JCSanders

7age/fe build with a twist urgent help

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Hi guys

Ok today i created a new topic cause ive searched a lot of forums but havent really found an exact answer yet. Sorry if this may have been asked and answered before.

So today I need help with the build of a 7age/f engine. The reason I name it like that is cause it's not an 7age build. So basically what I'm doing is:

Using a 7afe block with a 4af head and 4age pistons.

Now here's what I need help with: upon doing this, which parts would I need to use. Meaning will I use the 7afe crank and rods. Will the pistons fit on this rods. Also which oil pump, water pump, tensioner and t-belt will I use. And is the crank pulley the same as the pulley of the 4af block.

Now take note that I want to use the 4af head that I already have cause I already ported and gas flowed the head. And ive done a conversion to a 32/36 dgev weber already.

Now would the be other recommendations you might have. Let's say the 2 things in definetaley gonna use is the 7afe block and 4af head. Now do you have any other recommendations as to which pistons, rods and crank I should use. Also which gasket will I use. And then upon assembly which torque setting.

Thanks guys I would really appreciate your help.

This is quite urgent as the engine is already out but before I go ahead and buy things I first need help and recomendations.

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Greetings mate, welcome to rollaclub.

In order to help, perhaps you could enlighten us on why you trying to use a 4af head on a 7afe?

 

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Dave he said he has already flowed the head and modified it.

 

A quick look at an epc makes me think ae111 4afe and ae111 7afe 97-98 are the same head...  Might just work as per factory on the entire 7afe motor.

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Thanks for the reply.

That right LittleRedSpirit. I already ported and flowed the head. I also want to increase the valve sizes on the head and throw in 4age valve springs if I can find any.

Now just for a little recap as I've been doing some more research while I waited for a reply, here's what I came up with.

Also note that my 'rolla is an ae92 model. After doing some research I found that the head will fit on the 7afe block. The pistons might fit on the 7afe rods depending of year and which generation it is (Correct me if I'm wrong). Now what i want to know is which crank and rods should i use. Should i use the 7afe/4af/4age crank and rods and why?. Also in terms of belt pulleys and the tensioner which will i be using. And which oil pump and water pump will I be using. Just a few things I need to know before doing the complete conversion.

And like I mentioned any consents and/or advice or recommendations on what I should use would be appreciated 

 

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I think you're at the limit of what people might be able to just tell you when to comes to which bits to use and why.  If it were me Id just look for a complete 7afe and try to slap the head on that. 

Your ideas are all over the place, why would you take a 1.8 litre motor and then fit a 1.6 litre crank from a 4age?  It would just reduce the capacity back down to make it essentially the same as the 4afe you are getting away from, but with a needlessly taller block, and would need 2 grand worth of engineering to make it work, when you could have just used a 4age in the first place. 

As I see it its real simple, get a 7afe and put your modified head on it.  The belts and pulleys are just something you need to be willing to play with to get a good setup.  Its impossible for someone to have followed the same exact path, and if you're stumped by a few pulleys, certainly dont try and do a build as complex as this sounds in your mind.

I'm getting a vibe that this is all a bit overwhelming, and you're lost in possibility and cant make a decision beyond I spent money on this head so Ill save it, but it may be cheaper and higher performance in the long run to just get a 4age.  7age isn't known to be a great performer unless you go full house, and there are far easier ways to get 220 hp and decent torque.

That said, i admire people doing things differently and not following the crowd, but the price of that is that you are the one doing the research and engineering and nobody can really help you unless you ask really specific questions and build your own understanding.

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Thanks finally someone gave me a decent answer. And believe me if I say I searched and searched but haven't found one.

First of all I was thinking the same thing with the 4age crank but then I read somewhere that someone did this and then I got all confused. And your right it's all a bit overwhelming as I don't want to make a decision just to find out tomorrow that something else would've worked better. Now to answer the question as why I'm not going full age or 7afe is because I'm bussy rebuilding a taz which later on after that project is complete I'm gonna throw a 20v 4age in. That's why I want to play around a bit now with the rolla to see what I can do. 

Now in summary and after a lot of research and over thinking an finnaly getting a decent answer here's what I'm thinking of doing.

Throwing my 4af modified head on the 7afe block with a 7afe crank and rods and 4age pistons. Then trying out different head gasket to get the lowest gasket profile but still keep it a none interference motor. Or just throw the thin 7afe gasket on there as I'm gonna need to regroove the pistons anyway to fit the bigger valves. I'll also use the oil pump from the 7afe and the water pump and tensioner from the 4af. In terms of pulleys I think the 4af pulley might work but that's something I will play around with and find out which one works. And then I'll just modify the exhaust to fit the taller block. Not one of my biggest concerns as I want to build custom branches anyway.

So now you know what I'm gonna do and I'll keep you posted with the end result and also may come back for advice if I run into any difficulties. Any last concerns or opinions?

Thanks

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My concern is it will be an excellent academic exercise, heavy on the wallet, and not alot of benifit.

However that has never stopped me doing a project before. All the power to you, and post photos of progress:)

I reckon start with a complete 7afe, plonk your head on it and see how it fits..

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I think leave the pistons alone, (cue leave britney alone meme).  If you're head flows more than a stock 7afe head, put it right on and drive it.  Has it been shaved, might need to cc the chambers to get an idea of the CR.  Stroked motor will make more off the bottom.  Should be good.  Can you tune for the mods in the head or just stock ecu sorta coping with it?

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So far I haven't had any problems with the ecu not coping with it. And when you say I should leave the pistons alone do you mean I must use the 4af or 7afe pistons. It haven't been shaved but I want to do that also. My concern is if I shave it would it result in and interference motor?

Edited by JCSanders

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If my research is correct and the heads are very similar or the same, and they are the same bore, then they must be compatible with the valves, as its all the same isn't it?

Almost all engines are interference engines from the factory, meaning if the cam timing fails you smash valves and pistons together, but that's different to actually interfering when correctly timed.  Usually you can find a Toyota manual that tells you how much you can shave at a maximum, many heads have a check mark or step where the maximum machining point is.  Thin hg or a shave either way, but I am unsure if the 4afe and 4age head gaskets are the same, they should be similar, but this is where you need to fill in the blanks by getting a 7afe and playing around with it.

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Do we have combustion chamber volumes yet?  They will tell you what compression ratio you will end up with, and which head gasket to use. Your capacity is going up 12% on the 4AFE head, so the compression ratio will be too, and if the 4AGE piston already runs at 10.3 you will have 11.6 CR. See what the chamber volumes are on the 4A heads.

The hump on the piston will also determine compression ratio and whether or not it becomes interference. The 4AGE isn't an interference motor, judging from when Steve stripped a timing belt last year. We just fitted a new belt and away it went.

If the stroke is different then the crank & rods will be different. The crank needs a bigger swing to make the piston go from top to bottom, and the rod must bring the piston right up to the block deck.  So as LittleRedSpirit said, get the head and put it on a complete 7AGE block, then worry about it.  If you're lucky it will turn out to be really simple.

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Something that needs to be clarified here, a 4AF head is NOT the same as a 4AFE or 7AFE, and even amongst the FEs it is only the later 4AFE that has the same head as the 7AFE (at which stage they are identical down to the part numbers).  4AF is the 16V carby head from the early AE92s (they were sold here with extra emissions as 4AFCs).  The later AE92s had the early 16V 4AFE which is very similar to the carby 4AF except it has ports for the injectors cast in to the head.  They also got the 7AFE in a couple of models.  When the AE10x came around the 4AFE was upgraded to have the same head as the 7AFE, both have the injectors in the inlet runners.

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