Z3M V8 Conversion

For the M Powered Z3 derivatives

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Dino D
Joined: Fri 10 Feb, 2012 16:59
Posts: 376

  Z3 roadster 2.8

Re: Z3M V8 Conversion

Post by Dino D » Fri 30 Jan, 2015 17:31

Looks great! Even lower and wider.
Seems strangely unfinished without them.

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c_w
Joined: Thu 19 Aug, 2004 17:50
Posts: 4032

  M roadster S50

Re: Z3M V8 Conversion

Post by c_w » Sat 31 Jan, 2015 21:19

Deano1712 wrote:Hamann diffusers fitted today. I love 'em :D
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I'm not normally keen on these but I think they really suit it - I think it's the big wide tyres make it work, but would look a bit "over dressed" on a car with normal width 245/255 rear tyres.

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Gazza
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  M roadster S54
Location: East London/Essex

Re: Z3M V8 Conversion

Post by Gazza » Sun 01 Feb, 2015 15:57

Deano1712 wrote:Hamann diffusers fitted today. I love 'em :D
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I have a set of those in the garage, must get around to fitting them this year.
Gazza

"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"

S54 M roadster Image Mustang Fastback, BMW Z1, BMW M3 CSL.

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bertiejaffa
Joined: Fri 26 Jul, 2013 10:28
Posts: 1725

  M roadster S50
Location: Manchester

Re: Z3M V8 Conversion

Post by bertiejaffa » Wed 11 Feb, 2015 02:55

Dino D wrote:Have to make a plan to see and hear this car in action one day. Just awesome'
You have to come and see it... Under the bonnet is like looking into a JJ Abrams film but actually following it is immense....

From behind (default viewing option) it sounds amazing and leaves you like £10s in a strip club... Most impressive is how Mark keeps it under control... Ive seen it kick and scream like you have never seen but then when tamed it is like watching an F1 car
Here come the girls.....
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Deano1712
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Joined: Sat 05 Aug, 2006 13:56
Posts: 1393

  M roadster S50
Location: Leeds

Z3M V8 Conversion

Post by Deano1712 » Sat 02 Jan, 2016 20:16

Happy new year everyone Image

A few of you will know the car has had a small coolant leak for a while, getting worse in 2015. On Pingu's run last year it got me worried and I didn't drive the car much after for fear of coolant loss and overheating. The leak was coming out of the bottom of the bellhousing between the engine and gearbox. This made little sense unless there was a leak out of the back of the engine; eg core plug. I couldn't see a leak anywhere so the plan this winter period was to pull the engine out to find the damn leak.

So here is the culprit. A small hose ABOVE the engine at the rear. The hose has a small nick through the inner layer and the leak was coming through the end of the hose through the reinforcement fibres.

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The leak was dropping onto the top of the bellhousing and entering through an aperture passing through and out of the bottom!

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What a pain in the neck, two full days work getting the engine out. The hose must have been damaged when the conversion was done. The car has always used a little bit of coolant. The hoses at the back of the engine are impossible to access and see so now I have added new hoses running them across the back of the bay with no joints. There is just the one connection to the heater inlet on the firewall. I need to make a new coolant reservoir too.

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Now the engine is out there are a few jobs to do and I'm tempted to make a few upgrades Image

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Last edited by Deano1712 on Tue 19 Sep, 2017 21:37, edited 1 time in total.
Z3M with a few mods...and a little bit more power

Lewy
Joined: Mon 22 Oct, 2012 18:34
Posts: 203

  Z3 roadster 2.8
Location: Wolverhampton

Re: Z3M V8 Conversion

Post by Lewy » Sun 03 Jan, 2016 12:56

Wow! I've just read from the very start and what an interesting project.

I've been flirting with a V8 conversion for years although I haven't got the skills to pull this off myself.

Clearly it's not all plain sailing but it must be a fantastic feeling burbling down the road knowing you built this all yourself.

Loving the work on your garage too :)



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Deano1712
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Joined: Sat 05 Aug, 2006 13:56
Posts: 1393

  M roadster S50
Location: Leeds

Re: Z3M V8 Conversion

Post by Deano1712 » Mon 03 Apr, 2017 22:00

Hi all, I have been rubbish at keeping this up to date and generally posting on the forum. Must try harder :oops:

I got the car running again early in 2016 after making a new coolant header tank and simplifying the coolant hoses. That worked great for curing the leak at the bulkhead. The tank looks a bit neater too, here is a pic of the engine bay...
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In May 2016 a few of us did DTEC event (drive through every county) and it was a bril week. The car ran great over ~3000 miles with no problems at all. Averaged over 20 mpg too! Here are a few pictures.
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One problem I have been having every since fitting the v8 is with the starter motor. I am on motor number 3 now and think the problem may well have been with wiring rather than the starter motors failing, but its not possible to be sure. I now have a remote start solenoid and its staring great for now, fingers crossed this will continue. Its normal to wire the remote solenoid to parallel both the pos feed and trigger to the starter. I tried that but had a problem with starter over-run and now just use the solenoid to power the solenoid on the starter, with a perm 12v to the starter as normal. The only advantage is I'm running a big thick cable to the starter solenoid so there will be very little volt drop. I think with a small gauge cable the voltage can be too low to energise the starter, especially when it gets hot down there. The starter motor is located between the engine block and drivers side manifold.
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Fun day yesterday getting the car out of winter storage. I'm keeping the hardtop on for a few weeks to get some value out of the £2.5k cost lol. The daily driver is now a 335d and that's a fast car, but OMG the z3m is in a different league 8-)
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Last edited by Deano1712 on Tue 19 Sep, 2017 21:39, edited 1 time in total.
Z3M with a few mods...and a little bit more power

deni2s
Joined: Mon 25 Mar, 2013 22:02
Posts: 747

  Z3 roadster 2.8

Re: Z3M V8 Conversion

Post by deni2s » Tue 04 Apr, 2017 23:05

Love your strut bar. Could it be fitted the same way to the middle with stock engine? If yes, would you consider making another one?

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Deano1712
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  M roadster S50
Location: Leeds

Re: Z3M V8 Conversion

Post by Deano1712 » Wed 05 Apr, 2017 18:02

My car has a welded on bracket on the bulkhead to attach the brace to. To do this on a z3 you will need engine out to do same. So its not easy at all.
Z3M with a few mods...and a little bit more power

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Jonttt
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  M roadster S54
Location: Liverpool

Re: Z3M V8 Conversion

Post by Jonttt » Mon 10 Apr, 2017 00:26

Looking good Deano 8-)
Happiness is not around the corner........happiness is the corner
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Martini
Joined: Tue 26 May, 2015 15:24
Posts: 17

  M coupe S50

Re: Z3M V8 Conversion

Post by Martini » Thu 11 May, 2017 11:29

I smile every time I see a picture of the back end of that car :D

bertiejaffa
Joined: Fri 26 Jul, 2013 10:28
Posts: 1725

  M roadster S50
Location: Manchester

Re: Z3M V8 Conversion

Post by bertiejaffa » Wed 17 May, 2017 11:24

Its a bit slow.... need those turbos fitting...... :twisted: :twisted:
Here come the girls.....
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Deano1712
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Joined: Sat 05 Aug, 2006 13:56
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  M roadster S50
Location: Leeds

Re: Z3M V8 Conversion

Post by Deano1712 » Tue 19 Sep, 2017 22:49

I have just updated the photobucket links with the ~original trick so photos are back on - thanks for the tip Gary. What a pain they have caused!

Also listed here the full spec of the car (so I don't forget :roll: ) and will add to this as I remember more or make more mods.

Car
Z3M 1999
Motor
GM crate motor LS3 6.2 litre V8 LS376/480
Transmission 6-speed manual Tremec T-56 TUET2066
Twin Saikou Michi oil catch cans
Mishimoto radiator, 14” Kenlow electric fan ducted
GM engine controller
Walbro 450 fuel pump, 20A supply
Mild steel ceramic coated long tube headers 4 into 1, 1.75” diameter
Twin 3” stainless steel exhausts, Magnaflow X-pipe, Megan Racing Silencers MR-MU-MDT-T
Suspension
KWv3, H&R roll bars, Ireland Engineering rear beam bushes, Powerflex rear diff bush
Standard z3 (non-z3m) steering rack, custom front negative camber brackets, RAID steering wheel
Custom strut brace triangulated to engine bulkhead
Brakes
135i calipers front and rear. Z4M front discs 345mm, E60 rear discs 320mm. Non Z3M master cylinder
Wheels and tyres
CCW (Complete Custom Wheel) LM20 8.5x18ET25 and 11.5x18ET24 (plus 3mm spacer)
Michelin Pilot Sport 235/40/18 and 315/30/18
Bodywork
Hamann hardtop
Hamann rear diffusers (copy)
Hamann rear lights (not fitted)
ACS roll hoops
Z3M with a few mods...and a little bit more power

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Jonttt
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Joined: Sun 28 Dec, 2008 16:32
Posts: 6536

  M roadster S54
Location: Liverpool

Re: Z3M V8 Conversion

Post by Jonttt » Tue 03 Oct, 2017 19:56

Pretty standard then :lol:
Happiness is not around the corner........happiness is the corner
Image Video or Journal Garage: 2015 FFRR Black Edition, Porsche Boxster GTS, 1997 Porsche Carrara C4S, Ex 2001 BMW S54 Z3m Roadster

deni2s
Joined: Mon 25 Mar, 2013 22:02
Posts: 747

  Z3 roadster 2.8

Re: Z3M V8 Conversion

Post by deni2s » Tue 10 Oct, 2017 01:08

Hamann rear lights not fitted? Wonder why? ;)

Another thing I wonder is about Powerflex diff bush. Randy Forbes doesn't approve this.

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Deano1712
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Joined: Sat 05 Aug, 2006 13:56
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  M roadster S50
Location: Leeds

Re: Z3M V8 Conversion

Post by Deano1712 » Wed 11 Oct, 2017 21:12

They need paint before I try them out.

Second point - and? Why would you listen if there is no supporting engineering justification? Newtons first law applies.

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deni2s
Joined: Mon 25 Mar, 2013 22:02
Posts: 747

  Z3 roadster 2.8

Re: Z3M V8 Conversion

Post by deni2s » Thu 12 Oct, 2017 10:33

Deano1712 wrote:
Wed 11 Oct, 2017 21:12
They need paint before I try them out.
Let me know how is the "trying out" working out for you, very interested ;)
Deano1712 wrote:
Wed 11 Oct, 2017 21:12
Why would you listen if there is no supporting engineering justification?
AFAIK there is. That's exactly why I am wondering about your decision to put poly there.

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c_w
Joined: Thu 19 Aug, 2004 17:50
Posts: 4032

  M roadster S50

Re: Z3M V8 Conversion

Post by c_w » Tue 24 Oct, 2017 20:53

Eww don't fit the Hamman rear lights - stock lights are the best on the M! I reckon the car looks spot on as it is - I think your car carries off the rear diffuser because the tyres are so wide it works and look classy. Fitting those rear lights it will look a bit max power 1999 :dunce:

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Deano1712
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  M roadster S50
Location: Leeds

Re: Z3M V8 Conversion

Post by Deano1712 » Wed 25 Oct, 2017 20:35

You may be right Chris. I have had the lights for years and never had a strong urge to fit. Best try them and sell on if i don't want to keep them.

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bertiejaffa
Joined: Fri 26 Jul, 2013 10:28
Posts: 1725

  M roadster S50
Location: Manchester

Re: Z3M V8 Conversion

Post by bertiejaffa » Wed 08 Nov, 2017 23:13

Deano1712 wrote:
Tue 19 Sep, 2017 22:49
I have just updated the photobucket links with the ~original trick so photos are back on - thanks for the tip Gary. What a pain they have caused!
I will let you tell me the trick on Saturday
Here come the girls.....
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