Ok then, let's see how lethal we can make this thing.
Here we have a 2wd Cosworth engine off of a 1986 3-door whaletail Sierra Cosworth. The block (and possibly the bottom end altogether) is essentially identical to what the Donkervoort has fitted now. However the 16v head coupled with other modifications takes the original ohc pinto design (from the late 60's) and forms a much more modern design. Stock this engine has 204 hp, which really is enough, for such a light car, but why should anyone settle with power levels that are "adequate".. .. Just chip the ecu and it's good for around 270hp, which is really quite a lot.. But why should you settle with a "lot" of power, when you could have a touch more..
The engine will be dismantled completely, given a thorough service, some "mild" modifications, a more modern turbo, bigger injectors, a different exhaust manifold, etc.
Drivability will be key with this build, so I'd set a reasonable power level goal of 350hp. In the end It'll probably be able to produce more by increasing the boost, but that amount should retain low end torque and tractability.
"Proof pic" of the engine featuring the Cortina:
I'll try and finish the engine as soon as possible so arrangements can be made to mate the Donk and the engine, so updates in the build should be reasonably consistent, Today, I started the dismantling to see what we have to work with. The engine was a bit of a risky buy as there was no opportunity to inspect the insides of it, and it had sat for a long time, but the price was cheap enough for the risk to be worth taking. (Adrian can post the price here if he'd like, but let's just say that a typical used engine like this costs around 50% more than what was paid for this one) It was visible that it had ran with this setup, so it was quite certain that it wasn't completely shagged.
First thing I did was take the head off, for 2 reasons, to make the engine lighter (so it could be lifted up on a stand) and to inspect it, obviously
:
I could immidiately see from the valve seat height that the cylinder head hasn't been skimmed a lot. As these are high performance engines, rebuilds are commonplace, and the cylinder heads only have about 1mm of meat on them for skimming before you start getting too close to the inlet valve seats. By recessing the seats you can gain about 0,5mm more skimming material, but it's costly and frankly annoying to do (you need to shorten the valves by an equal amount to keep the hydraulic lifters working, etc.) The deck height of Adrians head is around 138,7mm, which is 0,65mm more than my own Cosworth cylinder head, so it had had a significantly easier life (up to this point
). There is around 0,6mm of material left on it, which is great news.
A quick visual inspection didn't show any cracks either, this will be confirmed after soda blasting, but as there is no evidence of coolant having been in the combustion chambers, I'm pretty sure it's fine.
Now, onto the bad stuff:
The block is worn, like REALLY worn:
[video]http://s1293.photobucket.com/user/Pozmo/media/20150429_200750_zpsxnibc77x.mp4.html[/video]
There are no honing marks to be seen, and the video should show the extent of the pistons rocking in the bores. However, this is by far not the end of the world, I have another block that is in much better condition that should accept the pistons in Adrian's engine. My own engine (which I'm building currently) will need a rebore as I have bigger pistons for it, if need be, I can bore this worn out block for my engine and reserve the better condition one for the Donkervoort. Absolute worst case scenario in this is if new pistons need to be bought, which after machining and (selling the old ones) would run around 450?. I'm pretty sure we can work around this problem, and if not, after a rebore the piston clearances will be absolutely perfect.
Also visible in the pictures is that fact that the inlet valves have kissed the pistons slightly, this should be nothing to worry about (I'll explain more in a future post
)
Last job of the day was to remove all the ancillaries and lift the engine up on a stand:
At a glance all the bottom end components are genuine Cosworth items, I'll know more once I take the bottom end apart. I also need to go through all the stuff that came with the engine to determine if anything needs replacing, fixing or modifying. A lot of work ahead, but overall it's looking quite promising.