OST-069: Transformation

[oldeskewltoy]

So... this package cleared customs 3 days ago....... what could it be.......





A full Toda BSpec valve train kit*... along with a pair of Toda 272 10.3mm cams...

* The BSpec kit is completely different then the "common" Toda springs I typically use, this kit is capable of handling 11mm lift cams




Too clear big cams, a bit of extra work is required so they can actually turn in the casting




small clearance pads are cut so the cam won't hit the head





more to come....

[oldeskewltoy]

So the head has come back from getting its valve job....









then the client asks me if it is too late to add an intake side oil drain.....





now that the drain has been fitted, I move on to get chamber volumes - 37cc each across the 4




Client wants 36cc, so the head will get machined .008".



More to come.....

[Vaptor]

SO another Newbie question

36cc vs 37cc, is there a sweat spot on a 4age, or is this just to get the correct combustion ratio?

What is the standard chamber volume, on a 16V Big port?

[banpei]

What does the intake oil drain do? Prevent oil from getting clogged up in the head?

[oldeskewltoy]

(01-02-2021 12:41 PM)Vaptor Wrote:  SO another Newbie question

36cc vs 37cc, is there a sweat spot on a 4age, or is this just to get the correct combustion ratio?

What is the standard chamber volume, on a 16V Big port?

We are fine tuning final compression ratio. In this case 36cc along with his piston choice, and gasket choice deliver the final CR desired.

Standard 16V chamber is 36cc. In this case to get the chambers de-shrouded it required adding 1cc of volume.

(01-02-2021 09:49 PM)banpei Wrote:  What does the intake oil drain do? Prevent oil from getting clogged up in the head?

It helps keep oil down in the oil pan. The 4AG largeport head only drains on the exhaust side - fine for transverse layout, but in a longitudinal layout a long left hand sweeper can emply the oil pan of oil and pack it into the head. Additionally it helps with a catch can as often times the catch can fills for the same reason.

[Vaptor]

Thanks for sharing your Wisdom

[banpei]

(01-05-2021 09:33 PM)oldeskewltoy Wrote:  

(01-02-2021 09:49 PM)banpei Wrote:  What does the intake oil drain do? Prevent oil from getting clogged up in the head?

It helps keep oil down in the oil pan. The 4AG largeport head only drains on the exhaust side - fine for transverse layout, but in a longitudinal layout a long left hand sweeper can emply the oil pan of oil and pack it into the head. Additionally it helps with a catch can as often times the catch can fills for the same reason.

Thanks! So it's meant to have the same function as the breather pipe.

[oldeskewltoy]

(01-06-2021 09:55 AM)banpei Wrote:  Thanks! So it's meant to have the same function as the breather pipe.

not quite right... with the added drain, the intake side of the head doesn't pack up with oil. Since it doesn't pack up with oil, the oil has less chance of going out the breather.

[banpei]

(01-06-2021 05:03 PM)oldeskewltoy Wrote:  not quite right... with the added drain, the intake side of the head doesn't pack up with oil. Since it doesn't pack up with oil, the oil has less chance of going out the breather.

Thanks for elaborating that, otherwise I made the wrong assumption!

[mad.matt]

(01-05-2021 09:33 PM)oldeskewltoy Wrote:  

(01-02-2021 09:49 PM)banpei Wrote:  What does the intake oil drain do? Prevent oil from getting clogged up in the head?

It helps keep oil down in the oil pan. The 4AG largeport head only drains on the exhaust side - fine for transverse layout, but in a longitudinal layout a long left hand sweeper can emply the oil pan of oil and pack it into the head. Additionally it helps with a catch can as often times the catch can fills for the same reason.

It's interesting as the F20C had a similar problem despite it's Longitudinal layout. It gets stuck up under the head baffle plate and makes a smoke screen.



People have to drill the head baffle to allow it to drain.


I've had friends with F20C swapped 86s black flagged because of it.