3S head question

**RAd28** · 24-03-2008, 10:38 PM

Hey all,

had a quick search and i couldn't find any useful information, so i'll ask here.

My younger bro is just rebuilding a 3S with all the goodies, but he had to replace his head since the old one was too soft in parts (over heated). however the head he's got is different to his original one... i'm not sure on the head number for his original engine but it was in a ST185R GT4 celica, the new head number is 11111-88381. one of the most obvious differences is with the cams, and valve train. another problem that's prooving to be a pita is the rocker cover. his original one was a boring looking single piece unit, and the new head appears to take a 2 piece setup...

anyone able to shed some light on the origins of his new head? what make/model was it from?

cheers

**Cuts** · 25-03-2008, 10:02 AM

Prehaps he has bought a gen3 (205 and late sw20 mr2) head, these run shim under bucket actuation as opposed to shim over bucket like the gen2 (185 head).

Although neither gen2 or gen3 run a 2 piece rocker cover, they do however run seperate gaskets to seal it.

pics would help us.

**Celica RA45** · 25-03-2008, 11:20 AM

he might have the early gen 1 cylinder head that came of the early gt4 and also na celicas ,beingST162/65

**Joshstix** · 25-03-2008, 11:57 AM

Sounds like he has a Gen1. The cams and buckets are smaller than the Gen2 and the cam covers are seperate rather than a single cover.

**RAd28** · 27-03-2008, 11:15 PM

he's done a bit more searching and apparently what he needs is a ST165 cam cover, which is apparently, 1 piece, but much lower in profile then the ST162 2 piece cover.

i'm almost 100% sure he's running shim under buckets just the same as his original (ST185) head... i haven't seen any shim over buckets at all...

anyone know where i might be able to track down a ST165 cover?

**Joshstix** · 28-03-2008, 10:32 AM

The Gen 3 is the first 3S to come from the factory with shim under buckets. The Gen 1 and Gen 2 are all shim over buckets.

**allencr** · 29-03-2008, 01:54 PM

Originally Posted by RAd28

had to replace his head since the old one was too soft in parts (over heated).

Hello, can you point me to a site that has anything at all about this 'soft head' stuff??
All I've been able to find is in the engine rebuilding/remanufacturing trade sites that mention baking them at too high a heat in their cleaning ovens(normal is at 450F/230C for many hours) might or will remove the temper aluminum has.
Thanks.

**twentyEight** · 29-03-2008, 06:16 PM

2 piece rocker cover points to a Gen 1 3S-GE in my opinion...

Gen 1, 2 and 3 3S-GTEs all have a 1 piece rocker cover...

Gen 1 3S-GTE Rocker Cover

Gen 2 3S-GTE Rocker Cover

Gen 3 3S-GTE Rocker Cover (will replace it with a better pic when I can be stuffed...)

**RAd28** · 31-03-2008, 08:14 AM

allencr - i don't have any information myself.. nor have i had any reason to look... the engine in question is m brothers, so the research is up to him...

twentyeight - according to road 'n' track up here in ipswich the early ST165 3SGTE came with a single piece cam cover like in your first pic (which is what we're looking for), but some also came with a 2 piece cam cover... i don't know for sure, but this might be mis-information because i agree the 162 3S came with a 2 piece setup.. so perhaps this is the "some" they were talking about...

either ways, we're now looking for a 1 piece ST165 Cam cover.

**Joshstix** · 31-03-2008, 10:30 AM

Are you putting a Gen1 head onto a gen2 motor setup?

I can't think of any situation where that would be a good plan.

**JustenGT8** · 31-03-2008, 10:49 AM

Gen I 3S = not real flash.

No go fast bits as mostly incompatible with later gen II and III. Exhaust manifold prone to warpage and leaking as too few studs. Inlet manifold is the crappest.

Sell it and start again...any more money from this point on is throwing good money after bad.

**madmont** · 31-03-2008, 10:55 AM

Originally Posted by allencr

Hello, can you point me to a site that has anything at all about this 'soft head' stuff??
All I've been able to find is in the engine rebuilding/remanufacturing trade sites that mention baking them at too high a heat in their cleaning ovens(normal is at 450F/230C for many hours) might or will remove the temper aluminum has.
Thanks.

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