| Author | Topic |
|---|
Location:
perth
Registered:
October 2004
|
|
2T/3T pistons
|
Sat, 18 December 2004 07:44
|
 |
ok so i know the 2T rods can be used on the 3T cranks if i use the 2T bearings. and then i can use the 2T pistons. how deep do i need to get the valve clearance sockets machined so that pistons wont hit valves. and what is the advantage of using 2T pistons instead of 3T pistons?
thanks. craig
|
|
|
Location:
On your mum!
Registered:
May 2002
|
|
Re: 2T/3T pistons
|
Sat, 18 December 2004 23:16
|
|
| cooter wrote on Sat, 18 December 2004 18:44 |
ok so i know the 2T rods can be used on the 3T cranks if i use the 2T bearings. and then i can use the 2T pistons. how deep do i need to get the valve clearance sockets machined so that pistons wont hit valves. and what is the advantage of using 2T pistons instead of 3T pistons?
thanks. craig
|
2T and 3T engine bearings are identical (if using aftermarket bearings) just be wary where the oil squirting hole in the big end is (they often need to be drilled in the correct location).
I am not sure that the 2T pistons will be able to be used then - but is is fair to say that if they can be used, then there should be no need to machine the valve pockets - bear in mind if there is any clearance issues at this point, is not going to valvle to piston, but rather that of piston deck height.
|
|
|
Location:
Tasmania
Registered:
May 2002
|
|
Re: 2T/3T pistons
|
Sat, 18 December 2004 23:47
|
|
If you are using a 2T crank, you need to use 2T or 2T-G pistons.
If you are using a 3T crank, you need to use 3T or 3T-GTE pistons.
2T, 2T-G, 3T, 3T-GTE rods are all the same dimentions and can be swapped around.
If you are using a 2T-G head, the piston tops need to look like a 2T-G piston. So if you are using 3T-C pistons, take all 4 of them plus one 2T-G piston to a machinist. Tell the machinist to make the 3T-C pistons look like the 2T-G piston. He will only have to machine the exhaust valve releif deeper. The inlet valve relief is already OK, and similar to the 2T-G one.
If you like you can double check the clearance by assembling on piston in the motor with the head and a few valves. Turn the motor over by hand. Use marking dye or something, I don't know.
One old timer setup is to use the normal 2T crank, with 18R-G pistons and the block bored out to match = about 1.8 liter. A more common setup now is to use a 3T crank with 3T-C pistons machined slightly = 1.8 liter. The best setup is to use a 3T crank, and 89mm forged Weisco pistons = 2 liter.
|
|
|
Location:
perth
Registered:
October 2004
|
|
Re: 2T/3T pistons
|
Sun, 19 December 2004 09:02
|
|
|
thanks for your helps guys. much appreciated
|
|
|
Location:
On your mum!
Registered:
May 2002
|
|
Re: 2T/3T pistons
|
Sun, 19 December 2004 10:02
|
|
| Jonny2TG wrote on Sun, 19 December 2004 10:47 |
If you like you can double check the clearance by assembling on piston in the motor with the head and a few valves. Turn the motor over by hand. Use marking dye or something, I don't know.
|
I just use some kids play putty like plasticine that you buy from BigW toy dept and make a disc on top of the piston - with the crank rod, piston, cams etc all dummy assembled, with 2nd hand bearings and head gasket (1 piston is all that is required). Turn the crank through 2 x full rotations - disassemble and see the depression left by the valve on the plastic putty. You will need to measure the clearance - NO LESS than 3mm.
All of these instructions are available from good hot rodding type books.
|
|
|
Location:
perth
Registered:
October 2004
|
|
Re: 2T/3T pistons
|
Mon, 20 December 2004 04:36
|
|
|
sorry yellow rolla but i cant see how that works. i need to have the exhaust valve cut deeper so i dont see how using the plasticine could be used to tell me how deep. if the valve is going to hit the piston the putty will be squeezed out andnot actually tell me how deep. and to Johnny 2tg y do i have to use the 3t pistons. if the rods etc are the same then y can i not just use 2tg pistons?
|
|
|
Location:
Brisbane
Registered:
June 2002
|
|
Re: 2T/3T pistons
|
Mon, 20 December 2004 21:47
|
|
|
the plasticine method is if you are not sure if the valve will hit the piston or not. You can use that method to check
|
|
|
Location:
perth
Registered:
October 2004
|
|
Re: 2T/3T pistons
|
Tue, 21 December 2004 08:28
|
|
|
i c. ta
|
|
|
