wiseco pistons for 2tgte

[cooter]

hey guys
im in the market for forged pistons for my 2tgte and the only forgies wiseco stocks for the 3tc are 7.4:1 - 7.7:1 comp ratio which is a bit of a bitch seeing as im wanting 8.5s.
everyone knows that when u make a hybrid 3tg (3tc+2tg) using stock 3tc pistons etc you get a rise in comp to around 10.5:1 yeah.

well my Q is if i was to use these wiseco pistons @ 7.4 - 7.7:1 along with my 88261 2tgeu head will it bring my comp back closer to 8.5:1 when using the 3tgte crank?

also what is everyones thoughts on mainstud and headstud kits for the 3tgte over new oem bolts? are they needed or do the new oem's do the trick. the goal is 180rwkw reliably so id rather spend more to get the better fatseners then have new oem bolts die on me n my engine go kaboom.

cheers for any help guys
craig

[peedman]

This place sells 8.5:1 3TG forgies: http://www.paradiseracing.com/pistons.htm

[Robbos_Toyotas]

im with peedman - get 3tgte pistons and bore the block if you need to, to accomodate for them.

Im sure yellowrolla on here can testify - i *think* he has wiseco's and makes about 200rwkw on his 3tgte

[cooter]

i would have thought that the 3tc/ 3tgte would take the same piston hence no actual listing for 3tgte. and then would also be able to be used in 2tgte. and that paradise racing has no listing for 88/88.5. i dont think i want to go 89mm with the turbo motor due to reliability issues with the water jackets. ive been told for n/a thats fine but with the cylinder pressures of turbo they would be weak.
anyways cheers for the quick replies guys keep em comin

[Robbos_Toyotas]

i would have thought that the 3tc/ 3tgte would take the same piston hence no actual listing for 3tgte. and then would also be able to be used in 2tgte. and that paradise racing has no listing for 88/88.5. i dont think i want to go 89mm with the turbo motor due to reliability issues with the water jackets. ive been told for n/a thats fine but with the cylinder pressures of turbo they would be weak.
anyways cheers for the quick replies guys keep em comin

no mate, i dont agree with what they have said, theres plenty of bored motors out there running big boost and power - if you look at half a mm, it is fuck all really - 7mgtes run a huge bore/ stroke for the motor, and dont mind having a bore 30tho which is .75mm.

[merc-blue]

mate do you understand the engine codes?
the 2T-G and 3T-G engines use different pistons
you will need to find some 2TG pistons not 3TG casue the comp height is different and the T-C and T-G pistons dont swap cause of the difference valve releifs

[Rinmax]

you will need to find some 2TG pistons not 3TG casue the comp height is different and the T-C and T-G pistons dont swap cause of the difference valve releifs

Totaly agree with you merc-blue.

The 3t pistons have a very big differance in pin to deck height than the 2t pistons regardless of the valve cutouts. The reason people use cutout 3t piston in the hybrid engine is that a 2t piston would hit the head when its bolted onto a 3t crank. I can see your point that putting a 3t piston with a 2t crack will drop the compression but I've never heard of it done.

I would like to know the results if you get it running.

[YelloRolla]

well my Q is if i was to use these wiseco pistons @ 7.4 - 7.7:1 along with my 88261 2tgeu head will it bring my comp back closer to 8.5:1 when using the 3tgte crank?

I have not cc'd a 261 head so I cannot say.

you will need to find some 2TG pistons not 3TG casue the comp height is different and the T-C and T-G pistons dont swap cause of the difference valve releifs

Except he is planning on using the 3T crank not the 2T.
You should also use the 3T GTE conrods - Eagle make some nice rods for them)

The 87mm Wisecos are suitable in the 3T GTE and the 2T/3T GTE (IE 2TG head on 3T GTE)
because the valve reliefs are oversize. I don't run them in my engine (I use 86mm SPS), but I have built some engines with them.

There is no way that I would bore a boosted 3T to 89mm - that represents a 4mm over bore.

HTH
Jase

[fade-e]

There is no way that I would bore a boosted 3T to 89mm - that represents a 4mm over bore.

LOL that would leave about 1-2mm from the piston to water jackets

a good enough hit and the piston would probably go through the wall and have water flood your engine

cheers

[lilcrash]

im also in the process of building a highish power 3tgte, im using 87mm arias forgies from paradise racing. why is 87mm too big for your application?? i dont exactly know much about building engines but i cant see a reason why 87mm's wont work.

[YelloRolla]

87mm are good - in my experience.
lilcrash - are they flat tops, and are paradise OK with sending to aus?

[TheToyman75]

Robbo'sToyota's,

Dude I know your trying to help but wrong information is worse than no information.

Cooter,

There tends to be allot of confusion out there when people talk about Hybrid T series engines. In all reality they are pretty straight forward tho.

All you are building is a 3T-GTE with a 2TG head really The 3T-C and 3T-GTE pistons will have the same pin height as they use the same size crank. As such yes you could use 3T-C pistons but they will need valve reliefs cut into them and yes the compression wil be different to whats advertised due to the difference in combustion chamber size. It will most likely be to high for your application, unless they were designed for Turbo use.
Basically before you spend some resonable money make sure your getting what you need and if in doubt order them form someone who actually knows what you need.

As for piston bore, the 2T and 3T range all have an 85mm bore. I personally run a 2mm overbore and expect no problems. the most common for Turbo applications is an 86mm bore hence leaving as much meat as possible in the block for strength. You don't want any bigger than an 87mm bore in my opinion for a Turbo application. My current engine has 87mm bore flat tops from SPS. The next engine will have the 87mm Ceramic coated wiscos.

The 89mm bores mentioned are for N/A use only and even then not recommended. Not all blocks can take an 89mm bore without hitting the water jackets and most 89mm bore engine have been sleeved to acheive that extra half a mm.

HTH's

[cooter]

yes yellow rolla you r right and thanks for the info on the piston size. with those oversize valve reliefs that means they wouldnt need to be machined for my application at all yeah?

sorry i should have clarified things a lil better
setup
88261 2tg head, stock cams
3tgte crank, rods etc
some sort of forged piston @ what loooks like itll be 87mm.

so for those that are missing it my original question was...
when you use 7.7:1 comp pistons as advertised in a 3tgte itll stay 7.7:1 comp ratio. i want to know will i get a rise in comp from 7.7:1 to closer to 8.5:1 if i use said pistons with a 2tg head.

anyone got any thoughts on the studs portion of my original post?
thanks for your input ppl.
craig

[YelloRolla]

anyone got any thoughts on the studs portion of my original post?

I use head studs, Toyman uses head studs, Merc blue hopefully has head studs now.
I recommend them and I have some for sale.

PM me if you want further details.

Tell me the cc of the cylinder head and what gasket you intend to use (ie 1.0mm thick) and I will tell you what the comp will be. BTW 7.8:1 isn't too bad with the stock 3T GTE cams BUT I cannot comment on how it will be with the 261 cams.

jase

[sillycar chick]

cooter,
I highly recommend you take the time to carefully measure your head and do some calculations. This may help on some background information in case you arent already aware of it....
http://www.toymods.net/forums/showthread.php?t=2038
I have a 261 head on my hybrid, it measured in at ~63.3cc using a burette and some perspex. Its not too difficult, but does take some care and patience. I cant guarantee mine is completely accurate, but it sounds about right, and seemed to work in my calcs. HOWEVER I do suspect the head may have been shaved by the previous owner....

Having said that, if you work out everything properly, it will save you spending a lot of money on pistons that dont give you what you are after in the first place! Good luck with it... (and listen to YelloRolla and Rod they're pretty cluey about these engines )