Ever since I was old enough to get a car of my own, I have wanted nothing more than a stomping v8 powered Falcon that can destroy tyres at will. Several bad decisions and compromises left me without for a few years, until I came across an XR Falcon that was for sale in the same suburb. I decided then and there that it was going to be mine no matter what. By the end of that weekend, the deal was done.
After cruising it around for about 12 months with a stock 302 Windsor, I decided it was time to give the XR a freshen up, and get serious with the running gear. After the body was stripped and sent off for panel and paint, I started looking around at possible engine combos. In 2011 a plan was formed to build a high revving combo based around a Dart SHP 8.2" block, and a set of 208cc CHI 3V heads, with 600hp being the goal. The bores were punched out to 4.165", and a K1 forged crank, K1 5.4" rods and Racetech forged pistons were purchased to make up the rotating assembly. The combination of the 3.4" stroke and the oversize bores brought the capacity up to 371ci.
Sorting out the intake side of things was next on the agenda. The limited available intake manifolds that would suit my CHI heads and 8.2" deck height all needed a bit of work to bring them up to scratch. The biggest problem was the massive difference in runner length between the two middle runners when compared to the outer runners. I started looking at other options - like ITB fuel injection manifolds. Most setups were incredibly expensive, but it didn't take too long to stumble across Hilborns range of EFI manifolds - and they were very reasonably priced. After a few back and forth emails, Hilborn were able to get some drawings off of CHI, so they could then make me a one off, modified 351 Windsor manifold that would fit my combo. Awesome!
The remaining bits and pieces were sourced, including a crank angle sensor, a cam position sensor (off an AU Falcon 5.0L), 8 individual coil packs and the MegaSquirt ECU to provide the brains for the whole deal.
Nearly 2 years later, the combo hit the dyno and fired up in anger for the first time! It did everything it was supposed to do - it made 630hp, 505lb/ft and spun to 8000rpm.
Check out the video here:
https://www.youtube.com/watch?v=qwjUExd8xUo
The excitement was short lived, however, as some serious oil leaks became apparent after I took the XR for its first test run. After much deliberating, I made the decision to pull the engine back out to see what could be done. Whilst pulling the sump off to sort that leak out, my mate and found a couple of teaspoons worth of swarf clumped up under the baffles...not happy, but bloody lucky none of that got sucked in to the oil pump!
The next surprise came when the camshaft lip seal was removed from the timing belt drive cover. This was an expensive bit of gear, and the bore that housed the lip seal had been DEVCON'ed up and repaired - sort of. This looked to be the obvious source of the major oil leak at the front of the motor. That setup got banished to the back of the garage while I sourced a Rollmaster timing chain and a trick looking Bullet timing cover to replace it. I might try and salvage the timing belt setup to use on another motor one day.
The new plan was to completely strip the combo, and replace the bearings, gaskets and seals. I didn't wan't to be caught out by any more surprises! I started working on it with a mate, but we both ran out of time with our hectic work schedules. I made the decision to send it off to the professionals instead, and now, nearly 3 years after I first bought the Dart block, it is finally ready to go again. With a bit of luck i'll get a couple of free weekends towards the end of the year to lift it in to the XR!
The combo will be backed by an AllFast 5000rpm convertor, a manualised Dynamic Racing Transmissions C4 with all the fruit, and a Final Drive built 9" with 3.9's and a Tru-Trac centre. I've never even raced down a drag strip before, but i'd love to give it a go in the XR. On paper, it should run in to the 10's with the right setup...but even more so than that, I cannot wait to cruise in to Collie with dad driving his XR Fairmont as well. The whole petrol head thing starts in Collie for me, (I've got several Uncles and Cousins to thank for that), and dad and I have talked about how great it would be to roll in to town with both of our XR's one day!
I took the opportunity to get some photos of the engine last weekend before it goes back in to the car again - It really is a great looking motor, and I wanted to show off the ITB injection manifold, and the cool looking accessories before everything gets covered up under the bonnet. As cool as the ram tubes look uncovered, I will run a single, large K&N sprint car air filter over them to make sure the engine is sucking clean air. The air filter definitely won't fit under the bonnet though, so i'm still working on that one :-)
