View Full Version : Mazda Capella RF7 engine - Biofuels and repairs

Tony From West Oz
10th March 2007, 10:55 PM
I had a Mazda Capella 2.0 litre diesel which I ran on used cooking oil for around 3 years. I had a few problems due to loss of coolant during the development of the veggie system and I eventually replaced the engine with a supercharged engine, as fitted to the later, auto tranny, Capellas.
The supercharged engine pulled well but the supercharger boost control was siezed at maximum boost and this resulted in stretched head bolts, and an oil leak from the head gasket at the fan belt end of the engine.
Although these engines were being operated on veggie oil (with biodiesel start-up and shut-down) I do not believe that things would have been different if I had used diesel.

Is anyone else using a Mazda Capella on biodiesel / veggie?


12th March 2007, 07:32 PM
Howdy. I have just bought a Mazda 626 diesel(capella) and i am looking at the possibility of running biofuel. i first have to set up the supercharger on the motor as it is currently no installed. if anyone has any pics of there set up with a supercharger this would be much greatful as i have no idea where the intercooler piping would go and any extra stuff you have put in for running boi fuel.
0439 555 045
p.s. it has a blown head atm but have another one to put on.

15th March 2007, 06:50 PM
Okay i now have some pics of the piping set up and the supercharger.
i just need to knwo if anyone who has or had one with and intercooler as
i need to know where the intercooler mounts behind the bumper.

Tony From West Oz
15th March 2007, 10:59 PM
Okay i now have some pics of the piping set up and the supercharger.
i just need to knwo if anyone who has or had one with and intercooler as
i need to know where the intercooler mounts behind the bumper.
I had one and I will try to link to some photos of the engine bay.
In the second photo, there are 3 plenum chambers (cast aluminium chambers behind engine, above the supercharger.
From the rear, they are: Supercharger intake plenum - connects to air cleaner.
Supercharger output plenum - connects to the inter-cooler which mounts to the right of the radiator, behind the grille, using rubber tubes to join the cast aluminium pipes.
The inlet manifold plenum - brings cooled air from the inter-cooler and supplies it to the cylinders. The connections are also by cast aluminium tubes and rubber tubes. The starting valve, in the pipe from the inter-cooler, opens when starting, to ensure a supply of air for the engine when starting. It closes when the supercharger provides a positive pressure to the inlet manifold, via the inter-cooler.
I hope this helps, as I do not have the Capella any more and I have no photos of this part of the engine bay.


16th March 2007, 09:10 AM
Thanks heaps for the last post. i think i already have pics of your car from Maarten and jason. your last explanation of how it all goes together is what i needed. thanks heaps.

18th March 2008, 04:24 PM
I apologize for bringing this back from the dead, but I am shopping for a capella here in japan, and wanted to hear some opinions on the vehicle itself.

Tony From West Oz
18th March 2008, 11:05 PM
The information on Mazda Capellas is of the 1990 models, so would be useless for you.


April 11
19th April 2008, 12:46 AM
Hi guys, i have just purchased my little girly biodiesel car.
I named her april 11 as this date is quite significant to her becoming mine.
I brought her off a friend that i met on April 11 2006.
That day i fell in love with her ( the car, not my friend... lol)
Two years later , yes you guessed it, i purchased her off my friend on April 11.
So that's what i've called her :)
She's a 1989 Mazda 626 capella .
I'm having an absolute ball with this car but have quite alot to learn about her.
My friends are totally fascinated and somewhat envious i'm supposing.
So far i have only ran her on straight diesel but intend on visiting a bio supplier in melbourne.
Apparently there's a guy who has his own station/coffee shop type set up somewhere in town
If anyone can give me any addresses in melbourne or places in vic that i can fuel up on i'd be very gratefull.