equal pipe lengths and that should give better performance.

Jamesx19 · 5 Jul 2018

I see your point Mike.

I'm unconvinced that the primary lengths are long enough to be effective at scavenging at a usable rpm any more than the stock item. Gas flow should be easier with less restrictive primary runner throats though....

pjvenda · 5 Jul 2018

Excellent thread. Shame about the damage but great to know the engine has been rebuilt to a great spec. I wish we could have some nice photos of the engine before it had been put together (I reckon it won't happen for known reasons).

I completely agree with the reasoning of keeping the engine at 3.4L, I sometimes wish mine had less power so I could wring it more often at much more sensible speeds.

Also wanted to share my personal experience re: light weight flywheel, even though it is not slightly late in the timeline of your decision process:

- Had it fitted to my 997 carrera S just around 1y ago and it certainly does rattle. Makes for an unpleasant noise that is heard around the car especially at idle. Rattling remains audible at very low loads up to around 2.5k rpm.
*But* the downside of the experience ends there. The engine is lovely and revvy, it is significantly stronger in the 3-5k range (and I did not believe it would until I experienced it), makes for much more satisfying heel&toe downshifts, etc. Makes the car feel quite a bit more special to drive. I love it.

The conversion was done at RPM Technik and took a sprung clutch disc in place of the solid original one. Together with this work I fitted a wavetrac diff which also had a significant effect.

Cheers,
Pedro.

Marky911 · 5 Jul 2018

Great progress J. 8)

I'm guessing without new pistons it would have been nearer £8500k.
Not bad at all.

Cmon then get cracking, have you not got it run in yet.

Jamesx19 · 5 Jul 2018

Ha ha! OK Marky .... How's this?:

Flywheel, Clutch, Gearbox and air distributor and exhaust boxes to go, then back in it goes......

You may have noticed that there is no air con compressor? The story to this is, that the aircon hasn't worked since I got the car. Originally I thought it was just a leaking condenser which I duly changed and re gassed. That lasted a week. Then noticed green fluid all over the compressor, which I took was a leaking seal from the join near that location. Changed it, re gassed, lasted a week..... then phut! :frustrated:

Also one of the main pipes it a horrid lash up repair that doesn't appear to leak, but I don't like it. So to be honest I'm fairly pee'd off with the aircon system. I don't particularly want to spend more money on it, but its certainly nice to have.

The options are to leave it off............
Hmmmm, saves a bit of weight, probably don't need it for most of the year, and prefer driving with windows down anyway, just not on the motorway.
Or, put the compressor back on and get round to fixing it when I can work up the motivation.

What do others think?

Pedro, Thanks for the interest. I must admit I thought long and hard about fitting a LWFW.

I had previously said that I would get the whole engine balanced and a LWFW etc etc. but in the end I decided that the car is required to do a bit of everything, not just a Sunday morning thrash about. And one of the reasons I like the 911 (And its been said plenty of times by others before me) is that its great at everything. I like the compromise that Porsche came to and don't want to push it to far from that.

Though it has to be said, its better to go LWFW, balance everything etc and then go back to a dual mass FW, if you don't like it. Rather than just fit one and then keep your fingers crossed the crank isn't going to snap (Rare occurrence I know).

Will update a bit more tomorrow...

wasz · 5 Jul 2018

Good progress!

Air con compressor is easy to get on at a later date, just need to drain the PAS reservoir to do so. You'll need a shorter ribbed belt if you don't fit it.

I would get it working though.... well worth it for winter de-misting and motorway.

Why did your engine need new cylinders?

Dammit · 5 Jul 2018

I often end up putting the aircon on when i've got the roof down, simply because the car is so much happier idling at 800 rpm than the 620 it idles at with the aircon off. I know that this is likely a really stupid thing to do, but there we go. I also enjoy the cool air.

Jamesx19 · 5 Jul 2018

Good points Wasz and Dammit

That is the only other reservation I have. I still put the aircon on to raise the engine revs at idle. If its not connected, I'm not sure the idle will increase and the low speed fans come on. Anyone any ideas?

Wasz, nothing except an increase in ovality (If that is a word) that would only increase. I did toy with the idea of 6 x support rings, keep the pistons, new standard IMS bearing and bang it back together with new bearings and chains etc.

Cost I think would have been about £5,500 (don't know this is an educated guess). In theory then, that would be pretty much the same result but £4k less. I went for the upgrades on the basis do it once, do it right. But I can equally see that another owner else might see things differently.

coullstar · 6 Jul 2018

Id swap out the pump at this stage even if the system needs work. Its easy to just fit the non aircon belt then swap over once system is working.

Ive been running like that for approx. 2000miles

eabeukes · 6 Jul 2018

A 'standard' rebuild will run about £3k + VAT
Ref: http://www.archermotorsportservices.co.uk/index.php/engine-development/watercooled-porsche-engines

Thats the price to pull it all apart, refresh whats there and check for damage (if any)
This wont include anything to rectify the cylinder issues however - thats another £300-400 a piece (3 or 6) plus associated bits (water pump, coils etc).

GMG · 6 Jul 2018

...my 70k miles 996 tip 3.6 engine is currently being rebuilt and thus far I think we are close to £7k in parts from Porsche; including all the timing bits,all of the variocams (4) I think; all of the oil pumps (3) I think? Plus a new (latest design) ims shaft with carrier and bearing plus a load of other stuff...ltt,aos etc...oh 6 new ringsets...

I am having the crank polished and the heads skimmed and rebuilt plus honing of the bores...

I reckon that the total cost will be close to £13k which when coupled with a £16,500 purchase price leaves me £30k in for a car worth;shall we say £20k!!!

Ouch...

Paynewright · 6 Jul 2018

Two of my new cars depreciated more than 10k in 3 years just to put it into context. At least you have a nice shiny engine to show for it!

Ian

deMort · 6 Jul 2018

A/C will still raise the engine revs regardless of wether there is an a/c compressor fitted or not .. the system doesnt have to work to increase the revs basically .

Compressor can be fitted later but its the dehumidifying propertys of the a/c system that are most benificial and not just the cold air .

M96 Engine Rebuild time

Jamesx19

Hockenheim

Jamesx19

Hockenheim

maldren

Albert Park

Jamesx19

Hockenheim

pjvenda

Silverstone

Marky911

Portimao

Jamesx19

Hockenheim

wasz

Paul Ricard

Dammit

Paul Ricard

Jamesx19

Hockenheim

coullstar

Singapore

eabeukes

Monza

GMG

Suzuka

Paynewright

Montreal

deMort

Monaco

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