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!

Great work, lovely to see.

Something I hope to undertake myself one day.

Will you be volumetrically checking each port system with a measured fluid capacity process?

 

I must say, I am very surprised that the engineers checked your valve concentricity by way of a chucking system as opposed to a precision collet system.

Even a simple paired V block arrangement would have been more trustworthy in my humble opinion.

Great work, lovely to see.

Something I hope to undertake myself one day.

Will you be volumetrically checking each port system with a measured fluid capacity process?

 

I must say, I am very surprised that the engineers checked your valve concentricity by way of a chucking system as opposed to a precision collet system.

Even a simple paired V block arrangement would have been more trustworthy in my humble opinion.

 

He didn’t check them using the lathe, that was simply the easiest method of showing me via video what he had noticed when he had put the valve in the valve grinder. I’m sure there is a more accurate method of showing the amount of bend, but it’s kinda pointless.... a bent valve is a bent valve and needs replacing.

 

Checking the ports volume, probably not as that info doesn’t really assist me in any way. I can’t make use of it for the tuning process as the Haltech Platinum doesn’t allow individual cylinder fuel maps, just injector trim. If I had something like an Elite 2500 or Motec M150, with individual IAT sensors per cylinder and EGT per cylinder then it would be information I could actual use to my benefit. Otherwise it’s just “nice info to have” for me at this stage.

I’ll be able to see the benefits/changes in the heads as I’m using VE based tuning rather than Speed Density, so my VE numbers in the map should be lower across the whole map in comparison to my old setup as both compression ratio and engine CC has remained the same

Edited August 5, 20196 yr by nickz32

This is the other vid EPR sent me that shows a bent vs straight valve in the same jig

 

[video=youtube_share;jHkHXqaxi3I]

Thats a good way to show the difference in bent and straight valves.

He didn’t check them using the lathe, that was simply the easiest method of showing me via video what he had noticed when he had put the valve in the valve grinder.

 

I see, that helps me understand things a little better.

 

Checking the ports volume, probably not as that info doesn’t really assist me in any way. I can’t make use of it for the tuning process as the Haltech Platinum doesn’t allow individual cylinder fuel maps, just injector trim.

 

Fair enough, granted it does not allow for individual port volume tuning per say, but as each cylinder will be drawing from the same source, then surely the closer the volumetric balance the better?

 

I’ll be able to see the benefits/changes in the heads as I’m using VE based tuning rather than Speed Density, so my VE numbers in the map should be lower across the whole map in comparison to my old setup as both compression ratio and engine CC has remained the same

 

I look forward to seeing your figures, as you say, the benefits should be awesome.

Keep up the good work sir.

I see, that helps me understand things a little better.

 

 

 

Fair enough, granted it does not allow for individual port volume tuning per say, but as each cylinder will be drawing from the same source, then surely the closer the volumetric balance the better?

 

 

 

I look forward to seeing your figures, as you say, the benefits should be awesome.

Keep up the good work sir.

 

Coolio

 

Yeah it would in an ideal world, but it’s being force fed by a Plenum (not drawn by cylinder vacuum once on boost) that isn’t supplying a balanced portion of air. By going down that rabbit hole I’d be chasing my tail for thousands of dollar more work... kinda gotta stop somewhere.

 

Cheers dude

Edited August 5, 20196 yr by nickz32

Another new addition that will provide a little more protection to the turbos

 

 

I’ll be plumbing one of these in the feed line for each turbo. Should anything go wrong in the future (I bloody hope not!) they’ll prevent any debris being sent off to the oil journals and potentially trashing a set of turbos. I’ll need to make up a set of custom -4 braided lines for the turbo oil feeds, but that shouldn’t be too hard to do

Edited August 6, 20196 yr by nickz32

Another new addition that will provide a little more protection to the turbos

 

[ATTACH=CONFIG]117878[/ATTACH]

 

I’ll be plumbing one of these in the feed line for each turbo. Should anything go wrong in the future (I bloody hope not!) they’ll prevent any debris being sent off to the oil journals and potentially trashing a set of turbos. I’ll need to make up a set of custom -4 braided lines for the turbo oil feeds, but that shouldn’t be too hard to do

 

How often do they need replacing or servicing and do they have a bypass function? It would be interesting to see how they affect flow and pressure through the turbos.

So they’ve got a 44 micron stainless steel mesh filter that’s washable.

 

There’s nothing about service life on the bumpf on the website, but I guess you’d just clean them out whenever you did a normal oil and filter change.

 

As for pressure drop, being TurboSmart, I doubt there’s any

 

A pic showing the inside of the oil galley that was opened cleaned and threaded that supply’s the lifters

 

What make of head gasket is being used?

What make of head gasket is being used?

 

OEM. They’re sprayed with a copper coating to help create a bond between deck surfaces.

Another little update.

 

As the late series cars did away with the EGR system, it means the EGR valve mount on the back of the lower Plenum is redundant. So, to make getting to the knock sensor that little bit easier, it’s been machined off. Here’s a little sneak peak of the lower Plenum porting aswell

 

Lower Plenum is now complete. EPR noticed that the Plenum was warped by 7 thou, so it’s been surfaced to correct. I also had a couple of iffy threads for where the upper Plenum bolts down to it. This has been resolved and all the threads have been replaced with Keen-Serts

 

 

Unfortunately, it appears that the stock gaskets appear thicker than previously experienced. This has caused the lower Plenum to sit a little higher than the port by a smidge. A shame, but budget doesn’t allow for rectifying at the moment

 

Edited August 7, 20196 yr by nickz32

 

Upper and Lower ARP idler studs installed

Edited August 7, 20196 yr by nickz32

Unfortunately, it appears that the stock gaskets appear thicker than previously experienced. This has caused the lower Plenum to sit a little higher than the port by a smidge.

 

That's with the lower plenum torqued down on the head(s)?

That's with the lower plenum torqued down on the head(s)?

 

Yep

Fantastic engineering going on here, looks like the trip around the world for your engine is really worth while.

Fantastic engineering going on here, looks like the trip around the world for your engine is really worth while.

 

Thanks fella

That's with the lower plenum torqued down on the head(s)?

 

Yes unfortunately but let me clear the air about why it's this way. The heads had been surfaced quite a bit before we got them. In order for us to correct this to how we'd of loved to do is weld the decks of the heads and mill the intake flange faces to get it dead nuts. There's 2 things we have working against us..time and more time. If the heads hadn't been cut so much prior (casting numbers were already milled off) this would of lined up fantastic like our other setups have been.

That's with the lower plenum torqued down on the head(s)?

 

Also just thinking, my heads have been skimmed 3 times, which is probably the biggest reason for the slight step

 

***edit, should read the replies first, what he said ^^^^***

Edited August 7, 20196 yr by nickz32

Fantastic engineering going on here, looks like the trip around the world for your engine is really worth while.

 

Agreed..

Yes unfortunately but let me clear the air about why it's this way. The heads had been surfaced quite a bit before we got them. In order for us to correct this to how we'd of loved to do is weld the decks of the heads and mill the intake flange faces to get it dead nuts. There's 2 things we have working against us..time and more time. If the heads hadn't been cut so much prior (casting numbers were already milled off) this would of lined up fantastic like our other setups have been.

 

Your idea to get it dead nuts is great, but as a cost/time effective compromise, would it not be beneficial to at least smooth the transitions slightly with a Dremel? I appreciate it’s not going to be perfect but it seems a shame to have all that lovely laminar flow slamming into a flat face like that, it can be made significantly better with little work?

 

I know it’s only a small face, but it will certainly cause turbulence and undo a certain amount of the good work already achieved; a small lip means it’s also easier to buzz a transition into?

Your idea to get it dead nuts is great, but as a cost/time effective compromise, would it not be beneficial to at least smooth the transitions slightly with a Dremel? I appreciate it’s not going to be perfect but it seems a shame to have all that lovely laminar flow slamming into a flat face like that, it can be made significantly better with little work?

 

I know it’s only a small face, but it will certainly cause turbulence and undo a certain amount of the good work already achieved; a small lip means it’s also easier to buzz a transition into?

 

Could but then we kill velocity by making the entry ways considerably larger just to save face of trying to match them. Even factory lowers to the heads don't line up correctly. It's all production tolerances. Only way to do it is right and the right way would have been to essentially replace the deck material then surface accordingly. Believe me it's not favorable but a picture doesn't show everything. It's not off as much as you'd think.

Yes unfortunately but let me clear the air about why it's this way. The heads had been surfaced quite a bit before we got them. In order for us to correct this to how we'd of loved to do is weld the decks of the heads and mill the intake flange faces to get it dead nuts. There's 2 things we have working against us..time and more time. If the heads hadn't been cut so much prior (casting numbers were already milled off) this would of lined up fantastic like our other setups have been.

 

Out of curiousty Mitch ,As the heads and intake now sit lower at what point would you say the cam timing is altered adversley ? I am loving this thread and the work looks epic by the way.