WP Fiesta Duratec Rebuild
 

Hi all, currently working on a WP Fiesta Zetec with the Duratec 1.6 (FYJA). It's almost completely apart but the Haynes manual essentially says the bottom end can't be worked on. I've measured up the bores and it really needs a re-do (79.1mm was the biggest number I saw on the bore gauge when 79.03 is supposedly the upper limit). So the question is, has anyone done a bottom end rebuild on one of these, and if so, where did you source parts from?

Re: WP Fiesta Duratec Rebuild
 

The factory WSM in our Tech Portal says exactly the same and I can't find any oversize bottom end components at all.

It's the aluminium block so it can't be rebored anyway. The rods are 'sintered' with a built-in notch where they are broken to fit on the crank and the joint shouldn't be disturbed.According to Ford, the block will distort if the mains are removed and there are plenty of comments around the interweb that support this.

In other markets the fix seems to be a new short block but it's not cheap.

Re: WP Fiesta Duratec Rebuild
 

The alloy block has liners but i have no idea if it is possible to remove and replace them, maybe the block is cast around them.... I'm pulling it apart anyway, even if it's just to have a look, up to removing #1 piston. The big end bearing still looks serviceable, a bit of wear. Surprised that there isn't any positive location at all for the bearing shells..



I have 1600 blocks from the early seventies that i can pull apart and rebuild time and time again. To have a little over 15 year old engine that you can't even do a basic refresh on, well, that's an advance in technology right there isn't it....

Re: WP Fiesta Duratec Rebuild
 

Burton in UK have the overhaul parts for it. Oversize pistons 79.5mm, bearings, racing cams, etc.

https://www.burtonpower.com/tuning-g...uide.html?p=6#

You can diamond hone or bore bore Aluminum cylinders also, but need a new coat of Nikasil afterwards. (Nickel Silicone Carbide coating). Or possibly fit new steel sleeves. Here is one that fixes aluminum cylinders in Australia: https://www.f1moto.com.au/view/nikasil-plating/51

Anything can be repaired ;-)

Of course cheaper and easier to find a 'grandma' driven engine from another wreck.

Cheers,

Re: WP Fiesta Duratec Rebuild
 

Sourcing the parts doesn't seem to be the problem and i have an engineering shop that says that boring the existing sleeves to 0.5 over isn't a problem either. The big issue is the reassembly method and the possibility for warping the rather light aluminium block if it isn't done properly. I can only assume that in the factory all of the main bearings are torqued together and to exactly the same value.

Re: WP Fiesta Duratec Rebuild
 

This engine was developed by Yamaha in Japan. I haven't seen the parts, but it is probably very similar to a 4-cylinder motorbike engine block. When assembling them you put the crank into the upper block, then after installing new bearing shells into the lower half of the crankcase, you lower that carefully onto the upper half, and you start torquing the bolts in a rotating pattern, gradually starting with a low value. Go in circles until you have the suitable torque.

Maybe have a look at the factory repair manual for a Yamaha motorbike engine. Suzuki motorbike engines are the same.

Why not try to call Burton in UK. Since they are a racing shop obviously with their own R&D team, they probably also assembles engines, and knows which torque is required for the crankcase on this one. It is worth a try.

Cheers,