OST-035: Silver Blaze

[oldeskewltoy]

My client dropped off his 20V silvertop for a bit of massaging



Mix in Toda springs, and Tomei Poncams, and stir to 7800 rpm.... for now....



More to come....

[Bempa]

Your threads are very inspiring. It all started with a google search in AE95 and i found your Grunt thread. After that I could not stop reading your threads, you do such i great job and you are kind enough to show it. But you might have to ship over your Alltrac to Sweden so you could sell it to me

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[Dream86]

I second that. Great knowledge and skill. Pleasure to read. Keep up your awesome work!

[oldeskewltoy]

Thank you for the kind words.... from both of you

Grunt is not for sale.... my wife would be greatly upset if I sold it, she has used it for the past year, and grown quite fond of it.



so proceeding.....
Although the head looks pretty clean, and it is(was), the exhaust ports are still moderately heavy with carbon, so for that reason, and I want to make sure the head is capable, I've sent it out to get cleaned and pressure checked. I'm also having it checked for flatness.



A bit more about this build.....

My client will be using Toda AE101 pistons



they carry a 4.6cc dome, static compression will be around 12 to 1 while using a .8mm head gasket - as per Toda. He will also be running Toda's AE101 valve springs - good to 11 mm of lift




He will be using 20V Poncams



more to come....

[oldeskewltoy]

Thanks for the cam card.

(responding to "having it checked for flatness") - Feeling sorry or tossing them a bone for goodwill?

How about a hardness test, the Toymods guys just love that BS.

client wants a bare minimum cut - .001", maybe .002" if required. the flatter the surface the lower the cut......

I've heard of testing the 7M heads... I've not heard of people checking the 4A heads....


Had to order some new equipment.... the 16V spring remover/installer doesn't fit the pockets the 20V springs fit into... so....





more to come.......

[Bempa]

Is there any problem with castings since people test hardness?

Where is that tool kit from?

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[oldeskewltoy]

Is there any problem with castings since people test hardness?

Where is that tool kit from?

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I've heard of testing the 7M for hardness consistancy... many.. when severely overheated (headgasket failure) would cause the head to become "softer".

BEFORE you buy that tool kit... let me make sure it will work..........

Had to order some new equipment....

actually quite a bit more.....

For the past 5 years I've used mostly Dremel motors(5), and flex shafts (4). I also was using a Black and Decker RTX (about 60% more amperage/torque) than the Dremel. I've used the RTX almost exclusively for that past 18 months, enjoying the torque advantage it offered.

Well, in the middle of OST-034 the RTX began to die. So it was finally time to really upgrade.....



I've purchased the 1/6 hp Foredom SRX, along with 2 handpieces, the larger of which you see in the above photo. For now I'm keeping the Dremel for finish work since it does still have a higher maximum rpm - useful in getting that nice finish.




More to come.....

[Bempa]

Ok, so if i understand correctly there is a chance for the head to go soft if it's badly overheated? How big is the chance ofta that?

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[oldeskewltoy]

Ok, so if i understand correctly there is a chance for the head to go soft if it's badly overheated? How big is the chance ofta that?

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I honestly don't know..... my experience with 7M heads is very little. For the best information, I'd look at forums with far more 7M experience. As far as "A" engines are, I've not heard of it ever being a problem

[Bempa]

I have never heard about it before. But i do got a story about Toyota cylinderheads, as tinkering with Toyota is very rare in Sweden, the machineshop i went to hade never shaved a Toyota head, (they manufactured stuff for the industry, but I knew he did some car stuff on the side just for the fun of it) The guy said after he had done the job, that it was by far the best aluminium quality in a cylinder head he had seen. It was a 2nd gen 3sge head.

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[oldeskewltoy]

That's a nice looking head!

It will only get better looking........

Well... that took a week??? to get this thing cleaned, and pressure checked.... I'm guessing they were busy????


ANYWAY..... the head checks out, and it is flat! this means a cut of .002" or less will provide the mating surface for a good metal gasket seal.


This head will be getting half a valve job.... yep, half a valve job!



The intake seats, already with 3 angles, will get a very fine (400 grit) lap in, while the exhausts will get a full on 3 angle.


and I've begun the port work.... the intake side is all new, like OST-034 was. Buuut... unlike OST-034, there is a fair amount of port to bowl transition blending required. As to how much.... I'm following OST's first rule of porting... do no harm, so could I take more.... maybe.....




now as far as the exhaust goes....

but the exhaust I've got well in hand....

Here is a view down(up?) the bowls to the roof... notice the ledge(angry eyebrows)...???



Anger removed... and all without Botox....


and a view at the short radius, and the transition to the port from the bowls






more to come.....

[oldeskewltoy]

Silvertop chamber volume.........




more to come......

[oldeskewltoy]

A bit more about this build.....

My client will be using Toda AE101 pistons



they carry a 4.6cc dome, static compression will be around 12 to 1 while using a .8mm head gasket - as per Toda.

Silvertop chamber volume.........

My math comes out to a few hundredths of a point different then Toda's, but for sake of chamber volume confirmation... 36cc seems to be the Silvertop's chamber volume

[oldeskewltoy]

Anger removed... and all without Botox....

anger removal from a different perspective....




more to come......

[101_gze]

Wow Dan. Thats really cool the way you label and number the seat angles like that! I mean, awesome work. WHERE DID YOU GET THAT IDEA??? I'm sure you'll give props where props are due right?

Also, this comment:
from another forum wrote:
Thanks for the cam card.

(responding to "having it checked for flatness") - Feeling sorry or tossing them a bone for goodwill?

How about a hardness test, the Toymods guys just love that BS.

Toymods guys love that BS?

What are you actually quoting here? Who are you quoting and what forum is it from, I know you love quoting other forums, but this does not make any sense?
Great to be able to chat to you here, without any static,
Awaiting your reply.

[oldeskewltoy]

As to props for marking the 3 angles?? I've been doing that for a few years, and I'm sure I saw someone else post it that way a long time ago.....originally, likely in some old car mag... and it was likely an article on Smokey Yunick... or some other engine builder.

as to the quote, the person quoted is also a member here, if he chooses to answer, he can, his original quote is here - http://www.mr2oc.com/showpost.php?p=6352361&postcount=5


Began the day @ 2 down 2 to go.....



Now @ 3 down 1 to go....




and comparing the yet to have begun, to the mostly finished...





more to come......

[oldeskewltoy]

working the final port/bowl of this head...








and now with the head ready to go back and get it's exhaust only 3 angle, and a minimum re-surfacing - .001"


more to come.......

[oldeskewltoy]

Back from the machine shop... surface was machined .002", isn't that pretty, and ready to accept a metal gasket.




Now carrying the exhaust 3 angle(bowl closest), and as you can see the intake 3 angle is still good, so I used a tiny bit of lapping paste to get the intake seats and valves mated



Clover lapping paste on left, Permetex/NAPA valve grinding compound on right... think of the Clover as a polish




that polish helped reveal..... a tiny bit more performance may be available with a back cut on the intakes. That is for another day/head.



the red arrow is pointing to the top of the seat-valve contact point, so the dotted green lines represents a bit of room for a simple, clean back cut.



Finally, my client asked me if I could do something to better accommodate his use of ARP studs....



Look back at the first pic in this post to see the bolt hole before.....


more to come.....

[oldeskewltoy]

I enjoy reading the detail in your threads but not being an engine builder guy I probably understand less than half of what you're saying...:confused:

What is the purpose/benefit of the multiple angles on the valve seats? Radiusing the openings for better flow?

Does the type of spark plug used during chamber volume measurement vary the reading? Or is something else used to plug the hole during measurement?

I use an epoxy filled spark plug with the ground electrode removed. This gives me a consistent measure. Yes - a "colder" plug will often times have a bit more room around the positive electrode, effectively increasing the chambers volume.

multiple angle valve seats - Air flowing past with minimal eddy currents. A steep angle on any of these faces and tiny eddy currents can cause poorer flow.

I've recently heard about a 7 angle... yes 7 angle valve seats... can't find a pic, but here is a 5 angle.... http://www.d-series.org/forums/attachments/engine-building/22492d1258097816-3-angle-valve-job-q-5angle.jpg

now if your machinist has the capability, this is what is often the top of the line for flow past the valve, it is a radius valve job - http://rennlist.com/forums/attachments/928-forum/904333-port-and-polish-by-comiittee-thread-cool-pics-throughout-pic3.jpg the only flat surface on there is the small area where the valve contacts the seat, the rest is a radius

[oldeskewltoy]

another new tool on the way..........

I realized that I needed a new support system to assemble this head...

and so now that the port work, the valve job and the machine work are complete, assembly follows.......



the nut driver under the head was my seal installation driver today


The 2nd new tool can be seen supporting the head.

so here is the 1st new tool (9/30/2015 post) up close, in "action"





and fitting the last valve....





assembled.... waiting for its owner.