T-Series heads

[TheToyman75]

As for the twin cam heads, this image should clear up any question as to why the unicorn is built with the bits it is.

Enjoy


The flow figures above are all at 28" of Mercury.

[toyota1515]

Thank you mr. Toyman,

By the way no intentions on convert a simple thread into a pissing contest, but you know one thing leads to another sorry for any trouble caused by yours trully!

[J-M kujala]

The flow figures above are all at 28" of Mercury.

to my eyes 28" of Water... Correct ?



Mine one 2T Head.. use that in my 184 hp street "T" engine with 284 cam..


~198 Cfm & 12 mm 28" of water..

with intake.



195 Cfm 28" H2o

Usually the intake drop a "peak of hill" of flow, but not in this case...

basicly in the pictures cant get whole idea of the port, but some advices to "home porters"

[J-M kujala]

plus one for the 3tc head for a turbo motor, so much cheaper and easyer to deal with.

yeap, i agree that, not so much possible place to do some mistakes and bendt valves...

early 2tc heads have larger intake ports, not sure if the wall OD is larger? ive never looked into that on the ones i have.

Nope, i have measured, heads fit into +-0.5mm range, quite small tolerances in castings in 70`s

Got couple big port heads, unfortunatly they are already ported, also those 2T-3TC modell heads and 12-13T:S have measured, all same OD 3 different size port have been found..

pushrods are limiting the width of port OD

[toyota1515]

No angle milled on the intake side?

As i see we got diferent aproach on port designs, as i do port straight down invading the water jackets a little on the port floor i milled the intake side of the head to give angle to the intake runners to match the head ports, also a little pocket porting is very helpfull, and to be honest i have no flow charts whatsoever cuz it is working so fine, and as the ports are made by an end mill specific sizes so they perfectlly the same each and eavery time on all 4 regardless size used, exhaust is where we make changes depending on what the engine will be used for.

[J-M kujala]

this head have been ported with intake... intake is tight fit.. not move at all... even when screws are loosen.

angle is milled after "base" intake before ITB:s (if i understand you correctly)

[toyota1515]

Yes right on the head intake side base, certain ammount of degrees!

[TheToyman75]

JM,

It's been over a decade since I did all my flow testing of heads and inlet manifolds. All were flow tested at 28" of Mercury at lift points to suit the valve size calculations. The CFM are compatible as they stand do to the calculation used.

[NME308]

...to be honest i have no flow charts whatsoever cuz it is working so fine.

Funny how there are quite a lot of the top guys in head porting these days who will flow test a head only if you specifically want the chart. Because they already know how the port needs to be shaped /sized to achieve given performance they will guarantee the results you are paying for without needing the aid of the flowbench. While it is a good tool the flow bench can be misleading sometimes! The old trial and error R&D program comes up trumps most of the time.

Dyno's fall into the same category. You can make sure an engine is healthy and running safe etc but if you are racing on a road surface then the tune will need polishing at the track! If one is only going to race the dyno then dyno tuning however will be the key to winning!

The heads on our turbo race engine are hand ported - never been introduced to a flowbench. We made sure the base tune was safe on a chassis dyno and went out drag racing. When we tune at the track we are well down on the dyno HP numbers i.e. 990 weight shifted HP to the drag strip gives 786RWHP on the chassis dyno. My 270RWHP in the celica is achieving the same drag strip time and MPH figures as a mate with 100RWHP more from his CA18DET in a lighter car. My N/A 355 Holden V8 was tuned on an engine dyno and after a full day the result was 514HP. At the drag strip it showed 520 weight shifted HP and - I'll spare the sob story - after only two successful race meetings had found another 50HP to the track with tuning changes.

What am I saying? I guess it is that flow benches and dyno's are useful tools but for real world results you will still have to experiment long and hard or pay for the services of someone else who has already been there and done that!!!

Cheers,
Jason

[J-M kujala]

JM,

All were flow tested at 28" of Mercury

i misunderstand because language or there is something wrong..

28" of mercury vacuum is like -0.95 Bar ~5 Kpa . any flow bench cant do that, with 28" mercury of vacuum we are like in the space..

Usually flow bech measures have been done with 10 or 28" of water.. 28" of water is like about -0.07 bar / 93 Kpa and youre flow results match to this 28"H2o vacuum..

What am I saying? I guess it is that flow benches and dyno's are useful tools but for real world results you will still have to experiment long and hard or pay for the services of someone else who has already been there and done that!!!

YEAP... with flow bench you dont port heads, like with dyno you dont make engines..

they are only tools for confirm results and help testing...

Like if had tools to measure, and wrong size drill, you cannot measure that drilled hole to be a correct size...

[toyota1515]

To achieve the best results a head must be flow tested, i will do it in any other head but when i start working with the 2-3tc was back in the mid 80's and back then in PR we didnt have acces to these tools so we went tru many heads port designs i say to be honest more than 200 get scraped due to different attempts, and then i came up to the desition of cuting a good head in half to see the port as it is and to determine how i can do it using a dodge hemi head port design book and came up with the design i got today and so far the best one we try and couple other guys arround the island eventually came up with basically the same thing if you are smart enough to see that it is a copycat of a dodge hemi is not that hard to look for comparation and seek some designs that suit your heads.

Just to share some history on how i get here where i am!

[toyota1515]

look here to see what i said the only diference is that the intake port is squared and exhaust round on these heads, the port is straight down to the valve edge for better results,









The people from M2 race systems have achieved this flow numbers on the 3tc heads, we are very close to the same performance with our own, enjoy!




here some other pictures



and some cad designs



Basically i just took whats works for the same design for years and translated it to this little head, just to show you guys that is not a big secret is just a matter of R&D if it works, good, if not lets try it again in a different way, a good advise is... just dont give a shit to much, do it and have fun!

[metcap]

Great great info and pics from you guys here!!! thanks heaps for sharing

angle is milled after "base" intake before ITB:s (if i understand you correctly)

No angle milled on the intake side?

sorry I need to ask but what do you mean by angle mill?

[toyota1515]

Angle mill is when i do my ports they are done with a milling machine directlly to the edge of the valve seat and that make the intake runner runs in an angle against the base of the intake side of the head so to solve that problen and match that angle so the intake runs simmilar angle we angle mill the base of the intake side certain ammount of degrees so the intake sits aligned with the intake port angle, if is a set of side draft carbs they will sit high on the stacks side!

That is an ol trick but it is tricky to get it just right!

[metcap]

Just curious, why is there a deliberate work to make the intake ports square and the exhaust round? Is this to maximize port wall space or is there some trade secret going on? he he