Would this work? (blacktop over silver?)

[CozmoNz]

Um, 4agze bottom end, forged pistons, rise compression ratio to 10:1.

4age 20v blacktop head, port head, obviously custom intake manifold to qtb, remove trumpets, runing around 8psi? with lightened flywheel etc, good responce, *enough* power without boost, then more when boost hits.

my point is, the blacktop wont go pop? and do they just bolt on? or is it not worth it, and just to put in a 4agze?

[Zak]

If you use the ze bottem end it should only have a c/r of about 9:1, but I think it would be easier and cheaper to just use the standard 4agze with a hair dryer slapped on the side

[t0ms]

i dont know if that has been done with a black top but i have heard of the same combination done with the gze bottom end and silver top head

the 20 valve has a good flow pattern through the valve's but its weak in the bottom end as you would expect. so the gze bottom sorts that

i would be wary about raising the compression too high, as when the boost comes on it create's an "artificial compression ratio" of alot higher than what it is off boost. if it goes too high it will induce detonation.

but yes i can imagine it can be done, action dan is doing the same thing atm with a silvertop head, making up a custom manifold onto the quad throttles....

cheers
tom

[TRDWGN]

How can a 20v bottom end be described as weak when compared to a ZE bottom end? Really the only obvious difference is low comp pistons compared to high comp pistons....

[spencer]

:lol: How can a 20v bottom end be described as weak when compared to a ZE bottom end? Really the only obvious difference is low comp pistons compared to high comp pistons....

spot on, this mod would be a waste of time not many 20v's n/a are gunna smoke pistons so whats the point? plus you loose the cut outs for the valves and the correct piston dome for compression, so you would have to shave half the head off/deck block to get compression back up

[vvega]

:lol: How can a 20v bottom end be described as weak when compared to a ZE bottom end? Really the only obvious difference is low comp pistons compared to high comp pistons....

spot on, this mod would be a waste of time not many 20v's n/a are gunna smoke pistons so whats the point? plus you loose the cut outs for the valves and the correct piston dome for compression, so you would have to shave half the head off/deck block to get compression back up

compleately incorrect

20v head is a bolt on to a ze bottom
just makes it a interferance head

im look ing at a blacktop head on a xe bottom right now

massive hp has been proven many times from this combo
and massive has been done teh 16v way
at the end of the day its your choice



v

[kingcorolla]

:lol: How can a 20v bottom end be described as weak when compared to a ZE bottom end? Really the only obvious difference is low comp pistons compared to high comp pistons....

spot on, this mod would be a waste of time not many 20v's n/a are gunna smoke pistons so whats the point? plus you loose the cut outs for the valves and the correct piston dome for compression, so you would have to shave half the head off/deck block to get compression back up

compleately incorrect

20v head is a bolt on to a ze bottom
just makes it a interferance head

im look ing at a blacktop head on a xe bottom right now

massive hp has been proven many times from this combo
and massive has been done teh 16v way
at the end of the day its your choice



v

so basicly, when you bolt a 20v head to a GZE bottom, all your getting is lower compression, "semi-solid" pistons, and creating an interferance engine. Only benefiting from the high flow rate of the head. I see this being pointless if you are running NA, as your comp ratio will be roughly 9:1, therefore making no use for the higher flow. (unless you crank up the c/r)

Though this setup will be a good combination on the FI side of things...


*edit:..Hey, im a very regular poster now ....meh.

[CozmoNz]

well, i mean, the 16v's can only flow so much at a certain point, thats where 20v will come in, certainlly cant hurt if ive already got the head eh saves buying the entire engine

[Zak]

The only problem with just using the head is the VVT-i won't work. Unless you have the t/b computer and loom and all the other s**t. But then you would need to use an after market ECU to run boost, and the list goes on. The easiest, and cheapest way it to just stick with the ZE really

If you could get it all working together it would be mad though

[Mr Revhead]

Really the only obvious difference is low comp pistons compared to high comp pistons....

the ONLY difference is the pistons and rings, rods and cranks are the same parts.

the best way to go about this is to buy a 20v s/t which are dam cheap. then fit 4agze pistons and rings. $5-600

for the price of a 4agze you can buy a 20v and fully rebuild it with ze pistons

[Caveman]

If i was going to use a 20v head on a GZE bottom end i'd convert to a turbo.

A 20v is designed for high rpm where a 16v would start to loose power. However the s/c isn't designed for high RPM so your combining the wrong things.

A (good) turbo will go to 10k, and so will a 20v head. A s/c will most likely fly to pieces at 10k.

my 2c

[Mr Revhead]

yes there is no point using the gze pistons without turbo etc.

10k is a bit much on stock rods etc......

[CozmoNz]

Ok ok ok ....

so um..

mr rev head..., lets say, (ive got a blacktop 20v), i go out and buy myself some 4agze pistons, and rings, or some new forged ones for the 4agze.... but wouldnt the pistons his the valves? since thye have a different.... *valve map* or wuteva u wanna call it on the face of the pistons?

how much to get them remachined... but will they still be forged then?

stick on a turbie, intercooler and new ecu....

(can any new ecus keep vairable valve timing?).....

[Mr Revhead]

first up youd prob be better off starting with a s/t, stronger rods.
the b/t ones may be as strong, but no ones proved it yet.

IF you are using ze low comp pistons then you wont have any valve/pistons problems, unless you snap a cam belt.

forging is the process in which pistons are made, machining them cant change that, how ever its strongly recomend you DO NOT mahince ze pistons, they have a rather special coating which is best left in place

[CozmoNz]

ok, so get new rods, new ones cant hurt anyway, the ze pistons and rings,

ok, so dont machine them, but what about the 4valve set on them? will that harm combustion and lose the point of having 20v?

[Mr Revhead]

its possible its not ideal, but nothing to worry about. definitly not to the extent of bining the 20v head

[spencer]

:lol: How can a 20v bottom end be described as weak when compared to a ZE bottom end? Really the only obvious difference is low comp pistons compared to high comp pistons....

spot on, this mod would be a waste of time not many 20v's n/a are gunna smoke pistons so whats the point? plus you loose the cut outs for the valves and the correct piston dome for compression, so you would have to shave half the head off/deck block to get compression back up

compleately incorrect

20v head is a bolt on to a ze bottom
just makes it a interferance head

im look ing at a blacktop head on a xe bottom right now

massive hp has been proven many times from this combo
and massive has been done teh 16v way
at the end of the day its your choice



v

never said it wont bolt on I have a 20v head on a ze bottom end now but its for a turbo setup. was just kinda sayin a n/a 20v aint gunna blow a hole in the piston in a hurry so whats the point of going 20v n/a on ze pistons

[Mr Revhead]

hehe
i think theres some confusion here....

the origianl poster was talking about using a 20v head on ze pistons in a na set up, which as pointed out would be a waste of time...

however if turboing itll be well worth while.

so i think you guys are talking bout 2 different things

[4AGTE]

The only time you would put ZE pistons in a 20v is if you are going turbo.
If you are not going turbo it will only lower your compression and their for lose power.
But if you are going turbo with a 20v head all good and mean as power!!
If you are doing this them make sure you are egtting AE101 ZE pistons and give me a call when you are turboed!

[vvega]

Um, 4agze bottom end, forged pistons, rise compression ratio to 10:1.

4age 20v blacktop head, port head, obviously custom intake manifold to qtb, remove trumpets, runing around 8psi? with lightened flywheel etc, good responce, *enough* power without boost, then more when boost hits.

?

oringinal post
he clearly states running 8psi of boost

that is what i was answering in refernce to :S
dunno where you got the n/a arguyement from

v