2.0L XE Aluminium Block Development
4th January 2021
Steve has worked between Christmas and the New Year on the new XE engine for our SBD Dallara. The dry build went very well with plenty of valve to piston clearance and the final assembly has been carried out. He had to make further adjustments to the idler and tensioner layout to accommodate a slight variation of the water pump mounting position on the block. He also machined a new oil pump mounting plate again due to a slight change in the block. He took into account that the aluminium block will grow slightly as it heats up to ensure belt tensions would not be too tight. The engine is finished with a temporary cam cover, which allows quick access if required on the dyno. Unfortunately, he forgot to take a photo after fitting the induction system before the engine went to DTW Engines dyno.
9th December 2020
Due to heavy workloads, Steve hasn’t had much time to work on the 2.0L XE engine development. However the cylinder head is now ready for hopefully the final assembly. We have had to change the cylinder head volume from what we would normally use due to the 88mm bore piston combined with the new shorter stroke in order to maintain a 2L capacity, so the final dry built of the head on to the engine block is to prove that all the clearances between valve to piston are perfect. The plan is to assemble it with the new cap and platform design that Steve has produced to work with the spring that was originally designed for use on our high spec Duratec engines.
10th September 2020
The aluminium block is now honed to size and the deck height has been finalised. Steve did the final assembly of the bottom end with the new pre-production conrods. The new rods are longer than the version used with the 86mm crank to accommodate the shorter 82mm stroke crank. We are now using a 5/16th ARP 625 bolt, this is a beautifully small but incredibly strong rod bolt. We have used this bolt in the past on a high revving 2.0L XE design and is also currently used on our 1.6L EcoBoost, so it is able to cope with both rpm and torque. This has helped us to reduce the size of the body of the con-rod and reduce its overall weight but also increase its strength by reinforcing other areas of the conrod. The new conrod weighs 430g, which compares to 490g for the 2mm shorter production conrod. Everything was carefully assembled over the weekend and the final dimension check was made on all the bearing clearances with Plastigauge to confirm all the measurements that were done with a bore gauge and micrometre. On to the next part of the build….
1st September 2020
Steve worked on Saturday on the new 2.0L XE engine, a specially prototype rod has been manufactured for us by Saenz in M300 material. This is about 25% stronger than normal and allows us to make a lighter and stronger rod at the same time. The rod is also longer than our normal design for the slipper piston. It is also equipped with ARP 5/16 625+ bolt as opposed to a 3/8 bolt. The weight is down to 430g per rod, saving approximately 60g. After the dry build this weekend, the block is going to have 0.005” machined off the deck, then the deck plate will be fitted and it will be honed to 88.00 — 88.01mm. It will then be ready for the next dry build. Also tested the new front cover design just to prove it all fits perfectly.
May 2020
Steve has been fitting the Ark Racing Limited starter motor to the new 2.0L XE Dallara development engine.
9th April 2020
While we are not racing, Steve has decided to develop the XE engine further. He is coming up with a range of new components to make the engine lighter. The first thing he worked on yesterday was the front block/crank cover, this replaces the original oil pump and on the SBD Dallara is very compact because it sits much closer to the front of the crankshaft. He spent some time in the machine shop milling away unnecessary sections and machining out pockets to lighten it, it originally weighed 656g and he has now got it down to 462g, a weight saving of nearly 30%. He doubts he can save that much weight on every component but he will do his best.
31st December 2019
Steve has working on a brand new XE block, modifying it ready to fit the SBD Dallara. Quite a few more stages yet before it is ready to use. Cleaning & first dry build next.