So i have spent the last few Weeks scouring this forum, the archives and Google. But im still lost on what version 4AG i have.

I pulled it from my 87 GTS, it is a largeport with T-VIS, the piston have 20mm pins and the crank is 42mm....now from everything ive read, I don't think this engine ever came in a AE86, but if im honest I don't know what is what now i so confused.

I ordered a full engine rebild kit for an 87/GTS and I got Pistons with 18mm pins i go well damn, must have been a goof. I send them back, i receive new ones, same thing.

is it possible that my old 87GTS my have had the engine from a 88GTS? I believe the 87's door sticker said it was Manufactured 10/1987. could have toyota just started throwing next years engine in the last few AE86's to roll off the line?

I just want to know what piston to order,and next to none of the listings tell you wrist pin size. Other then the high dollar beast mode stuff and I'm just doing a stock rebuild so I don't want/need $500 pistons.

thank you in advance
Sean

The main variations of 16v are gen1 largeport 3 rib with 18/40 internals. Gen2 Largeport 7 rib 20/42 internals and smallport.
I am much more familiar with the AW11 history but I have heard that later AE86 did or at least may have gotten 7 rib motors. Even if they didn't it's plenty possible over the last 25-30 years someone put a different motor in it.
I should also note that model year is different than year of manufacture. A car made in 10/87 would be considered an 88 by model year.
Whatever the case for your concern with pistons the wristpin is really all that matters. If you have a 20mm wristpin then get gen2 pistons.
I can get you DNJ smallport pistons which would get you s nice bump in compression.

Some '87 model year came with a 7-rib, 42/20 bottom with a largeport head and tvis.
A good upgrade for this would be a set of High comp, small port pistons. Still available at dealer.
I would advise getting OEM o/s pistons, gaskets, bearings. I only buy OEM parts from Cabe toyota, longbeach. Good prices, fast shipping, plus Herb is a good dude.

Thank you, I'll check out cabe Toyota.

My engine defiantly has a 7-rib block, I bought the 87gts for stuff like that and better rear axles, lol even thou I prefer the 85 rear tail lights.

Can Herb be found through the forum?

Are the pistons press fit? or free floating with c clips?

My engine is out of an 87 mr2 and it's a bigport 7 rib block with 18/40

I know the 2nd gen bigport has the 7 rib block but i'm still confused on if they have high comp internals or not.

M.fate wrote:Can Herb be found through the forum?

He used to have a post in Classifieds section in the dealers part.

http://yhst-99618682857744.stores.yahoo.net/

demby123 wrote:I know the 2nd gen bigport has the 7 rib block but i'm still confused on if they have high comp internals or not.

No, they're still 9.4:1, but with the 20/42 piston/rod/crank setup. From everything I've read, that crank is the same from when it first appeared (1st gen 4A-GZE and AE92) until the end of the 4A-GE 20v.