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Differences Between 4ac And 4af?

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Hi there,

 

Looking at getting into some cheap motors to learn off.

 

Firstly, Ive tried searching, but I can't find out much about the differences between the 4AC and 4AF blocks. From what Ive read, it is possible to bolt on the 4AGE head onto a 4AC block, but what about a 4AF. The reason for asking is that my workshop manual (Toyota 4AF 4AGE Repair Manual) only covers the 4AF model. Are the blocks the same? I would hate to torque up the bolts to the wrong specifications etc etc.

 

Secondly, are the mounts similar/the same as the 4AGE mounts? Mates have a broken Corolla with a dead 4AGE, can I drop the 4AC/4AF and test it out? (Ignoring road rules for the moment)

 

Reason for all this is I want to start building/experimenting with motors. I'm sure the suggestion to just buy a 4AGE will come up, but I'm trying to spend as little as I can during the learning process.

 

Cheers,

Mark

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http://en.wikipedia.org/wiki/Toyota_A_engine

 

Start here, good basic info. With Toyota engines, If there is an 'F' it stands for '[email protected]$ked', and a 'G' it stands for 'Great'. No idea about the technical aspects of bolting it all together, but it does beg the question, WHY? If you want to go down a very similar path to what you have suggested, build yourself a 7AGE. 4Age head, 7AFE bottom end. Have a look at this beauty:

 

http://translate.google.com/translate?hl=e...ion%2Fe68187188

 

Google has bountiful info on Toyota's these days...

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The 4a-ge block has the mounting holes (cross member mounts) to use the motor in a rear drive car, so does the 4a-c but the 4a-f block has the mounting points but their un-drilled.

The 4a-ge's intake manifold support bracket is just an un-drilled "boss" on the 4a-f block.

If you use the "g" head on the "f" block, use the 4a-ge gasket and head bolts cause the bolts and gasket are different for the "f" motor. Don't know about the 4a-c motor.

The other things you'll also have to swap over to use the "g" head is the cam gear on the crank and the pulley, the "f" motor uses different ones.

 

LittleRedSpirit - don't let Bill Sherwood catch you saying that :P

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little red spirit: I might upgrade my modified 20v blacktop engine for a highly modified 7afe head, I am sure some people would be foaming at the mouth hearing that but I will see them at the lights as the V8 boys say.

 

beams: try and grab a 4ac block, cheap, easy and very close to a earlier model 4age, but not the same

Edited by Sam_Q

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little red spirit: I might upgrade my modified 20v blacktop engine for a highly modified 7afe head

 

 

So you are swapping a modified blacktop for a 7afe head? I don't think thats what you meant to say is it? If I had to guess I'd say you were using the 4age ae111 head and the bottom end from the 7afe, 7age. Just like that sexy sprinter above. That page is gold because it has a list of a lot of the parts he used to bolt it all together, if you can decipher the japenglish.

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So you are swapping a modified blacktop for a 7afe head? I don't think thats what you meant to say is it? If I had to guess I'd say you were using the 4age ae111 head and the bottom end from the 7afe, 7age. Just like that sexy sprinter above. That page is gold because it has a list of a lot of the parts he used to bolt it all together, if you can decipher the japenglish.

 

 

No, he said FE head........there's a lot more behind this than you or a lot of people know about.

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How different are the 4AC 4AGE blocks Sam Q?

 

4AF / 4AGE Repair manual has the same diagram for both the 4AF and 4AGE block. Any one know if their the same then? Toyota has used the same diagram for both, so I'm assuming their identical?

 

Funnily enough, Ive asked the same question over at twincam...

 

On another note:

 

http://forums.performanceforums.com/forums...&highlight=

 

Bill says the F heads flow better...? Discuss

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i "belive" that the 4ac block has diffrent water galeries so the 4ag head wont match upto these. also they are 1 rib? meaning they are abit weaker than a 3 or 7 ribbed 4age block.

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With Toyota engines, If there is an 'F' it stands for '[email protected]$ked', and a 'G' it stands for 'Great'.

 

LOL thats going into my sig.

 

I'm assuming that you already have either or both a 4af and 4ac?? Any combination of the af-ac-ag engine you will think of building will have been done, persevere and you'll find some info I'm sure.

 

Not that I'm much of wiz when it comes to cars but what is the engine for? purely for learning purposes or something you will want to drop into a car? Maybe it would be easier if you want to learn (depending on previous experience) to start by building a 4AC or even the 4AF as they are more basic and then try the GE or cross's...

 

as i said i don't know a whole lot but what i said is just what makes sense to me.

Edited by smacko84

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If you're going to muck around with motors, probably the 4AC is the way to go. They'd be a bit older, so you should be able to get more of them for less money, if you're going to blow them up!

 

4A refers to the blocks specifications, bore and stroke will be the same with all motors, and you should be pretty sucessful at swapping parts. I can't guarantee that you can swap everything though.

 

G heads are generally designed to be high performance heads (3SGE, 2TG), so for performance that's what you want. Generally it's easier to get hop up parts for them to. F series heads are designed for fuel ecconomy, so are less desirable. There are a few design factors which make them better heads than the G in a way, but it's probably not enough of a difference to consider them over a G head, plug getting go fast bits isn't as easy.

 

All blocks should look pretty similar, so if you're modifying, just check that everything lines up and holes are drilled in the right place, and you should be OK.

 

The only other thing is that different heads will have exhaust etc. in different spots, so you'll have to change that every time. Could get expensive!

 

Have fun!

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damn lack of email notification. Sorry guys if these comments were posted a long time ago I only just saw someone commented on this thread.

 

anyway....

 

 

beams: all 4a blocks have the same water galleries, there are some fundamental differences between the earlier and later blocks. With the exeption of some oddball engines the earlier blocks used by the bigport engines, 4ac and earlier 4af all used the "3 rib block". The later versions had the "7 rib block" which had the extra reinforcing, one threaded gearbox hole offset, the oil squirters and some other junk. I made a typo before I meant to say the early 4ac and earlier 4age blocks are the same. However it is a bad idea to swap the heads, apart from the massive compression ratio drop the 4ac didnt come with a full counter balanced crank and instead has something that a more common crap hole engine has.

 

beams: Hiro is right I definately meant a 7AFE head on a 20V bottom end, here see for yourself, heres my dummy fit:

 

FEdummyfit3.jpg

 

 

and this is my inlets half finished:

 

fehead08.jpg

 

 

Theres quite a few thiungs that the FE series of heads have over the G heads, if you like I can explain them.

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it probably wouldnt matter because the crown would be so low and all A series twin cam engines are non interference from the factory anyway. Although despite what has been reported I have doubts about the 20V blacktop being non interference but thats another story.

Edited by Sam_Q

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