Fitting the 24v Cosworth engine into a 2.9 XR4X4

The Sump

Once the flywheel and clutch has been completed it will be necessary to modify the sump, this is due to the fact that the Cosworth cylinder heads have oil return pipes to allow oil to drain to the sump. This added pipe-work must be positioned very carefully on the driver’s side of the engine as it has to be between the webs of the cross member just under engine mount.

The sump has to have two pipes fitted in so as to allow the oil from the cam box’s to return back to the sump. there are two ways for this to be done.

The first (positions to drill sump shown in red)is to just fit the pipes directly to the sump, these can be tapped in or welded.

The second way is for new alloy pipes shapped to end below minimum oil level to prevent any air blowing back oil up to the cam box.

On the differential side of the sump, its best to keep the new alloy pipe as close as possible to the in-side wall of the sump, this keeps it out the way of the baffle plate and crank, it has to go from the minimum oil level in the sump forward on one side (same place as above)

The other side, is a simple L shape entering the sump at the bottom and also welded to the drive shaft web for strength.

The pipe used is a thick wall alloy tube; the maximum outside diameter must fit into a rubber hose like a heater hose. This is hose is bigger than the standard Cosworth uses, but this will allow for the extra wall thickness of the alloy pipe.sorry i didnt take any picture of this but i hope i have expained it well enough for you to understand.

Once you have completed the sump and flywheel you need to remove the sump on the Cosworth engine and try it for fit (deep intake of breath)! You can also remove the Cosworth baffle plate and oil pick up pipe as you will need to use the four by four ones, these you take from the engine being removed.

Before going any further it would be best to check the chain tensioner on the Cosworth engine. This requires removing the timing cover; however, you cannot remove the timing cover with the sump and the heads on. As we have the sump off it is possible to take the timing cover off at the same time, but be careful as there are locating pins in the top, so gently lever it off. Once it’s off replace the tensioner slipper (on the left hand side as you look at the front old the engine)It must be locked prior to installation or removal by compressing the component together while screwing clockwise. When installed, it may be released by turning anti-clockwise with suitable allan key. Replace any worn parts you find here, look closely at all the timing chain guides at the same time.

After all you don’t want this to happen.

The gasket often is damaged on removal and you may have to make a new one as Cosworth gasget sets from ford are expensive, also plastic gasket would do the job.

You might find this helpfull, seeing how it all fits together.

The tensioner can be bought from XR4i Spares Centre. Barry Tucker,Unit 10, North Hill, Horndon-on-the-Hill, Stanford-Le-Hope, Essex, SS17 8QA Tel: 01375 672641 Mobile: 07901 702406 or 07786 437472 Fax: 01708 853604 (also he supplies new cam cover gasgets for the BOA)