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Mini Cooper 998 Screamer Nut And Bolt Rebuild


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#781 Petrol

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Posted 12 December 2014 - 11:44 PM

Totally agree about waxoyl. I hate the stuff personally.

 

Bit more info on waxoyl. I posted this on another forum some time ago and have copied and pasted into here.I hope this info is useful,

 

Pete

 

 

 

I thought long and hard about the products I used on this project. I have been working on it for over 12 Months now and didn’t want to compromise on finish or protection knowing the massive effort that was going into it. I have read mixed reports about Por 15. There are some interesting reads on Pistonheads. Maybe the metal wasn’t prepped properly but some have had problems. The best primer is 2K but you have to guarantee there is no rust whatsoever. A 2K product will offer much more mechanical protection than a 1K product. The thing is, you can’t guarantee there are no microscopic rust particles even after shotblasting or wire brushing. When shotblasting for example, there’s rust dust in the air and this can deposit on the part. On the other hand if you use a 2K primer and 2K gloss and the paint chips to bare metal, the 2K primer offers no corrosion resistance whatsoever.

For me the best option was the Electrox primer, yes it’s not as hard as 2K primer but if there’s any microscopic rust particles, the Electrox primer will sacrifice itself to stop the corrosion. Applying 2K paint over the Electrox gives the best mechanical protection and if it does chip to bare metal, the Electrox will prevent the rust spreading.

It’s not easy to understand and I wish I could explain it better. Best analogy is plastic coating, if that chips things look OK until you see a slight rust spot. The rust will have travelled right under the coating.

As far as box section wax goes, I have had disappointing results from Waxoyl over the years. So much so I have decided it can accelerate rust. There are too many problems with it – you can’t get a good finish so it holds water; that’s the last thing you want in box sections with little ventilation. It’s a recipe for very humid environment. It also seems to hold water by surface tension.

To be honest the box section wax was so important on this project I decided to do a back to back test between Waxoyl and Dynax. The last thing I wanted was to spray inside of box sections with something that would do more harm than good. After all, it’s irreversible.

Started the test with 2 plates of very slightly corroded steel

001_090507.jpg

Dynax on the left - Waxoyl on the right. I tried to get a good finish with the waxoyl but failed as you can see. It's also interesting to note that when I moved the 2 sample pieces, my thumbprint remained on the waxoyl but the Dynax was thin enough to cover the area.

002_090507.jpg

Surface tension holding water on the waxoyl plate the morning after. It didn’t rain overnight

004_130507.jpg

The plates a month later after spraying with a salt solution

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After 6 weeks and the wax removed with solvent, Dynax on the left

012_220607.jpg

Pics say it all.



#782 Petrol

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Posted 13 December 2014 - 08:59 PM

Back to shot blasting today. I re use the media by using a tarpaulin

 

1053_zps38135c71.jpg

 

Front subby mounts are new, I just blasted the black paint off

 

1054_zpsc54a761f.jpg

 

 

Got rid of any burrs and sharp edges on the rear subframe

 

 

1057_zpse75bd5c6.jpg

 

 

Used an angle grinder with a flap wheel for this

 

1062_zpsfa6f0e15.jpg

 

 

 

Blasted the places the plastic brush in the electric drill wouldn't reach

 

1056_zpsa1ff19e5.jpg

 

Like the spot welds

 

1058_zps664930cd.jpg

 

Sprayed zinc in all of the seams then across here

 

1059_zps1e092780.jpg

 

Hung it up like this

 

1060_zpsa774b582.jpg

 

Then primed the rest of it

 

1061_zpse89e35ac.jpg

 

 

I'm ditching the injected 1275 and going carbs 998 screamer so the fuel system needs to be changed. The Injection setup is pump in tank and 2 large fuel lines - flow and return. There's another smaller pipe run to the front of the car that goes to the carbon canister (which will be ditched) This pipe is to vent the tank through the canister to prevent fuel vapours escaping to atmosphere. This smaller pipe is the same size as the MK3 5 1/2 gallon tank outlet and the mechanical fuel pump inlet pipe so I will be using it for the fuel supply - Happy days :thumbsup:  Shot blasted and primed it

 

1055_zps47da1173.jpg

 

The front to rear brake pipe is fitted to the shell and once the fuel line is fitted, I can fit the rear subframe. Then it's steering rack, front subframe and rolling shell

 

Pete

 

 

 

 


Edited by Petrol, 13 December 2014 - 09:01 PM.


#783 RossKnight

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Posted 13 December 2014 - 10:13 PM

What spec 998 are you aiming for?



#784 Petrol

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Posted 13 December 2014 - 11:23 PM

What spec 998 are you aiming for?

 

Spec I want

 

Bad to start

Poor idle - lumpy

Standoff whilst idle

Good induction noise (going twin 1 1/4 SU's)

50 HP will do - I'm not interested in big power as it slayes the gearbox

 

To achieve this I'm thinking

998 bored +20 with forged pistons

Crank ground, tuftrided and balanced

Steel strap to center main cap

Lightened flywheel, ring gear and balanced

Pre verto clutch, balanced

 

12G295 ported Cooper head with rimflow valves and unleaded exhaust seats

Cam - dunno  at the moment

1.5 roller rockers

 

If I get the time, I might volumetric balance the chambers but the way things are at the moment, it's unlikely.

 

From what I can gather, I have a light (thin steel) shell and that's what's important on this build. I'm not looking to build something fast, been there done that and bored with it. What I want is something that's fun to drive.

I just hope I'm on the right track

 

Pete



#785 Steve220

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Posted 14 December 2014 - 12:17 PM

Pete,

Just out of curiosity, why 998 and getting rid of the MPi?

#786 RossKnight

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Posted 14 December 2014 - 08:07 PM

More fun!

#787 Wigeon Incognito

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Posted 14 December 2014 - 08:26 PM

Nice spec. I have a 1275 Cooper S and a 998 Cooper, I love the 998!

It was rolling roaded at a mighty 58bhp a few weeks ago but it's an absolute pleasure to drive.

Don't get me wrong I like the 1275 too and it is quicker but revving the little 998 is such a joy.

Matt.

#788 MINIMADrt

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Posted 14 December 2014 - 08:31 PM

just out of curiosity what are the advantages of the 998 spec?? what sort of dring would it be good for?? just always assumed people wanted the 1275 speed factor??



#789 Petrol

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Posted 14 December 2014 - 09:39 PM

I’m fortunate enough to drive a lot of cars and to be absolutely honest, I’m bored of big performance. My Nissan S14 is 286HP in 1250 Kg, the Nissan S13 is 200 HP and the same weight.  Recently sold a Honda  S2000 that was similar performance. Other cars I have driven recently are the latest M3 (the V8 jobbie) and a Nissan GRT. IMO they are that fast there is no fun factor. I also don’t like driver aids. Another fast car I drove was a 400HP 800 Kg Astra and again the fun factor was nil.

At the end of the day, even if I went full on 1430 with a crossflow head it still won’t be as quick in a straight line as a modern car. FWD has traction limitations and what I don’t want is a scrabble wagon. I drove a 100HP Mini and didn’t particularly like it. With regards to the injection setup, the extra weight added with all the brackets, relays and additional loom is significant. You only have to look at the coil bracket to see what I’m talking about. Then there’s the electronics that I don’t really want so I’m ditching everything. The loom is not the best of designs and has a relay on everything. I have probably halved the weight of the loom by removing what I don’t need. The same goes with the fuel tank and pump, the list goes on.

With all this weight loss and fully adjustable suspension it should handle well. Brakes will be alloy 4 pot vented up front and mini fins at the back. The 10” wheels will be the lightest available all to keep the un-sprung weight down. This should give it the fun factor. As far as the engine goes, the 998 has a shorter stroke than the 1275 so will rev better. Increasing the rev capability of an engine is effectively increasing performance as you can hold lower gears longer. By having the right final drive ratio, power becomes less important providing you are not looking for a motorway cruiser.

With a high revving 998 I will be able to use every single HP and if I get the handling fully sorted, it will carry the speed through the twisties. I really don’t care about 0-60 times but the measure of how good it is, will be how much it makes you smile. I guess the brief is “pantomime as soon as you fire it up”

At the end of the day everyone builds a car to meet a specific requirements. If we all built the same thing, life would be dull.
 

Pete



#790 MINIMADrt

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Posted 14 December 2014 - 09:54 PM

no fully agree with you i no what u mean about electrics i always prefer old school NA set up rather than the modern junk. mechanic by trade and still cant beet the oldies.



#791 Petrol

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Posted 14 December 2014 - 10:49 PM

no fully agree with you

 

If I've got it wrong, I'm open to suggestions. At this stage, I could still fit a 1275 ;D

 

Pete



#792 RossKnight

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Posted 15 December 2014 - 01:15 AM

I've got a program if you want to put full specs up when you decide on cam, carbs etc i can show you torque and power curves.



#793 pmplovesminis2006

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Posted 18 December 2014 - 08:56 PM

Pete,

Just out of curiosity, why 998 and getting rid of the MPi?

 

reliability  simplicity  and it will be a proper mini


Edited by pmplovesminis2006, 18 December 2014 - 08:57 PM.


#794 pmplovesminis2006

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Posted 18 December 2014 - 09:43 PM

PETE .you stated "50 HP will do "

it had better do more than that !!



#795 Petrol

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Posted 19 December 2014 - 11:26 PM



I've got a program if you want to put full specs up when you decide on cam, carbs etc i can show you torque and power curves.

 

That sounds cool, thanks. I'll post up the proposed spec :-)

 

 

 



PETE .you stated "50 HP will do "

it had better do more than that !!

 

Indeed I did and having thought about it, the plans not changed :thumbsup:

 

 

I want reliability and simplicity so it's 998. I've no doubt it will make a lot more than that but I'm not hung up on numbers, I have met too many dyno queens over the years and driven their cars  - it's not about about power curves and 0 - 60 times in my book it's about driveability.

 

I'm confident I'm on the right track by ditching the big fat wheels, limited lock rack and all the baggage that comes with the MPI. As pmplovesminis2006 said "it will be a proper mini" - For me that means no bumpsteer, tramlining, torquesteer but completely Chuckable in terms of handling, the true essence of a Mini ;D Fast in terms of straight line acceleration, it won't be.

 

Progress is slow at the moment due to bad weather - I need to spray some parts outside. Started to fit the loom though

 

1063_zps104a1c35.jpg

 

In the above pic you can see I have fitted the vents into the flitch panels. I bought new foam seals for these but for added protection I sealed under the wings with butyl sealer

 

1064_zps876a86dd.jpg

 

I have re-wrapped the wiring loom, this is not insulation tape but proper looming wrap

 

1065_zpsc73c8145.jpg

 

I removed all the metal tabs to hold the loom in as they are poor fasteners and can harbor rust. I'm using cable tie mounts and fastening everything up properly like the windscreen washer pipe

 

1066_zps580db108.jpg

 

 

Pete


Edited by Petrol, 19 December 2014 - 11:28 PM.





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