Toyota 3.4 5vz cylinder head options

[Justa1time]

Good evening,

I realize many of the OEM castings are cracked and worn out. Is everyone just finding decent oem cores and making them work?

Has anyone had success with new Chinese castings on these heads? If so which ones?

I have seen supertech valves & springs for these engines. Any other offerings that are worthwhile?

Has anyone done much flow testing or porting on these?

Can't find much info and I appreciate anything I can get for this project.

Bryan

[mag2555]

What are your goals for the motor?

[Justa1time]

Mag,

These heads belong to a borderline street/off road truck turning 40" tires. Appropriate gears. Dual transfer cases that sees deep snow during the winter months. The truck sees everything from street driving, idling up rock walls to high tire speed snow situations and is naturally aspirated. Any additional power is welcome.

Thanks,

Bryan

[mag2555]

And your running headers on it now?

[Justa1time]

The engine is apart now. Had factory manifolds on it. Am going to look at potentially doing headers when it goes back together. One of the oem castings is cracked.

[mag2555]

You should see if you can get the head(s) flow tested with and without the intake bolted on.

Many times with 4 valve motors the I take is right at the limit of being able to feed the heads, or worse yet it’s the cork and can not even fully meet the flow needs of the stock heads.

If that’s the case then there’s no sence in porting the heads to a hugher level of flow.

[Justa1time]

You should see if you can get the head(s) flow tested with and without the intake bolted on.

Many times with 4 valve motors the I take is right at the limit of being able to feed the heads, or worse yet it’s the cork and can not even fully meet the flow needs of the stock heads.

If that’s the case then there’s no sence in porting the heads to a hugher level of flow.

One of these heads is cracked so I have to look at getting different castings. I have seen some Chinese castings online that claim to have improved castings online but can't find any reputable person to vouch for them.

In my area no one has a flowbench. I have been looking for a flowbench and have tried to snag a couple Superflow 110s. Many of the benches are on the east coast and the shipping kills the deal. I do not have the time currently to build my own bench but it's a distant dream.

Thanks for your time,

Bryan

[mag2555]

Don’t even think about getting or building a flow bench until you have made a valve opener that opens both valves at the same time , at the same amount and is rock solid stable.

This is a project all of its own!
At low lifts having a valve open even just .003” more or less then you think it is can make a big difference in the flow numbers you see, and especially at test pressures above 15”.

[Justa1time]

Mag,

Thank you for the advise. I am really holding out for a turn key bench. I have found a few different openers. What are your thoughts on this one?

https://www.precisionmeasure.com/produc ... g-fixture/

Bryan