As with most projects and rebuilds, they all start in the same place, mine was no different. However, this isn’t truely the start of my forever ongoing Z project. I’ve owned this car (my second Z) since 2008 when I purchased it from a former member. For the first 5 or 6 years I did the usual mods with suspension parts and basic bolt ons. For reasons unknown, whilst running stock boost, piston 5 cracked a ring land during a track day at Castle Coombe. A forged build and a remap later all was well until a sunny October’s day 2013 at Bruntingthorpe killed that engine with what at the time was a suspected head gasket failure at 181mph..... And this is where I shall start my journal.

 

The Z was stored off the road from Oct 2013 until March 2015. I’d had a major knee operation at the beginning of 2015 which meant I was going to be off work for 6 months. I’d saved up enough to start thinking about a parts list to rebuild her and frankly, after a couple of months of staring at the same 4 walls, I was going stir crazy! I employed the help of a good friend and decided to pull the engine and see what was what.... just a head gasket my arse!

 

March 2015

Problem 1: It turns out stainless steel, exhaust wraps and condensation don’t mix well

 

Before I’d even got the engine out, a new set of downpipes was added to this list. These AMS items were only 2 years old, so I was far from impressed! I contacted the retailer and after a bit of tooing and froing I secured myself a set of replacements for free... how long they will last, only time will tell!

Pistons and rods installed. Just waiting on a set of STDX King rod bearings to make some adjustments to my big end bearing clearances…. Unsurprisingly, the STD size bearings EPR used produced 0.0017” clearance not the 0.0035” quoted in the build sheet. Targetting 0.0025” for this build. Also reinstalled the @brettdempseyengineering oil tree. Oh and I will never use a ratchet piston ring compressor ever again, these ring compression sleeves are SOOOOO much easier to use!!

Bottom end is now complete.

Hopefully get it back to my unit soon so I can start work on the heads and get the long block complete

Goodies courtesy of CZP and SZ

2.5” turbo intake kit

BDE low profile engine mounts

CZP replacement lower rad hose, clutch booster hose and intake valve cover crush washers

Gates Kevlar belt

Upper plenum gasket

New turbos have already been ordered, hopefully be here before the end of the month

Bit of a backward step this yesterday.

Got the short block back to my unit and installed the BDE engine mounts, water pump etc. After spending a ridiculous amount of time clearing the crank timing gear (wasn’t smooth going on the crank snout) I span her over to start working out true TDC, when I felt a gear like notchyness at a certain point in rotation. Given it was smooth as silk when I span it over prior to pump install, I instantly thought oil pump. Removed the sump and pump, and all spins over smoothly again.

Pump was a replacement sent by EPR immediately after its failure, and clearly wasn’t new as it had very little assembly lube inside it. Having taken it apart I can see it galling inside the pump on the leading edge of the small gear, so in the bin that goes and a new pump on order….. dear lord they’ve got expensive!!

Edited June 11Jun 11 by nickz32

More tinkering yesterday.

Spent some time finding true TDC ready for timing the cams up.

New oil pump arrived courtesy of @conceptzperformance (brilliant service as always) and got the cylinder heads on.

Next job will be set up cam timing and measure piston to valve clearance. Once complete I can order the new set of head gaskets and start the final assembly

More progress. Verifying the cam timing and found the exhaust cams were off by 3 degrees. Surprised that the intake cams were spot on where the should be considering the new block and heads being skimmed.

Next job is adjust the cam timing to get it to spec, then pull the heads off and play doh the pistons and check Piston to Valve clearance. Will also advance the intake cams 10deg to simulate VTC activation and make sure everything has plenty of room

Haven’t messed with Play Doh for probably 40 years 😅. Cam timing has been finalised, so was time to check piston to valve clearance. Turns out I’ve got LOADS. 4.4mm on intake and 4.9mm on exhaust. Finally day of tinkering complete before the family holiday to Sicily. Straight back to it when I’m back, and hopefully take delivery of my new Singapore swirly boys

Back from my family holiday to find goodies awaiting

New turbos by Pulsar. They’re GTX2860 Gen 2 with a 0.64 AR. They’ll provide plenty of boost headroom at the top end and get the most out of my head/cam/valvetrain set up. I’ll no doubt lose some response, but the GT525’s used to build boost too fast resulting in issues with boost control and boost spiking in the midrange and they ran out of puff after 6,000 rpm where they were effectively choking the engine.

With these and my Haltech setup, I should be able to have progressive boost build early on but still a strong midrange and not have boost taper off at the top end, and not have to push them to the absolute limit to get the performance levels im after.

Ok, so a bit of a photo dump.

plenty of progress recently, and I think the engine is pretty much ready to go back into the bay.

Well, for the first time in nearly 5 years, my Z has an engine in its bay.

And the first thing I see is a new bonnet insulation 😁

On 24/07/2026 at 18:40, Gaz 300 said:

And the first thing I see is a new bonnet insulation 😁

Actually had that a while, did that in 2020. It’s not exactly had a lot of use 😅

About 90% there

Congratulations.

Much like my own, long time coming.

Congratulations on your milestone Nick! Very much looking forward to seeing the dragon in the metal.

She breathes.

Had a great couple of days with the Z.

Gave her its first wash in years to get rid of all the dust that had gathered on her.

Then took her on its maiden voyage over to East Sussex/Kent borders for a close friends wedding. Was a nice 200 mile round trip to . Apart from fuel economy (which has yet to be tuned), it performed faultlessly! Deffo need to further exhaust work to kill horrendous drone between 2-3k rpm, but I can’t express how nice it was cruising through the southern English countryside on a sunny day with the roof off. It just reminded me how much I love this car

Is that a Wlldtrak or a Raptor in the background ?

What a journey it’s been. Yesterday, 4 years and 362 days since the terminal engine failure of my EPR “built” VG30DETT, my Z was back on the dyno.
I’m happy to report the engine that I specced, prepped and assembled survived and took everything that was thrown at it, with oil pressure being reported as “fantastic”. For a “hobbyist” I should be proud.

But I didn’t get the dump of dopamine I was expecting at the conclusion of the day, that rush of “I did it”. Instead I got the cold sweat of dread when Romain of RaceCal Ltd came off the dyno to debrief me. Fundamentally, everything is fine and the Z has a solid tune, but not without issue…. and I think it’s that very BUT that has taken the sheen off was a good day.

Firstly, the engine has a fuelling imbalance between banks that shifts dependant on load. I have a vague recollection that I’ve had this problem before and never got to the bottom of it.
That in combination with an issue with one of the hub dyno’s having a peculiar loading issue, brought about the conclusion of the day in the interests of safety. And I’m completely content with that decision!

A few other minor issues including a small oil leak that needs to be found as well as the curse of the ATi damper PS belt issue, meaning a 85 mile drive home with no PS.

I think the final factor in my overall post dyno emotions are that I thought i had everything in place to get the optimum output for this setup….. and I don’t. I need to invest time in making proper intercooler ducting to get that IAT recovery and efficiency to be able to make back to back runs. I need to add a second fuel pump to give me more head room to allow the potential maximise the 2860 turbos. I need to find the cause of this imbalance to remove any risk of misfuelling so that tune can be absolutely bang on to really optimise this setup. So, the journey isn’t over yet….. more work, more learning, more money 😂😂😂.

Just a quick one to say thanks. Thanks to Romain of RaceCal Ltd for his time, for his ability to recognise my level of understanding and communicate to me where I can solve issues and make improvements. I look forward to working with you again! #vg30dett #z32 #300zx

(And depending on your chosen calculation, that’s 640 hp and 550 lbs ft at the flywheel, roughly)

Bit of update

so while on the dyno we discovered a few drops of oil under the car. A bit of investigation reveals the most likely culprit is a cam seal…. Annoying! So at some point I’ll have to pull the front of the engine off and install a new seal.

I’ve also been speaking to Brett at BDE and will be purchasing his now PS pulley for ATi crank pulley, which will resolve the issue of it spitting off its PS belt.

I’ve also been going through the datalogs of some of the drives I’ve had to identify the cause of the imbalance of fuelling between banks. While I’m not sure it’s totally the cause, I have found that the alternator is not keeping up with demand. While the pic shows voltage drop during a pull down to 13.06v, wider analysis identifies a direct correlation between the fuelling of the engine and the electrical systems being above or below 13.5v. So I’m going to have my alternator inspected, and if it’s performing as expected I’ll either look at having it uprated to 120amp (to offset the 24amp draw of the 525lph pump) or if that’s not possible I’ll look to upgrade to a 200amp unit from WPS or WOSP.