valves - does the 2LT share with any other engine

[nomadix]

Howdy Folks:

Anyone know if the 2LT shares the same valves with any other Toyota engine

perhaps someone has already gone there and has some information to share

Cheers thanks:

[plumb bob]

Hi, I would say the best solution is to either ask Nifty Nev, or ask Toyota for part numbers and cost of each item ( without giving them the reason why) and then ask if they are the same.

I would guess that they are not, probably different length and diameter.

Let us know if you find the answer.

Robert.

[nero279]

pn: 13711-54020-, prod_date: 8809-9505, part_name: Valve Intake, Models: 2LT#,2L,3L..LN10#,13#,8#
pn: 13715-54040-, prod_date: 9003-9505, part_name: Valve Exhaust, Models: 2LT#, 3L..LN10#,13#,81,86

from the EPC, make of it what you will, or pm some more vehicle info this way and i'll run it through again and see if i can come up with anything else

[nomadix]

Howdy nero;

For some reason cant PM - so I post this - hope you dont mind

Cheers thanks

Any possibility you can look up those no.s for a 1st gen 2LT - production date 1984- 1988

and if is not too much trouble
supra turbo - 7M-GTEU engine - late 88- 92

cheers thanks in advance

[nero279]

can't find the 1st gen, but the supra's a 24v engine pn#s 13711-42020 Intake, & 13715-42010 Exhaust and they're only used in the 7MGTEU engine

[NiftyNev]

1st gen will be LN6# series. These have a roller rocker set up.
11/83 - 3/89
Intake: 13711-54010
11/84 - 6/87
Exhaust: 13715-54020 sub 13715-54021

Without specific Model and Frame numbers that's about the best I can do.

There's also another listing where both Inlet and Exhaust are the same valve. This may be a non turbo model though.

Nev

[nomadix]

Howdy Nifty:

Cheers thanks for the info ; i wonder if the specs are available on any of these toyota engines - dimensions of valves - I thought of the Turbo Supra as its 4 valves per bank - so valves will be small-ish - turbo to handle heat and be hard

ok - got my work cut out

Cheers:

[TonyN]

Why all the effort? 2.4 2L motors are everywhere, new valves are cheap as well.

[nomadix]

Howdy TonyN:

on this side of the pond 2LT's are rare indeed- we only got 1st generations

its more about - can I improve what I have ?

cheers:

[Terry Syd]

Big valves

Here's a link for you - http://www.steves.co.za/Performance_valves.html

Maybe you can get some valves that are 2 mm larger. Then if you cut the seats so they sit out on the edges you will have about a 4mm larger valve pocket.

I too feel that the valves in the 2LT are on the small side, but that is because of the head cracking problem. The area between the valve seats really can't be reduced by putting in bigger valve seats. However, if you used the existing seats and then used bigger valves with a good valve job, you could probably substantially open up the flow on the head. (It would never flow like a 4-valve head, but hey, any improvement would help)

You could also try a 3L cam in the 2LT. It has a bit more duration and lift on the intake valve.

[nomadix]

Howdy Terry Syd:

Good to see you on this board:

I will look into this option you propose.
would you be concerned with the increase size changing the vibration and heat displacement of the exhaust valves - on the head

I am aware that the second generation 2LT's- were prone to more head cracking than the roller rocker head of the 1st gen- ( though they are not immune )

Am reading more on certain sites about new materials for higher tuned diesel - Si3N4 - Silicone Nitride ( ceramic) valve guides , exhaust valves , bearings - etc..
mostly used in high volume for military applications and aeronautics right now - so the likes of me cannot afford the minimum order amount being asked right now- just trying to see what improvements I can make on a simpler scale as I am rebuilding - and living in 3 months of 44ºc + temps

Tossing ideas about - as it were , many heads think better than one

cheers:

[Terry Syd]

2L head

I had one of the early 2Ls with the rocker assembly. When I did an overhaul, I found that two of the cylinders were cracked between the valves. Thankfully, the cracks didn't extend into the water jacket. Since it was an old vehicle that I was just freshing up, I didn't bother replacing the head. If it blew up (dropped a seat, etc) so be it. I ran it for another 40,000 kms before I junked the van (too much rust to get through rego).

When I was building heads for high performance work I generally made the exhaust seat a bit wider than stock. It is the valve seat that transfers most of the heat from the valve. Adding a bit more seat area always seemed to be a good idea for an engine that was going to be operating at higher combustion pressures and temperatures. I never burned a valve, even with some of the outrageous modifications I made.

Most people put too much importance on the size of the valve. It is not the outside diameter of the valve that is the governing dimension, it is the INSIDE VALVE SEAT DIAMETER. That is the size of the 'hole in the head'. Many times you can simply shift the valve seat out to the edge of the valve and pick up another couple of millimeters of 'valve size' without going to a bigger valve.

However, if you do that you will also have to sink the valve deeper into the head. This requires you to shim the valve spring to bring back the pre-load on the spring. You also have to watch (on your engine) the rocker arm geometry. You can shave the same amount off the end of the valve stem to maintain the geometery. If you move the seat out 1 millimeter, you will have to shim the valve spring .7mm (if the memory of my old trigonometry figures are correct). In any case, a before and after measurement of the valve stem protrusion through the valve guide will give you the best measurement - just be sure to write down the figures before you start cutting!