20v head and 4ag piston swap - Toyota Nation Forum : Toyota Car and Truck Forums

Punisher · 01-03-2004, 10:42 AM

Alrighty now.. I'm running a 4A-F and lately I've been thinking about turbo or supercharging it.. but, I don't think that is for me... One reason why I like my 4A-F is its simplicity and that it is a very reliable and strong engine in my opinion.

I've decided to go with light-weight internals and keep it N/A. But I'm considering doing a 20v head swap.. and since no one makes light-weight pistons for the 4A-F I was thinking of getting light-weights 4AG pistons and conrods as well as the 4AG crank because I do believe it is stronger, right?

The 4AG pistons and rods should work with out a hitch, right? I've done some looking and the stroke and bore are exactly the same.

Can anybody here shed some light on the 20v head swap, if it is worth it.. and what work would be involved to get it done?

Would a 4AG, G head swap be easier than the 20v? I'd imagine so, but there is a huge arguement over which is better for the main, 20v or 4AG..

Flashmn · 01-03-2004, 11:14 AM

4A-G pistons from a 16V head wont work with the 20V because the valve indentions are different. Wiseco should make raw pistons with certain specs that you can give them and make your own set of pistons for the 4A-F. I've never seen anyone try a 11:1 compression 4A-F. Although that will kill the non-interference design.
Also take note that the 20V head would have a separate timing system, as far as I know you'd need to run an ECU and a sensor from the crank/cams for the timing. Otherwise I guess you could carb it without much problems.
Oh and btw, the 4A-F internals are lighter than the 4A-G.

Punisher · 01-03-2004, 11:20 AM

This puts me between a rock and a hard place then.. I was wondering about the difference in piston cuts with the performance head over the F head.. which is why I was considering using G pistons..

So I guess I should swap in a 4AG head.. Any idea what the pistons and rods in a 4AF weigh and the 4AG?

My plans would be to get light-weight pistons, rods, and the 4AG crank and get that knife edged.. I won't be able to use my 4AF cams with the G head will I?

What about valve work.. Port and polish exhaust side and then port the intake side and 3 angle valve job?
I guess I will need to fetch a light-weight fly-wheel as well

Punisher · 01-03-2004, 11:22 AM

I did want to up the C/R though.. but I only wanted to do it very slightly.. like take off .2mm from the head...

What about the conrods.. can I have those custom made?

Flashmn · 01-03-2004, 12:24 PM

Quote:

Any idea what the pistons and rods in a 4AF weigh and the 4AG?

Dunno, but 4A-F has thinner and smaller conrods, but I would say they'd work up to 200hp...so if you arent getting them that high, I doubt you'd have problems...