2TG Rebuild

[Turdinator]

Let me just clear something here. When I mentioned LOW HP, I was referring to the 2TG engine itself with the non-hemi head in stock form.

Am I starting off on the wrong foot here?

Relax Q.C. We're not having a go at you (well i'm not and i don't think the others are.) Welcome aboard.

The point i was trying to make is that the 88262 non hemi head is not as bad as everyone says. It just requires some stuffing round with pistons. Is it worth the effort? Is it better than a traditional hemi 2TG? I don't know. I'd love to know why toyota made the design change but i doubt i'll ever find that out. All i know is my hybrid has one, makes good power and is very drivable.

The motor your building looks interesting. What specs are you building it to and what sort of HP are you expecting from it?

[jeffro ra28]

this should be cleaned up........

[jeffro ra28]

this should be cleaned up........

[jeffro ra28]

What do you mean? All intake ports are designed to create swirl. Cylinder head designers created a cross section within the intake port to produce velocity and good flow and promote swirl within the port.

Man, can u build me a rocket? cause you sure seem like a rocket scientist. That peice of literature is just mind boggling.


First you say i should pay more attention to the straightness of the 2tg port.
Now you are saying that the swirl comes from a change in a cross sectional dimension???
Yet i still see no documented proof or swirl test results? Face it dude. swirl is not what yamaha had in mind when designing these ports.

Now where and when the fuck do we ever want swirl within a port?

Fuck dude, you keep digging the hole deeper.

[q.c.autosports]

Man, can u build me a rocket? cause you sure seem like a rocket scientist. That peice of literature is just mind boggling.


First you say i should pay more attention to the straightness of the 2tg port.
Now you are saying that the swirl comes from a change in a cross sectional dimension???
Yet i still see no documented proof or swirl test results? Face it dude. swirl is not what yamaha had in mind when designing these ports.

Now where and when the fuck do we ever want swirl within a port?

Fuck dude, you keep digging the hole deeper.

You just wont stop.

[jeffro ra28]

this should be cleaned up........

[mynameisrodney]

can we get this thread cleaned up? it was quite useful until recently.

[q.c.autosports]

<br>
<br>
The point i was trying to make is that the 88262 non hemi head is not as bad as everyone says. It just requires some stuffing round with pistons. Is it worth the effort? Is it better than a traditional hemi 2TG? I don't know. I'd love to know why toyota made the design change but i doubt i'll ever find that out. All i know is my hybrid has one, makes good power and is very drivable.

Looking at its design, it does have a larger squish area.<br>
<br>

The motor your building looks interesting. What specs are you building it to and what sort of HP are you expecting from it?

Was this question for me? the engine is for a customer. The setup consists of 12:1 89 mm Arias pistons, Eagle Rods, balanced internals, SI valves, Isky dual springs, KAMAERI/TRD cams 304/292 and some other minor upgrades. I'm planning to make 200 or higher. Here are some of the egines I am building.

4AG 20 Valves


This 2TG is for rebuild. Ready for disassembly.


Just finished this one and will be ready for the dyno.

[TheToyman75]

Q.C,

I wouldn't worry about Jeffro he is an abrassive Mother fucker sometimes.


Jeffro,

You of all people should know the importance of Squish and Swirl in a combustion chamber - How about you pull your head in and stop being a picky C#nt. Or maybe you want me to go high light your inacuracy's ?


As for the 88262 Head, What QC has said in term of not used in performance aplications is dead on, They are NOT used in performance applications. I know importers who would throw the 88262 head out as a waste of time before even trying to sell them. This is not to say the head is not a good thing. Just that typically they are not used.

[q.c.autosports]

Q.C,

I wouldn't worry about Jeffro he is an abrassive Mother fucker sometimes.


Jeffro,

You of all people should know the importance of Squish and Swirl in a combustion chamber - How about you pull your head in and stop being a picky C#nt. Or maybe you want me to go high light your inacuracy's ?


As for the 88262 Head, What QC has said in term of not used in performance aplications is dead on, They are NOT used in performance applications. I know importers who would throw the 88262 head out as a waste of time before even trying to sell them. This is not to say the head is not a good thing. Just that typically they are not used.

No harm done. If there was something to be corrected, he could have asked in a nice way or he could have sent me a PM. The kid is a year younger than my eldest son and if my son talked to me in that manner, I'd slap the living hell outta' him.

Thanks TheToyman75. I just wish the best for that boy.

Let's go back to the thread.

[TheToyman75]

QC,

I'll be very interested to see how that Turbo 261 headed engine go's.

What sort of boost levels are intended for it ?

[q.c.autosports]

QC,

I'll be very interested to see how that Turbo 261 headed engine go's.

What sort of boost levels are intended for it ?

It's going to be a street driven car and the head is basically stock except for the after market dual springs. It will be a conservative 15 psi using 91 octane but we are planning to test it with 116 octane and see what will happen. The turbo is an EBAY Special and seems to really kick in early so I don't think we will bw able to do some serious boosting. Right now, my friend is just drib=ving it around town to sit break in the rings little before the dyno tuning.

[jeffro ra28]

Ok, my apologies. Especially to you QC. Best wishes to you also
I was indeed an “abrasive” asshole.
But I am not your son so you cannot “slap the hell outa me”

Perhaps I should also edit all my posts to nothing eh? So that no one can see anything I previously said. Worked for someone.


Yes I am a picky C#nt, but without picky C#nts people reading forums for technical information would be going backwards. Although most of QC’s information is very good and I did go about it the wrong way.


I would just like to say a few more things.

As far as the basic combustion theory is concerned, that kidney shaped head is a far better design then a full hemi chamber as It does promote squish more so and may even improve flow. Unless of course the engines purpose is for TF drag racing and you will be forcing 40-50 psi of boost and 90% nitro methane into the cylinders. Even now, TF has veered away from the hemi chamber.

Yes Rod of all people I do appreciate the importance of squish and swirl which is why I am sticking to my guns about the improved design of the said head and in theory its ability to improve performance. My problem here is no one has told me a valid reason for why it isn’t recommended?


Swirl isn’t what it’s all cracked up to be.
I don’t think Reher Morrison, Joe Mondello, Don Terril or any other well endowed head porter all combined understand it fully. But there is enough information out there about it to make some sense of it to make improvements. If not then find out for yourself, like I partially have.

Also, recent developments prove that we want swirl in the chamber, not the ports. Otherwise, if all we had is swirl in the ports then we wouldn’t get any air in the chamber. Swirl within the ports disrupts flow. So what we need to achieve is the optimum direction at which the air enters the cylinder to create swirl within the chamber. Not swirl within the ports. In my mind a 2tg head in no way promotes swirl in the chamber in any way, if anything it “tumbles” its way into the cylinder. I haven’t actually swirl tested a 2tg, but I have an 18rg (very, very similar), to which its swirl result was extremely poor. Heck a Toyota 3k engine has a swirl inspired intake, can you see the difference? I know an engine in operation is completely different to flow on a flow bench. However it is proven that this information does correlate somewhat to the dyno and overall performance.


I am also trying to point out that just because people don’t use or have an un-educated "recommendation" that that style of head doesn’t mean it isn’t the better head for a performance application. All I have heard so far is that "I didn’t have time to experiment with this head" but they can still make assumptions that it’s not recommended for performance use? Which I did question. Still without an answer.
I think largely the reason for this un-educated "recommendation" is because people couldn’t be bothered with custom pistons or simply haven’t tried it! Fair?

End rant
My head is now pulled in.

Regards to all.

[TheToyman75]

Jeffro,

We all have our bad days dude.

If you read my post carefully you will see that I in no way said the 262 head was a bad design. I just tried to clarrify the reason for the 262 head being dismissed. From an economic point of view the 262 head when used in a high compression application requires the use of custom pistons which add an increased cost over using any other of the 2-TG heads.

Having spent many many hours and $$$ of my own both personally and professionally flow benching and testing the 2TG and 3T-GTE heads AND 2-TG and 3-TGTE inlet manifolds I am more than confident with my personal head selection and if I ever get the car finished and performing at a level I am happy with I will release the flow data I have recorded. Until then its just not information I am prepared to release.

As for swirl, your dead right about swirl in the ports being bad and swirl in the combustion chamber being what your after. Its also something I have always assumed people understood but now i think of it I don't remember ever seeing it being discussed or cleared up for the less imformed.its actually one of the things I prefer on the 2TG head, The ports are basically a straight design with a central valve location, there is no major turn in the port direction.

[q.c.autosports]

There is also some faults that some have made when porting the 2TG head is the intake floor. They tend to get excited with the grinder and grind away the floor area to make it round. and then shortening the short side. This will pretty much mess up the flow. As much as possible, you want to leave that area alone and concentrate around the valve guide boss area. Also, as you will notice on some of the photos I posted, the tear drop shaped path going toward the intake guide, the newer porters should take note, there is no power gain when you grind away that area and you have a high risk of hitting the spring seat area, so be careful.
Here is a shot of a 3TC head. Notice the port floor was flattened creating more area. When you have more area, you'll get more volume.