Installshield's NA Build

^^yeah, man...thanks.

Do you know which is the size used from the factory? Like which size mazda starts with?...I'm hopeful factory tolerances are close enough that they start with one specific shim, and offer the others simply for overhauls...that way i can easily order the sizes i need for the exhaust side right away...the dealership dude had no clue...figures...
 
Just talked to Ryan (2.0T03speed) and it seems there is no 'factory' shim spec...they are shim'd accordingly at the plant...

So that slows me down a little...i need to get the cams off again (oh well, had to anyway) and measure all 8 exhaust discs...and go from there...
 
I just came across this the other day. The shims for Miata should be the same size. Adding the Nissan shims to the list will give you a lot more options. link
 
He shouldn't have a problem getting the thicker shims for the exhaust side. He just has to figure out what sizes he needs. They are only $8 a shim so not terribly expensive.
 
Got it back apart this evening. Cams are out, both plugs were easily removed. No damage to the journals or anything, still seem in great shape.

I'm getting my dial caliper back tomorrow, a friend was using it for model helicopter building...and i just ordered a full replacement timing belt kit from proparts, which includes all the gaskets and everything else i've been meaning to get around a replace...

A few more pics of whats up right now.

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the cam'less head. I'll get it cleaned up soon, pulling the entire engine for the clutch and flywheel installation

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and 1 more

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Starting to believe the twiggys really are cursed...

The set i have never had a hex ground in to hold with a wrench (to torque the cam gear bolt, or break it lose)...no big deal, as i have a bunch of strap wrenches that usually work great for that sort of thing...so to install the gears, it was pretty easy...and got it right at the recommended torque (46lb/ft iirc)...

earlier tonight, removing everything...the strap wrenches weren't nearly as effective with the cams soaked in oil...so i just un bolted the caps and everything, and brought the cams and gears inside still connected...and used some wood with my vice to break the gears lose...worked fine...they were tight, no sign of slippage or anything...

then as i pop the gear off the exhaust cam...i see the dowel pin just hanging there sideways...snapped in half right on the face of the cam end.

I already have a machine shop set up to take the cams tomorrow, and properly plug the opposite ends...now i'm hoping they're able to drill that old stub out and press a new pin in...if not...thats going to be trouble...
 
I stayed up and researched 'broken cam pins' for over an hour last night...sadly, it seems pretty common...which in a way is good news.

or at least, it gives options...I'm not sure what type of material was used for the pin itself, it just looks like a simple stainless smooth stud...and it seems it sheared off when i was just removing the cam gear...those Focus gears fit on the cam end very tightly, and it got a little sideways as i was tapping it off...I guess that put too much pressure on the pin...and ruined it...but also makes it seem the pin material is pretty soft...which is great news, as it can then be easily drilled out...a new pin pressed in...and i'll just remember to be more careful from now on...

if its some case hardened type of thing...that may be there to stay...which i could either leave it alone (a lot of V8 guys do that), and just eye-ball the pin location when pressing the gear on...and making sure the gear is perfectly torqued...or weld a little bit of material onto the stub, and polish it down with a dremel...but i'm doubting the material is that hard, as i easily scuffed it with a small punch and a regular drill bit...just to see what i was up against...i just don't have the tools availbe to mount the cam perfectly straight and stable, and a real drill press to not get sideways when drilling the pin out...

its not a deal breaker in any way...those pins are never used as load bearing reinforcement...its just to guarantee proper gear location on the cam...with adjustable gears, its not really a huge deal if the pin isn't there...as adjustment can be made around it, although its then a 'blind' adjustment which i'd rather not have to deal with.

Taking both cams to the machine shop now...i'll let you guys know how it goes...
 
dropped them off...the tech didn't seem freaked out by the pin, just was worried he wouldn't have the right size pin to press in and replace it...but drilling or tapping it out, he didn't seem to think that would be trouble...he mentioned even if the surface of the pin is hardened, since it sheared off..it left a nice soft center to drill through...i took an old stock exhaust cam in i had laying around, and he was going to try removing that pin to put in the twiggy...fingers crossed...but if that doesn't work due the twiggy pin diameter vs. stock...I'll cut a small drill bit of the right size, and carefully press that in myself...

He was also going to tap a 1/4" thread or so into the open end of the cam...and seal it with a small bolt and some industrial loc-tite...If that doesn't seal the cam and keep internal oil pressure, i don't know what will...

I guess more than anything i'm just nervous having these rare cams in someone else's hands currently...If i get a call that he split the entire cam up the middle, or destroyed the gear end face trying to drill the pin stub out...i might lose it haha.

Picked up my electronic caliper too...my stock shims are .127" all the way across...and i need about ~.004" LESS lash on the exhaust side, other than 2, which need to be .006" or so for cylinder 3...so i'll order 6 shims that are .123" thick, and 2 that are .121"...am i doing that math right haha?
 
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Normally there would be tuition fees, book costs & travel to a campus to get this level of useful, educational information...........subbed.
 
^glad you're getting something out of it man. A lot more to come, just been busy with ordering stuff for the time being...

Ordered the 'adjustment discs' i needed...about $8 each, not great, but not as bad as full dealership mark up at nearly $12 (thats sad)...

After fully remeasuring and writing everything down, they weren't quite .127" each...I had one that was .129", and 2 that were .1255"...the rest .1265 - .1270"...so i got 8 new slightly thinner shims to replace them...which should bring everything between .200 to .240" of clearances for the entire exhaust side...I ordered from an Arlington VA dealership with free shipping, and free part replacement if i ended up messing up a measurement...they claim they'll send me the right one, with a paid USPS label for returning what was wrong...even if i messed up...so not bad, pretty good source for OE parts it looks like...
 
#4 Properties of air...

Anyone that has followed the first 3 write ups should have a decent idea of how the mechanical aspects of an internal combustion 4 cylinder engine operates...with one very complex issue left aside; camshafts...which will need a write up all of their own...but before that, there are some...very annoying...properties of our atmosphere that need addressed...

1st is the make up of whats hugging this planet...and to keep it simple, this is the 'troposhere', or the layer of gas that sustains terrestrial life (us, animals, plants, etc.)...and more importantly...our engines...

the layer touching the surface of earth is made of roughly 78% nitrogen, 21% oxygen, 1% (variable by climate) water vapor, and a small amount of trace gases (one of which, surprisingly, is C02...which if you listen to the news, you'd think it made up most of the gas surrounding earth)...

for our engine purposes...we only need to really be concerned with 2 of them...the most important is obviously Oxygen...the oxygen molecules are very willing to react and combine with the hydrocarbon chains that make up gasoline...and reaction results in an exhaust accumulation of water and carbon dioxide, but more on that later...Nitrogen is also deemed 'important', as it acts as a stabilzer for that reaction...this, too, will be discussed in a future 'whatever you want to call these essays'...

Aside from the chemical make-up, there are a couple of properties related to ambient air that directly effect our engines...most of which are annoying, hard to understand, hard to predict, and annoying...

First is pressure. At sea level air surrounds everything with about 14.7 psi of pressure...the higher you go up from sea level, the more that pressure drops, and the less available air you have to burn in your engine...thats pretty straight forward, and without getting heavily into density, volume, and temperature...i'll just leave it at that...

the other quality though...is the hard one...Air is very elastic, mostly due to the fact that at only 14.7 psi...its not held or 'squeezed' together with that much force...and therefor isn't very dense...the elasticity of air is pretty much the single hardest thing to overcome understanding when building a naturally aspirated engine...as from the get go...you're forced to only use this ambient pressure to get air into the engine, and its not exactly easy...

for me at least; the best way to think of a charge of air...from the filter of the intake system...all the way to the intake valves of the cylinder head...is that its kind of like an invisible slinky...its filling the intake system...but pushing on one end, or pulling on the other...doesn't make the entire 'spring' move in any uniform motion...part of it will do what you want, part of it will fight and not move anywhere...and even worse...part of it will go the other direction...then start coming back, start squishing on other parts of the spring, then move forward again...and it just goes on and on...

So this property makes an absolute mess out of an engine...its why its so damn hard to make an engine have a lot of low end torque, but still make a lot of power up high...piston speeds at one location will suck in air and get volume moving perfectly...but at other locations will cause air to slam into itself and just jam up in there...

These simple 'facts' are much easier to understand than the complex systems engineers have come up with to address them...The next write up is going to be about my most disliked parts of an engine...the camshafts (i've always disliked them; not because recently mine are giving me trouble...)...and i'll address why i think they're archaic, and should've been replaced with systems that make a whole lot more sense (NOT VTEC, cams entirely should be gone)...given the atmosphere we're stuck with...
 
#4 Properties of air...

1st is the make up of whats hugging this planet...and to keep it simple, this is the 'troposhere', or the layer of gas that sustains terrestrial life (us, animals, plants, etc.)...and more importantly...our engines...

the layer touching the surface of earth is made of roughly 78% nitrogen, 21% oxygen, 1% (variable by climate) water vapor, and a small amount of trace gases (one of which, surprisingly, is C02...which if you listen to the news, you'd think it made up most of the gas surrounding earth)...

I like how you view a working engine as more important than life itself. Cheers to the engineer in all of us.
I was surprised to find out that the atmospheric concentration of CO2 was only 0.0387% when I Googled it about 6 months ago. I was expecting to find it at about 100 times that amount or more. Lets hope the plants can suck it all up, they must be pretty good at it working with that level of concentration.
 
yep, not the concentration of carbon dioxide one might expect given the media attention, but that doesn't change anything eh? ;)

subbin'
 
^^yeah, i remembered that it was a very low concentration...but was again surprised when i saw it recently...

No real updates over the weekend...The car has been apart since last Wednesday, and i'm still waiting on word from the machine shop...After probably too much research on broken cam pins, i'm fairly confident i have some options to try myself if they can't get it...i'm just hoping they at least get both cams properly plugged so i don't have to worry about that after a week long wait...

My adjustment discs and proparts timing belt kit should be here early this week, too...I did get around to completely removing everything from the head cover, including the pcv baffle and grommet (the grommet of which was completely dried out and useless in any sealing sense)...and cut a window into the sprocket area to adjust the cams without cover removal...it actually went very well, and ended up better than i expected...since the car is down anyway, i took my time and hand filed the edge to a nice taper...creating no risk of cutting a finger on a burr or something...Tomorrow after work i'll do the same to the upper belt cover, which is plastic, so will probably be a little trickier...I'll also better clean and paint the cover, as the kit i ordered includes all the grommets and hardware...should look pretty nice when i'm finished...

i've pulled that valve cover 4 times in just 10 days haha...the valve cover gasket had NEVER been replaced, and is pretty much dust at this point...surprised it took this long to leak, and even then...it barely let anything out other than a very thin film of oil on the front side...kit includes a water pump too, so i'll get that over with while im in these areas anyway...
 
2 pics of the valve cover 'window'...you can see the old gasket...in a bunch of pieces that it shouldn't be in...underneath haha...

the cover is standing on my seat belt 'hats' that go on top of the rear strut towers, inside the car...i drilled a 2.5" hole out of those as well, to give access to the damper adjustments for my coil overs...I only need to pop the plastic trim off to access them now...

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Are you going to cover the opening in any way? I remember the water pump even had two square rubber grommets on it to seal up the T-belt area. I remember wondering why they didn't make the valve cover out of two separate pieces when they designed it. I'm sure they could make the part above the cam sprockets out of plastic. That would have saved a lot of steps in a timing belt job. My neighbors Accent has the entire valve cover made out of plastic.
 
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I'm probably just going to leave the window opened...i'm in there regularly, and that location seems to get very little moisture or anything...even when driving in down pours...

I'm leaving the lower timing belt cover and most of the upper cover in place...i'll just cut a small section out of the upper plastic cover to leave more room for getting to the adjustable gears...

yeah, kind of sucks that the valve cover is one peice like that...the oil seal doesn't go out to the sprockets, its goes up and over both thrust bearing caps where the cam seals are in place...its just a 'hat' for the sprockets, serves no other purpose other than protecting the top of the sprockets and belt when working around the top of the engine bay...I didn't remove that hat entirely, as you can see from the pics...as i wasn't doing this to make a timing belt change easier (i'll always check valve clearance when replacing the belt, so the cover is coming off anyway), but it will be very easy to adjust the gears with very little effort now...

i've been running the car for over 100,000 miles without that passenger side splash shield in place, too...crank pulley (which i just replaced with a udp late last year) was in perfect shape, and everything inside that cover looks brand new...so i'm not too worried about anything other than debris (misc bolts, nuts, etc) falling in the belt area...i'll have to be very careful about that when doing any work in that location...
 
I'm probably just going to leave the window opened...i'm in there regularly, and that location seems to get very little moisture or anything...even when driving in down pours...


There's always duct tape ya know. You can pick out a color that matches your newly painted valve cover,... or a red white and blue ensemble to show your patriotism!?!?

I'm Canadian EH. We use a lot of that stuff. I'm making myself a new wallet out of it.
 
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