OST-026: "My White Hatch"

[oldeskewltoy]

oldeskewltoy Wrote:Equipment failure is annoying

lost a week...

but now that I have the new burettte, the chambers get measured...




35cc is the goal. the head was machined .016" (.4mm), and along with my chamber work...



2 chambers came in on target... 2 came in a touch small @ 34.7 cc. I did a little bit of additional work in the chamber walls between the valves on the small two and moved them up to 35cc as well.


With all the chambers @ their intended volume.... I begin re-assembly...






assembly of the head is finished.....





More to come.....

[oldeskewltoy]

oldeskewltoy Wrote:assembly of the head is finished.....




More to come.....

note #1 on the exhaust cam and #2 on the intake cam (between cyl 2 and 3)... Since these are the same cam - both 272 ~ 9.0, the fact that they carry sequential numbers is a blessing for me... Why?? because it is now that I have to choose which cam goes where so that I can determine the final clearances....





and to determine the final buckets.... yep I said buckets.



My client is going the 1SZ one piece bucket route and it is up to me to determine the CORRECT bucket for each valve/lobe combination. The buckets above are the thinnest available - 5.12mm

First I check the clearances for the exhaust side...





I then swap the 8 sizing buckets and then I check the intake side....



I can be one of those crazy people who likes things as exact as I can make them.... sometimes, when you are checking valve clearances you sometimes wish you had the capability to measure down to .0005".



This is important when I'm purchasing 16 buckets and they are $12 each, I'd rather not get this wrong....


more to come.....

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oldeskewltoy Wrote:

This is important when I'm purchasing 16 buckets and they are $12 each, I'd rather not get this wrong....

Ok.... since I don't want to get this wrong.......

how about a bit of a brain teaser...


the photo above is an intake cam lobe. Tell me what 1SZ bucket I'll need (10 digit part number, please)???

[Bean]

What clearance do the cams need? If you tell me that I'll tell you the part number. But only after I catched some zZzZ

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[oldeskewltoy]

(05-14-2014 10:29 PM)Bean Bandit Wrote:  What clearance do the cams need? If you tell me that I'll tell you the part number. But only after I catched some zZzZ

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already given.....

[Bean]

Still a bit sleepy but should be 5.42 which is 13751-23180
5.12+0.495 = 5.615 - 0.2 (for intake clearance) = 5.415 (all numbers in mm).
As the lifters are available in increments of 0.02 the 5.42 is the closest match.
Taken from the list here

PS: interesting to see that the cams ask for slightly different clearances for intake and exhaust side. My catcams ask for 0.02 on both sides.

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[oldeskewltoy]

from another forum Wrote:my math says you need a 5.415mm thick bucket.
So the closest bucket is 13751-23180 @ 5.42mm thick

Bean Bandit Wrote:Still a bit sleepy but should be 5.42 which is 13751-23180
5.12+0.495 = 5.615 - 0.2 (for intake clearance) = 5.415 (all numbers in mm).
As the lifters are available in increments of 0.02 the 5.42 is the closest match.
Taken from the list here

from another forum Wrote:13751-23280.

Edit.. nope that's less then .002" left.


13751-23180 (5.42)
that should leave about .0072"

Closest... yes.... but I wont be using that one, I'll be using 23170.

Here is why...

The cams call for an intake clearance of .2mm (.0078") If this head had either a plain lap-in, or a street 3 angle, I would say it was good enough.... BUT, remember this has a "race" 3 angle, the valve is cut 1 degree less then the seat. This means during break in the valve may move a tiny amount up on its seat. I asked a few machine shops who build race engines and .0005" should be accounted for....

So as much as I would really like to get the 23180, I purchased the 23170 instead.

**IF** I had my own equipment, I could disassemble that valve and clip the tip of the valve .0013" and be perfect with the 23180.


More to come....

[oldeskewltoy]

from another forum Wrote:We change the seat width not angle the valve grind.
.040 wide for hi-po stuff and .060 wide for street.
A quick hand lap with ultra fine paste and the valves seal
Instantly. Recleaned before assemble of course.

I'm told this is a track engine, typically I use 040 for intake and 060 for exhaust on 4AGs...

from another forum Wrote:How hard is it to grind the top of the valve? Measure the length of the valve before and after and use a grinding stone to cut it down?

Why do you run a 1 deg difference from the valve to the head? and what direction is "less"? Is the valve making contact with the head further inward or outward with the 1 deg difference? If it just seating pressure why not run a smaller seating surface?

Questions/suggestions are not a criticism I am asking because your work is beyond mine and the above is how I would do things

no criticism taken...

With the right equipment the valve is installed in a valve machine vice, and the machine will measure the tip, and then you set the grinder to take off the appropriate amount... very easy...

The contact point is further outward. As you break in the engine* the valve and seat pound together to form a nice tight seal. This pounding distorts the valve and seal slightly to provide an adequate seat and is why the valve may move up. The added degree on the valve allows for added filling on the initial opening and just before closing of the valve... think of it as an extra back cut

the exhaust valve ISN'T similarly cut, just the intake.


* another reason to break in an engine "hard"

[oldeskewltoy]

Wow...

its been 30 days... I TRIED to order the buckets through Toyota... they sold me the 8 sizing buckets... but alas they didn't "release" the 16 needed to set clearances (boooooo). Soooo... My client got them directly from Japan... and so we had a 30 day wait...


In the quote below.... see the cam lobe barely in frame on the right... that is #2 intake valve assembly...

ost Wrote:

oldeskewltoy Wrote:

This is important when I'm purchasing 16 buckets and they are $12 each, I'd rather not get this wrong....

Ok.... since I don't want to get this wrong.......

how about a bit of a brain teaser... :eek:


the photo above is an intake cam lobe. Tell me what 1SZ bucket I'll need (10 digit part number, please)???

..... and I should have had everyone check me on that one....

15 of 16 buckets are all well in tolerance... but #2 intake is too tight. It measures a tight .007" (.178mm), minimum is a tight .008" (.203mm), so I'm going to TRY (hope... prey... beg) that Toyota will release the one bucket I need....


here's hoping.... more to come......

[robokill]

There is a guy in the netherlands who tuned a 4age by removing the 4age head and replacing it with a tuned 4afe head. He got cat cams to grind some special cams for it and I believe its making between 205 and 215 hp in a Yaris .....

So that would make sense looking at your explanation

[oldeskewltoy]

(06-27-2014 03:55 PM)robokill Wrote:  There is a guy in the netherlands who tuned a 4age by removing the 4age head and replacing it with a tuned 4afe head. He got cat cams to grind some special cams for it and I believe its making between 205 and 215 hp in a Yaris .....

So that would make sense looking at your explanation

The intake port shape on 94+ AF heads is superior to all the 4AG 16V heads... but as I point out the biggest problem with the AF head is the exhaust ports.

Bean Bandit Wrote:couldn't you get it machined down? or is that more expensive than a new one?

from another forum Wrote:Or remove the valve and have them take just a tad off the top of the stem if you didn't want to grind the bucket.

.001" to be exact... thank you for the suggestion. Toyota FAILED :thumbdown

so I popped the valve out brought it over to "L" and asked them to tip it .001". 10 min later I got my valve back, installed it and we are good to go. The head is all boxed up and ready to ship...