4AGE 20v Options

[Coomer]

Like I said earlier, the pistons work, they just turn the motor into an interference motor. You have to have them machined if you want them to not hit the valves if a timing belt breaks.

[turboinduction]

Like I said earlier, the pistons work, they just turn the motor into an interference motor. You have to have them machined if you want them to not hit the valves if a timing belt breaks.
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sorry Chris, I reread what I wrote. I wasn't asking a question, I was moreorless pondering my possibilites. Like "new pistons or cut pistons?.. what to do what to do... even though I did ask a direct question - I knew the answer I was just thinking outloud

Do you know if Toda will make custom pistons? Because they already have an AE101 kit available, just at a high compression.

Also I understand what your talking about with the belt and the pistons hitting the valves... but I've never heard the term interference motor until your first post. What exactly is that? More forward... do people run engines like this?

EDIT: I went ahead and did some research. Apparently, many companies make motors like this to cut emissions and quiet down the engine. This way the engine can be smaller, more effective, and quieter. However, with every advantage, there is a disadvantage. The timing belt doesn't even have to break, but slip causing the timing to be off just a bit. And whammo. Luck of the draw I guess.

-Ti

This post has been edited by turboinduction: Apr 28, 2005 - 3:56 PM

[Coomer]

Hmm, you have a ton of researching to do before you begin a project like this.

An interference motor is one where it's possible for the pistons to hit the valves if a timing belt breaks. Off the top of my head, I think that some Honda motors are...I know that the B20A in the third gen. Prelude is, as my friend just had her timing belt break, so I did some research into whether it was non-interference or not.

If Toda doesn't list low compression pistons for the AE101 4A-GE, then they probably don't make them, and I doubt they would custom make you a single set...they might, but it'd cost a ton of money probably. Why don't you just get 4A-GZE pistons and have them machined?

[nik]

here 20 VALVE FORGED TURBO PISTONS 8.5:1 @ http://www.toysport.com/webpages/WebUpdate...MARCH202002.htm
maybe contact
http://www.fensport.co.uk/fensportcars.htm

i saw a site some where that had 5 valve low comp pistons
but you always can buy 4agze ones and have them machines to match the valves but it probably wont be cheap

[frotou]

http://forums.club4ag.com/topic.asp?TOPIC_ID=94447

Slow'n'rusty in 4agclub know a lot about turbo 20valves

Good luck !!!

Claude

[Kwanza26]

Toda doesn't make low-comp anything because they only do n/a race builds... ;]

Contact Drag86 from club4ag if you're serious. He can get some made for you... pretty good prices too.

http://forums.club4ag.com/topic.asp?TOPIC_ID=99156

[turboinduction]

Hmm, you have a ton of researching to do before you begin a project like this.

An interference motor is one where it's possible for the pistons to hit the valves if a timing belt breaks. Off the top of my head, I think that some Honda motors are...I know that the B20A in the third gen. Prelude is, as my friend just had her timing belt break, so I did some research into whether it was non-interference or not.

If Toda doesn't list low compression pistons for the AE101 4A-GE, then they probably don't make them, and I doubt they would custom make you a single set...they might, but it'd cost a ton of money probably. Why don't you just get 4A-GZE pistons and have them machined?
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I do research I'm intellegent, but I am (was) limited to my knowledge. I really only know outside the block. I understand compression, know what cranks and rings are, etc etc. However, I really just take the motor for what it is. I couldn't put one together if I tried. I know suspensions like the back of my hand, and I know parts outside the block fairly well. I'm an electronic guru with 13 years working on computers. Now its time to further more my knowledge. Its time to learn how the internals work. Thus this project. I wont learn until I do it. And I believe that this will be a good lesson for me. It accomplishes two things. One - swaping a motor. And Two - turboing a N/A car. I came out of the DSM line before my toyota and nissan. So I understand turbos, but only since it was pre-built on the 4G block. I will do the research to complete the goals and I have another car to drive (sentra spec-v). So yes, I may sound like a 16 year old newbie wanting to swap a 3S into a 94 ST, but I am more knowledgable than that. I really appriciate the help everyone has given me. When I started this thread I had only known that a 20v existed because of Kwanza and Coomer, besides that I hadn't a clue. Business in the auto industry has been slow, so for the past week I've spent 4+ hours a day reading mr2oc.com posts, googleing to find complete 20v swap how-tos, finding aftermarket parts, and finally researching how the damn engine is put together to begin with. Back on topic, my little knowledge on engines doesn't allow for pricing. Thus my confusion with machining the GZE pistons or buying new ones. I dont have clue how hard it is for a shop to machine new heads on the pistons. Or what the cost. Or where to go, if there is any place in Central Wisconsin for me to go. So, I figure I can install pistons once in hand, so if I can just find them already made - even if more expensive, its better for me. Thats why I'm posting here. Maybe new 800 dollar pistons aren't worth it when Kwanza might know someone that can make them cheaper. Maybe Coomer knows that all it takes is 100 dollar GZE pistons machined to do the job for little money. I'm still much into my knowledge gathering stage and again, appriciate the help you guys give me. Sorry for the long post.

EDIT: Off topic question. Cams. I know what they are, but...
AFtermarket side of them. What does a longer duration and lift do for me. Obviously allows for more air to breathe in to exit. But why wouldn't you want the longest possible time then? How would I know what duration and lift I would need for a project? I really couldn't find much about them on the net other than "I put these cams in to get this effect" but no explaining on how to pick cams at all. I.E. ToySport Cams - half way down

-Ti

This post has been edited by turboinduction: Apr 28, 2005 - 9:05 PM

[turboinduction]

anyone know?

[Coomer]

As I understand it, a higher lift pushes the valve down more, allowing more air to enter because the opening is bigger. While a longer duration keeps the valve down longer, allowing more air to enter over a certain amount of time.

I think with a big change in cam lift over stock, you need to upgrade your valve springs to handle the extra movement.

[turboinduction]

As I understand it, a higher lift pushes the valve down more, allowing more air to enter because the opening is bigger. While a longer duration keeps the valve down longer, allowing more air to enter over a certain amount of time.

I think with a big change in cam lift over stock, you need to upgrade your valve springs to handle the extra movement.
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If thats the case, why wouldn't you want to opt for the highest lift and longest duration? What your saying makes perfect sense to me, but I dont understand why there are options

-Ti

[Coomer]

If thats the case, why wouldn't you want to opt for the highest lift and longest duration?  What your saying makes perfect sense to me, but I dont understand why there are options

-Ti
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Because at a certain point, you need new valve springs, which cost money. And the length and duration affect the RPM range and idle too I believe. I don't know if what I posted is correct though.

[frotou]

Catcams are listed for the 20 valves but better to keep the head stock (no parts in north america)

Claude

[frotou]

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...me=STRK:MESE:IT

218 whp @ 7 psi

Claude

[turboinduction]

hrm - seems like I'll have to do a little more research on cams and springs.

-Ti

[Dr_Tweak]

With cams, you have to watch the overlap. Overlap is when both the intake and exahust valves are open. More overlap=better top end and worse idle. That's why they made VVTi, it increases the overlap later in the RPM band so you have the best of both worlds.

Anyway, with a turbo you DO NOT want a lot of overlap, because the exhaust will actually backflow into the cylinder (because of the pressure built up against the turbine). However, going with higher LIFT cams is fine. The problem there is you put a lot more pressure on the valve springs and you need high performance ones... and it's more wear and tear.

Those are the basics anyway.

This post has been edited by raven_101: Apr 29, 2005 - 9:57 PM

[turboinduction]

So stock overlap would keep VVTi in check, but maybe check the possibilites of higher lift (with new springs). Now, should a turbo 20v disable the VVTi and just go with adjustable cams?

-Ti

[Dr_Tweak]

A lot of people do that, yeah.

[turboinduction]

A lot of people do that, yeah.
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would you suggest this?

-Ti

[nik]

if your still looking for pistons the guys over on club4ag.com are getting a group buy together for ROSS pistons might want to check it out