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I thought my Zen thread was formidable.. OP makes the Zen thread look like it was done by a drunken 4 year old..
Hats off to you, xworks. I’ve never before read a project thread with more detailed information and wit.. yes, wit – which is a word I never thought I’d use to describe a project write up.
Thank you for taking the time and care to compose it. I have a taste for what it takes to be constantly getting the camera out every step of the way – then loading all the photos – then generating post material. You have done so with remarkable skill – as you build a very remarkable car.
Also, this:
Originally posted by xworks
Restorations where the odometer should be set to zero are few and far between. You’ve earned the right to do so in spades.
many thanks for the kind words lads, it's always nice to see
at least some of this waffle is proving interesting.
Just another small bit on prep to go before the engine gets nailed together
and then we can stumble into the mystical world of little black boxes and engine
management. Wonder if there's enough room on the interweb.........
Question about finding the true TDC. When you were setting the piston to deck height you were measuring the high point on the piston, but when you put you gauge in through the plug bore after fitting the head you were measuring the bottom of the dish.
My question. Wouldn't that cause some variance between the two TDC measurements since your "zero" would allow the piston to be slightly higher in the dish, or does it not matter because you the piston set to deck height before fitting the head? Basically you're just wanting to know when the piston has dropped 5mm, right?
Amazing thread BTW. I've been watching this thread for over a year now. Good luck hiding from the credit sharks!
Basically you're just wanting to know when the piston has dropped 5mm, right?
Thats it in a nutshell, all your interested in is an accurate measurement
of when the piston drops 5mm either side of TDC. And having said that,
5mm is just a figure I decided to use, you can drop it 8, 10, 12mm or any
distance you want, so long as you drop it the same distance either side of
TDC.
When you fit the dial gauge, whether it be on the raised edge of the piston
or down through the spark plug hole into the dish in the piston, the first
thing you'll do is crank the engine over and back around TDC to find the
highest point the piston rises too. When you've found this point the dial
gauge is zero'd and it's using this zero that you drop the piston back 5mm
either side of TDC. Whether the pointer is on the rim or in the dish of the
piston will make no difference for this measurement, all your interested in is
the exact point the piston has reached the top of the cylinder.
Haven't had much of a chance to work on the car lately, but, by way of a
small update to the thread I've routed out the last of the pic's for the
engine prep section.
One of the final items on the list to check were the valve springs...........
both the outer and smaller inner springs first had a quick check to make sure their
free standing heights were all equal.......
tolerance I'm using is 1.5mm, so, any spring thats over 1.5mm shorter
than it's brothers and sisters bites the bullet.
happy that none of the springs were deformed or "squashed" from previous use
the next check was to ensure each one was straight.........
tolerance this time around was 4mm, any spring displaying a drunken lean of
more than 4mm gets shown the door.
Before finally the poundage of each spring is checked using this little gauge......
Each spring is placed into the screw press and using the dial gauge each
one can be compressed the same distance while the force it takes to do
so can be read off the little gauge.........
The idea behind the check is to highlight any weak springs which may struggle to
control the valve when the engine rev's start to rise, and having seen in the last
section how close the valves run to the tops of the pistons the last thing you want is a rebel
valve doing it's own thing as the piston hurtles up the cylinder at warp
speed trying it's best to make shite of it.
Schrick list pressures in their catalogue so you can check each springs pressure at it's installed
height and at it's fully opened height (valve fully opened, spring compressed) to make sure they're
on the money.
However, when testing other makes of springs or even the standard BMW valve
springs it can be hard to track down this info and in this is the case each spring is just compressed to
it's installed height and it's fully opened height and the pressures are noted and all are checked to see
if they are within 10 percent of each other which is usually good enough to show up a weak
spring.
After this was done it was on to the coma inducing task of checking
valve spring installed heights.
So,
whats the deal here,
nobody asks.
Looking at the picture below you can see all the valve's in place and
and the springs pulling the valves tightly closed into their seats..........
The springs need to be pulling the valves closed into their seats just the right
amount. The smart folk that design valve springs do so in such a way that when the
valve is installed in the head, and it's spring is fitted, the valve spring is compressed
just enough to hold the valve shut with the right amount of force.
This is all bloody marvellous when the engine leaves the factory, but now we've had
a chance to screw around with things by cutting the valve seats and fitting aftermarket
valve springs we were going to have to check the new valves were going to be pulled shut
again just the right amount.
To do this we were going to have to measure the "valve spring installed heights". And
hopefully the diagram below should help to show what this measurement is........
As you can see above the valve spring is trapped between the lower and upper
valve spring retainers. The distance between these two retainers is the valve spring
installed height and Schrick kindly list what this measurement should be in their catalogue.
So next we need a way to measure what the installed heights were on my valves so
we can check it against this figure and below you can see what we use.
It's called a valve spring micrometers............
Basically the little tool is inserted instead of the valve spring and you rotate the
two halfs of the tool to extend it. When the tool is extended as much as the valve
spring retainers will allow you read off the little increments on the side to see
what the distance is between the top and bottom retainers...........
Unfortunately due to the nature of the design of the S14 cylinder head and the
shape of the retainers I'm using the little tool took some serious modifying to
fit into place and do it's job right. After a little bashing and much swearing
it worked and what it showed was that my installed heights were too large
as things stood which would mean the valve springs wouldn't be squashed
enough at rest to hold the valve shut with the right amount of pressure.
Thankfully the cure is rather straight forward. Some valve spring shims,
which are available in a variety of different thickness's, were purchased
and fitted below the bottom retainers to return the installed heights to what
they should be.
While up the top of the engine it's probably worth
mentioning another two small jobs that were carried out in the valve train area
during the engine prep. The first of which is camshaft clearance.
The cams being used are a higher lift than the standard items and as such the
lobes on them are naturally a little taller than the standard ones, hence the higher lift.
The standard cams are a rather "snug" fit in the cam box and when your fitting larger
ones this "snug" can become "tight" or "interference" depending on the size of the cams.........
and while the cams I'm using didn't actually hit the cam box while being rotated
they came a little close for comfort and it was a fair bet that if larger cams were
being fitted down the line things could get funky.
So, mark up the areas where the cam lobes and surrounding metal are trying
there hardest to become intimate (which is usually only on the inlet cam)..........
whip out the belt sander........
and mow chunks out of it........
The other little task needing doing was to check the oil clearance on the
camshaft bearings. The cam box is bolted down tight to the cylinder head........
and each bearing journal on the camshaft gets a little piece of the plasti-gauge
stuff we used earlier fitted before the cam caps are torqued down on top of it...........
removed the caps and checked how squashed the plasti-gauge was......
and thankfully they were all within the listed tolerances of
0.0011"-0.0021" (0.027-0.053mm).
With that done, it was time to take a break from the measuring part of preparation
for a while and concentrate on some "blinging", because if e-bay has thought us
nothing else it's that bling adds at least 100hp to any car.
The rocker cover was looking reasonably well upon engine dismantling as she had
taken a lick of paint not long after I bought the car.........
so it didn't need to be stripped back to the bone again. A little wire
wooling to scuff the surface and give a fresh coat of paint something to cling on to........
and a little block sanding of the raised aluminium pieces just to brighten
them back up again..........
bit of masking tape, splatter of satin black and bob's your uncle......
the other thing getting painted at this stage was the airbox I had purchased
a long while back in a group buy. We'll probably get into how it works and whats
involved fitting the airbox down the line at a later date, should any of us live that long,
for now all we are interested in is how it looks.
As mentioned, I purchased this airbox a good while back and it's a little different
from most airbox's people may have seen as it's constructed from fibreglass rather
than the usual carbon fibre. The upside of this was it cost a fair deal less than a
similar carbon one.............
Although the airbox is an exact replica of the motorsport derived units there
was no escaping the fact it didn't quite have the same bling factor of the
carbon version. So, I decided to try brighten it up a little (and in the process
waste some more f*cking time which would have been better spent getting
this car finished and on the road).
The airbox came with a sticker of the same logo that adorned the rocker
cover............
which was cut up and the individual letters were stuck to some aluminium.........
and then we used our state of the art, computer guided, CNC controlled,
water cooled, 3d, 5 axis..........hacksaw to cut the letters out and then
file them down.......
after about the 3rd letter I realised this was going to take an eternity, after the
fifth letter I tried introducing alcohol to the procedure, the rest is a kind of blur
funnily enough.
Eventually the lettering was done and after detoxing the task of bonding them
on straight could begin............
the curvy nature of the airbox very nearly seen alcohol been reintroduced
to this step...........
the letters were bonded on with this stuff, which if you ever get the chance to use
it you'll find is good gear, i'd say there's a fair chance you could glue an elephant
to the blades of a windmill with this, should you need to...........
with the letters bonded on and me having recovered from very near disastrous
experience of a quick toilet break while using industrial strength glue, everything
was taped up for a final coat of satin black to match the rocker cover........
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