GE to GTE block?

[zachm611]

hey everyone i have a 87 turbo thats running good now...but i have a spare GE block sitting in my garage, i bought it expecting it to be a GTE but it was a GE so im wondering what is the difference between the blocks and what all should i do to it? I want to build it up so whenever the stocker goes i have one to drop in and wont be as much down time. sorry everyone i am new to supras, any help is appreciated. thanks,

Zach

 

[CRE]

Well, where the block is concerned the GE doesn't have oil squirters (as far as I know adding them would require a fair amount of custom work), has no bung for the oil return from the turbo and has only one port for one knock sensor (where the GTE uses two both in different locations than the GE's).

The GE uses higher compression pistons, which will give you a benefit when coming off the line. In a high boost situation you'll either want to look into swapping in some lower compression pistons or adding meth/water injection. The higher compression pistons in itself isn't a bad thing at higher boost levels as long as the bottom end is in very good shape.

There are some other differences, but I believe most of them are just external bolt on affairs: Thermostat housing, oil cooler, cams, etc.

 

[supradavenz]

oil squirters arnt a must are they? the oil drain for the turbo.. well the area for it is there but needs to be drillled and tapped. also oil filter location is different on GE and GTE

 

[zachm611]

thanks for the replies... lol well there goes that idea.

 

[CRE]

The oil filter location isn't different, it's in the same place. The turbo has a thermostat and oil cooler outlet mounted between the filter and the block.

No, the oil squirters aren't required. IIRC, the Turbo A MKIIIs don't have them. I don't know about the other JDM 7M's.

 

[supradavenz]

yeah thats true it is just bolt on, on the oil filter thing that is.

tho my GE block still runs a oil cooler line without that bolt on..

and yes, jdm still have squirters hmm i may try make my GE block gte? lol

 

[Nick M]

Toyota did, why can't you?

 

[CRE]

yeah thats true it is just bolt on, on the oil filter thing that is.

tho my GE block still runs a oil cooler line without that bolt on..

and yes, jdm still have squirters hmm i may try make my GE block gte? lol

There was a long thread about the squirters on SF. Some GTE's didnt come with them, I *think* it was the Turbo A's.... unless the whole thing was a massive joke.



EDIT: I'd love to post a link, but SF's dead..... again. There were a couple regulars involved in the discussion, I just can't remember who.

What it came down to was that someone got a JDM GTE and tore it down for a full build. As best I can recall, it had the regular positions for two knock sensors, turbo oil return, and a couple other GTE only items. Just no squirters and nowhere they could have been installed and removed, I don't know how they are installed but I've heard that there would be alot of machining needed to add them to a GE and this was the same scenario. If SF ever comes back to life I'll try to find the thread.

 

[supradavenz]

yeah ive read about the oil squirter thing on one of the supra forums. but i can assure you jdm has squirters. i havent pulled apart my "jdm" ge yet tho who knows that may even have squirters *shrugs*

 

[IJ.]

Group A's were built on non squirter heavy casting NA Blocks.

There were some non squirter GTE's but I've only read about these and suspect they were NA's that had been drilled for the Oil Drains.

Never heard of a Squirter NA.

There is some very tricky machine work in converting an NA to squirts and even with my machine shop I'd think twice about attempting it.

Late model "Heavy Casting" top early model "Light Casting" lower

 

[Nick M]

Great pics IJ. Toyota did not release this or the crankshaft upgrade in the TSB's that I could find. One dealer I worked at kept a stash all the way back to the mid 80's.

A new model tech book might have had it, but I haven't seen one on older models, just new ones.

Thanks.

 

[starscream5000]

Wow, is that heavy casting block just for the Group A's, or did they also leave that design on there in the +89 supras?

 

[IJ.]

Nick: Yep my parts guys couldn't find a mention of the change over either!

From asking around it seems the change happened earlier on NA blocks with GTE blocks going heavy around the 89 change over!

SS5000: See above!
The heavy casting is on average +2mm everywhere and doesn't have the undercut on the deck to cylinder water jacket that the early blocks have so "should" be less prone to cracking!

They are a good starting point with the only negative being a LOT of core shift in the casting compared to the early blocks!

 

[themadhatter]

as long as you are running forged pistons the lack of oil squirters shopuldn't be a problem there only there to keep the cast pistons cool

 

[starscream5000]

I'd call it "added insurance" .

 

[zachm611]

yeah i was planning on doing forged pistons and rods, i was mainly just wondering what all should be done.