>>Hey 6GC friends,

It's been a minute since I have been on here. Happy new year to all of you.

Regarding the pistons for the 3SGTE All-trac motor: is 8.5:1 the stock compression?
The JE Pistons/Rods combo I find on ebay has a compression ration of 9.0:1

See link below:

http://cgi.ebay.com/ebaymotors/JE-Pistons-...2#ht_2627wt_860

p.s. Does anyone know where I can obtain the stock specs on both the rods and pistons for the 3SGTE?

Thanks in advance!>>

Manufacturer: Toyota
Model: ST185
Year: 1990-93
L/CID/VIN: 2.0/122/3SGTE
# of cylinders: 4
Bore & Stroke: 3.3858-3.3870" (85.999-86.03MM) x 3.386" (86.004MM)
Compression Ratio: 8.8:1 (gen 1 and 3, 8.5:1)
Firing Order: 1-3-4-2

Cylinder Head
Thickness: 4.6950-4.6990" (119.253-119.355 MM)
Maximum Warpage: .008" Overall (.203 MM)
OHC Bore Data: 1.0614-1.0620" (26.96-26.975 MM)
Valve Info
Installed Stem Height (Intake): 1.4600-1.4850"
Installed Stem Height (Exhaust): 1.4700-1.4950"
Stem Diameter (Intake): .2346-.2352" (5.959-5.974 MM)
Stem Diameter (Exhaust): .2344-.2350" (5.954-5.969 MM)
Total Length (Inatke): 4.12600-4.1535" (104.8-105.499 MM)
Total Length (Exhaust): 3.8917-3.9193" (98.849-99.55 MM)
Angle (Intake & Exhaust): 44.5 degrees
Margin (Intake & Exhaust): .020" Min. (.508 MM)
Valve Guide Info
Guide Height (Intake & Exhaust): .323-.339" (8.204-8.611 MM)
Guide Clearance (Intake): .0010-.0023" (.025-.058 MM)
Guide Clearance (Exhaust): .0012-.0025" (.03-.064 MM)
Spring Info
Free Length (Intake & Exhaust): 1.749" (44.425 MM)
Installed Height (Intake & Exhaust): 1.354" (34.392 MM)
Closed Test Press (Intake & Exhaust): 45-53# @ 1.354"
Valve Seat Info
Seat Width (Intake & Exhaust): .039-.055" (.991-1.397 MM)
Seat Angle (Intake & Exhaust): 45 degrees
Valve Lash Info
Intake Valve Lash: .006-.010" Cold
Exhaust Valve Lash: .008-.012" Cold

Cylinder Head Torque Spec. 36 FT/LBS, + 90 degrees

Block Info
Cylinder Bore Diameter: 3.3858-3.3870" (85.999-86.03 MM)

Piston & Pin Info
Skirt Oil Clearance: .0028-.0035" (.071-.089 MM)
Pin Diameter: .8660-.8665" (21.996-22.009 MM)
Pin Type: Float
Ring Gap: Top .013-.022" 2nd .018-.026", Oil .008-.024"

Housing Bore Info
Torque: 43 FT/LBS

Crankshaft Info
Stroke: 3.386" (86.004 MM)
Cylinder Bore: 3.3858-3.3870" (85.999-86.03 MM)
Rod Journal
Journal Diameter: 1.8892-1.8898" (47.986-48.001 MM)
Oil Clearance:.0009-.0022" (.023-.056 MM)
Main Journal:
Position 1: 2.1648-2.1654" (54.986-55.001 MM)
Oil Clearance: .0005-.0024" (54.986-55.001 MM)
Crankshaft End Play:.0008-.0087" (.02-.221 MM)

Connecting Rods Info
Big End Housing Bore: 2.0079-2.0087" (51.001-51.021 MM)
Big End Side Clearance: .0063-.0123" (.16-.312 MM) Big End Width 1.055"
Torque: 18 FT/LBS, + 90 degrees
Small End Finished ID: .8663-.8668" (22.004-22.017 MM)
Center to Center Distance: 5.4280" (22.004-22.017 MM)
Twist/Bend: .002/.006 @ 3.94

Camshaft Info
Cam End Play: .005-.009" (.127-.229 MM)
Cam Journal Specs: 1.0614-1.0620" (26.96-26.975 MM)
Cam Journal Oil Clearance: .0010-.0024" (.025-.061 MM)

This post has been edited by Mstoochn: Dec 30, 2009 - 12:32 AM

In regards of the piston manufacturers compression ratio spec is off of different head gaskets.

for example, CP list their pistons at 8.5:1 where as JE lists them at 9.0:1.

But in reality its what head gasket you use at the end. The manufacturer is listing their compression ratio off of the head gasket they are using for measurement.

that # is still modified based on what headgasket you use, for instance HKS offeres a 3s 8.8 and 8.5 gasket, where as you can also use the 5s 9.0 or 9.5 gasket.

but prefabricated pistons for the 3s-gte from CP, Eagle, Pauter or other manufacters for the sake of clarity are going to measure based off of a stock headgasket.
custom pistons will be a different story depending what specs are go by

This post has been edited by Mstoochn: Dec 30, 2009 - 3:28 AM

Would I be better off going with an 8.5:1 or 9.1:1 since I can't find the factory spec of 8.8:1?

Meant 8.5:1 or 9.0:1 (sorry).

>

according to http://www.celica-gt4.com/tech-data
st205 (gen3 3sgte): 8.5:1
st185 (gen2 3sgte): 8.8:1

>


Compression Ratio: 8.8:1 (gen 1 and 3, 8.5:1)

... 8.5, see my PM nemesis