Toyota 4.7 L Head Job

[les_garten]

Hello,
I'm doing the Heads on my 4.7 L. for a freshen up. When the valves are ground, i am assuming they will recess into the head a little. Is there a spec I can give the machinist for installed valve height so that the shims will be 'in the Ballpark". When I did my Porsche, I speced installed valve height and Valve spring heights for my CAMs. Anything like this here?

If not, how do you start roughing in the valve lash after a top end job? Buys an assortment of shims and start out thin? If so which shims would I get to start? 1st Toy motor as you can no doubt tell.

Thanx!

Les

 

[spf_lexus]

Witha valve job the shims tend to be a must and usually make the job expensive... toyota V8 shims run around $20 each.... so $700 in shims should be expected. Once you get the seat/valves cleaned up and sealed the lash will need a re shim-guaranteed.


To check lash you need to install your cams and measure the distance between the cam's base circle and the shim height... this is measured with a feeler gauge. Once you have a common lash difference (before/after valve job) then you do the math on the change and buy shims of the overall lash height.

 

[les_garten]

Witha valve job the shims tend to be a must and usually make the job expensive... toyota V8 shims run around $20 each.... so $700 in shims should be expected. Once you get the seat/valves cleaned up and sealed the lash will need a re shim-guaranteed.


To check lash you need to install your cams and measure the distance between the cam's base circle and the shim height... this is measured with a feeler gauge. Once you have a common lash difference (before/after valve job) then you do the math on the change and buy shims of the overall lash height.

Holy Mackeral!!! $20/shim! I hope I can use some of the old ones. It would seem that you could spec an installed valve height to grind the valve tip. It seems I need an assortment of shims to start with.

Is there a chance, I'll have no lash to start with?

Do I just reassemble with the shims back in their original buckers and go from there?

On a stock engine, are all the shims the same from the factory? Or was it setup with all different shim thicknesses from the factory?

Thanx for the heads up here!

I've read that the Multi layer head gaskets do not need retorquing, is that your experience with them? Please don't shatter that perception.

 

[spf_lexus]

yeah I know, very expensive but it's the downside to a 32-valve setup. It is guaranteed you will need to re-shim all 32 buckets because the machining of the seat/valve will raise the valve stem heights and therefore raise your lash for every valve, requiring shorter shims. I bought a set of 272' degree regrinds and ended up selling them back after finding out I needed the $700 in shims plus $250 in valve springs and labor. I suppose you could machine off from the underside to suit but never tried, but I would leave that to an experienced machinist.

 

[Zuffen]

I just had my heads rebuilt.

We didn't use a single new/replacement shim!

We reduced clearances by machining the valve head and increased the clearances by machining the tip of the valve stem.

If you have the right machines it's easy.

 

[les_garten]

I just had my heads rebuilt.

We didn't use a single new/replacement shim!

We reduced clearances by machining the valve head and increased the clearances by machining the tip of the valve stem.

If you have the right machines it's easy.

That's what I was talking about before. On my Porsche I spec'd installed valve height. I'll chat with the machinest about doing this. I think he wants the Cams and everything, so perhaps he knows this.

 

[les_garten]

Hello,

Change of plans.

I am trying to find an "On Engine" valve spring compressor. I have an oily plug and want to change out the Valve seals without pulling the heads. I've been looking and can't find one. Anybody seen one of these for a 4.7L?

Thanx,
Les

 

[cribbj]

We use the rope trick or compressed air in the plug hole to hold the valves up, and a tool like this Valvemaster by Toyotool: http://www.toyotool.com/ to pop the keepers off.

 

[les_garten]

We use the rope trick or compressed air in the plug hole to hold the valves up, and a tool like this Valvemaster by Toyotool: http://www.toyotool.com/ to pop the keepers off.

Hi,
What's the rope trick? Had not heard of that one.

For air, you just put some air in the cylinder, how much PSI?

Is there an adapter to go from an air fitting to a Spark Plug thread?

Will that Valvemaster work on the Toy Valves?

It shows on their website about multi groove keepers being a problem.

I was about to give up finding something.

 

[cribbj]

The rope trick is putting "some" small diameter rope down in the plug hole, then rotating the engine until the piston approaches TDC and the rope is mashed against the valves.

Compressed air works to hold the valves shut also, but I've found when doing a leakdown test, that over 50psi with all the plugs out will cause the motor to rotate, so you might have to block the crank. (This was with a 2JZ-GTE Supra motor coupled to a manual tranny which was in neutral - it may not happen with an A/T in Park.)

There are loads of plug/hose adapters. Buy a good compression & leakdown kit, there's bound to be the adapter you need in there.

The Valvemaster works well on our valves. I've used it on both 2JZ-GTE and the 1UZ engine. It's a real time saver.

 

[les_garten]

The rope trick is putting "some" small diameter rope down in the plug hole, then rotating the engine until the piston approaches TDC and the rope is mashed against the valves.

Compressed air works to hold the valves shut also, but I've found when doing a leakdown test, that over 50psi with all the plugs out will cause the motor to rotate, so you might have to block the crank. (This was with a 2JZ-GTE Supra motor coupled to a manual tranny which was in neutral - it may not happen with an A/T in Park.)

There are loads of plug/hose adapters. Buy a good compression & leakdown kit, there's bound to be the adapter you need in there.

The Valvemaster works well on our valves. I've used it on both 2JZ-GTE and the 1UZ engine. It's a real time saver.

Hey Thanx!

I talked with the Valvemaster guy today and watched the video. Neat tool! I'm picking up a Leakdown tester at Harborfreight and found a Cylinder locking rod at ZDMAK who has really interesting tools. Thanx!

How much pressure do I need to hold the valve up?

 

[cribbj]

25-30 psi should be fine, but if you've got the crank blocked, you could go to 50.

This is also a great time to do the leakdown test as 1) the cams are out, so no hassles with turning the engine and finding TDC for each cylinder and 2) you'll already have a source of controlled air pressure.

So before you begin popping keepers with your new Toyotool, run a leakdown on each cylinder to see how well or how badly things are sealing. 4-5% is ideal, however up to 25% is OK for a high mileage engine as long as all cylinders are consistent. More than 30% is indicating time for rings or a valve job. These aren't hard & fast numbers, and what you should be looking for is a cylinder with a big variance from the others, just like with a compression test.

Also, it's good to know where the air is escaping, so if you hear leakage from:

the intake manifold (throttle body): you have leaky intake valves

the dipstick tube: leaky rings

exhaust tail pipe: leaky exhaust valves

 

[les_garten]

25-30 psi should be fine, but if you've got the crank blocked, you could go to 50.

This is also a great time to do the leakdown test as 1) the cams are out, so no hassles with turning the engine and finding TDC for each cylinder and 2) you'll already have a source of controlled air pressure.

So before you begin popping keepers with your new Toyotool, run a leakdown on each cylinder to see how well or how badly things are sealing. 4-5% is ideal, however up to 25% is OK for a high mileage engine as long as all cylinders are consistent. More than 30% is indicating time for rings or a valve job. These aren't hard & fast numbers, and what you should be looking for is a cylinder with a big variance from the others, just like with a compression test.

Also, it's good to know where the air is escaping, so if you hear leakage from:

the intake manifold (throttle body): you have leaky intake valves

the dipstick tube: leaky rings

exhaust tail pipe: leaky exhaust valves

I got the leakdown tester this weekend. Since I'll be using it to pressurize the cylinders, the Leak Down test will be easy. Thanx for the helpful info.

Les