| Author | Topic |
|---|
Registered:
May 2002
|
|
2TG 1600 to a 2ltr conversion????
|
Fri, 28 June 2002 07:45
|
 |
Hi Guys,
I'm planning on converting my std 2TG motor to either a 2ltr (using the 3T crank and 89mm bore combination) or just a semi stroke (using just the 3T crank only).
I guess if i wanted to choose the 2ltr option, all the mechanical work would be customised to suit and match. But if i want to ONLY do the bottom end (add the 3T crank), would i need to change the pistions and/or conrods, etc or will the original gear be useful?
Would the journal sizes match up, etc??
Does anyone know of a workshop who have completely successfully this modification?
Any help would be great!
|
|
|
Location:
melbourne
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Fri, 28 June 2002 11:39
|
|
|
if doing the 3t, will have to use 3t pistons and have them fly cut the the correct depth as is the 2tg pistons ,but everything else will fit
|
|
|
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Sun, 30 June 2002 23:10
|
|
|
will the bores havce to be enlargened to suit the 3t pistons?
|
|
|
Location:
melbourne
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Mon, 01 July 2002 07:01
|
|
|
3t has same bore as 2tg
|
|
|
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Mon, 01 July 2002 07:33
|
|
|
What are the common prices for this set up? (if you're farmilar with the prices).
|
|
|
Location:
melbourne
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Mon, 01 July 2002 09:30
|
|
3t 85 bore 78 stroke
2tg 85 bore 70 stroke
as for cost who nows these days repco 3t pistons 1mm over size 200 fly cut the pistons maybe 100 then all you have to do is bore to suit pistons and hone and thats the 2tg block and rods and the 3t crank will give you 1813 cc and will still rev to 8000
|
|
|
Location:
Brisbane, Queensland
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Mon, 01 July 2002 10:19
|
|
I am also keen on this conversion.
I don't have a 2tg block but all the 2TG bit's
so I was planning on using the 3T block and boring it out.
Should I buy the 3T pistons first?
Can anyone in brisbane help me with this or be prepared to talk about it?
|
|
|
I supported Toymods
Banned User
Location:
Brisbane
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Mon, 01 July 2002 13:30
|
|
|
Maybe i could do this to my 2t! As long as it does'nt cost too much!
|
|
|
Club President
I supported Toymods
Location:
Sydney
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Thu, 04 July 2002 11:09
|
|
Cool 1,
Cost to much is a kind of relative statement. we all have differnt budgets and time frames to work too.
This topic has been discussed quite a bit so if you want some background reading then do a Search for "2TG" you'll find alot has been covered.
Still if you have an further questions I'll answer them if I can.
|
|
|
I supported Toymods
Banned User
Location:
Brisbane
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Thu, 04 July 2002 12:15
|
|
I was only thinking about doing this if it only involved changing the crank and pistons!
But what the hell is fly cutting? Tis all new to me!
|
|
|
Club President
I supported Toymods
Location:
Sydney
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Thu, 04 July 2002 22:10
|
|
Cool 1
The Valves in the twin cam heads enter the combustion chamber at a steaper angle (45 degrees) than a single cam head. As a result the bottom part of the valve would hit the piston if a stock 3T/2T piston was used.
Flycutting is the process where they machine in a groove in the top of the piston to clearance the valve. This is why cam timing is so important on a 2TG or 3TGTE. If its to far out the valve will smash into the piston and thats never a good thing.
|
|
|
I supported Toymods
Banned User
Location:
Brisbane
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Thu, 04 July 2002 23:49
|
|
Ahhh, Thanks for clearing that up for me!
So you only have that problem on the twin cams?
I just have the single cam, so i would'nt need to get this done?
|
|
|
Location:
Newy, NSW
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Fri, 05 July 2002 02:46
|
|
|
Do u still need to flycut pistons if u use 3tgteu crank, rods, and pistons in the 2tgeu? I have been told there are different block hights, is this true?
|
|
|
Club President
I supported Toymods
Location:
Sydney
Registered:
May 2002
|
 Re: 2TG 1600 to a 2ltr conversion????
|
Fri, 05 July 2002 03:33
|
|
Cool 1,
Block heights are all the same.
It is only the crank and Pistons that change the Conrods are also all the same length.
If you use the 3TGTEU pistons it will be a PIG in N/A form. 3TGTEU pistons are around 8.0:1 comprerssion so not good unless you are Turboing or Supercharging it. Flycutting requirements also depend on cam lift and Timing. Different settings push the Valves Further into the Combustion Chamber.
|
|
|
I supported Toymods
Banned User
Location:
Brisbane
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Fri, 05 July 2002 03:50
|
|
|
So in my single cam, I only need to change the crank?
|
|
|
Club President
I supported Toymods
Location:
Sydney
Registered:
May 2002
|
 Re: 2TG 1600 to a 2ltr conversion????
|
Fri, 05 July 2002 06:00
|
|
Nah Mate you still need Pistons  The 2TG pistons will poke out the top of the Block.
|
|
|
Location:
New Zealand
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Tue, 09 July 2002 05:33
|
|
I can get you some Repco sold 3T, 40" over pistons and ring set, brand new unopened box for about $110AUS.
Karl
|
|
|
Club President
I supported Toymods
Location:
Sydney
Registered:
May 2002
|
 Re: 2TG 1600 to a 2ltr conversion????
|
Tue, 09 July 2002 05:51
|
|
Karl,
Do you know what compression those repco pistons will produce ?
When going withthe replacement pistons keep in mind the bigger the lift cam the bigger the flycuts need to be and hence the need for Forged pistons becomes apparent. 
As far as I know the most lift you can get away with with cast pistons is 410 tho and I'll let you know if they give out 
|
|
|
Location:
New Zealand
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Tue, 09 July 2002 06:26
|
|
they are standard 3T pistons, so who knows what the compression would be. Maybe a bit more then standard?
Also, i have some "Group A" (apparently) cams, which i must measure the lift of to get measurements for flycutting.
Really need someone to test this first, and i'm a bit on the poor side atm. Jonny2TG: how's your 3T pistons going?
|
|
|
Location:
Tasmania
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Tue, 09 July 2002 13:29
|
|
I bought some of these 3T 1mm over pistons from Karl. He must have a few sets. I have had a good look at them, not in use yet. They will be sitting in the box for a bit more yet.
The valve relief on the inlet side will not need modifying, as it is just as deep as on the 2TG pistons I also have here in front of me. The valve relief for the exhaust valve will need machining though. Considering this only needs to be as deep as the intake one already is, I doubt there will be any problem with enough meat in the piston. I don't think there will be any high lift cam problem either.
The standard 3T pistons would probably ment to be about 9:1 compression in a 3T-C engine, not sure. The 2TG head chamber is smaller, so may give about 10.3:1 compression with my rough calculations.
|
|
|
Location:
New Zealand
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Tue, 09 July 2002 22:16
|
|
hmm, that's a damn near perfect compression ratio.
If I can get you the lift on my cams, do you think you could work out roughly how much to machine the pistons?
If the standard pistons are 9.8 int and 10.3 exhaust mm lift.... then these cams are probably only another millimetre ontop of that, just with extra duration. How much lift is normally run with aftermarket cams in 2TGEU?
Someone I know has a few sets that he bought real cheap and is just selling them off.
|
|
|
Club President
I supported Toymods
Location:
Sydney
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Wed, 10 July 2002 00:21
|
|
Guys,
Standard 3T pistons have a compression ratio in the low 8's Just trying to find the actual spec now.
|
|
|
Location:
Tasmania
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Wed, 10 July 2002 14:51
|
|
Karl, I think you just got a bit confused there. To machine the exhaust relief in the piston, just make it to match the inlet side. Otherwise compare it to a 2TG piston. You will only need to calculate things if you are going wild with big lift and duration, where the valves would normaly hit a stock 2TG piston. Compression ratio is something different, and not related to valve lift.
If you can get some 2TG camshafts with about 290 degrees duration (I think that would be good right?) then I will buy them. Especialy if they have near stock lift, like 10-11mm. Lift is not so important.
|
|
|
Location:
New Zealand
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Wed, 10 July 2002 20:58
|
|
okay, I didn't know how much room there is to accomodate more lift.
Sorry, but I don't have any camshafts for sale. By a few sets, I meant a few sets of 3T +40" pistons.
|
|
|
Location:
Mentone
Registered:
May 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Thu, 11 July 2002 02:07
|
|
have a funny story about 3t rebuild. I helped a friend do a simple rebuild of a single cam 3t. We just reringed and bearings and a little head work. Anyway when w fired it up all sweet but once it warmed up the thing started getting a huge rattle in it like the tappet clearance was growing huge. Ti was only on cyclinder 3 and 4. I thought we had just chewed out the reground cam. We reset the tappet clerarance but it was perfect. Left it a day and started it again. Same thing. Pulled the head of and noticed some wierd marks on the head.
The dickheads at a machine shop on Nepean Hwy Stkilda road had machined the head crooked and when everything expanded with the heat the pistons were banging into the head. Not good.
Sorry for the essay but i thought you might apprechiate my story
Brad
|
|
|
Location:
Melbourne
Registered:
August 2003
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Fri, 06 February 2004 11:15
|
|
| Quote: |
The dickheads at a machine shop on Nepean Hwy Stkilda road had machined the head crooked and when everything expanded with the heat the pistons were banging into the head. Not good.
|
I'm 98% sure I know where you're talking about.
(thread mining tonight...)
|
|
|
Location:
Melbourne
Registered:
October 2003
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Sat, 07 February 2004 01:03
|
|
im in the process of doing the same thing, and i'm also a little scared, cause i may also know who your talking about.. is this place near carlisle and chapel streets?
What happens when the timing chain stretches a bit? no probs with the inlets opening late, but what about the exhaust closeing late? has anyone ever had valves hitting after 50,000km?
Thanks.
|
|
|
Location:
nth ringwood, Victoria
Registered:
August 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Sat, 07 February 2004 01:52
|
|
|
i have some forge 88.5 pistons that will fit into your 2tg and there new
|
|
|
Location:
Melbourne
Registered:
October 2003
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Sat, 07 February 2004 07:01
|
|
|
what would you want for the 8.5:1 forged pistons? They're standard 2TGEU size right?
|
|
|
Location:
nth ringwood, Victoria
Registered:
August 2002
|
|
Re: 2TG 1600 to a 2ltr conversion????
|
Sat, 07 February 2004 07:57
|
|
|
no they are 88.5mm and you need a 3t crank std bore 85mm and these are 10.5 to 1
|
|
|
