20V silvertop head on gze bottom end - head gasket thickness?

[RT40Corona4AGTE]

Just a quick question about this swap, i have searched and read all i can find on this conversion. Is it true that a thick head gasket is required when using gze pistons due to the valve setup in the 20 valve head? I am aware that if a timing belt breaks i will lunch the engine, etc, etc. But just want some clarity on this and if so, what is the minimum thickness?

I am planning to use a 1mm thick copper head gasket with my silvertop head and o-ringed gze block. Is this thickness OK? or do i require a thicker gasket?

[KARNAGE]

The stock head gasket from toyota for the 20valve is 1.6mm before compressed and goes down to 1.2mm so thats for the normal set up. the trd metal head gaskit is 0.8mm either one of those is fine to use for compression etc. It is true about the engine being a interferance engine ie. timing belt breaks there goes the valves and then in need of a rebuild. but a good timing belt and getting it changed at the right times will be safe. lots of people including myself have run this setup. which pistons are you using the gze gen1 or gen2? as the compression is different between the two

[RT40Corona4AGTE]

I believe i have new gen 2 ones as it was a late model GZE and i ordered later model ones (MAP sensored GZE). When i ordered them I remember they gave me the wrong set of rings. Compression rings no. 2 were too thick. They soon ordered me in the correct ones though. Thanks for your help again and again mate.

Also i believe i need to run a 20V timing belt to suit this application? and can i use the gze timing drive on the crank or do i have to use a 20V one? or are they the same? I know my 16V 4AGE's but 20V's are new to me so far. lol.

[RT40Corona4AGTE]

also, any idea on where i can find an online manual for the silvertop cylinder head? I can find plenty of blacktop stuff, and i have read somewhere that they are the same as far as valve clearances, etc, go. Can anyone confirm/deny this?

[KARNAGE]

Couldn't tell you where to get the silver top manual as i have the bt but they are very similar. Yeah you do need to use the 20valve belt and for ease i used the 20valve oil pump and belt tensioner even though the bt tensioner sucks balls lol. Ok you can check the pistons easily as the gen 2 has a flat top no dish where the old pistons are lower comp and are dished. Since you are doing the internal change i guess you are going turbo? with a .8mm gaskit and the gen 2 pistons you end up with around 9.02 compression pretty good for off boost response so you will be laughing. And mate if you need any help with this just pm me cos i have been through this conversion last year very pleasing in the end

[RT40Corona4AGTE]

The pistons have no dish as such, just the grooves for the 4 valves. And i am using a 1mm thick copper head gasket. Yeah thinking I am going to go a little crazy with the turbo in terms of size, just to have a play around. Thanks for the info on the timing belt, oil pump, etc. Good guidance there!!! I will definately keep in touch as I could possibly run into some trouble somewhere along the line. Have just spent the last two weeks prepping and painting my RT40 Corona for this project. The paint job hasnt come up too bad considering that I am not a painter or anything (as i am an electrician by trade) still need to re-do the roof and do a little touch ups here and there. But it is coming along.

Around 9.02 compression eh? thats not too bad.

[KARNAGE]

Oh yeah not bad mine is getting ready for an aw11 which is deffinate need of a paint job lol. What size turbo you thinking of going when i did mine i talked to the boys at rigoli performance they said that on the project the did they started with a t28 but bumped it up to a t30 in the end as the t28 ran out up higher, didnt think a 1.6 litre would push a t28 that hard. With the 1mm you will have slightly lower compression maybe around the 9 barrier but to be certain would have to get it measured.

[RT40Corona4AGTE]

cool bajool, havent really decided, but the ones i have been looking at have rather large rear housings, so lag will be my friend, but hey thats what nitrous is for right? lol but yeah i dunno what turbo yet. Rigoli's Corolla is nice, i have seen it in action before. not bad at all.

[KARNAGE]

Yeah havent seen that bastard in action but heard it runs 11s or some shit. what ecu you planning on using to run the beast?

[30psi 4agte]

Whats your HP goal ?

That will help you decide on what turbo

[RT40Corona4AGTE]

Karnage - Already have a Microtech for the ecu. LT10s with X4 ignition module to be precise.

30psi - Yeah i dunno yet, thanks for the tip but.

[oldeskewltoy]

Arias makes a piston specifically for a boosted 20V......... 9 to 1
http://www.ariaspistons.com/products/toyota.html - bottom of the page

[RT40Corona4AGTE]

cheers for the info oldeskewltoy but i already have pistons, etc.