4age bigport head: port & polish

[firehawk]

Here's a few photos from my Levin/Trueno bible concerning the N2 engine specs - I hope they are useful. The bible also says that the N2 engine used the TRD 11115-AE801 head gasket, which is 1.1mm thick when compressed.

[Os7213]

Hey thank! Firehawk
I have order today the Levin\Trueno bible cause like i can see these infos are very useful since they give the valve angle grinding and ect...!
So i think ill be able to build up the motor with the N2 blueprinting spec.
I just hope they give infos about clerance\tolerance for all parts of the engine! My setup for now is this one 4agze smallport head+black-top block and i hope matching this with the N2 specs.

Thank for the infos about the clay! I think ill be able to build the head with no problem So the clerance of the piston to the head 0.050in -0\+0.030 but be as close as possible to 0.050in with squish area machined.

So firehawk tell the N2 spec 4age use a 1.1mm(0.028in) gasket compressed. So we have 0.022in to play for the piston top-dead center and the squish area. So if the piston is at 0.015in of the top of the block we have a squish area of 0.007in who give 0.050in clearance but im sure we can add almost a +0.002in tolerance without problems! Hope my math are okay this is just for exemple! But hope im in the right way!

Just for info someone have found something about all the specs for the 4age 20v black-top? Or even a manual for ae111? Cause im looking since many weeks now for anything about specs\tolerance\clerance of this motor but only thing i can find is about crankshaft compared to other 4age...but nothing about tolerance\clerance!

Thank a lot guys
Ugo

[BenR]

Os7213 Wrote:Hi BenR I got a question about your porting job..Why do you remove material all around the cylinder bore line around the chambers?:


(For the image can you right click and open it i dont know why the image dont work when using left-click sorry )

Or can you tell me what serve this deck and how much material have been remove from Z axis?

Here my second question, i projected a porting job on my 4age smallport 16v head , and here my idea for the chambers... My idea is to reshape the chambers to the cylinder bore-size for more sqish area do you think this is a good think or it will ruin the head?



Sorry i hope im not too off topic since the question is about porting.

Thank a lot in advance
Ugo

Ugo, sorry it took me so long to reply, but i do not check on here that often.

The Chambers were recedded in the quench areas because we were running a special piston combination that saw them sit 20 thou proud of the deck face.

And in my opinion, do not open up the side of the chambers to the cylinder bore size like your drawing indicates. You want to run the smallest piston intruder as possible, and the larger you make your chamber, the larger your intruder has to be, which impedes flame front propagation.

In our extreem applications we actually weld the head into cloverleaf design and run a specific piston to maximise the quench area available for effective combustion and to reduce the chamber size so we can run less ignition timing and a faster burn.

[Os7213]

Nice no problem with time that happen really often in forums thank a lot for the answer!
I now understand why u keep chamber size intact and just doing squish area.
Oh! im not sure if you have read the entire post but do you think i going in a right way to calculate the squish area depth?

Os7213 Wrote:Hey thank! Firehawk
I have order today the Levin\Trueno bible cause like i can see these infos are very useful since they give the valve angle grinding and ect...!
So i think ill be able to build up the motor with the N2 blueprinting spec.
I just hope they give infos about clerance\tolerance for all parts of the engine! My setup for now is this one 4agze smallport head+black-top block and i hope matching this with the N2 specs.

Thank for the infos about the clay! I think ill be able to build the head with no problem .So the clerance of the piston to the head 0.050in -0\+0.030 but be as close as possible to 0.050in with squish area machined.

So firehawk tell the N2 spec 4age use a 1.1mm(0.028in) gasket compressed. So we have 0.022in to play for the piston top-dead center and the squish area. So if the piston is at 0.015in of the top of the block we have a squish area of 0.007in who give 0.050in clearance but im sure we can add almost a +0.002in tolerance without problems! Hope my math are okay this is just for exemple! But hope im in the right way!

Or you have your own techniques to calculate the area depth? Im really interessted to learn more about 4age porting and head configuration and your help is very appreciated thank you all! And sorry sometimes for my bad english Oh i almost forgot i have few questions and drawing about port configurations if you guys are interrested in talking about it let me know.

Ugo

[BenR]

I run 35-40 thou quench depth on all my engines.......i would run it smaller but i have to account for rod stretch at high rpm as it effectively closes up to 1 thou at 10,000rpm.

For your calculations, to get the quench depth you need to add the deck height of the piston to the gasket thickness.

So for a stock engine a 1.1mm gasket (0.043") and a deck height of say 0.5mm (0.020") then you will have a quench depth of 0.063" or 63 thou, which is too large to be effective.

If you have any questions regarding port configuration or ideas, feel free to post them up.

[Os7213]

Thank a lot BenR for your answer!
Here how i see it:
I project to run a 0.5mm(0.012)head gasket.
With a deck height say 0.020in.
We have a 0.032in quench wich is to small for high rpm. So the depht of the squish area machined on head is about 0.003-0.008in depth to account for the rod strech at high rpm. Everything look fine in the calculation!?


Oh and here my few question about the ports configuration:



Thank a lot in advance
Ugo

[BenR]

No, total quench depth with the deck height and gasket thickness is 40 thou (0.040) or 1mm.........since 1mm is 0.040, that makes 0.5mm = 0.020"......not 0.012"

And when you account for rod stretch, i am talking about using steel rods and forged pistons, not OE items as they are not good enough.

As for your port questions:

1. You can alter the port inclanation, but you will see no benefit for the massive cost required. The 4age ports are already too big for such a small valve so you have no problems flowing enough so long as you do configure the port and valve seat correctly. If you do alter the port inclanation, you will have to spend time developing new valve seat profile and the back of the valve head will have to be of a different shape. And current trends at the moment are not to have high angle ports, but the highest flowing heads from Honda and the likes, have a generous short side turn.

2. Cutting is fine, it does shorten lifespan a little, but nothing too crazy. I prefer to install bronze guides and shape them correctly, you do not loose flow by having the guide protruding. A splitter design is bad, flow does not like to meet a sharp edge as it causes turbulance, shearing and absorbs energy.

3. The idea is flawed since the exhaust port is a high-low pressure setup with ever expanding volume gas due to heat, there is no suction direct and time is better spent working on anti-reversal properties. Use the header to tune pulses for scavenging effects or 'pulse tuning'.

[Os7213]

Haha nice thank alot!
Lol sorry for the maths think it was late when my math have been done

For rod stretch since im using OE con-rod from a Ae11 blacktop i think ill be good cause my engine will not rev 12000 so

For the splitter in front of valve guide you are totally right...my bad...havent think about the round diameter of the valve guide ive just see something in the port!!! Thank for the advise

I think the head will be perfect, im using the 4agze since i want "middle" power what the blue-top head cant provide... The only thing i need to think about is the perfect dimension of the port for "middle" power and high rpm almost near 9000rpm or more since my cam peak power is near 7500. Do you think this kind of combinason is possible!?Ive also think about a 264deg ext cam since im running itbs who good on high rpm. Ill trying to check the port size by begin with the N2 port size specs..I already know they are too big for my application so i need to make them smaller but how can i have the best port dimension?! Ill find something between the dimension of the stock port and the N2 specs I think it can work! Since i dont have to change port configuration i have all my time to check these meusures.If you have tips dont hesitate!!

For the scavenging effect i have only begin to read about it... The only thing i know is the exhaust manifold have a restricted volume but in fact that help!! The thing you need to check is for too much rapid restriction if i have understand right...Dont you think a simple porting or the headers can help a lot? I only know the cat-bak intern desing play an important role so a test pipe its not the way to go and since i dont want to "reshape" the interior of a cat i think i will just install one..Where im lost is the part of the exhaust line leight im not sure wich type of headers i can use, i suppose a nice smooth curved one no high rise... And the total leight of the exhaust im not sure i dont find proper infos about it...
Thank a lot to help a guy who want to lear and have poor english skills

Thank a lot in advance
Ugo

[jamiemirror]

Quote:And when you account for rod stretch, i am talking about using steel rods and forged pistons, not OE items as they are not good enough.

BenR, whats wrong with OE items ?

[BenR]

jamiemirror Wrote:

Quote:And when you account for rod stretch, i am talking about using steel rods and forged pistons, not OE items as they are not good enough.

BenR, whats wrong with OE items ?

Their tensile and compression strength is not strong or reliable enough for competition use.