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M96 Engine Rebuild time

Thanks Graeme. Reassuring to know. And great to hear it's not just rebuilt, but has noticeably stronger performance than before. I imagine you've got some great roads up there to enjoy it on as well.

Did you find a buyer for the alloys by the way?
 
I sold the wheels to Fast bug off the forum, he should hopefully be getting them today.

My car is currently sitting on axle stands as I sold the turbo twist wheels also, I've not actually found a wheel I really like for it yet and I've tried a few now
 
Baz - A question if I may, does/can a rebuild solve the oiling problems on the M96?

Would your 3.7 be able to reliably endure track work on trackday rubber, Cup2's, Trofeo R etc?
 
Know what you mean Graeme, I thought seriously about some Oz Alleggerita's. Love the idea of low weight, but also want to keep things 'Porsche' looking rather than aftermarket. - Fuchs?
 
I'm going to keep it Porsche also, for me the Alleggeritas are nicest aftermarket wheel I've seen on a 996 but as I say I want to keep it Porsche. I'm not a fan of the Fuchs, the search will continue.

Right about the weight difference though, the OZ's are unbelievabley light compared to some.
 
Hi Baz

In short, all of them and I welcome your experience on the topic.

On track however oil starvation would be a primary concern. I am keen to acertain if should I go down the 3.7 route can the M96 be made to endure prolonged cornering G.

I notice the X51 has an additional scavenge pump to help elivate this issue, what are you thoughts on this solution? Can it be retro-fitted during a rebuild? Is it worth it? (I already have the X51 baffled sump)

Have you every looked into a dry sump solution for the M96?

(And prior to anyone stating the obvious, yes I know a GT3 solve the issues)
 
We looked at all the available sump extensions kits years ago and most use an extension with the original sump underneath. The problem with this is that the spacer plate has holes on each side (to let the oil drip back in) and in a corner they let all the trapped oil out again - so although you have more oil we did not think this was good enough.

Furthermore if the car goes off track and hits a verge or rock the standard sump is very brittle and often shatters.

We made a whole new sump casting in strong aluminium and arranged it so all the oil from one side of the sumo has to go through the centre (where the pick up is) before it could reach the other side in a corner. Then we fitted flap valves that stop the oil escaping in the outer side in a corner.

The original baffle is then fitted and completes the set-up with a sump pick up extension and this has proven 100% reliable. more details, photos and fitting instructions can be obtained from Dan in our stores (phone).

We also fitted numerous recording devices when we were developing our own race cars and found that maximum G was decelerating into a corner just before the peak of the corner. at this point oil that has gone up the chain cam housing has flowed forward to the front of the bank 2 cambox where is can hydraulic lock the tappets and crack the flimsy dinky toy metal tappet housing. The additional scavenge pump on that side was to evacuate that area and prevent that problem.

The 997 later engines had the casting changed so the oil would fall and flow back to the chain housing - so should not present the same problem.

However it was only with slick tires and a very fast driver that the maximum G was reached and in fast road car use few drivers would ever reach enough G to cause a serious problem.

It is important when using our sump to realise that you do not then fill the engine to the original oil level mark but can leave it nearer the bottom "fill" mark - to get the best results.

The X51 system goes some way to addressing the problem and should be sufficient for all but the fastest of race cars on race slicks and at the front of the field.

Baz
 
Quick update:

Not spoken to Hartech re the full picture yet, will call tomorrow. In the meantime I have been:

1.) Cleaning everything that came off the engine, and reassembling again.

2.) Replacing the alternator voltage regulator. I had a slow parasitic drain which discharged a full battery over about a week, and the charging voltage would drop down after initially showing 14 + Volts. (Though this may be normal?)

3.) Partially dis-assemble the starter motor to spray grease onto the internal gears (The starter cranked veerrrry slooowwly when the engine was hot) This may cure it, but I have also cleaned off the electrical contacts and tested resistance of the starter leads. All looks OK, but I may put additional new leads in parallel with the old ones to assist electrical conductivity. There is a junction box in the engine bay tucked away in the top of the transmission tunnel. When opened up, it looked like this:

kYmtM7C.jpg


Sorry, not the best pic. but shows the corrosion, and where its situated.....here:

BpQVtdd.jpg



4.) Other rusty parts to tackle are the transmission carrier bracket. I didn't take a picture before, but rest assured it wasn't pretty, and took some serious work with a drill and wire brush to clean it.

r22MsUU.jpg


Js4BQhL.jpg



I have used POR15 previously, and while I liked it, it was a pain to clean the brushes. The process of using "metal prep" beforehand, and then having to top coat it was a pain as well. Instead, I have been trying/using Bilt Hambers Hydrate 80 rust converter. Initial thoughts are that although you have to completely clean all the oxide away down to bare (pitted) metal. It goes on easily. dries quickly. You can wash the brushes in soap and water. It can be overcoated in 24 hours. It promises good results. We will see!

F14JpoC.jpg



There are areas of the engine bay that need attention while I can get access. Thi it top of the transmission tunnel where it meets the engine bay:

lEYPHEF.jpg



Exhaust brackets need some corrective work:

gATgNfq.jpg


LeRjcrl.jpg



Lastly, I spent a morning tidying up the inner welds on the "Direnza" Stainless Steel exhaust manifolds I have bought to replace the originals, which Hartech had to prise off. Every one of the 12 bolts snapped in the heads apparently....

I just wanted to minimise any exhaust port to manifold downstream mismatch that might affect the efficiency and flow of gases leaving the engine. The left manifold needed a fair bit of grinding, but the right side appeared better made. Different person making each maybe?

HzRpGos.jpg



Other purchases have been a new fuel filter and stainless steel manifold studs, stainless spring washers and brass nuts.

The oil filter tube has snapped. A new one is £38 +Vat!!!! I have bought a new O ring, and will fix the tube with heat shrink rubber tubing. Total cost £6. Fuel rails have been sorted on previous occasion, so they are good to go.

Cheers
 
Getting one........ Honest. :)

Think getting it back in might be more tricky than getting it out.
 
Excellent thread James and you are going about it the right way. Best of luck :thumb:
 
James - great thread. Impressed with your attention to detail! Keep us posted with the diagnosis you get back from Hartech and what you choose to go with :thumb:
 
I use a phosphoric acid wash then two coats of POR-15, wrap the brush in cling film between coats and chuck the brush after. Use the small tins as it starts curing when its opened so they are single use.

POR-15 cures by taking in water to its chemical reaction - it doesn't have a solvent which evaporates like paint - it reacts with moisture. This is why I like it as it will suck any moisture from the metal.

I'm not sure how the bilt hamber coatings work but they also have a good rep.
 

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