20v head on a 4agte(ze block)

[Dongaz]

I have had a look through the conversion threads and cant find anything in there so im going to ask. What needs to be done to get the 20v head on?

I understand a new intake plenum will need to be fabricated up so it faces fowards and not towards the driver. What wiring is needed to be done? Can you use the 4agze std ecu and wiring? The wiring that I have is already done for the RWD ae86. I have both engines so im wondering if it is worth the effort of putting the 20v head on or putting the complete 20v into my other 86 shell and the 4agte in my current 86 and just use the std head.

Cheers

[skiddz]

its do-able

you will fuck a good head if the timing belt goes unless you put in low comp 20v pistons

new wiring

probably not worth the effort

[Dongaz]

Yea I wasnt to sure as I read somewhere that you had to have the 20v pistons in there aswell for the head to work well.....just an idea atm. I guess its 4agte in one and 20v in the other

[KARNAGE]

That incorrect about the head to work well. You can use the 4agze pistons no problem but skidz is correct if timing belt goes the head is wrecked. i run a 20 valve black top with
4agze internals it works extremly well. You can also go down the road of using the gze internals and just get a set of 20valve low comp pistons they aren't to expensive these days and then you will have no worries. If you currently have a 4agte the trouble of going 20valve is pretty excessive as what skiddz said again new wiring.
but if you want to go this way hell yeah go for it very nice engine set up if done correctly and they sound awesome to.

[Dongaz]

Why is there a concern about the timing belt going?

[skiddz]

bent valves dude, 4ages are non interferance engines, ie if your timing belt snaps then your bottom end can keep spinning without making contact with the valves, if the fly cuts in the piston arent correct and you snap a timing belt (not un heard of) you are pretty much throwing away $4-500

if you didnt know why one should be concerned about the timing belt going then maybe you shouldnt fuck with it? .... just a thought

[Dongaz]

Well its all a learning curve, that's how I see it. If I don't know something, I ask. Otherwise you won't be learning anything. Cheers for the info though.

[adamaw11]

That incorrect about the head to work well. You can use the 4agze pistons no problem but skidz is correct if timing belt goes the head is wrecked. i run a 20 valve black top with
4agze internals it works extremly well. You can also go down the road of using the gze internals and just get a set of 20valve low comp pistons they aren't to expensive these days and then you will have no worries. If you currently have a 4agte the trouble of going 20valve is pretty excessive as what skiddz said again new wiring.
but if you want to go this way hell yeah go for it very nice engine set up if done correctly and they sound awesome to.

Do you happen to know what compression ratio you end up with using GZE internals with the 20v head?

[KARNAGE]

depending on the head ie. st or bt and the pistons used ie gen 1 gze or gen 2 gze. bt with gen1 gze works out about 8.14 comp with standard hg but with a metal gaskit it is about 8.4. bt with gen 2 pistons and standard hg it works out 9.01 with metal hg it is bout 9.1. im not sure about the silver top as i haven't measured it hope that helps

[adamaw11]

cool, good to see some figures. Unsure how you would have worked it out though. would you say those numbers are pretty accurate within, say .1 worth of error?

[KARNAGE]

Yeah mate they are acurate to that level my housemate measured them when we put the engine back together with a syringe he said they were acurate to .01 or something i believe him as he knows his shit lol.