4AF head prep and porting

[Sam_Q]

maybe that was it, I just never saw any quoted info anywhere for anything more than 8mm. But you know how internet information is.

[oldcorollas]

It was done a while ago, I can't remember it being a big problem though.

Bill, did you ever get this engine together, and did it make the numbers predicted by EAP?

[Billzilla]

Bill, did you ever get this engine together, and did it make the numbers predicted by EAP?

Not enough spare cash at the moment so sorry no.

[oldeskewltoy]

[dangdang]

Love your work Oldskewl

[oldeskewltoy]

I ask for your assistance.... since I currently do NOT have any spare "F" heads, I need to "practice" somewhere.

And since toymods.org is the brightest Toyota Think Tank I know of....

here is my 1st idea for porting the crappy port.




at least with the above, there is very minimal chance of breaking through to either oil, or water galley. I chose NOT to remove more material from the thinnest part of the wall, but to remove the large arc, for far more port wall, and a much smaller arc - 2 arcs actually, the port floor and roof......

Like it? Hate it? Why?

edit... this head will get flow bench time to attempt to equalize exhaust flow

[Sam_Q]

while I really like this thread and all I would like to ask why work on this version of the F head at all? why not the later version with the upright ports?

[oldeskewltoy]

while I really like this thread and all I would like to ask why work on this version of the F head at all? why not the later version with the upright ports?

because it all has to go back in my 1989 AE95 and function on THAT management system.


I also don't have a last gen F head and intake

[Billzilla]

because it all has to go back in my 1989 AE95 and function on THAT management system.


I also don't have a last gen F head and intake

I really wouldn't waste a second on the early heads, they are rubbish.

[PrettyCoolWagon]

Yeah Bill,

Old Skewl's working to a budget using only his skills, resources & knowledge in porting. Making improvents with what's on hand.

(If he had sh*tloads of money to throw at this I'm sure he'd do something else.)

The work's patient, careful & he's making good adjustments.

Most people wouldn't bother but it's an interesting little exercise.
--
OldSkewl you'll enjoy the work once the superchargers on & she's back on the road

[Sam_Q]

it is an interesting excercise and I have to be the downer but with the OEM ECU choking it with the sedate ignition timing would there be any real change at all with any amount of porting?

[oldeskewltoy]

it is an interesting excercise and I have to be the downer but with the OEM ECU choking it with the sedate ignition timing would there be any real change at all with any amount of porting?

not denying the likely mild ignition timing... but do you know the timiing #s?

Let me go back to the beginning.... the 1st generation engine has a CRAPPY torque curve..... the 2nd generation uses the same, or very similar head, a shorter narrower manifold and more torque, eariler. (see pdf link I posted) What I'm after right now is to just allow smooth efficient operation.... to maximize what is there.....

I NEED to replace the engine in my daily... it has a rod knock. the replacement block is a 20V unit(machined to accept the all-trac drivetrain) the internals will be 4AGE bits - using 4AGZE slugs under the "F" head gives me a CR of 10 to 1, or a 1/2 point higher than stock. Sooo... what I'm trying to do here is get a strong replacement bottom end in. Since I have a new bottom end, I thought I'd just do some cleanup porting to improve what is there.... so back to my original request... knowing things could be better... what should I do to make this as good as I can.......

[Sam_Q]

I don't know the timing numbers.

Now don't get me wrong I like what your doing and I am finding this thread really interesting. I just didn't want you have less results than what you could have. I do understand why your doing it and I would probably do the same in your situation.

Too bad I haven't got a spare one of those heads, I could put it under the saw and chop a few slices out of it for you.

anyway as you where

[PrettyCoolWagon]

I don't know the timing numbers.

Now don't get me wrong I like what your doing and I am finding this thread really interesting. I just didn't want you have less results than what you could have. I do understand why your doing it and I would probably do the same in your situation.

Too bad I haven't got a spare one of those heads, I could put it under the saw and chop a few slices out of it for you.

anyway as you where

I'm interested to see.. (improved results)

Old Skewl - Did you do any dyno tests before this project?

I know on my 4afe I noticed a difference just by changing oil, air, fuel filters & running engine oil & fuel treatments + I whacked on some headers.
Not heaps of difference on the highway - top speed with trafic lights but definitely a little more responsive & didn't slow down as quick when I took the foot off the pedal..

I really noticed the difference on open road - wanted to charge better, over 100kph

Switching to high octane was another great step up - it's worth the money in fuel I rekon - especially on an economically built engine like the 4afe

[PrettyCoolWagon]

Sorry meant to say - top speed 80kph on highway w/ traffic lights - y'know stop start all the time...