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M96 Engine Rebuild time

Jamesx19 said:
Getting one........ Honest. :)

Think getting it back in might be more tricky than getting it out.

Yes it will be ..

My concern is lifting the car off the stands when jacking the engine / box back up .

One of my collegues did mention he wouldn,t mind giving a hand ( foc of cource ) refitting if we could arange a date to suit him .

I do feel thought that this might be like stealing the thunder from you .. 2 Porsche mechanics putting it back together are going to kinda take over and just do it and im not sure thats the best way forward .

A helping hand is one thing but 2 of us doing our job is a bit different i feel .
 
Good to know EGTE

Thanks Y2K and Jerzybondov. I;ll do my best to give you a good explanation. I have spoken to Grant and Baz at Hartech today. Impressed how much time they invest, and patience they both have in explaining and advising someone like me. Proper customer service.

Thanks Demort, That would be ace..

Happy for anyone to lend a hand, but the offer of two Porsche mechanics to come round and help refit your engine isnt something that happens often I imagine! ..... and very cool, if a bit crazy. Very much appreciated. Thank you.
 
Bit of an update:

In deciding what spec I should go with, I have spent a lot of time thinking, doing internet research and asking opinions and listening to answers. This included PM'ing some members on here who have relevant experiences with the type of questions I was asking - Thanks to all who shared their thoughts.

I have been fairly conflicted on the subject, and still have a little doubt, but
the spec I have decided on, is to keep it a 3.4.
Keep a dual mass flywheel rather than go single mass light weight, but pretty much upgrade and strengthen all that can be done.

I know that some of you are convinced a 3.7 is the way to go, and ultimately of course, given more money, that was on the table.

My decision is partly financially driven, though the increased cost of the 3.7 wasn't too far out of the ball park. Ultimately though, cost was not the final arbiter.

I have been happy with the performance of the 3.4. Sure there are faster cars, but I like the combination of a revy engine, and enjoy the process of allowing the engine to "rev out" to the redline. Having to change gear to get the oomph is not an issue for me. Admittedly, I haven't had an opportunity to drive the bigger motor, but I think I'll be happy enough with an "optimised" 3.4.

A 3.7 would be a more flexible, grunty motor. Plus allow scope for future upgrades to camshafts induction and exhausts, and ultimately give much more torque and power.

However, I don't want to get into all that. Its expensive, and I feel I have "done" that with my last car which I rebuilt with forged high compression pistons, flowed the cylinderhead, bigger valves, made a bespoke tuned length stainless exhaust system, fitted bike carbs on a bespoke designed inlet manifold etc etc etc. Great fun, but a lot of money, and other cars were still waaaay faster (and cheaper).

OK, Single mass flywheel. This was a difficult one. On the one hand, having handled the Dual Mass Flywheel together with the clutch, let me tell you its a massive piece of pig iron hanging off the end of the crank!

Also, after speaking to a few specialist Porsche independents and owners that have fitted them, there appears to be little evidence from them as far as crankshaft failures go. The only constantly mentioned issue is "chatter" at idle or very low rpm.

But despite this, there are many well sourced and referenced "experts" inc. Porsche themselves, that say that harmonics, combined with upstream stress loading from the drivetrain, can destroy the (sintered not forged) crank, not to mention the extra vibration and stress caused to associated parts such as gearbox internals, camtrain etc. In the end, I had to make a decision, and being that I am into future proofing the engine so that it lasts at least another 10+ years of no nonsense mix of driving conditions including commuting, touring and a fair wack of Sunday morning B road thrash, I have decided that, for me, I will trade the potential gain in low gear engine response for peace of mind. Also, this is my only toy, I don't have access to lots of high end motors. unless you include my Ford Puma 1.7 :D

For me in this case, less is more as they say....

There will be opinions on that I'm sure. Would engine bearings last longer with a lighter flywheel for example? I don't know, but they generally last between a representative, (based on received wisdom) 80,000 to 120,000 at the moment (Plus lots of cars that do much more).

So in essence the spec is:

6 x new cylinders
Large IMS bearing in re-engineered intermediate shaft
New chains plus tensioners and pads
2x cylinderhead overhaul inc valve stem seals.
New bearings (Of course)
ARP conrod bolts.

I'd also like to say again, just how patient and generous with their time that Hartech have been. You might consider that to be taken for granted, but I for one don't. When you have spent time phoning around to get a base to reference something like this on, it quickly becomes apparent who actually seems to know what they are talking about. It is surprising just how many companies say "Oh we don't release the details of who we use for machining" or where they source the parts from, or whose pistons they use etc. Just expecting the customer to accept that they "know best".

Time wise, I'm looking at somewhere between 2 and 4 weeks before I have the thing back, so maybe by the end of May it'll be back in the car and I can start running her in. Can't wait!

Cheers
 
Good choice James, make it bullet proof for years of fun, if it's going to be a road car make it great car for the road not the track with drivability that rewards.
Maybe try to lose a little weight instead for a bit of extra performance and handling, the first page of ELA's thread let's you know where the main savings are to be had.
Good luck and keep posting.
 
I would do exactly the same. Single mass is fine for trackday toys, and if you are always "hooning", but it would damage the all rounder ability of the car for me.

I would consider a puma 1.7 a fantastic fun car! One of the best ever handling focussed hot hatches 8)

Its not always better to have "moar power"
 
Thanks guys. Comments appreciated.
 
Sounds like a very well reasoned and thought out plan James - worth investing the time and research, as at least you know now going forwards you won't have that nagging thought in your head - "maybe I should just have... "

What was your previous car you did all the engine work on? The Puma?

I did an engine swap in my DeLorean - didn't go as far as you but went for reprofiled cams and free flow headers. Car went brilliantly until rocker wear (cam run in failure) forced me to take it apart again and go back to stock.
 
Exactly what I'd do James.

3.7 would be nice but it's a bit too far from original spec for me. I've learnt over the years that if I want a faster car, I'll change cars, rather than fiddle about with one.
The standard 3.4 is a nicely balanced package.

Same with the flywheel. I loved the lightweight one in my GT3 but I've heard too many whispers about them causing issues on M96 engines.
A risk not worth taking. Stick a new standard part in and away you go.

I'm not dissing 3.7s, as I'm sure they're a riot to drive, but I generally only do easily reversible mods to my cars.

Good to see it progressing anyway. :thumb:
 
Thank you V much for the comments:

Jerzybondov - I had a Fiat X1/9. Maybe not the most sought after track car in the world, but a brilliant little 1500 SOHC motor. The block was originally designed by Aurilio Lampredi as a race engine, then adapted for road use. It has a short stroke 64 mm and 86mm bore making it very revy. Mine was OK for 8,000 rpm, but kept it to 7,500 rpm for reliability. I got it from 85 bhp and 84 lbft to 143 bhp and 112 lb ft with a conservative 'rally profile' camshaft, which for a 1960's reverse flow head, 1498cc's and single cam ain't too bad....

911munKey - Thats a good idea. Might look at rear wiper delete. The aircon pump might not make it back on either.

Wasz - Yeah my wife thinks the same re the Puma, I barely get to drive it!

Marky911 - The 3.7 is definitely very very tempting. And as you can expect from Hartech, they have done a 'proper job' developing it to be as refined, probably more refined than Porsche's original motor.

I have replaced the voltage regulator on the alternator. See below. I'm sure others have posted this up before but its a simple job. Who knows if it will stop the slight parasitic drain. Lets hope so !

GMj4Yj8.jpg


craV46b.jpg


IN6cTJ3.jpg


A8Uzzay.jpg



Also treated and painted the exhaust brackets. Not pretty, but despite the amount of rust and degradation, they are still very solid around the bottom mounting holes and the welds to the bracket arms are still solid. Definately serviceable and don't need replacing for a while yet..... Just as well because they are fearsomely expensive new.

8sJlNRA.jpg


PEpgva4.jpg


Cheers
 
Do you have a sunroof? If not, before you delete the aircon, you should try motorway driving in the summer with it switched off.
 
Hi Maldren, sorry missed your last. Yes I know, the air con was U/S last summer. Windows down on a motorway jaunt can be a very weary experience.

Whilst waiting for the engine to return, I've been busy tidying up the engine bay and transmission tunnel. The first pictures were taken part way through when after 6 hours I was board of sitting on the floor covered from head to foot in dirt and rust that had been power drill wire brushed, and paint stripped from the car.

Rust was starting to take hold in a few areas, especially underneath the plastic pipe retaining clips that secure to the rear chassis. Not badly pitted, but left unchecked I can see these cars having issues with chassis needing welding in a few years time. Pictures below:

Rear suspension back to rear bumper

Ce95vY3.jpg


kOL64yY.jpg




Chassis before rear wheel, Passenger side, underneath all the brake/clutch/PAS pipes

ALcAmhT.jpg


VYimC88.jpg



Other side the same

UCxJR8G.jpg


Zwg5oRD.jpg



Overall, a bit tatty

ije8nyF.jpg


Looking better

L917Q0L.jpg



I won't pretend I've done an A class cosmetic job in there. More utilitarian conservation, but may be the chassis might have a chance of lasting as long as the engine now!

All areas were treated with Bilt Hamber Hydrate 80 (Two coats) left 24 hours then primed, painted by aerosol and then lacquer applied to finish.

I will give all the nooks and crannies and pipes a liberal coat of waxioil before putting the engine and box back in.

Cheers
 
When I had my engine out last year I was able to do all the seams but it was only slight staining to the edges rather than needing the wire brush on them. I hope I have saved mine for a good few years to come.

With the 996 in the hands of the DIYer they are going to last a very long time as long as we keep on top of things.
 

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