Clayed my engine, then CC'd my heads
 

So I did the clay test on my engine today to check my PTV. Set is forged 347, diamond -2cc pistons, 232/236 112LSA 112ICL, tea stage 3 heads with 2.055/1.57 valves.

I put the clay in, torque the heads down, turn the engine over twice by hand, pull the head, and then sliced the clay up to check thickness of all areas with my dial caliper. Keep in mind that accecptable PTV is .80 intake/.100 exhaust. The thinnest part of my clay was where the exhaust valve almost meets the valve relief, and let me tell you it was tight. It was like .130 or very close to it, and that was with my old used stock gasket @.050 and I will be running a .040 gasket on my final setup. So i am wondering why its so damn tight when the heads are advertised at 63cc on teas's site. I bought them slightly used so who knows. I was dissapointed because I figured i cant mill much off the heads now to get my DCR up.

So then i get home and decide to CC the head myself so I pop the spark plug in on one chamber and get out my milliliter syringe and start to fill it up. I filled it up to 57 CC and it was almost overflowing, @ 57CC and it had the big surface dome on the top too so i took 1CC out and it looked filled but without the huge surface dome. heads must have been milled when they were ported/polished. So I am estimating 56-57CC on the chambers. :)

So now I am pleased with the setup because I dont have to send the heads out for milling and i still get some really good DCR without having to mill or advance the cam. Should be 8.65-8.75. Not too bad.

Figured id share the experience with you guys. If you buy used stuff i highly recommend doing this before milling and before assembling the engine. I feel much better about it now that i know the actual sizes of everything and how much clearance I have.

Measure twice, cut once. Thanks for pointing this step out. I'm pulling my heads to put in some Cadillac lifters and was going to put some .036" Cometics. However, I think I will invest in a beurette and actually measure my chambers so I know what I've got.

I was gonna use a beurette but i got lazy and didnt feel like going to the store to buy one so I just used a medical syringe and eyed it up, i actually redid it a bunch of times to verify it.

I am so glad i didnt jump the gun and have them milled beforehand or i would be screwed right now. Id either have to get a smaller cam or sell the heads, or do like a ricer and double stack 2 head gaskets. :jest:

Probably a stupid question that could be easily answered by a search, so please forgive my mini-hijack: What did you use for clay?

Thanks,
Josh

Modeling clay, you can get it at any art/craft store. Just dont use play-doh, it puffs back out after compression, modeling clay stays put after its pushed in.

Nice job man, I'm curious to see what you put down on the 5.3s!

-J

Well i hoping for a FAST 90/90 before i drop the engine in, but it looks like i might just wait on the intake till later on. Hoping to make 450 at least with the LS6 intake and PP stock TB.

This may be a stupid question, but I'm new to the CC chambers thing. Do you have to put the springs on to seat the valves or would gravity be enough? Also, did you use a sealing plate or just eyeball it?

If youre just CC'ing the heads you need the valves installed and i would want the springs installed. Plug a spark plug in too.

I eyeballed it up, 57cc filled the chamber and left a nice sized dome on the surface, 56cc was a more flatter surface that i think was more accurate. 55cc started to empty the chamber and 59 overflowed it. It was definitely 56-57cc, not a big margin of error.

Where do you get an accurate syringe?

science store, doctors office. You can also use a beaker or a beurette.

Did you use a modified roller lifter (plunger doesn't plunge)
If not, better do it again ;)

Or checker springs...

Yeap,
I use a lifter and adjustable p-rod checker (that way I know it is definite max PTV).

No, the main reason being that this motor and heads were ran together by the person that i bought if from, so I knew it would clear, I was pretty much trying to see how much I could mill. Since I didnt use a solid I gave myself some more buffer room too. My cometic gaskets and other little items will be here today and i will have it assembled next week and will be sure to check it out again.

Take an old lifter and weld it up so its solid.

Where do I weld it at, on the roller?

I just went to a drug store and they gave me 2 syringes free when I asked to find some that I could purchase...they come in handy in your shop for other thing too. I use one to remove flud from the clutch resovour and to refill it with clean fluid...use a level and make sure your head is nice and level when you fill it and you can eyeball it and get very close to the correct CCs of your chamber.

I bought a 50CC syringe from a medical supply store. When CCing heads, you should add a drop of dish soap to the water in the syringe, as this breaks the surface tension and allows a more accurate measurement to be taken. Otherwise you can actually fill the chamber with slightly more water than it holds. The valve springs do not need to be installed, just put a thin layer of grease on the valve seat and push the valve in.

Im gonna try that when i get home, i did have a big surface dome on the top and still got 57cc.