3FE vs 2/3F carb cyl. head (1 Viewer)

[FJ40Jim]

For reference, here's some pics of the 85-later 2F or 3F cylinder head, and a 1988 3FE cylinder head. Both heads have been cleaned, milled and had valves changed to 1.50 & 1.84 stainless SBC parts.

Notice how the FI intake ports have a significantly raised gasket surface. It would be pretty much impossible to get the 3FE intake manifold to seal on a carb'ed head.

Also notice that the 3FE head uses 2 more dowel pins for locating the manifolds. Again, this might make it more difficult to retrofit a FI manifold on a carbed engine.

 

[FJ40Jim]

Combustion chamber

Here's the combustion chamber for comparison.
The 3FE uses a tighter kidney-shape chamber which gives better turbulence and more squish. But at the cost of more valve shrouding. To keep the 3FE C.R. from being too high w/ the tighter chamber, the stock valves had very recessed faces.

Both heads benefit from the new flat faced valves, as that raises the CR, and reduces heat loss to the valve. Valves run hot, so reducing the temps of the valves, while increasing performance, is a good thing.

 

[PabloCruise]

Here's the combustion chamber for comparison.
The 3FE uses a tighter kidney-shape chamber which gives better turbulence and more squish. But at the cost of more valve shrouding. To keep the 3FE C.R. from being too high w/ the tighter chamber, the stock valves had very recessed faces.

Both heads benefit from the new flat faced valves, as that raises the CR, and reduces heat loss to the valve. Valves run hot, so reducing the temps of the valves, while increasing performance, is a good thing.

Jim,
In the first pic is the 3FE head on the ground while the 2F head is up on the milk crate?

The different sizes are messing with me!

 

[D'Animal]

Did they ever import Carburated 3F's rigs to America?

 

[FJ40Jim]

Jim,
In the first pic is the 3FE head on the ground while the 2F head is up on the milk crate?
The different sizes are messing with me!

No, both heads are on the milkcrates. But they are angled slightly, and the camera is not equidistant from them. For comparison, look at the valves. Both heads have been upgraded to the 1.84/1.50 SBC valves. There is a fair amount of room around the 2F valves, not so much on the 3FE.

Did they ever import Carburated 3F's rigs to America?

No.

 

[GLTHFJ60]

Wild. Is it just me or are the 3FE exhaust ports larger than the 2F?

Opening up the valve throats has to be done by a machine shop, correct?

 

[FJ40Jim]

I think you're right, the ports do look like they extend closer to the 3FE manifold bolts.

Portwork is done with carbide burr(s) in a die grinder.
Cutting the seats and resizing the guides is done by the machine shop.

 

[Cruiser Jimmy]

Any chance for even bigger valves? Looks like there's room between the valves, only you're going to have to open the side walls, which will lead to some CC chamber work.

 

[RockDoc]

Any chance for even bigger valves? Looks like there's room between the valves, only you're going to have to open the side walls, which will lead to some CC chamber work.

Carbed head or EFI?

 

[FJ40Jim]

No, going up to 1.94/1.60 will require hogging out the seat inserts and starting over. Big price increase & possible reduction in reliability, for little gain. As you mentioned, the bigger the valves, the more shrouding there is @the chamber edge.

The chamber can be rolled back to clear the valve, but then CR drops.

 

[Genesis4X4]

Hi Jim - Here are some pics of the manifold for that 3F head.

Note the elongated carb base.

Dave

 

[Spike Strip]

Any advantage with the 3F Int/Exh assy on a USA late 2F (with a 2F/3F head ) over the stock late 2F exhaust setup ? Can't run headers in CA, but could prolly get away with that.

Also, is the 3F carb different than a late 2F ? Base ?

 

[lehiguy]

the 3F head seems to be begging for some grinding around the valves to alleviate the shrouding, and some head milling to get the CR back. CR on the 3FE is crazy low to begin with.

 

[TobyB]

Yeah, a big whallop with the mill to a hemisphere, then a domed piston to match...

...ohh, I've been spending too much time on the race car.

t

 

[PabloCruise]

Hi Jim - Here are some pics of the manifold for that 3F head.

Note the elongated carb base.

Dave

It hass been a while since I read in this thread, is that a factory Toyota manifold for the 3FE, or are you producing this to w/ 3F head and exhaust?
I too wonder what carb would run on there...

Are you selling this piece in the US? I would think there would be interest (depending on price, as always...)

Thank you for posting those pictures!

 

[Genesis4X4]

This is an OEM Toyota New Old stock set of manifolds. I am selling it. More details here:
https://forum.ih8mud.com/sale-parts/518096-usa-3f-carb-version-nos-int-ex-manifold.html

Open to offers!

Thanks. Dave

 

[Yspen]

Real 3F carbed head

Just an update on this thread :

I have a 3F carbed head ( Africa spec ) - It does not look like the 2F head but just like the 3F-E head without the injector pocket .

So I reckon it is possible to cut pockets into the 3F head if you want to retrofit the 3F-E intake manifold and convert it to eFI . Can someone tell me how deep , wide and how high the injector pockets are so I can make plans to cut these pockets . I can easily import a intake manifold but to import the head as well will be too expensive .

Pictures of 3F carbed cylinder head

 

[Trollhole]

Very interesting.

 

[RockDoc]

snip....

Can someone tell me how deep , wide and how high the injector pockets are so I can make plans to cut these pockets .

snip....

Post three of the turd polish thread in my sig line should give you an idea, even more so once you get a 3FE manifold gasket for reference.

 

[Yspen]

Thanks Rockdoc
Forgot about that - this following pic gives me the idea of how deep the pocket is :