Cus' NA6

[ManiacLachy]

Fair enough, looks like a good long term plan.

Seeing as you're not in a hurry to build the ultimate 400whp MX-5, you could probably get away with a visual inspection like you describe, a clean then slap it back together with new seals etc (if there's nothing terribly amiss). Even if it doesn't run perfectly, such as compression is a little down, it'll still be fine for the next few steps until time/money/significant other allows for the full bottom end build.

I'll be keeping a keen eye on proceedings, I enjoy watching the engine build process - maybe one day I'll try it myself.

[Cus]

I'm interested to see how it turns out too!

I've seen a couple of engines built with my own eyes, read quite a few build threads over on mt.net and watched "a few" youtube videos - basically it boils down to "read the docs" "clean everything" "pay attention" and "don't rush" - I figure I can do most of those things, so I can probably dismantle and reassemble an engine!

In other news, I've found the source of my disappearing clutch fluid posted either here or on bookface. It's the clutch slave cylinder - I've just got a new clutch slave cylinder and a HEL braided clutch line (because bling) - they'll go on this weekend, and my clutch-fluid-top-up-days should be over!

[Cus]

Today, more pictures.

Sad pictures.
Distressing pictures.
Potentially expensive pictures.



So, first, Cylinder #1, Ex side:


Cylinder #1, In side:


Cylinder #2: Ex side:


Cylinder #2, In side:


The culprit was the little blob next to the red arrow. He came off and disappeared (probably into the water jacket) while I was cleaning.


It does look like it's been stationary for a while though, which is .... an observation.

First 2 cylinders after some cleanification:


Top of the piston:


The options I've come up with are:
1) pretend it's not there, likely detonate engine once it's built and boosted (not a problem for the time being)
2) new head, sell this one to someone who wants to try their hand at port work.
3) get someone that knows what they're doing to machine it out, get 11:1 pistons.
4) deck the block a shit-ton, hope it solves the problem, get 9:1 pistons.

So, on a scale of one to "sucks to be you", how bad is it?

[StanTheMan]

I'll take it off your hands

$50 delivered to sydney.

in all seriousness though. are you able to tell how deep those Pitts are ? surely you can get those out with a hero shave

[Okibi]

Or could you grind out the same depth from each, lowering the compression a touch.

[ManiacLachy]

Deck it, and then go E85 asap to reduce further det due to high compression? Then when you do the rebuild go for low compression pistons which should balance out to a nice moddest ratio? Might make boosting it a little tenuous though until you do the pistons.

[Cus]

they're about 1mm deep. I'm not sure if that's hero-shave territory or not, you'd know more than me on that one STM! What worries me most is the deforming at the edge of the lip inside the combustion chamber.

I'm somewhere between 'throw money at it' and 'throw it in the bin' at the moment.

I got some vague numbers for the bottom end - $3500 for the bare minimum with forged goodies + shop work, and then hunt around for another VVT head for not-unreasonable money.

or i could just buy a whole other VVT engine, and pretend this one never existed for a few years until I'm actually ready to build an engine.

[StanTheMan]

they're about 1mm deep. I'm not sure if that's hero-shave territory or not, you'd know more than me on that one STM! What worries me most is the deforming at the edge of the lip inside the combustion chamber.

I'm somewhere between 'throw money at it' and 'throw it in the bin' at the moment.

I got some vague numbers for the bottom end - $3500 for the bare minimum with forged goodies + shop work, and then hunt around for another VVT head for not-unreasonable money.

or i could just buy a whole other VVT engine, and pretend this one never existed for a few years until I'm actually ready to build an engine.

Meazure the thickness of your head. Probably somewhere near134.5 or something.
I dont recall what the min is right this minute.
Its somewhre around 133mm
My head is somewhere around the 132.4 mark. Anything below the min recomendation to me is a hero shave. I took off about 1.6mm and ended up with the 132.4 mark.
With turbo in mind down the track. Id measure the head. Figure out how much you need to take off to get it flat .If its below the min recomendation have a good think if you want to continue. But i think in the other thread somoen mentioned hardness test. Thats also a good idea.
You will most likely also reseatl valves & look at the valve guides. So check hardness first. Also gapping the solid lifters will all be a waste of money if the head is toast.
Having a custom thickness head gasket can also be an option if the heas shave goes further than expected.
Any pits inside the head can be polished/ground out. This will reduce your compression i bit but whatever you take out in 1 cylinder be sure match the others. Changing the shape of the cylinddr dome may also affect your quench. Depending how much gets taken off.
So it can all be fixed. Just depends on what you want for your end result with thicker head gaskets affecting quench area as well as whatever compression you end up with when going turbo.


Sent from my SM-G935F using Tapatalk

[StanTheMan]

How do the cylinder walls look?


Sent from my SM-G935F using Tapatalk

[Cus]

The cylinder walls look to be pretty good, there's a small indent at the top of the combustion chamber, but not anywhere down the walls from what I can see. The indent looks like it could be taken care of with some 84mm pistons and a bore expansion

Step one will be a hardness test by someone with more clues than me, and then decide from there. I'll measure the head tomorrow, I have a feeling (blind optimism) it will be stock dimensions. If adding some volume to the combustion chamber looks like a viable option, I might just do that too.

I've decided to have a little look around for a VVT head in better condition - if one comes my way for a reasonable number of rupees I'll just get that and rebuild the bottom end and carry on my merry way. The girlfriend is somewhat upset at the numbers I'm throwing around in the finance department, but I explained to her I've been in love with the car longer than her ... If you're ever thinking of saying that to a woman, it's not recommended!

Fixing this engine will result in basically having to build the bottom end and get some head work done. None of that adds up to cheap. But also it's all stuff I wanted to do "eventually" - so the choice becomes "build a turbo-ready engine I won't be able to turbo for a long while" or "take the loss and get another VVT engine, and still have a chunk of change left over for the application of boost in less of a while"

But I really don't know. My plan was "gaskets and seals and install it" - and I'm not known for deviating from my plans too far - so I'm having to assess my thought process all over again, I really don't want to install an engine I'm not happy with, I just know it'll end up biting me in the arse later.

[3gress]

Seems like you have a serendipitous opportunity to build the block now.
Get the short block machined and roll the sleeves up ready to assemble components yourself to save on cash. Since you're aiming to turbo in the future perhaps source another standard vvt head as the extensive headwork necessary to repair damage within combustion chamber is just going to chew money and isn't crucial as with a high comp NA build. Also combustion chamber alterations require careful consideration regarding piston selection, extensive chamber C.C. measurement/matching, swept volume calculations etc whether or not forced induction is planned. It would be wise to strengthen the short block you have with an overbore and forged internals and use a more or less standard replacement head to avoid issues when adding boost. At best give the ports of the new head a light going over to remove the dags and remove casting imperfections on the bifurcation edge where ports divide to valves. Usually this area is pretty chunky with casting misalignment. Something you can easily perform yourself.
If it was a daily driver sourcing a new long block would be the go. Whack it in and add the turbo as finances/significant other allows.
I've not messed with a whizzer for years but loved the relative ease of significant power increases without opening the engine. I wish i could help out more, i had an opportunity to acquire a fresh vvt head when i bought the later model short block but it wasn't needed for my build.
Good luck on the build mate.

[Cus]

What do you do when your motivation to work on your MX5 wanes?

Drive it!



Left at 2PM, got home about 10PM after discovering (which, in hindsight isn't a surprise) that all of the tourist-towns had no accommodation with zero notice on a long weekend. Whodathunkit?

In other car-related news, I've fixed several rattles with stick-on foam pad things "Surface savers" from the stupormarket. They stopped the hard top latches rattling fairly effectively - I pulled the previous, now hard and worn foam pads from inside the latches and replaced them with the felt ones. It's "heaps good"

A HEL Braided clutch line and accompanying slave cylinder went in at some point recently too. There's way less clutch line in the car now, and was easier than expected to bleed - and, this is the best bit - all of the clutch fluid i put in a few weeks ago IS STILL THERE!!!

And, my final improvement - winding the suspension all the way down to soft - it's still pretty bumpy, but a lot nicer about it, which is great considering I usually drive to work and back, and getting to any interesting roads requires road trips like the one above.

I'm officially on the lookout for another VVT Long Block.

[mekros]

Good to see you're enjoying the car again, keep the updates coming!

[Cus]

What was I doing?

Let's set the scene: It's the middle of winter. School holidays. I have a VVT engine, it is not installed, or in one piece.



There is a lot of stuff in this picture.
Movable Fluro Light, with all of the fluro parts pulled out and replaced with about 2.5 meters of LED strip lighting. Most excellent.
Unifi AC Pro access point, running on POE and wireless uplinked to a Unifi HD, which is in turn Wireless Uplinked to another Unifi HD. All APs are from work - I'm .. umm .. testing them. I have 50Mbit/s up and down, in the shed. You don't need 50Mbit/s for spotify ... but it helps. If anyone wants a recommendation for a Wireless Access Point, get the unifi gear, AC Pro or HD. not the LR, they're terrible (HDs have better antennas, so much so the laptop pictured sometimes stays connected to the HD in the house instead of jumping over to the AC Pro that's literally centimeters away from it)

Why am I talking about APs? This isn't UniFiAccesPointTalk!



A VVT Head, sans head, tuesday last week.



It's mah dremm'l!



It's mah port work! .. wait, what?



Yeah, nah, no idea what I'm doing. But, much like carrying a bundle of paper and walking fast in an office leads people to belive you're doing something more important than walking around carrying a stack of paper, showing people photos of a dremel and a sandpapered head will make people think you're porting your head.

I've just taken the casting flash off, and given it a little tickle with some 80/120 grit. Someone that understands what they're doing really needs to fix the bowls on the intake side. That won't be me though!



I was totally looking forward to cleaning these bad boys!



Big milestone here! The first charge finally wore off my batteries. I was all prepared to not clean valves anymore ... but it turns out I have a quick-charger. Battery was charged back up in the time it took me to have a coffee and stand in the sun for a bit.



All done!*

Or so I thought.



THESE LITTLE MOTHER FLUFFIN MOTHER FUNKERS.

I didn't even know they existed until I picked the head up from being upside down on the bench, and there were 9 of them. I counted 6 in the head, and spent the better part of an hour trying to find the 16th. it was stuck to one of the "9" that had fallen out of the head. Glad it wasn't lost, less glad i spent an hour discovering that fact.



That's where they live!

*screen flickers and the channel changes*



The exhaust fell off the back of the cat. It was quite loud. Old people stared at me as I drove by. $80 later and someone with a welder and a hoist had fixed it for me.

*screen flickers and the channel changes back*



Ooohh what's this thing? Well, it's valve facer thingo. I just had to make a belt for it, out of the supplied leather strap. If you nede to make a belt out of leather, CAT6 network cable strands seem to be working so far.

Do I know how to use it? Well. No.
Is that going to stop me? Probably.



Removing valve stem seals is about as much fun as cleaning valves. It goes a lot better with a shiney new set of needle-nose pliers. First on the bottom left, last on the top right. The "missing" one is somewhere in the shed. It landed on something soft, by the sound of the quiet thud it made.



Exhaust valve about to be lapped in



Exhaust valve after being lapped in.



Intake, pre-lap.



Intake, post-lap.



And finally, I used the valve grinder to put a 30 deg back cut on the intake valves. Entirely because there's a machine in the shed that does that.

5 days later, and I think I'm up to re-assembly. Even if I'm not, I'm going to start to put it back together anyway.

[Cus]

one, two, skip a few, ninety-nine, ONE HUNDRED!!!



It has very recently dawned on me that i need a water pump....





The head is all done up to specs and is ready to roll (as far as I'm aware - I'm yet to re-measure lifter clearances, they were a few thou over when I pulled it, I doubt it will be magically better now)

I'm more excited than I should be to use the bleed on the reroute:


shopping list is - oil filter x4 million, oil, na8 altinator, water pump, engine mounts, some kind of spark solution.

side question: there's one or 2 degrees of rotational wobble on the TTV actuator, is that normal?