Thread: DE head package - on a budget - infotainement

Hi,

As I have noticed, my stock SR20DE will come out in winter. It needs a little rebuild, as the stock DE oilpump starts to go weak.
In my opinion this is the right moment to think about a 'little power package'. I am not willing to spend big money on a build, neither on a VE swap. I just need to rebuild my engine, and this is the right moment to 'reengineer' a few things.

During the reengineering I focus mainly on the head - and I want to make this knowhow and work available to the community.


Figure in WHP.

The guy working on my head - and helping me developing a 'reasonable' package is Dan. Dan is a very knowledgable guy! He did quite heads, mainly 4a-ge. In fact, he did a few years ago on for me. As Dan and I had no clue about the SR20DE, he aimed for a used and abused head to start doing some research.








And this is where the story starts!

Cheers!
Martin

ok what are we looking at here exactly? I know that's not an sr20 head so are you just showing us this for an example of things to come or what? This seems a bit vague...

My engine is a super stock 10:1 highport - and with the rebuild I will optimize it a little, within reason!

And the pics are generic - they are from an 4age 16V, but I wanted needed to make you curious about what will be coming...

Ok, so now the real deal - no fake images .

Meanwhile the head arrived at Dans place...





It is a highport SR20DE head. I decided to go this route because it is the one in my car, and its the easiest to get.

More to come...

Interesting

Obviously the first thing to be done - was cleaning up the mess





And for easier imagination the paths through the head have been painted...



The intake and exhaust bowls have been measured - nothing fancy so far...

Intake:


Exhaust:


And now the important things - how to improve the ports to increase the heads performance. I am not aiming for a high-on-top power gain, I need a working package to gain midrange till up on top. And as I know Dan for a while, I have no doubts that we will not reach our goals.

A few quotes from his side:



And as usual - more to come

uh.... thank you mods/admin.......


As MartinS alluded too... "infotainment" - I'll be discovering what I can with an SR20DE highport cylinder head.


As I alluded too in my introduction....



First... correction, MartinS was owner to OST-008


I've been porting, massaging cylinder head castings for about 5 years. Often times I record these porting jobs.

This is my first chance @ an SR20DE head... a highport model This is the condition that I got it in....





NOT a good looking head... and as can easily be seen, this head has spent a fair amount of time wet, and not the good kind either... look at the rust all around #3 intake bowls/seats....



but a "bath" goes a looong way sometimes...



and sometimes the bath reveals more extensive issues... as in this head, look at the #1 and #5 exhaust cam journals. The "rust" you see is embedded into the aluminum, to clean this area up and make it proper again would be a pricey endeavor... so, instead of fixing, lets do a bit of discovery instead...


Initial impressions.... the casting itself is a bit rough, more deburring could be done to the castings, especially the top of the head which holds the cams and valvetrain. The chambers on the other hand appear to be well placed, with very little evidence of edges that would promote detonation (ping). The intake paths are bow legged shaped to allow for the HLA, the intake seat/bowl could use blending to better take advantage of the angled port, and mild short radius. The exhaust bowl/seat is far worse, significantly too small, the port provides little or no room for an adequate short radius, while the splitter, port roof, and narrowing walls are far too intrusive, and appear to truly restrict airflow.



Too begin with... this head is one for discovery.... and as such I'll be performing different porting on 2 of the 4 cylinders, leaving 1 cylinder to use as a control. What do I mean when I say "control", I'll be using my flowbench to monitor any gains, or losses do to my porting work. I'll be leaving #2 cylinder and its ports completely untouched. I'm leaving #4 untouched for the time being, but may use it to "assemble" the knowledge I learn from porting #1 - within the lines, and #3 - outside the lines.

My flowbench... checking a Toyota 7MGTE head




1 - as I mentioned, the casting is a bit rough leaving many areas containing sharp edges. From my experience, often times poor casting areas lead to sludge build up because the oil and debris sits in these areas "cooking" into place as the miles go by. Making these areas less prone to holding the oil and debris, helps keep the engine cleaner, and easier to shed oil back into the oil pan. A second, and purely selfish purpose is with me constantly changing its position on my porting bench, the roughness really hurts my hands.....

2 - below is a view of the Chambers #3 and #4 , I've blacked out the valve openings to avoid distraction....

As you can note, other then doing a tiny bit of blending around the seats, putting a ~.020" radius on both "squish" pads, and polishing the chambers I've had to do very little.




As a comparison here is a small gif showing a 4AGE combustion chamber as it goes from stock, to finished






More to come.....

Often times during my work, I will ask my readers questions... kind of to see if their awake


So... for the SR20 crowd...




what on earth is this????? And what does it have to do with porting an SR20???

Really exciting post here.

No guesses... really? Not even a shot in the dark? This is audience participation time.....


How about a few hints.......

The lexan sheet you see is just a template...., the final version will be in steel



Does that make it easier??? How about if I add that the "14 1/2" you see written on the steel plate refers to degrees, does that help at all???