1UZ Valves Interchangeable with 2JZGTE

[Lextreme II]

Lets start this thread here.

 

[Zuffen]

Can anyone post the dimensions of the 1UZ and 2JZGTE valves?

 

[928s]

Yes that would be very interesting, also the weights of the valves and stem sizes please.'

Thanks Greg

 

[cribbj]

OEM 2JZ-GTE valves:

Head OD: 33.6/29.0mm (I/E)
Stem OD: 6mm
OA Length: 98.55/99.10mm long (I/E)

I'd be curious to see what sort of GP deal Manley would be willing to do on the 1UZ motor. They make a real nice package for the 2JZ: SS valves and springs, with Titanium retainers.

John

 

[elhsupra]

Unofficially from O'reilly autoparts website
OEM 92 LS400 valves:

Head OD: 33.5/28.0mm (I/E)
Stem OD: 6mm
OAL: 95.0/97.0 mm (I/E)

 

[Lextreme II]

OEM 92 LS400 valves:

Head OD: 33.5/28.0mm (I/E)
Stem OD: 6mm
OAL: 95.0/97.0 mm (I/E)
--------------------------------------------------------------------------------

OEM 2JZ-GTE valves:

Head OD: 33.6/29.0mm (I/E)
Stem OD: 6mm
OA Length: 98.55/99.10mm long (I/E)

Comparing 1uz vs. 2jz.

Head OD: +.1/+1.0mm (I/E)
Stem OD: Same
OAL: +3.55/+2.10 mm (I/E)
+ postive means longer.

They are very similar.... If we put stronger springs,,, it might help.

 

[autronic]

The longer valves from the 2JZ-GTE makes it possible to regrind the camshafts without the usual hassels + a few other benefits:

a) You will not need thicker shims to get the clearance right, grind of the top end of the 2JZ-GTE valve to compensate for the smaller base circle.

b) possible to use more lift as the valve springs can be longer, ie no coil bind.

c) it should be possible to use the 2JZ-GTE valves on the stock 1UZFE valve seats, bigger valves is a good thing in combination with a ported head.

 

[cribbj]

Seeing that the valve sizes are pretty similar, I'm surprised the stock 2JZ head outflows the 1UZ as much as it does. I'm attaching a graph showing the flows of the stock 1UZ head vs a stock and a ported 2JZ.

Comparing the stock 1UZ to the stock 2JZ shows improvements in flow from 59-64% on the intake side, but as much as 79-84% on the exhaust. This could mean that the 1mm larger 2JZ exhaust valve really helps its port flows.

Comparing the stock 1UZ flow to the ported 2JZ shows improvements from 73-103% on the intake, and 93-115% on the exhaust. (One of the things we already know about the 2JZ motor is that it's exhaust ports are cr*p and they respond really well to porting)

FWIW, Manley make +1.00 mm oversize valves for the 2JZ-GTE, and their stems can be cut down to compensate for overground or sunken seats. Frankly, however, I don't think anyone in the 2JZ community will say that the 1mm oversize valves helped them make more power (unless it made a marginal difference up in the insane levels above 1000 RWHP)

Bottom line for me on this, it would seem that a 1.0mm oversize valve (2JZ stock valve) or maybe even the 2.00mm oversize Manley exhaust valve (if there's enough space in the head), coupled with some judicious porting, could make the 1UZ head really rock.

 

[cribbj]

The data on that graph is pretty jumbled together.

Here's two graphs instead, one for the intake and the other for exhaust.

 

[MaxPower]

Have a look at the valve angle in a 2jz and compare it to a 1uz...2jz-gte vs 1uz-fe - two different design philosophies.

 

[cribbj]

Agreed, and I'd forgotten that. Different designs completely; the "F" head on the 1UZ apparently has only 21 degrees between the intake/exhaust, while the 2JZ-GTE head has a full 45 degrees. THAT'S a difficult hurdle to overcome with porting....

Another thing, apparently in the VVTi motors, both the intake and exhaust valve face diameters were increased by 1.0mm, while the stem diameters were decreased from 6.0 to 5.5mm. I'll bet the head flow data that we have on the 1UZ is based on the earlier heads with the smaller valves.

John

 

[Lextreme II]

Cribbj,

Excellent and motivating info.... jpi1 is getting the true measurements on the parts this weekend so we can compare the two. It possible.... than it will be awsome.

Can we get a graph of the 1uz head flow with 2JZ parts.

 

[cribbj]

Anyone interested in contributing to a flowbench test?

I've got both an early 1UZ and the later VVTi engine, and access to a flowbench, but I don't know what it'll cost to flow the heads. The owner of the bench has all the usual adaptors for SBC's, Ford's & Mopar's, but nothing for the 1UZ. Hopefully it wouldn't cost a bundle to knock up something.

If there's sufficient interest, I'll make inquiries with the builder and see what he'll charge.

John

 

[chrisman]

excellent!.. im glad to see guys that are serious about improving our mutual knowledge about these engines..keep up the good work guys!!

 

[cribbj]

Let's see if Max (Red Supra) will chime in. I think he's having some head work done ATM; he may have had the heads flowed already, or will have after the porting.John

 

[Lextreme II]

I just called up Manley. Here is the price i got as a group buy:

Spring Kit (Springs and Titumum Retainer & Lock) is $289 per six (Regular Price is $380 per set)
Valve (Steel) is $14 each
Valve (Titamum) $100 per valve... ouch...

 

[928s]

This would be the best thread on this board at the moment. John great work, I really appreciate your efforts. I would contribute something but have my ass hanging out at the moment, for reasons I wont bore you with hear. I've got to say, I'm fasinated by the 3uz. I have heard it has the best heads of all.


Also guys I got to say, those ported head flow figures are impressive also. Especially with that relatively low lifts. Can somebody give us a horsepower reading from those flow figures? ( I came up with 480hp) I heard that you can go to bigger cams? Although I did see the flow starting to tail off. This may not be a problem with the 3 uz heads though.

Has anybody got any photos of the 3 uz? If it showed the camshaft mechanisn, port design that would be of interest.

Thanks again

Greg

 

[Lextreme II]

With 2JZ longer valve stems. This would cause more lift no? More lift will generate more flow?

 

[cyberdiamond]

The 2JZ valve stems will not 'cause' more lift but they will 'allow' you to have more lift before the springs bind up.(each coil touchs eachother)

So you can run a bigger lift cam with higher installed spring height.

It will generate more flow if the ports are capable of flowing the extra air.

 

[Zuffen]

Cyberdiamond,

Not only will the 2JZ valves allow more lift you can also introduce more duration as you can start opening the valve earlier and closing it later. Win/win.

If you went all the way and had new cams ground (from Kellfords) you could have whatever lift and duration you wanted.