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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Sun Aug 03, 2014 11:28 am 
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So with the ports nearly finished... I proceed to the chamber work. Basic, or minimum deshrouding to start....

Image


... but more will be required...

Image

...because we have already lost some of our volume.... this head has likely been cut .012"-.014"........



More to come..... :mrgreen:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Mon Aug 04, 2014 5:03 pm 
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oldeskewltoy wrote:

Image

...because we have already lost some of our volume.... this head has likely been cut .012"-.014"........


but the surface has some flaws... and the finish on the cut is not as good as I like to have...
Image


So the added cut cost me and my client .004"...


Image

... but now I have a final surface I'll fit the valves and get chamber volumes..... and proceed with final chamber sizing



but... we have a problem.... remember how well this was all packed? Well the valves were packed in individual marked bags.

Image

Each bag contained a valve, a spring, a retainer, a spring seat, and 2 keepers, a lifter/bucket, and a shim. It appeared that the valves had previous been machined as well... not just clean, but machined.

Since this was the first head I had accepted that had come with valves already machined, and me, being careful, I had the guys @ Loynings check the valves for me.... just in case.

It was a good thing I did... 12 of the 16 valves are either ever so slightly bent, OR they were machined incorrectly

Image

There is a .003" "wobble" to the above valve. Acceptable "wobble" is .001". Of the 12 valves out of spec, they range from .002" to .004".

The valves may be able to be re-cut, but the few that are the furthest out might not get concentric before I run out of margin (edge of valve). So I've recommended to my client I can supply him with 16 good used valves that I'll have cut to specification... OR the client can opt for Supertech valves. I await his decision....



more to come........ :mrgreen:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Tue Aug 05, 2014 12:00 pm 
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oldeskewltoy wrote:

So I've recommended to my client I can supply him with 16 good used valves that I'll have cut to specification...



Image

going through some exhaust valves... looking for valves with a good margin - over 1mm, so they can be cut and still have enough margin for durability. Did the same with intakes...


more to come.... :mrgreen:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Thu Aug 07, 2014 4:06 pm 
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oldeskewltoy wrote:
So with the ports nearly finished... I proceed to the chamber work. Basic, or minimum deshrouding to start....

Image


... but more will be required...


I wasn't sure how much... after all... the clients valves were not going to be used, I had picked through my old valves for a decent set. So "new" valves, and had them ground, along with the 3 angle grind.... after all of that....

Chamber volumes were....

Image

35cc, 35.2cc, 35.2cc, 35.1cc (based on beginning meniscus levels)

All in all not too bad, well within acceptable tolerance... but I worked #1 a bit more then the other three, I'll have finished chamber volumes by Monday...



Now here is the progression of chamber #2....

Image


More to come.......... :mrgreen:

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Last edited by oldeskewltoy on Fri Aug 08, 2014 2:40 pm, edited 1 time in total.

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Thu Aug 07, 2014 8:59 pm 
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Location: Ohio, USA
Have you worked on any Nissan L-series heads?

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Fri Aug 08, 2014 2:30 pm 
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Italian wrote:
Have you worked on any Nissan L-series heads?


Not since I wrenched for Datsun back in the early 80s.... (C&M Motors in Denville NJ... not sure if they even exist anymore)

It's been a while... but the shop that does my machine work (valve jobs, surface milling) has VAST experience with the Datsun "L"...

Image

If there is something I have a question about... I can inquire with them..... :wink:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Tue Aug 12, 2014 5:34 pm 
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The port roofs are now blended to meet the delete plate


Image




and the injector ports are ready for filling.... :shock:


Image

5 - 3/32" holes about 2-3mm deep spaced around the injector port. These, along with the top of the injector port, will be the anchor points for the JB Weld...


Yep JB Weld.... I've done a LOT of research into this. I've looked at some of the other products - Devcon for instance, and none of them offer the temp, and holding capability of the JB Weld - http://www.jbweld.com/faqs/


More to come........ 8-)

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Wed Aug 13, 2014 8:28 am 
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Image


more to come........ :mrgreen:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Wed Aug 13, 2014 12:18 pm 
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The above 2 panel was injector port #1...



here is the work on injector port #3

Image

Its just been finished(filling).... note the change in the clay... it is a vital tool in this operation for it allows "adjusting" the volume of JB Weld - by either pulling the clay, or pressing the clay, i can change the level at the port roof.


Image

Also I learned from injector port #1(center in photo above), that it is a bit better to begin filling the port with the clay slightly free to allow the JB Weld to completely fill the injector side of the port. There is enough JB Weld on #1, but #2(far right) is a more complete fill.


Quote:
it is a vital tool


and here are a few others....

Image

I use builders shims in a LOT of my work... they are great for setting the head up for checking chamber volumes, and here I'm using them as applicator/spatula, and as my palate for mixing, and applying. The dental tool helps remove the clay, or as much as I can... the spent tubes of JB Weld... and my finger! A wet finger allows me to shape and fill the voids... I prefer to use water... but saliva works in a pinch :P



more to come....... :mrgreen:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Wed Aug 20, 2014 11:10 am 
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Image

Here is a clearer view of the filled and finished injector ports - the coarse appearance is a 100 grit surface finish to aid in keeping the fuel atomized - closer view of this finish to follow



Image
The lower photo was taken with a different camera setting... that is why the bowls appear smaller in the lower view

Another OST 3 -panel... This one shows the bowls, ports, and delete plate. The Green dotted horizontal lines show the excessive size of the delete plate, the green arrow shows that I slotted and "moved" the whole plate up, eliminating the bottom horizontal... but doubling the upper one, so the port roof was tapered to meet the raised delete plate. The dotted yellow line shows the cavity that was the injector port. The red dotted lines attempt (poor drawing skills - apologies) to show the areas ported around the port to bowl transition - the port floor at the transition point to the short radius is left untouched! Finally, the blue lines show the guide boss areas that are blended back for improve volume and velocity, the guides have been knocked back for the same reason.


more to come........ :mrgreen:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Sat Aug 23, 2014 11:29 am 
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so... the head is mostly finished... porting wise. My client has ordered a set of Toda valve springs, when they arrive, I'll be re-assembling... and setting the valve clearances for the clients Pon cams.


In the mean time.... the manifold/delete plate "compromise" needs improving... #1 and #4 intake paths are pretty crappy... actually really crappy! If nothing is done... the air speed coming out of the carbs will slow dramatically making low rpm operation less than enjoyable.


Remember... this is the problem.....

oldeskewltoy wrote:

....lets looking at the problem from a different perspective....


Image

The red lines represent the air path from the carb mount flange to the valves. The carb spacing is wider than the ports, and leads to the awkward set up you see.........


So I got to thinking..... what if.....

Image





Above is a bit of an extreme... and is difficult to pull off because the correction passes through 3 different sections of the intake - the manifold, the delete plate, and the head... but the idea is spot on.

A more practical way would be to exclude the head, but to try and correct the intake and delete plate.

First... the manifold surface is not flat... so off to the machine shop to get a minimal machining to get it flat


Then back to my friends mill......

Image


Besides where the bit is currently drilling, can you see any other "new" holes?


Here is a bit better perspective...
Image



And finished.... 5 new holes from the back side of the delete plate... each hole needing to be drilled 3 times (once for tapping, once for thread passage, and finally for recessed Allen bolt head)

Image

I can now permanently attach the delete plate to the manifold - and when I do make it permanent I'll use red FIPG to seal the two.


Prior to making them permanent, I'll need to add some anchor points inside the manifold, and the delete plate for the filler to affix too.



So... here is the idea....

Image

The black dots are small random drillings about 1mm in depth, the "T" is a small flat head screw embedded in the deepest part of the correction



and from another perspective... the red arrow shows where I'll drill for the flat head screw, the red dots are the 1mm deep random drillings for anchoring.

Image

The green "slice" inside shows the significance of the change.



LOTS more to come......... :shock:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Thu Aug 28, 2014 10:35 am 
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A familiar view........ maybe not??

Image


A not so familiar view.... Here are both intake ports #1 and #4 mostly prepped for filling....

Image

I still need to do a few drillings into the delete plate.




I'll be using 2 different compounds to do the above "fill job" The first one is called "Splash Zone A-788", it is a 2 part epoxy compound.

Image

If your eyes are good you will read it even sets up under water. I don't need its marine qualities, I do need its strength, its mold-ability, and its relative high temp capability. Although strong, and highly recommended in the advanced engine porting world, it is not fully resistant to fuels.


The 2nd compound I'll be using is POR15 fuel tank sealer as a top coat.

Image

This will fully encapsulate the Spash Zone A-788 and seal it from fuel decay...

For those who read the por15 label reading combustible.... read further - http://qr.absolutecoatings.com/QR-asset ... Sealer.pdf (to those that don't want to read it... once cured the POR15 sealant can withstand 315 degrees continuous, or 450 for 72 hours


a LOT more to come........ :shock:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Mon Sep 01, 2014 9:36 am 
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oldeskewltoy wrote:

I'll be using 2 different compounds to do the above "fill job" The first one is called "Splash Zone A-788", it is a 2 part epoxy compound.

Image

If your eyes are good you will read it even sets up under water. I don't need its marine qualities, I do need its strength, its mold-ability, and its relative high temp capability. Although strong, and highly recommended in the advanced engine porting world, it is not fully resistant to fuels.


a LOT more to come........


internets garbage.... research.... research.... research... and then research some more!!! http://lonestarspecialties.net/wp-content/uploads/2013/05/CARBOLINEA788.pdf

Short version 200 degrees steady, 250 for short periods of time... fail :(

Image


Oh... besides the above tasty tidbit (chart)... I got a response from JB Weld from an email I sent.....

ost email to JBWeld wrote:
Customer service rep.....


I'm looking for a heat resistant (300) putty, that will function in an air and fuel(gasoline) environment. I've included a short gif (animated photo) showing what I need to do.

The red dots are small drilled dimples, the single grey dot shows where I'd drill and then fit a screw, or similar threaded shaft as a protruding anchor. The thickness, at its thickest point will be about 7/16"

Thank you for your assistance


Image


JB Weld Customer Service wrote:
Dan,

I would use our Original JB Weld (8265s.) Thanks for your inquiry, and good luck with your repair!

Sincerely,

Customer Service
JB Weld



Soooooooooo after all this.... it looks like the original JB Weld, along with the POR15 fuel tank coating...



MORE to come.....

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Wed Sep 03, 2014 2:52 pm 
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Image

Manifold ports 1 and 4 are now filled, the client also asked me if I could supply him with a power brake port, as well as ports for an ignition MAP signal.

Image




oldeskewltoy wrote:
the JB Weld is in... BUT.... because the JB Weld is a paste, it doesn't want to cooperate in providing me the shape I want... so I'm stuck using a form to help keep the shape :thumbsdown:


So the form would release, I used wax paper between the form, and the JB Weld, it worked pretty well, releasing, but it caused a few issues as well. The biggest issue is although wrapped tightly around the form, when inserted the wax paper wrinkled and left a less-than desirable surface

Image

This is port 4, and although the wax paper left a less than desirable surface, I contributed a bit to the problem by under filling this port, not by a lot mind you - 1/4-1/2 a teaspoon.... but by under filling I got the surface flaws seen.

For a better example, port #1 was a better fill...

Image

still wax paper flaws, but with more fill, the flaws were easier to blend away.



Image

I was a bit disappointed... until I let perspective show me MY mountain (flaws), was really no more then a molehill... if that.

Perspective... yes, this is just a larger view of the 2nd photo in this post, but look at the center 2 ports... the casting lines are far more significant then the "flaws" left by me....

Image


Now as to the vacuum... my client asked me to supply him with a port for his brake booster, and ports for his ignition MAP. I utilized the delete plate to carry all of these vacuum ports.

Initially I thought I'd tap the port floors for vacuum, and then I remembered this was a carbureted engine and thought better of having the ports in the floor(gasoline environment), so I put them in the delete plate roof instead.

Image

Image

Typically (largeport) the power brake vacuum is pulled off a plenum. No plenum like that with carbs. The smallport applications tap off the #4 intake runner, and that is what I did, but I did this one a bit differently.

I decided on going in from the side based on advice given to me by someone who has researched carb type 4AGs more than I. His reasoning was it allowed for the brake booster port to NOT interfere with linkage, or other hardware associated with carb installations.

Image

The taper drilling is an attempt to minimize any air flow disturbance


Image



I'm just waiting on the valve springs so I can begin re-assembly, and then set cam-valve clearances......


More to come.... :mrgreen:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Wed Sep 10, 2014 6:20 pm 
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oldeskewltoy wrote:
It isn't just Toyota's,


More to come....... :mrgreen:



oldeskewltoy wrote:

Some "new" heads have crept into my shop....

ImageImage



more to come..... :D


While waiting for OST-028's valve springs... I thought I dig deeper into the Nissan SR20DE head... :mrgreen:

Its gotten cleaned... after cleaning it does show some damage, but it might still be usable... I'll need to check, but for now its future use isn't a big concern....

ImageImage



And I "plotted" the the intake and exhaust paths...

Image
Note both splitters are shaped similarly to a tear drop, and in both cases (intake and exhaust) the splitter is a significant obstruction in the path.



So why did Nissan shape the splitters the way they are??? The Nissan SR20DE head (fwd model) uses a "Y" shaped "rocker" assembly to actuate the valves....

Image


This rocker needs a fulcrum, Nissan uses an HLA (hydraulic lash adjuster) to act as the fulcrum.
Image


the HLA fits into the holes pointed out in green.

Image

The "H" in HLA means it is a tiny hydraulic lifter (only 17mm wide) and as such is pressurized by the engine oil - note casting between each lifter bore that looks tube shaped for oil supply... and look at the small hole in HLA, this is for pressurizing the HLA

But... as small as that HLA is... it causes havoc inside the ports because it fits between the paired valves, and although it is "only" 17mm in diameter, the port walls must accommodate a fair bit more for casting imperfection - I don't have a long thin set of calipers to get an accurate measurement so the best I can do is make an approximation on the width, and for the intake side(worst between the two) at a minimum it is 25mm, and maybe as wide as 30mm, and yet the two intake valves have less than 10mm between them.

Image

The reason the intake side is worse is because this is a high port head, and so the high port requires enough room for the HLA..... the exhaust side is lower... so less intrusion.



More to come.... :shock:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Fri Sep 12, 2014 4:12 pm 
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Besides dealing with(working around) the HLA, there are a few other issues that need to be approached. One of these will be the short radius of both the intake, and exhaust sides The SR20 intake short radius shouldn't be tough, especially since it has a high port, or aero port. the exhaust on the other hand............

As seen in the above drawing, this SR20DE is a highport, its purpose is high speed air flow to a mild angle just before the valve head. This is similar to formula one type heads, and later designed 4A heads (last gen "F" heads, and the 20V heads have a similar downward angle port)

Image

Here is one of the SR20DE's intake seats and bowls before any work begins (#2 cyl)

Image

You can see the short radius has the bowl inside the seat, this doesn't allow for complete cyl filling because the intake charge has to navigate past the bowl, and then flair out to the seat. I'll need to clean up the short radius. Besides the short radius, the entire bowl is considerably narrower then the seat, or the valve.

Here is a view showing what I've done to "create" a short radius on one side

Image


I've managed to make a smooth transition from almost nothing :P

A different perspective... showing the overall shape of the bowl and seat transition - the key areas to note in this view are the 3 and 9 positions inside each bowl

Image



oldeskewltoy wrote:
the exhaust on the other hand............


:td:

A high port intake's short radius doesn't have to be huge, its just needs a nice transition.... but the exhaust seat/bowl NEEDS a short radius to optimize flow from the seat through the bowl, and into the port.

Borrowing from the above 3 panel... I used the 4AF bowl/port to show the faults of the SR20DE - the short radius is beyond pretty bad, it could be called non-existant, the redlines represent the bowl to port transition for the SR20

Image



There is not very much of a port floor in the SR20......

Image

so creating a short radius from nothing... isn't half bad... (if I do say so myself) :mrgreen:


More to come....... :tu:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Tue Sep 16, 2014 3:12 pm 
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progression of #1 intake........

Image



This is just about finished...





more to come...... :mrgreen:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Wed Sep 17, 2014 9:33 am 
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the view above only shows some of the intakes path...

from a different perspective... here shows 3 views of #1 and #2(on left) intake ports. The views gradually shift from showing the roof, to the floor.....


Image

Some areas.... got "hogged out", while other areas were left untouched :shock:

all in the pursuit for efficient airflow





more to come... :mrgreen:

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 Post subject: Re: Oldeskewltoy's Headshop....
PostPosted: Wed Sep 17, 2014 2:22 pm 
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What on earth is this.......????????

Image


One thing it isn't is a smart phone overlay... so... what is this?? :mrgreen:

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