Well... OST-022 represents a few new numbers for me.... The first one is 6.... for 6 cylinders

My client has asked me to do a bit of porting on a 7MG head. It had the "typical" head gasket failure back by #6, so before he re-assembled it, he asked me to see what I can do.......

Now more numbers....
.10 - 62.66, .15 - 92.20, .20 - 111.38, .25 - 123.08, .30 - 127.93

Confused yet?

How about another set of numbers......
.10 - 73.83, .15 - 107.50, .20 - 135.85, .25 - 155.95, .30 166.40

So what do all those numbers mean???

What... no photos? What's an OST head build without photos????? Well... another "new" number... 7 as in Windows 7... as in Windows 7 doesn't support MS Photo Ed anymore
MS Photo Ed was a very simple capable photo editing/cropping program that I've used FOREVER.... for this... I MAY have a solution, but I won't know till tonight.

MORE to come.......

Lots more flow per given lift ... Is that a turbo 7M?

oldeskewltoy wrote: Confused yet?

Yes.

Feedyurhed wrote:

oldeskewltoy wrote: Confused yet?

Yes.

Lets see if I can clear up some of the confusion....

Slippery wrote: Lots more flow per given lift ... Is that a turbo 7M?

correct...

XNC wrote: First set is inches of valve lift @ cfm for intake and second set is for exhaust?

You are right... kinda... you have the intake and exhaust reversed. Intake numbers are always greater then exhaust.

Running a 7MG head on a flow bench. As you see the 4AG valve tool works PERFECTLY... thank you MACK Engineering :thumbsup:

checking the intake side...

and the exhaust side...

All heads from now on will have one port checked(no extra charge) throughout the entire porting process so the client, and the rest of my readers can SEE the results. :D

Above is a 2 panel showing the overall head - intake and exhaust, chamber view as well as the top of the head.

Lets take a more isolated view of the intakes....

Can you see what I see??

What do I see?

Why do I think it is a problem??

More to come

from another forum wrote: Intake valves are shrouded as hell? Subscribed to see what you do with this, especially in the chambers :-) I would STRONGLY suggest having it hardness tested before you put too much work into it. 7m heads go soft as buggery and from there will keep blowing gaskets no matter what. If he is pouring some decent $$ in you would want to start with 90-100rc so it has a few years of hard work left in it. Also you can see at the back of #6 where they missed a water jacket in the head (wonder why they all blow #6, duh). Easy fix with a small drill bit while you're at it, just go straight down and it will come out in the main water passage.

Thank you!.... I've shared what you said with the owner... do you have a view showing the drilled water passage?

Now as to what I see.... let me show you a bit closer.... here are the 6 intake ports up close

Port #6

Port #5

Port #4

Port #3

Port #2

Port #1

Is it any clearer?? What bothers me about these ports??

More to come....

Not sure what you are getting at ... But I am sure it would be an easier thread to follow if you just say what you are thinking ...

Also the EGR system is back there between 5/6 ... Thats usually another contributing factor to the headgasket problem.

Slippery wrote: it would be an easier thread to follow if you just say what you are thinking ...

party pooper.... (j/k)

ok... here is what I see... I see fuel tracks in the port ceiling. This means the injectors/ports are NOT delivering fully atomized fuel. A substantial amount of the fuel is contacting the port roof, and injector port, this is not good for emissions, or power. Ideally the fuel is not dripping from the port roof........

For some interesting 7M cross sectional photos - http://www.ma70.ru/head-7m-gte-toyota-separate/

I've picked a few out to post here....

oldeskewltoy wrote: ok... here is what I see... I see fuel tracks in the port ceiling. This means the injectors/ports are NOT delivering fully atomized fuel. A substantial amount of the fuel is contacting the port roof, and injector port, this is not good for emissions, or power. Ideally the fuel is not dripping from the port roof........

So you're saying it has crummy/gummed up injectors?

Bryce

Nashco wrote:

oldeskewltoy wrote: ok... here is what I see... I see fuel tracks in the port ceiling. This means the injectors/ports are NOT delivering fully atomized fuel. A substantial amount of the fuel is contacting the port roof, and injector port, this is not good for emissions, or power. Ideally the fuel is not dripping from the port roof........

So you're saying it has crummy/gummed up injectors? Bryce

nope... I'm saying the twin pintle design sprays on the port roof because the injector port, and the port roof shape is pretty bad........

Here are the 6 intake ports... cleaned, and ready........ Oh, for point of fact, the 7MG head groups the intake ports together in 3 groups of 2. Each grouping has a right favored, and left favored port shape.

1

2

3

4

5

6

The first thing I see is the gradual shift the seat bores are at as compared to the bowl placement. Notice how the bores shift and go from a left shift to a right shift on a gradual basis as you proceed from #1 thru #6.

The next thing I see is this amorphous blob at the edge of the injector port. It appears as if it was designed as a port divider, but it acts more like a damn then a divider...

Anyone remember OST-011? Grunts head(4AFE)? It also had an amorphous blob in each port before I tended to them.....

Besides the blob... the guide bosses are poorly shaped, progression from port to bowl is just nasty.......

Tomorrow I'll post up some exhaust port views, and see where we can improve things on the out going side of the cylinder head

More to come.......

Nearly forgot this..........

....... and now for more numbers..........

.10 - 64.10, .15 - 95.97, .20 - 113.73, .25 - 124.32, .30 - 129.58

Exhaust.....

.10 - 75.73, .15 - 111.48, .20 - 141.57, .25 - 163.67, .30 - 176.37

Intakes

Now lets take a look @ the differences.....

Exhaust:
Before cleaning - .10 - 62.66, .15 - 92.20, .20 - 111.38, .25 - 123.08, .30 - 127.93
After cleaning - .10 - 64.10, .15 - 95.97, .20 - 113.73, .25 - 124.32, .30 - 129.58

Intake: Before cleaning - .10 - 73.83, .15 - 107.50, .20 - 135.85, .25 - 155.95, .30 - 166.40 After cleaning - .10 - 75.73, .15 - 111.48, .20 - 141.57, .25 - 163.67, .30 - 176.37

There is improvement... but remember I have cleaned more then just the ports... I've also cleaned the valves, removing deposits from the back of the valves.

One thing is clear... the exhaust side shows only minimal improvement, almost within a tolearnace factor, while the the intake side... on the other hand.... seems to show substantial improvement.....

Now... for some numbers my client found.....

http://www.supramania.com/forums/showthread.php?54-7M-Cylinder-Head-Flow-Numbers&p=300&viewfull=1#post300

link from above wrote: Stock: Intake lift-flow .100-77.4 cfm .150-113.9 cfm .200-141.4 cfm .250-162.8 cfm .300-176 cfm .350-179.6 cfm .400-179.6 cfm .450-180 cfm Exhaust lift-flow .100-60.4 cfm .150-93 cfm .200-112.9 cfm .250-123.2 cfm .300-127.8 cfm .350-130.7 cfm .400-133.2 cfm .450-133.2 cfm

Well... at least my numbers seem to compare similarly to Defiant 7M's....

The head likely has a few out of tolerance valve guides(4 to 6)... I'll know more Monday afternoon...

More to come.......

The head is off getting it's 3 angle. Before I let it go, I took a few more pics... this time the exhaust.....

1

2

3

4

5

6

These will get a more gradual taper to them, along with the bowl/seat work, and they will get a bit of work along the splitter.....

More to come......

Actually... I'm still waiting on a pressure test of the head BEFORE the 3 angle. Once the pressure test is verified good, we will commence with the 3 angle.

During dis-assembly I checked for bad guides, either too tight, or too loose. I had thought I had found 3 loose guides (where the valve was too loose in its guide). The suspect valves/guides were all on the exhaust side. I had the guides checked prior to the pressure check and all the guides are usable* - good news for my client as it saves him hundreds of dollars.

• • the worst guides measured out to about .0017" of "play". That is well within the standard of a 4AG valve stem, but is it the same for the 7MG head? Well, having the 7MG engine manual(pdf), they are also well within specifications.

More to come....

oldeskewltoy wrote: Actually... I'm still waiting on a pressure test of the head BEFORE the 3 angle. Once the pressure test is verified good, we will commence with the 3 angle.

Well... the pressure test went fine.. and the 3 angle is now complete....... apologies for the delays... but this is racing season and Loynings is very busy...

I've not yet had the head surfaced, that will be the last task once all the porting work is accomplished. Below is the head showing its 3 angle, and the valves are showing their back cut... albeit the exhaust valve back cut is barely 1mm in width, while the intake valve shows a much more substantial back cut.

This is #5 chamber... the same chamber I've been doing all the flowbench work on. This chamber will be the exhibit.. after each process I'll be getting #5 back on the flowbench so we can follow the progress.

....... and a bit closer we can see the back cuts, and we can see the 3 angle on the seats...

Before I work the chambers, I'll take a volume measurement and then massage the chambers. All of the machining marks in the chamber will be smoothed, the chamber shrouding around the intake ports will be tapered a bit to improve flow past the valves. I'm not sure how good your eye is... but if you look at the chamber shrouding on the intake valve closest to you... you may see an imperfect arc around the valve... This will be smoothed and blended as well....

The next step is a bit more flowbench time to see if nicely machined seats, along with a 3 angle, AND back cut valves improve flow...... remember no porting as of yet.

More to come.....

Interesting on the injector pintle design....

I actually run those same injectors in my DD. I noticed that there were two holes on the 440s, and only one on the 330s i replaced.

I figured this was a good thing.

Maybe not?

I'm going to have to get in contact with you after my trip, methinks.

More new numbers........

I'll begin with the exhaust side.... 64.0, 95.2, 115.3, 125.8, 130.8 and posting the earlier numbers.... .10 - 64.10, .15 - 95.97, .20 - 113.73, .25 - 124.32, .30 - 129.58

All are more or less inline with the numbers prior to the 3 angle. The tiny back cut doesn't look like it did anything... the numbers just don't show it..........

Now for more numbers.......

90.9, 130.7, 166.16, 191.52, 205.66...

I don't need to post the previous numbers, but I will below, to know we hit the ball clear out of the park with this 3 angle and back cut...... I also checked the numbers TWICE and they came up less than 2% different, so I know the newest intake numbers are genuine.....

For comparison......

the old - .10 - 75.73, .15 - 111.48, .20 - 141.57, .25 - 163.67, .30 - 176.37

the new - .10 - 90.90, .15 - 130.70, .20 - 166.16, .25 - 191.52, .30 - 205.66

just... WOW...

A simple backcut, on the back of the 7MG intake valves, along with a 3 angle... really allows far more air flow... So... for those building 7MG engines... get those intake valves back cut!!!!

MORE to come........

from another forum wrote: are you sure its not just from cleaning all of the carbon crap and sludge from the valves and intake ports? the pcv system really gums up the intake side. i doubt that very mild back cut of the valves increased the flow over 25cfm at .3in lift all on its own.

I actually have 3 sets of numbers now... and the intake side did improve substantially once it was cleaned....

Intake: Before cleaning - .10 - 73.83, .15 - 107.50, .20 - 135.85, .25 - 155.95, .30 - 166.40 After cleaning - .10 - 75.73, .15 - 111.48, .20 - 141.57, .25 - 163.67, .30 - 176.37

I checked these numbers twice... could I be mistaken.... yep... I could be... but the fact that the exhaust side didn't improve... and I tested those at the same time I did the current intake readings... for now I'm going to trust that the intake back cut and 3 angle are showing real(genuine gains).

I'll know more once I begin porting... (if the numbers remain.... )

2 hours later.........

William(original doubter of my numbers)... you KEEP ON QUESTIONING everything that doesn't make sense... because it just didn't make any sense to me either. The exhaust numbers are so there... so how could I have screwed up the intake side so seriously........???

SIMPLE... I didn't change the program to read the intake side. I had changed all the connections, but failed to switch the software from reading exhaust to reading intake....

The CORRECTED numbers........ .10 - 79.42, .15 - 113.57, .20 - 144.88, .25 - 166.91, .30 - 179.37

Intake: Before cleaning - .10 - 73.83, .15 - 107.50, .20 - 135.85, .25 - 155.95, .30 - 166.40 After cleaning - .10 - 75.73, .15 - 111.48, .20 - 141.57, .25 - 163.67, .30 - 176.37

so now it all seems pretty interesting as the numbers are climbing. At least with the corrected numbers the actual porting should show up with a bit more ease....

Thank you once again. This is new equipment... and the only way I'll get proficient is to use it. I thank you for keeping me honest....

With the head off the bench... but prior to disassembling #5 for porting, I took a measurement of the combustion chamber volume...

I got a volume of 39cc.

Not being as familiar with the 7MG head, as I am with the 4AG head, I do not know if this is standard volume. BUT... we have what we have... I'll do some chamber work, get another measurement and calculate how much the head will need to be machined to retain the 39cc volume

More to come.......

There are many things the 4AG and the 7MG share.... unfortunately for this test...... cylinder bore isn't one of them

thank you gentlemen.......

7MG has a bore of 83mm, this one will have an 84mm bore...... my flowbench has an 81mm bore.......

Here... for those who don't understand.... below is a 2 panel...

the right view is the combustion chamber ported out to 83mm, the left view is showing a 4AG gasket centered, overlayed on the 7MG - note how the gasket cuts the corners, how close the gasket is to the outer edges of the valves... now remember the 4AG gasket is 82mm... my bench is another millemeter narrower

There is no way my numbers are accurate.... because well over 10% of the valves are buried behind an 81mm flowbench bore

I still have numbers mind you... but I'll show the pretty pictures first..... :)

The combustion chamber retains its original configuration, I've tapered all the valve shrouding to allow for improved cylinder filling.

let me introduce to you exhaust port #5....

and a slightly deeper view......

I promised some numbers....

Intake:

Before cleaning.... .10 - 73.83, .15 - 107.50, .20 - 135.85, .25 - 155.95, .30 - 166.40

After cleaning..... .10 - 75.73, .15 - 111.48, .20 - 141.57, .25 - 163.67, .30 - 176.37

After 3 angle..... .10 - 79.42, .15 - 113.57, .20 - 144.88, .25 - 166.91, .30 - 179.37

After porting..... .10 - 79.32, .15 - 115.20, .20 - 146.32, .25 - 170.10, .30 - 182.74

Exhaust:

Before cleaning... .10 - 64.10, .15 - 95.97, .20 - 113.73, .25 - 124.32, .30 - 129.58

After cleaning..... .10 - 64.00, .15 - 95.20, .20 - 115.30, .25 - 125.80, .30 - 130.80

After 3 angle...... .10 - 64.15, .15 - 95.90, .20 - 114.91, .25 - 126.62, .30 - 132.60

After porting...... .10 - 64.20, .15 - 95.35, .20 - 115.84, .25 - 127.70, .30 - 135.60

Now just 5 more to go.......

from another forum said: What is needed to convert to the correct size for this head? Ian

Sent you a text... in essence... I need a 3" long section of 3.5" OD plastic grey pipe, bored out to an ID of 84mm

Since this is my first 7MG head, and it is going on to a street use 7MGTE... I follow OST rule number 1... do no harm!

oldeskewltoy said:I'm going to be working with the casting, keeping some of the shrouding but shaping it better.

Here is #5 chamber

All of the original machining marks that can lead to pre-ignition have been blended into the chamber walls. The bowls and seats have been blended together as well

Here is a different view... here I'm show chamber 5 and chamber 6... (both using the same light source)

Here you get a better idea of the chamber work(note no sharp edges), as well as the work performed in the bowls, as well as the gentle taper all the valve shrouding now has...

Note I've pushed the chamber edges, surrounding the valves, to the very edge of the gasket, remember the client is using an 84mm bore, the gasket above is 83mm, this allows me enough room to taper the valve shrouding to improve cylinder filling

Here is a different view of the chamber work performed.

Both valves are set @ .300" lift, and you can see the exhaust valve shrouding is now about half as much as what it was

More to come......

Yes... those are 4AG intake valves... I have no spare 7M valves so 4AG intake valves work in a pinch to protect the 7M valve seats... adequate for both intake and exhaust.

Soooo.... up to now I've shown you #5 exhaust port, and the #5 chamber...

now for a little comparison #5 intake short radius.... and #4 before I work its short radius

Note the port floor is still the port floor (horizontal light line in port center), the short radius, as well as the bowls have been blended.

You can see the ports are directional the port on the right leads away to the right, while the port on the left leads away to the left. Also note the far left bowl, the bowl and port wall are intruding inside the valve radius, note the far right port bowl flows smoothly into the port and out. The very sharp of eye will see the radius change on the inside bowl of #5 where it meets the divider, as compared to #4.

Now that I've got the intake side "designed", I proceed on with getting another exhaust in shape... this time #6.

6 has an "irregularity" in it... the EGR port - hole in far right port.

Here is #5 and #6, the splitter for each is just visible in this view, the only light in this shot is shop light

The edge of the EGR port closest to the of port outlet received a mild radius, The other edge was not radiused. I did what I could... considering there is a big hole in the side of the port. I was able to do quite a bit to the bowl and port.

And a 3 panel.... bowls mostly in shape, port transitions from raw to finished* (some hand finishing remained)

The major work is performed between the top and center panel... large sections of the outer walls are removed to allow for a more gradual transition. Those transitions are blended between the center and bottom panel.

More to come.......

Thanks for writing this up in such detail. The more you do, more pictures, more numbers, the better I understand the process. Simple things like putting in the valves to protect the seats. It's blindingly obvious when you show it, but I admit to thinking that you must be a surgeon with the grinding burr to never nick a seat and screw up that beautiful 3 angle job.
Thanks.

oldeskewltoy said: The very sharp of eye will see the radius change on the inside bowl of #5 where it meets the divider, as compared to #4

I found (with help from a few friends on toymods.org.au) a view I could use to demonstrate above mentioned "radius change"

3 down... 3 to go....

This type of photo allows me some interesting comparisons....

2 ports opposite each other in view....

More to come....

andrw mx83 said: sorry for the delay getting pics, been absolutely flat out! full port view:

here is my full port view... this is 2 ports... they are similarly directed, but alas... I didn't get a before view of 5 from this angle so I took port 3 as a before

before #3

after #5

You can see the splitter taper, and how it allows for more of the valve to draw on the air fuel mixture. The short radius has a lengthened horizon allowing for more air to follow the short radius to the valve

More to come.... and next time it doesn't look nearly as nice as this post