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!

the exhaust side that were installed by Roland Alsop were not machined correctly and were 4deg off concentric.

 

4° or 0.4°? 4° is a huge error.

4° or 0.4°? 4° is a huge error.

 

Yup, 4 degrees.

 

And for those of you who are wondering what it means for the valve guides not to be concentric.... here’s a quick read

 

https://www.enginebuildermag.com/2013/10/cautioning-on-valve-seat-concentricity/

Edited July 12, 20196 yr by nickz32

How is Mitch measuring concentricity between valve seats and guides in degrees rather than

the thou used in the description you linked?

I’m guessing it’s either the pitch at which the valve guide has been honed, or the angle of the valve seat is off.... but I’ve asked for clarification

How is Mitch measuring concentricity between valve seats and guides in degrees rather than

the thou used in the description you linked?

 

So as you rightly pointed out, concentricity is usually measured in thou. That measurement is, if you imagine, looking square in the face of the valve seat, how central the guide is to the seat. A concentricity dial gauge measures the run out in thou. My issue is with the guide, in that while it’s central the the seat, it’s pitch isn’t at 90 degrees to the seat (it’s 4 degrees off). This has happened either during machining of the guide and it hasn’t been detected, or during the reaming and honing of the guide during installation.

A bit of faffery today. As the OE ducts block both the entirety of the top and bottom rows and 20mm in on each side, reducing the surface area exposed to the cooling air significantly, I decided to mock up my own ducts for my @Z1Motorsports SMIC’s (normal ones not the BA version) to maximise their cooling efficiency. Fabrication has never been my forte, but SMIC duct V1.03 appears to do the trick (v1.00, 001 and 002 were rubbish :lol: ). Just need to mount the front fascia back on to check for clearance issues, tweak a couple of the dimensions then on to the first draft of the metal version

 

Next time I’m at the car I’ll take a pic of the OE duct as a comparison.

 

I’ve also had a bit of a play with ducting the air out of the intercoolers, through the vents I installed into the arch liners. What a PITA that turned out to be!

 

Not sure how to be work the angles on this..... much more pondering required. But in the mean time I’ve bought a Mushimoto expansion tank for the radiator and fully deleted the carbon canister. For the driver side I’m going to down size the washer fluid reservoir, which I’m still in the process of sorting

Edited July 20, 20196 yr by nickz32

New H pipe has been remade using the 3” Vibrant Ultra Quiets. I always thought my Kakimoto system was 3” bore, but it turns out that it was actually 70mm, so a touch smaller. As I’m still using the Kakimoto rear section, we’ve kept the flanges in the same position and rotation as they originally were. Be interested to see how it sounds now

 

Edited July 21, 20196 yr by nickz32

Another little job finished today. Cleaned up the coolant pipes on the front of the engine. Will ceramic coat with the Carbon Collective Platinum Wheels to keep that fresh out of the cast look

 

Complete spec: @cp_carrillo 88mm pistons treated with @techlinecoatings black Diamondyze, crown and skirt ceramic coating, @saenzperformance tri-beam forged con rods, @kingbearings XP series mains and big end bearings, @arpbolts 2000 series main studs and rod bolts, EPR Billet mains caps, modified crank, modified oil pump and extended and baffled sump.

 

 

Also had the waste gates ported an extra 1mm to help reduce the boost creep issues.

Just mind blowing to someone like me who feels great changing my spark plugs and it all still works. :ohmy:

All looking good Nick! When is it all coming home?

All looking good Nick! When is it all coming home?

 

I’d like to think it will be ready for shipping at some point next week. The heads will be cam lobe clearance, skimmed, deburred, cleaned and assembled this week, after that it’s install and set the cam timing. Shouldn’t be far off

Edited July 25, 20196 yr by nickz32

Love it [emoji106]

By how much has that sump increased oil capacity then? Pick up tube is certainly different to stock.

By how much has that sump increased oil capacity then? Pick up tube is certainly different to stock.

 

It’s an 8 quart sump, so 9 litre capacity

 

Head #2 being cam lobe clearanced for the EPR Genesis 1 camshafts

 

 

A little vid showing the cams in situ

Final stages of the head work are under way!

 

First, lapping the valves into the seats... with a little tease of the CNC work

 

Then onto surfacing the head

 

Leaving something like this

 

And then the small details. This access hole is normally sealed with a solid aluminium plug. It’s an access point into the oil galleys that feed they hydraulic lifters. Once the plug is removed, the galley is cleaned and the port has a thread tapped and a grub screw installed to make that access point serviceable in the future. Things like this really reinforce the decision to have EPR build my engine.

Just when the build starts gathering momentum.......I’ll start with the bad news...

 

So for those of you who’ve followed this thread from the start, you may recall a lucky escape I had when a backing plate bolt worked its way loose as jammed itself into one of my intake pulleys...... Post #15 in this thread if you wish to remind yourself.

 

Well it turns out I didn’t get away with it after all!

 

As Mitch has started to cut the seat angle in the valve, he noticed one of the valve wasn’t spinning concentrically in the cutting machine. So he put it on a dial gauge and this is what he found

 

[video=youtube_share;xFHyq-m-pyg]

 

It turns out I have 6 intake valves in the exact same condition... bent. How this car made over 550hp on 6 bent valves is beyond me! Yet again, Mitch’s diligence has made sure that I have a 100% perfect engine and nothing less. So I’ve ordered 6 replacement SuperTech valves from CZP.

 

On the good side, the heads are progressing well.

 

Some before and afters with the head work

Do they port match your manifolds and gaskets to the lovely new machined heads?

Indeed.

 

The lower Plenum has also been cnc ported. This is done by bolting the lower Plenum to the head to ensure the transition from Plenum to head is as smooth as possible

 

Edited August 4, 20196 yr by nickz32

It turns out I have 6 intake valves in the exact same condition... bent.

 

Any witness marks on the old piston crowns?

Any witness marks on the old piston crowns?

 

Nope. It must have just glanced them

That’s so crazy, good luck hope no more dad news, so close to the end.