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Splitting HEAD'ache - 56K beware.


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68 replies to this topic

#51 Gravityman

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Posted 23 March 2007 - 07:18 PM

Sorry about the slight neglect, I will make that cut but I am going to do that to a different part of the head after I finish practicing my porting.

#52 Gravityman

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Posted 23 March 2007 - 08:50 PM

Here is an update.

Well I finally got all of my porting tools and started practicing and testing specific areas that I felt required some attention to. First before I jump in too deep I will show you the before. You can see that the HLA bump is a very big protrusion into the port and would restrict the incoming air and cause major turbulance. Also the casting marks in to bottom of the valley. One other part I was looking at fixing is the bottom lower right of the port you can see where the metal was pushed in due to allow a socket to reach around the spark plug.
Posted Image

I first started with the Hydraulic Lash Adjuster bump which is quite intrusive. I wanted to cut along this plane to see how much I had to work with when I port it. I cut quite a bit of material out of the bump and still had plenty of metal between the HLA housing and the port. It actually smoothed out better then I thought it would. With the unported side next to it you can really see how much of a difference this will make for flow.
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Next I radiused the valve seat. I was again suprised about how much I material I could remove to gain a very straight flow into the combustion chamber. Take a look at the difference between the uncut side compaired to the ported side, big difference! This area actually has a lot of material to work with before you get anywhere near the water table.
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Next I worked on the side of the port where the spark plug bump is. There is very little material to work with here so I flattened out the bump as much as possible and then left it alone. You can see this area in the red circle. The yellow is the valve seat and the green is the HLA bump.
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Now you can compare the before and end of the porting work and you should see how much of a difference a little bit of porting could go a long way! Here is a side by side of the after and before for comparison reasons.
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Posted Image

#53 Uberoo

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Posted 25 March 2007 - 01:36 PM

Once you actually port complete heads are you going to have room to port some of those areas?

#54 Gravityman

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Posted 25 March 2007 - 04:20 PM

Once you actually port complete heads are you going to have room to port some of those areas?


I think I follow that question, let me verify. When I start porting the uncut heads that I am putting on the car, will I have enough room in the port to move the carbide cutting burr around to get into the tight corners? Well, when I was working on them I tried to keep the carbides in the port opening as much as possible, I may have wondered out a few times. But for the most part, I really hope so! Does that answer your question?

#55 Uberoo

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Posted 25 March 2007 - 04:31 PM

yes.

#56 Gravityman

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Posted 30 March 2007 - 06:44 PM

Well here is the next update. I am still practicing and testing. Today I finished one of the intake ports. I ground it as if the block was whole therefore I only used the space that the regular uncut head would allow me to use.

Here is a pic of the intake port prior to porting. Mind you that this is not the actual intake port I ground but it is exactly the same as the one that I did. Notice the big indented lip on the bottom of the port and the sharp angles of the valve guide and the material around it. Also note the short side radius.
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Here is a pic after the porting. You can see that I have eliminated a large amount around the short side radius and the bottom lip as well as around the valve guide. I could also open up the flow around the sides of the valve guide and smooth the port floor to V/G transistion. The back of the valve guide was very difficult and very tight to get to. I plan on pulling out my dremmel and clean it up with a grinding stone. It should work.
Posted Image

Next you can see the short side radius before I started the port. It was an easy pic to take, there was enough material there for the camera to focus on.:rolleyes:
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Here is the post port short side radius. It is kinda blurry sorry. The hole in the port is where I drilled through the HLA bump into the port to see how much material I still had even after extensive cutting, about an 1/8 of an inch thick. My machinist said that as long as I keep it more then .100 inches in limited sections I will be ok. Its .125inch
Posted Image

None of these pictures are of the final grind with the 80 grit sand paper so there and not as smooth. The intake should be ground with no more then 80 grit to help improve fuel atomization through minor turbulance.

#57 Gloyale

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Posted 16 April 2007 - 11:09 AM

Bump for an update

#58 daeron

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Posted 23 November 2007 - 04:24 AM

Bumpage!

I somehow missed this thread, mustve been while I was without telephone/internet earlier this year...

http://forums.hybrid...ad.php?t=104420 this is a link to a VERY long thread about headwork on the L-6 Nissan motors, and contained within that thread is an ENORMOUS horde of knowledge from a few very very experienced engine builders.

I have heard some talk that there is a distinct possibility that the engineering that went into the EA series combustion chambers, was very closely related to the engineering that went into the Nissan motor; FHI and Nissan and Hitachi have ALL been making lots of subcomponents for each other in the past. I know nothing of the factual CONCRETE-ness of this, but its been bandied about and I sure see alot of similarities between some of the cL-6 combustion chambers and the EA. Anyhow, thats my disclaimer as to why this is relevant to subaru people...

Now, in that thread, read post fifteen. BRAAP is the poster's name. TonyD and johnc and a few others are also among the true wise men of that very wise place, just FYI. The rest is rigamarole that is essentially tangential to the soob-world, but from post fifteen (and likely more later in the thread, I didn't review the entire thing)

There is ALOT of good head designing information in some threads over there (mostly what has been stickied in the "L-series" subforum) and ALOT of it is very very applicable to our own heads, at least in terms of combustion chamber design, and in a more theoretical way the port flow stuff.

Skim through most of it to find the meaty nuggets of knowledge, backtrack to read the posts where questions were asked if needs be, and sponge up some knowledge. I would KILL to be in a position to start working on a cylinder head for my datsun, just so I could start getting my hands dirty and cut up on this subject and have some actual firsthand experience! Seeing pictures of things like this only teaches me so much; I need to be able to handle it and see things in person to REALLY grok the full four dimensional machine that the cylinder head and bottom end wind up forming in the end....

Anyhow, if I dug this up, and wrote a novel, just linking people to more novels that they won't read, I apologize.. but, as I said, there is experience and knowledge to be gleaned for those who want.

Oh yah, any updates? :Flame: :Flame:

#59 Gravityman

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Posted 23 November 2007 - 06:01 AM

Bumpage!

I somehow missed this thread, mustve been while I was without telephone/internet earlier this year...


Thanks for the info. You are correct about you can only learn so much by pictures. This is why I started this project, enhance my knowledge of the engines, practice porting methods, learning flow and how to improve it. I have learned so much just from hacking this "chuck of aluminum" that most could only dream of.

As for this project, It has been put on hold along with the rest. Shortly after I started I bought a house and started "moding" remodeling, and then got deployed:headbang: . So when I get home I will have tons more time to fiddle with all my projects and mabe get this motor running twin turbo running.

again thanks
Scott

#60 SubaruJawn

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Posted 23 November 2007 - 06:50 AM

i wouldnt use those heads anymore.

If You Need a Set Of Heads for your ER27. I Have A good set.
Make Me An Offer.
PM Me for quicker Response.

Subex

#61 Gravityman

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Posted 23 November 2007 - 03:03 PM

Actually I am going to tig weld them back together when I am done. It is a new method of porting "explode porting".

Are the heads in good condition? I have 2 sets of heads right now but, since I am doing so much experimental things going on with the engine I might need a 3rd set. So, I am not hard up but how much.

#62 SubaruJawn

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Posted 23 November 2007 - 03:25 PM

Actually I am going to tig weld them back together when I am done. It is a new method of porting "explode porting".

Are the heads in good condition? I have 2 sets of heads right now but, since I am doing so much experimental things going on with the engine I might need a 3rd set. So, I am not hard up but how much.


oh i'd say ummm $100. For Both
so its $50 ea. but i only sell them as a set.
And yes they are very good heads. thats why i must sell them instead of Scrapping them. (like i do with most of them)

#63 daeron

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Posted 24 November 2007 - 06:20 AM

THAT'S right, you are overseas right now.

If you enjoyed the read that I gave you, then I would recommend either mining the stickies on that website, and skimming topics that might have something of bearing.. Basically go through any subforums you might find something interesting in, and breeze through looking for things to catch your eye.... BUT, if you really don;t have idle web time to do the hours-long browsing it really takes to glean the full effect from the forum, I am more than willing to try and go through at some point and pull out certain other bits that may be vaguely pertinent to the head discussion at least.

I am about due for another periodic re-read on everything I read several months back, over there, to review the information covered, so this would be a good first step at doing that anyhow. Since you seemed to appreciate it, I will try to update this thread anytime I come across something that may be of note to the EA head customizer, unless many people think its really too much of a stretch to think that the datsun/soob head similarities are close enough to make the info useful.

#64 discopotato03

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Posted 09 December 2007 - 05:17 PM

Thankyou for the handy info and pics , we are just about to section a pair of dead EA82T heads so that we can port a pair of good uncracked/non cooked ones . Very interesting to see the 125 thou still on the HLS port bosses after reworking .

I am truly sorry someone doesn't have a used up EA82T piston to cut along the gudgeon pin boss just to compare .

One burning question I REALLY need to know is the differences or similarities between turbo and NA piston ring lands - basically crown design and thickness apart is the area around the rings the same ? If so do factory turbo rings fit the NA pistons ok ?

Lastly no ones ever been able to tell me how NA pistons varied in CR ie 9.0 and 9.5:1 . Is this again a crown volume thing .

Thanks for all your help , cheers Adrian in Australia .

#65 Gravityman

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Posted 10 December 2007 - 06:45 AM

Thankyou for the handy info and pics , we are just about to section a pair of dead EA82T heads so that we can port a pair of good uncracked/non cooked ones . Very interesting to see the 125 thou still on the HLS port bosses after reworking .

I am truly sorry someone doesn't have a used up EA82T piston to cut along the gudgeon pin boss just to compare .

One burning question I REALLY need to know is the differences or similarities between turbo and NA piston ring lands - basically crown design and thickness apart is the area around the rings the same ? If so do factory turbo rings fit the NA pistons ok ?

Lastly no ones ever been able to tell me how NA pistons varied in CR ie 9.0 and 9.5:1 . Is this again a crown volume thing .

Thanks for all your help , cheers Adrian in Australia .


I am about 6000miles from home so I am answering this off of memory. I belive the ring lands are the same from N/A to turbo pistons (EA and ER block) I have a picture of a side by side comparison of the 2. When I bought my piston rings I could not find a different part number between a turbo and N/A piston set.

The CR can be affected by a few things It might be the piston dish volume, head gasket thickness, not sure. I know that the crown volume is what drops the CR for the Turbo piston.

This is a pic of an N/A ER27 (same as the EA82) piston cut in half.
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This is a picture of an EA82 turbo piston that I drew in almost exact detail and cut it in half to show you how they are constructed. I think I screwed up on the oil ring land, the aluminum is built up a little more closer to the bottom of the piston.
Posted Image

This is the bottom of my balanced turbo piston.
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I hope some of this helps.
If you would like to see more pictures check out my albums. I have some good pics in there.

#66 4x4_Welder

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Posted 11 December 2007 - 01:44 AM

The last time I had a head to hog out, it was off a Ford 300-6. I spent about two hours on each port, and when combined with a 4BBL carb, dual exhaust, and big cam, the engine would pull to nearly 6k.
After fully bowl porting the head, it did loose some low end, and fouled plugs horribly. Pulled the head back off, gasket matched the exhaust, and carved a bit of rifling into the intake runners. I just put a line on the floor from left to right, and on the roof from right to left, it would have made a couterclockwise twist looking at it from the manifold surface.
The difference was like night and day. No more fouled plugs, no more random misfire, and no more high rpm dropped cylinders. Also reduced the detonation problems, even though the thing had 9.5:1 compression and no EGR.
Might be something to consider-



#67 daeron

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Posted 11 December 2007 - 01:52 AM

The last time I had a head to hog out, it was off a Ford 300-6. I spent about two hours on each port, and when combined with a 4BBL carb, dual exhaust, and big cam, the engine would pull to nearly 6k.
After fully bowl porting the head, it did loose some low end, and fouled plugs horribly. Pulled the head back off, gasket matched the exhaust, and carved a bit of rifling into the intake runners. I just put a line on the floor from left to right, and on the roof from right to left, it would have made a couterclockwise twist looking at it from the manifold surface.
The difference was like night and day. No more fouled plugs, no more random misfire, and no more high rpm dropped cylinders. Also reduced the detonation problems, even though the thing had 9.5:1 compression and no EGR.
Might be something to consider-


That is like, my dream American Iron motor.... Drop that engine into an early Mustang and you've got me hook, line and sinker.:burnout:

#68 nncoolg

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Posted 17 January 2010 - 04:47 AM

does anyone have copies of these photos, as they are not showing up?

#69 Sonicfrog

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Posted 17 January 2010 - 08:08 AM

I was wondering the same thing, and found it by chance. Go back to the "New Posts" tab and click. Where you see the title "Splitting HEADache" there is a small paperclip icon. The pic is there.




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