June 2025 – Maxim's Blog

Good progress recently. I had a bung welded in the sump just above max oil line by one of the guys at work. The fitting was a little worse for wear after welding but I think it should seal fine. I had to shorten my drain line a little, which I may have overcooked it as it was a bit of a pain to tighten but I think it will be fine.

I also installed the Walbro 255 which was a lot more difficult than expected due to the pump being slightly wider and a lot longer than the OEM pump. I made some modifications to the housing and got it to fit but it’s not the prettiest solution. In hindsight I should’ve just bought a Denso equivalent which would’ve dropped straight in with very similar specs to the Walbro.

I used the sanding wheel on a dremel to remove a small amount of material evenly from the inside of the housing. Then I cut various tabs and screwed in some stainless screws at the 3 factory tab locations to hold the pump up, allowing for the extra height and giving the filter sock about 3mm of clearance from the bottom. You have to be careful doing this as the pump housing has a cavity around it, you can only drill in to the ‘sleeve’ that has the tabs.

Before re-installing the fuel tank and pump I hot wired it to check it ran fine – which it did. Hopefully I am not missing anything!

I also got the engine all sealed up, pretty much ready to chuck back in once I sort out the wiring (which I am procrastinating a little). I also mounted the fuel rail with my 1000cc injectors. I’ll need to do a quick check once it’s in the car to see if they’re sealing properly. I will be adding a fuel pressure sensor, which I’ve added a tee for.

Here is the wiring table, all I’ve managed to do is some practice crimps using open barrel splices and putting a Deutsch connector on my boost solenoid. I have purchased some fancy wiring, including shielded ground wiring and nice heat shrink. There has been some revisions to my wiring/pin table too which you can see below.

In my previous post I detailed how I planned to run the turbo lines and work around the oil cooler sandwich plate etc. Well, the parts arrived, and it went mostly as planned.

The exhaust manifold and turbo are now torqued up, good to go.

It took a lot of fiddling to get the oil pressure line to work without contacting either the exhaust manifold or coolant line. I ended up just re-using the HKS kit line with a 90 degree M-F swivel off the top of the turbo. The return line was simpler; however it took me 3 attempts to get the height just right. First it was to low (in the oil), too high (no room to weld), just right (I hope..).

I still need to clean the sump thoroughly for welding and drill the locator hole for the bung. Hopefully, how I have it now is above the oil line as I am finding the stainless braided line a real pain to work with. Even when taping the cut location, it still frays quite badly, making the fit up of the nut very difficult. The plan is to fill the sump with water post cleaning to double check the return is above the maximum oil level but I’m quietly confident.

I’m also hoping the coolant line is OK with the heat sleeve around, everyone seems to think so, but time will tell. Doing a walk around, admiring my work I also noticed the wastegate actuator was sitting on the block. I managed to pry it so there is a circa 2-3mm gap – “clearance is clearance”. The ZC31S block must be slightly different in this location as I can’t imagine HKS had this kit leave the factory colliding with the block.

Before: