OST-017: Ed Sullivan it ain't!

[oldeskewltoy]

Just to keep this up to date.... "we" are waiting on Toyota's parts system currently. The previous porter had supplied the client with 16 of the shallowest 1SZ shimless buckets (13751-23030).

While Loynings was preparing to machine the seats, they came back to me and told me that with the buckets, valves, and cams supplied, the valve seats would be about .030" deeper than they liked. They asked me if there were any buckets that were taller.

I did my research and the 1SZ buckets have a minimum of 5.12mm, and a maximum of 5.68mm. The tallest buckets will claw back .022". The tallest buckets(13751-23310) are on order.

The plan is to cut the seat based on the the valve + the bucket + cam clearance. Calculate that and machine the seats so the valve clearances are set.

[oldeskewltoy]

OH... MY LORD..............

The parts delay, and machine work for this head culminated back in mid September, that was just before/as I began "OST-019". I chose not to run both threads @ the same time... AND I used OST-019 to re-familiarize myself with removing material from the chamber...

mind you nothing other then doing it gets you comfortable with removing MASS QUANTITIES of ALUMINUM from the combustion chambers of a $2500 head........ and hoping you don't fudge it up :eek:

But I move a bit too quickly over the machining details... so let me catch up. There is much required to do and check when preparing an O/S valve head that runs 300 duration 10+mm lift cams. Many here have checked valve to piston clearance when building their engines.... but how many of you had to check for valve to valve clearance??? Some of you know what I'm referring too, but the rest???

Valve to valve clearance is something that must be done on 40+ degree valve angle heads(Toyota 4 valve "G" heads) when using LONG duration high lift cams in conjunction with O/S valves. The camshafts are installed, and "timed" to each other. The camshafts are rotated slowly to make sure the intake valves don't hit the exhaust valves... and visa versa.


not the head I'm working on, but it shows potential for valve to valve contact

Once this is verified, final depths are determined by measuring the 1SZ buckets (the thickest set) and then calculating the depth to the camshafts base circle for that particular lobe. Times 16... then doing the math and "mixing" buckets and valves till all you have are a valve tip or 2 that gets "tipped". Now all the buckets, valves, and cams are set :eek:

So... with all the machining(over 12 hours @ Loynings :eek: ) now finished... I get out the burette.........



and measure the chambers.... #1 - 36.6, #2 - 36.5, #3 - 36.3, #4 - 36.6 if you remember a few chambers had seen some tool work by the previous porter, as well as a little bit from me... that explains the .3cc difference between the larger ones, and the smaller one

Once measured..... cutting begins... I begin on #4 chamber. I need to increase the chambers volume by 2.9cc or a little over 8%....

The top view is the chamber prior to resizing... you can see the Sharpie outline of the head gasket.....


another 3 panel

the middle panel shows the right hand side of the chamber roughed out, and in the bottom view, the chamber has been opened up 39.3cc, the last 2/10 of a cc I'll get while hand shaping, and polishing.



More to come.......

[oldeskewltoy]

oldeskewltoy Wrote:5mm is quite a bit....

this one shows how much material and the depth

More to come.....

[oldeskewltoy]

from another forum Wrote:do you have a template to ensure repeatable shaping? From looks alone it seems you're being very consistent with your final shape.

I do have a few things I use... but making a chamber 39.5cc with O/S valves is not easy, and right now "we" are in a tempory hold pattern. Each of the chambers are getting pushed out to 39cc (+ or -) and I'm waiting for the client to send me one of his pistons.......

An Atlantic pistons has a dome peak of about 7mm, and the width of that peak is about 68mm long centered in the piston. my client told me his dome peak is close to 10mm and 74mm long.....

That is HUGE.... I did some sample measurements and the peak of the chamber measures out to a little over 15mm total depth...... the spark plug sits about 7.4mm tall........ "Houston, we have a problem"

I've asked the client to send me one of his pistons so I can see how his pistons fit my chamber work..

If the pistons interferes.... I'll be bringing it all to my buddies (Loynings) to get their take.... and try to figure out an effective solution if one is needed

[[Walaki]D`Lair]

I know a solution...throw the f*ck out those pistons... :mrgreen: :mrgreen: :mrgreen: :mrgreen:

[oldeskewltoy]

[Walaki]D`Lair Wrote:I know a solution...throw the f*ck out those pistons... :mrgreen: :mrgreen: :mrgreen: :mrgreen:

oldeskewltoy Wrote:I did some sample measurements and the peak of the chamber measures out to a little over 15mm total depth...... the spark plug sits about 7.4mm tall........ "Houston, we have a problem"

I've asked the client to send me one of his pistons so I can see how his pistons fit my chamber work..

If the pistons interfere.... I'll be bringing it all to my buddies (Loynings) to get their take.... and try to figure out an effective solution if one is needed

We indeed have a problem! The piston is resting on the spark plug electrode..

about 2mm to tall........ Next week it is off to Loynings to see what can be done.

[Project D]

What is the brand of the pistons ? (look like Arias)

One option would be to use racing spark plug (Denso IQ01-24 or 27 for instance)

IK24 VS IK01-24


The second option would be to mill the top of the piston (if they have enough material to be milled without going through)
But that would decrease significatively the compression...

[oldeskewltoy]

Project D Wrote:What is the brand of the pistons ? (look like Arias)

One option would be to use racing spark plug (Denso IQ01-24 or 27 for instance)

IK24 VS IK01-24


The second option would be to mill the top of the piston (if they have enough material to be milled without going through)
But that would decrease significatively the compression...

the pistons are Arias....

may be solved already.... I'll consult with Loynings, but using Moroso spark plug indexing washers(.064" thick), along with the .020" head gasket should net me all I'll need.... it'll be close.

I tested this idea by backing off the plug 3/4 of a turn (270 degrees), the plug stopped contacting the piston somewhere between 180 and 270. The .064" index washer equals 312 degrees...

[Project D]

.020" (0.5mm) head gasket, TRD I suppose ?
Or maybe custom made, since 3.2680" (83mm) pistons are not a "standard" size
(common oversized pistons are 3.209" and 3.228")