3T GTE Tech

[steeko]

That "general opinion" from the Honda forums is qualified by what? Sticking your finger in your ass then pulling it out for a sniff? Sounds like a BS random comment to me.........

damn man, didn't mean to offend you

thread i was reading:

http://forums.beyond.ca/showthread/t-73008.html

[steeko]

i built a engine with the 8.5 pistons and drove it n/a and it ran awesome. i'm planning on running big boost and the 8.5 i'll have no trouble doing it. i have another mate running the same pistons on stock turbo and is pushing comfortably 150 to 160 rwkw on 14 psi boost. Definitely go the 8.5.

Are you changing any other engine parts such as rods, head bolts etc?

Yeah head has been done with the ARP head bolts and shaved posts.
We're also doing conrods, bearings, etc and getting the engine balanced.

[turbotoy]

read on some honda forums about this same question.

The general opinion seems to be you only gain around 5hp off boost by going to the high-comp pistons.

You have got to remember the engine they are talking about is twenty + years newer technology. Better quench, better cooling, Better rod to stroke ratio, newer engine. Some of them even have oil squirters to cool the bottom of the piston for better cooling allowing them to run compression and boost. It is true you can run higher compression for better off boost driving that is the nature of an engine but that will limit your total boost for pump gas. You are still limited by the maximum cylinder pressures the engine can handle before detonation whether boost or compression . I tried 8.5 pistons and ended up dropping my compression to 8.0 for more boost.
This old motor is just not as efficient as the newer Hondas you can't really compare them.

[steeko]

many thanks turbotoy, that is the information I need.

[TheToyman75]

You have got to remember the engine they are talking about is twenty + years newer technology. Better quench, better cooling, Better rod to stroke ratio, newer engine. Some of them even have oil squirters to cool the bottom of the piston for better cooling allowing them to run compression and boost. It is true you can run higher compression for better off boost driving that is the nature of an engine but that will limit your total boost for pump gas. You are still limited by the maximum cylinder pressures the engine can handle before detonation whether boost or compression . I tried 8.5 pistons and ended up dropping my compression to 8.0 for more boost.
This old motor is just not as efficient as the newer Hondas you can't really compare them.

Turbo Toy,

What was the boost limit and power level you were you finding at your 8.5:1 ratio ? And what management were you using. It might also pay to define pump fuel, Over here we get 98 Octane (98RON) pump fuel and a couple of Octane points makes a big difference.

The old low compression for boost theory is about as current as the technology for single cam push rod engines and since Steeko is not looking for "Big Power" I would have personally gone with the 8.5:1 items for better off boost performance.

My Turbo T series is around 8.2:1 and while it has never fired a shot there are a number of Engines in this configuration turning high boost levels with very nice results.

[turbotoy]

I use a walbro 255 hp with 550cc injectors, Management with the 8.5 pistons was a Haltech E6S. I made 267 HP at 1.2 bar boost with stock intake and exhaust manifolds, 2tg 222 cams. We use 93 octane here in the states. The reason I think the "old low compression for boost theory" is old is because of the advances in turbo intercooler and most of all engine efficiency. I wasn't necessarily telling him to go with the 8.0:1 pistons. Just telling him my experience. I honestly think he would be fine with the 8.5:1 pistons. That is what I started with. For a street car they will be great!! However I got used to the power and wanted more and turned up the boost till I "needed" 8.0:1 pistons

[steeko]

Am finding dealing with BRDracing.com very trying. I have to ask the same question three times, they just always reply with "pistons are $439 thanks".

Anyway quick question. Do the stock 3TGTE pistons have a curved top or flat top? As the Wiseco pistons are flat top, not sure if this is a problem as it seems quite a few people here have used the Wiseco forged pistons before.

Also apparently BRD only has the 7.8 : 1 pistons, anything else costs more and will be custom made. This is all contradictory to their website

[YelloRolla]

The stock 3T piston has a dome of 6cc (from memory). Josh recently delivered me a set of pistons and rods that I believe that he bought from BRD that are the Arias 8.5:1.

The Wiseco flat top pistons work pretty well in the scheme of things, the static CR is raised somewhat by having 2mm larger bore, but it still doesn't get it back to the 7.8:1.

The driveability (if there is such a word) is still pretty good off boost because the stock cam timing is sensible, coupled with a decent modern turbo and well thought out exhaust manifold, you wouldn't really know from the driver's seat.

[Diz44zy]

Arias I sent Jas came from Paradise Racing. They were bloody cheap awhile back when the Aussie dollar was ridiculously strong against the US dollar. I Wish I had of done what my dad did and imported a whole heap muscle form the US to sell back here in Aus and make a pretty dime.

[turbotoy]

I have set of Arias 87mm 8.5:1 pistons I am not going to use BNIB. If you can't find any there maybe we could work something out. Shipping is going to be a pain but I have shipped to NZ before with no problems and I have revived stuff from AU. Use me as a last resort.

[RiceburnaGTV]

Any more news on head gaskets guys? I am about to start putting my engine back together.

cheers
Nath

[3jcelica]

RiceburnaGTV,

I am using a cometic MLS 3t gasket and just modifing the timing cover a little. Reason being finding a MLS in 2tg/3tg was extremley difficult and ridiculusly expensive. Did I mention the cometic MLS cost me $70 Aus, picked it up when I was in the states.

Turbotoy, 276 on pump fuel (93 ron) is pretty good, equivalent to 205 rwKw, we can get pump fuel at 100ron (E10-E15). So for the street I think the 8.5 would be very good. In improved production the restricter limit power to around 225rwkw so again the 8.5 look ok with the right fuel and you could probably go higher compression with E85 fuel.

Roger

[steeko]

thanks for the info yellow-rolla and turbotoy. Am getting some more words out of BRD now so hopefully I can order in the coming days.

Will keep you in mind turbotoy if I don't buy from BRD.

And yeah interested in head gasket options too.

[steeko]

BRD have a cometic gasket but it doesn't explicitly say "MLS" tho:

Cometic Head Gasket
$69.99
Other Applications Available
We carry the complete line of Cometic Head Gaskets for the 2TC and 3TC. Custom Bores are Available!

[TheToyman75]

steeko,

before i bought my hks mls headgasket i ordered one from commetic in the usa. What arrived was a composite gasket so i emailed them telling them they had sent me the wrong thing only to be told they didn't make one. The product description on the site was wrong.

They might do one now that hks have stopped making them but be careful.