T, 2T, 2T-B, 2T-C & 2T-G Specifications & Diagrams

[TheToyman75]

Rohan,

Deffinatly not a myth mate.

It was common practice for the valves in the 88220 head to be replaced with bigger ones by anyone chasing big numbers. The old 88220 heads are also pretty thin on the ground these days. I wil have a look through mystuff and see if I still have some 88220 valves kicking around.

[river]

Hi,

River,
Ive linked to this thread in another thread to help someone out, but all your nice pretty diagrams are down
Any chance you could be a gentleman and fix them up for us? (Im such a suck up I know!)

Ahh crikey, I forgot about the 2T-G pics. Okay, I'll try and get onto it this evening. It just takes so damn long....

seeyuzz
river

[river]

Hi,

Alrighty!!!! How exciting!!!!

I've finally added the images to this thread. They're thumbnails to make your download a little faster.

Again, sorry for the delay.

seeyuzz
river

[Steve M]

Were there any differences in piston crown to suit the different combustion chamber shapes?
I've seen two heads in the last week or so that have had different CC shapes.
One was a hemispherical, like an 18RG.
The other appeared to have a much smaller volume and the chamber had metal surounding each valve that was scooped out, just like the flow work around the spark plug.

[GasedT18]

Good one river!

SteveM wrote

Were there any differences in piston crown to suit the different combustion chamber shapes?....

Good question. The 2T-GEU's are reported to have a lower Compression Ratio either 8.3:1 or 9:1, The 2T-G's according to the same site 9.8:1 and the 2T-GU's 8.7:1 according to Matti's site:

ToyotaGasolineEngines.html

Presumably this was acheived through either different piston crowns or combustion chamber design changes or both. Photo's would be good.

merc-blue

I have Early and late heads but never found any different size valves

That's why I asked you what number was cast on the heads and stamped on the cams you have.

Not only was there a valve size difference but different cams were used - there was more lift in the latter cams (post April 1973) but I'm not sure about the specs for duration???

The 2T-Gxx's production was some 13 years starting in 1970. That means the oldest head could be 37 years old! In a tech article on head torquing on the ACL web site there is a point made that aluminium alloys soften over time and this produces unpredictable results. So apart from valve size there are other reasons to prefer a late dated head (The 2T-GEU's apparently had more internal webbing, presumably making them more rigid).

GeneSPIDA, "2TGEU with an 88266 head". That's an interesting number. I thought the latest heads were 260's not 26x. That's impressive HP you are making. Is this on a stock crank or the 3T crank? Did you CC the head and pistons and work out your CR? What gasket were you using? More details of your engine would be appreciated.

Cheers

David

[GeneSPIDA]

I'll have to double-check my head number when it's light. It may have been a 260 and not a 266, but can't remember if I checked before I made the original post.

The head was CC'd, and that along with description of the dome shapes given to a Toyota guy in Melbourne (Sean Malony) who is a bit of an expert and knew how to organise the forged pistons to suit with a reasonable compression for a turboed 2TG (8.5:1 from memory).

I was supplied with 3TGTEU conrods to replace the 2TG ones, but the crank is the 2TG original item.

Using normal (i.e. not metal) head gasket as sourced from Veale for the 3TG/2TG motor.

Runs a Wolf 3D version 4 computer, RX7 injectors and coil packs. Has an intercooler, oil cooler and Garret GT25 turbo. Not sure what else you want to know?

To my knowledge there are at least 2 "dome" shapes for 2TG heads. One is symmetrical (like mine) and others are kind of "sloped" to one side. For my motor I had to replace the old head as it had been milled too much previously, so found another head of the same number by locating the exact same motor at a local Toyota wrecker and using the head.

I think I've still got the old head under the tarp over that "spare" motor.

Gene

[GeneSPIDA]

My head is an 88260. Either I mis-typed it or had a brain fade. But my original understanding that there are some differences in valve sizing is my understanding.

Gene

[AE25]

heads that i've come across...
88220
88222
88223 (norway spec te71 2tg)
88260
88261
BLANK

[TheToyman75]

Were there any differences in piston crown to suit the different combustion chamber shapes?
I've seen two heads in the last week or so that have had different CC shapes.
One was a hemispherical, like an 18RG.
The other appeared to have a much smaller volume and the chamber had metal surounding each valve that was scooped out, just like the flow work around the spark plug.

Steve,

The piston crowns are very different for the later model 88262 head (The non domed chambers) I'll try get apic for you when I pick up one of my spare bottom ends.

[NME308]

Dammit, I must be too much of a scrooge on giving out rep...

This is the third time I have dug up this thread for some VERY much appreciated/needed bolt torque information etc. Each time I attempt to give Rivs some rep and the old
'you must spread the rep around before giving to River again' message appears!

Sorry old man!

Cheers,
Jason

[river]

Hi,

Awwwww....

Glad the thread still finds itself useful.

Which reminds me, I must add some more techo stuff into these threads. I got lots of info - just need time to get it in.

seeyuzz
river

[Hurricane]

very helpfull thread u have made river, keep up the good work

[river]

Hi,

Thanks. Glad it's of help.

I've got the 18R engine stuff to put up also. I'll do that thread very soon.

seeyuzz
river

[Bos55]

Digging up an old thread here I know but this is the single most useful thread i have read on any of the forums i have been trolling through.

Spot on River.

I recently acquired a 2T-G with the head number 222. I have read elsewhere that these heads have larger valves which i think was confirmed in a post above but i also read that this head had lower Comp Ratio. Given i am planning on putting a touch of boost into this old girl the lower comp will be handy.

If anyone knows if what i have written is correct or not i would love to hear from some people who have some experience with these engines.

Again sorry for digging up an old thread. Everyone working on a 2T engine needs to see this thread.

Cheers

Bos

[Joel_mcd]

Since the thread has been revived... I came across this online scan of the complete 2T, 2T-B, 2T-C, 2T-G, 3T & 3T-C repair manual recently. It's broken down by chapter so you can just grab the bit you need.

Cheers,
Joel