Another update

[mcramsay]

Figured I would keep everyone updated with my progress on my m3 powered 5 series marlin build! And I'm pretty exited tonight as I have hit a bit of a milestone!

The last few weeks I have been focusing on getting the fuel system in and wiring the bmw engine loom up to my car loom. I have went for. 6 bar 350l per hour pump. As the m3 engine requires 5 bar fuel pressure and a fair bit of flow and I have mounted the hp pump and filter on the passenger side firewall in the engine bay


I have now also fitted the battery, this took me ages to work out as I didn't really want to put the battery in the boot, and I had reserved the space next to the swirl pot for the header tank. Hover I managed to find a small race battery with the power to run the engine and leave enough room for a header tank . The battery came with its own aluminium holder however I had to do a bit of rebending and cutting to get it all to fit




The mile stone tonight was I managed to get the engine to crank through the ignition switch which proves the immobiliser is working. I'm also getting power to the fuel pumps and they are priming for 5 secs so the ecu is doing its thing! ( I had to just measure voltages on the pump plug as I have the fuel pump fuse pulled at the moment!(

My next task is to get the radiator mounted at the weekend and workout the pipe work routes and order the bits to get the coolant plumbing done, then it's find a small alternator and make some brackets up ( and I will prob have to machine a pulley for it aswell) and mount it where the air con pump I used to go on the exhaust side of the engine. Once all that is done I am on to fitting the Rest of the bodywork and lights.

I seem to be getting there and fingers crossed will have the car. On the road this year! Sadly donut I will make it in time for the summer though!

[morris]

good stuff. Is this a 3.2 or 3.0 engine. It's interesting you say your pump primes on ignition as that was what I had expected on my M50 but my relay doesn't provide power until you crank the engine. I wondered if it was because you had a later ODB2 3.2 than the ODB1 3.0.

Could you let me know where you got that battery from? I've been thinking about down sizing to one of these racing batteries as although my normal size one is happy sat in the boot, I'm worried that it's actually so high it will foul the harness running over the top of it. One of these smaller ones on it's side would solve the problem nicely.

[mcramsay]

It's the 3.2 engine. Most injection systems will prime the fuel system as soon as the ignition is turned on, but as you say it may be the difference between the obd1 and obd2 engines.

The battery is an odyssey pc680 I got it from a company called powervamp on eBay.

[morris]

Thanks, I've just ordered one. As my car doesn't have any accessories to speak of, one of these little batteries should be fine. The difference in size is quite marked, nearly 1/3 of my standard one which will make access to it so much easier

[mcramsay]

That was my reasoning for using one, the electrical load from my car will be far far less than standard. Really the battery will be keeping the ecu going. As I won't be having a heater blower or sat nav or anything like that. And the battery will give more than enough starting amps