2TG info

[sillycar chick]

If you want to get into the compression side of things, I have a post up called "2t-g/3t Hybrid compression Problems" which has a lot of info there about lowering compression, using formulas to work it out etc. and alot of people have put up some good solid info as well.

ACL Specialised Gaskets up here in Brisbane will do a custom thickness head shim for $50. You can use all the formulas to work out what thickness you want based on what compression you are aiming for.

You can PM me with any questions if you like, I am more than happy to help. But I would also suggest getting the valve recesses in the pistons cut out, it will cost you more in time, money and frustration if you end up bending a valve! And if you want to want to use a 3T crank, you are better off getting yourself a 3T block as most of the 2T blocks will need to me machined out or the 3T crank will hit. Good luck!!

[Rodger]

Thanks september squall. That 2T engine of mine has 10.5:1 compression which is gained actually by a 1mm shave off the head, decreasing the chamber volume and the cam is what was refered to as a three quater cam with around 9mm lift.

My summery:

Go the 2T/3T-G hybrid. Modify the 2T-G block to clear a 3T crank (solves other issues with dummy cams and all the extra timing chains etc). Use the 3T rods and get a set of Toyota 1mm O/S 3T pistons. Flycut the pistons to match the 2T-G ones.

Use a standard thinkness 2T-G head gasket from HJ Gaskets.

The compression will be around the 10:1 ratio and still run on regular unleaded once the 40mm Solexes are tuned and the distributor is regraphed.

The simple increase in capacity will up the compression to a good value. There is no need to drop the compression as the Toyota pistons will cope.

Regards

Rodger

[jeffro ra28]

10.1 comp is to high for regular unleaded, unless you want to run the thing with retarded spark.

[merc-blue]

Thanks september squall. That 2T engine of mine has 10.5:1 compression which is gained actually by a 1mm shave off the head, decreasing the chamber volume and the cam is what was refered to as a three quater cam with around 9mm lift.

My summery:

Go the 2T/3T-G hybrid. Modify the 2T-G block to clear a 3T crank (solves other issues with dummy cams and all the extra timing chains etc). Use the 3T rods and get a set of Toyota 1mm O/S 3T pistons. Flycut the pistons to match the 2T-G ones.

Use a standard thinkness 2T-G head gasket from HJ Gaskets.

The compression will be around the 10:1 ratio and still run on regular unleaded once the 40mm Solexes are tuned and the distributor is regraphed.

The simple increase in capacity will up the compression to a good value. There is no need to drop the compression as the Toyota pistons will cope.

Regards

Rodger

ok
modding the 2T block to fit the crank no issue with (can be done reasonably cheaply)
using the 3t rods no problem
3t pistons they wont fit will they?
solexes i wanted to run dual webbers if i could get some (std solexs my stay on for abit)

all the machining im looking at is the block for the crank and the piston fly cut

can anyone tell me whats wrong with losing compression VIA a thicker gasket i dont get why i should have to get the valves done and the pistons done

[jeffro ra28]

You can do this with a thicker HG, but by doing so you are losing the affect of your valuable squish area. This is probably not all that desirable but not a biggy in a streeter.


jeffro

Its already been said.


jeffro

[merc-blue]

thnx jeff
this keeps getting more and more expensive initialy i had about a 1K budget (not including engine or exaust/extractors) now im looking at what about 2K to produce under 100KW

just gone through my project budget and i have 6 months and about 1500 to build a engine (also in the time putting in a T50 and maybe a hilux diff)

[mynameisrodney]

i dont see it costing you 2k. keep your eyes on the toymods classifieds and on ebay. i'm also looking to build a hybrid and so far have picked up a 3t crank for $60 and some 3t rods and pistons (5 pistons, 3 already machined) for $20.
happy hunting.
chris

[merc-blue]

nice,
yeah i just PMed a guy about a crank
most of the cost is in machining over 600 bux worth of machining but we will see

[Jonny Rochester]

Many times myself and others have said EXACTLY what it takes to build a 2T-G, or "3T-G". Search the old forums. But people just won't believe how simple it is. I will spell it out again:

If you are not racing in a 1600cc class, go with the 3T crank or "3T-G hybred" as it is called.

These are the exact parts I have, nothing more, nothing less.

2T-G head (88222 or 88260 are good)
3T-C block (or late 2T-GEU block, or 2T block with some grinding done)
2T or 3T or 3T-GTEU conrods (makes no difference)
3T-C or 3T-GTEU crank (makes no difference)
3T-C pistons with the exhaust valve releif machined. (You don't even have to measure or calculate anything, just copy a old 2T-G piston by eye.)
2T-G head gasket (a normal 2T one will work also)
2T or 2T-G or 3T-C flywheel, lightened down to 6.5kg and balanced. (Maintain 1/2" thickness.)
Fit the unused bearing shells in the cam tunnel to block the oil holes, as the normal 2T-G would have.

You can buy the 3T-C pistons new quite cheap, and 1mm oversize. Maybe $175 with rings.

Thats it. In addition I have 305 degree camshafts, reground with shims to match. And I just use the stock 40mm Solex Mikuni carbys.

With some playing around, I guess mine could have 160hp at engine. It could beat a AE92 Corolla SX with "100kw" motor on some days, some days not. The Corolla SX driver can just stomp on the throttle at any time. The 2T-G driver will have to plan things ahead a little, be in the right gear, and get the revs up before launching and that sort of thing. 2T-G/4A-G can be built with even power, but the 4A-G is nicer. But I like a 2T-G in the old Celica GT/ Corolla Levin the way is was ment to be.

[merc-blue]

jonny i love you and if you were a female i would marry you and have my way with you many times (not in that order)

cheers for the info
no problems with compression?

[Jonny Rochester]

That combination turns out to be about 10:1, maybe more or less. My calculations were different everytime because I didn't acurately CC the head and pistons. Use a normal head gasket, which I assume is 1mm thick. It will run fine on 95 octain. It will even run on 91 octain, depending on cams and that, but may run on a bit after a hard drive.

[jeffro ra28]

yer it might run, and break a ring land. Be on the safe side and run atleast 95 octane.

[merc-blue]

hmm i will run it on high octanes and when i have time to do compression calculations i willl work it out
would it be worth while getting a slightly thicher gasket made up just to be safe?

[Hokey]

I have nearly all the parts for a 2TG/3T hybrid engine that i was going to build up but want something with a little more now. PM me if you need anything
-Calvin