20v head on 4af block ? - Toyota Nation Forum : Toyota Car and Truck Forums

FCON_VPRO · 03-19-2005, 04:23 PM

Hey guys...

I know a 4ag(16v) head fits on the 4af block, but does the 4ag(20v) also fit on the 4af block?
I know the 4ag 16v and 20v heads have the same code(4ag) but they differ in placement of the distributor so thats why Im wondering if the 20v head also fits on the 4af.
Im sorry if this has been asked before but Ive searched and searched but cant find anything about it anywhere.
I know about everything else. Its only the head story i need to know about.

Thanks I appreciate the time taken to reply

***REN69*** · 03-19-2005, 04:24 PM

That's probably cuz no one is crazy enough to do this when they can probably just swap a 20V for cheaper into their cars.

Kwanza · 03-19-2005, 05:16 PM

It's better to just get the entire motor. The head will bolt up to the block, because they are essentially the same thing... but you'll also have to swap in pistons and such, so there will be no point and you won't save anything...

Absin · 03-19-2005, 05:17 PM

no they will not interchange. the oil passages in the 20v are differant.

Kwanza · 03-20-2005, 01:08 AM

Quote:

Originally Posted by Absin

no they will not interchange. the oil passages in the 20v are differant.

They are the same block dude...

and it has been done before I'm sure. I believe the 4AF blocks are 7 ribs and everything.

toyotaspeed90 · 03-20-2005, 03:44 AM

7 rib.... but the 4af used a 40mm journal crank in it though.....(i believe)

Kwanza · 03-20-2005, 01:30 PM

Quote:

Originally Posted by toyotaspeed90

7 rib.... but the 4af used a 40mm journal crank in it though.....(i believe)

Correct... This only makes a head swap more impractical...

toyotaspeed90 · 03-20-2005, 02:10 PM

Quote:

Originally Posted by Kwanza

Correct... This only makes a head swap more impractical...

unless you just want to go high revving.... there's no need for the heavier 42mm crank

Flashmn · 03-20-2005, 02:42 PM

if you find a head of a 20V block which threw a connecting rod through the block, I dont see why you couldnt use it, just get connecting rods made to fit the 20V pistons and the 4A-F crank

Kwanza · 03-21-2005, 02:34 AM

Quote:

Originally Posted by toyotaspeed90

unless you just want to go high revving.... there's no need for the heavier 42mm crank

Correct, but because the rod journals are 40mm... this would lead me to think it uses the old rods with 18mm pins. These cannot house the 20V pistons without some machining... so again, would only make a head swap more impractical. Based on my books, the 4AFE uses pressfit piston pins. It doesn't mention the size, but I'm gonna assume it's like the old 4AGE, since the rod journals are like the old 4AGE...

toyotaspeed90 · 03-21-2005, 04:08 PM

who says you have to use 20V pistons? i thought n/a pistons cleared the 5th valve (or can easily be made to)

but what do i know.... i'm not a 20V guy... if anything i'm "anti" 20V

Kwanza · 03-22-2005, 02:43 AM

Quote:

Originally Posted by toyotaspeed90

who says you have to use 20V pistons? i thought n/a pistons cleared the 5th valve (or can easily be made to)

but what do i know.... i'm not a 20V guy... if anything i'm "anti" 20V

Cause if you don't... you're gonna be pushing somthing like 8:0 compression...

Basically, the FE pistons are dished in because they serves as part of the combustion chamber...