4AGE Build - 4age Experts Please Comment!

[pro86]

Hello 4AGE experts!

I'm planning thr rebuild of my 3 rib, bigport 4age. It's currently in my ae86 and has been since I performed a swap conversion from another written off ae86 approximately 15 years ago, just before the craze hit! Now back then I was all up with it and in the Toyota game.. But not for the last 10yrs. For about the last 8-9yrs the car has been in storage then 18months ago I brought it out, cut the rust and re-panelled, full vehicle teardown and respray. Now it's all back together to a respectable level.

Now it's time for the engine........!!

So when I got the donor wreck, the glovebox was full of engine build receipts from Sydney. I don't have these anymore unfortunately.
The motor ran, and it was beautifully balanced, standstill revving between idle and redline would barely tip a glass of water!

It's had about 150,000km put on it since then and in dire need of a rebuild. Don't get me wrong, it still runs well, puts down a good powerband, slightly noisy tappets, not as well balanced, and uses more fuel than it used too.
I also did mild engine maintenance recently to get it to a good driving state.

Current Spec:
4age
Bigport + t-vis
3 rib
6 fly bolt crank
No colour cam covers
Pretty sure cams are std
Mr2 distributor
Fwd cut n shut to rwd plenum
Ecu needs identification - redline is about 7k
Awesome no-name 4-2-1 headers with long radius bends and long primary and secondaries, sounds amazing and looks professionally made but never seen an identical set anywhere!
Oil filter sandwich cooler
Near new every HD clutch
Near new ignition leads and iridium plugs
Near new timing belt (gates racing) and idler
VL triple core rad


Now, onto the rebuild plan.
I'm looking for an extremely reliable and medium performance oriented streetable build.

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What I need is your expert help with your experience, opinion & procurement advice for the following configuration I have in mind and where I can source parts locally in Australia, or buy from the internet only with adequate referral.
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Planned Spec:
1. Keep all parts as currently on the motor.
2. Refresh block, hone etc. Don't want to go oversize pistons but will if the block needs it.
3. New pistons to up compression - recommendations? Must suit 18mm pin unless I get new Conrods...??
4. New rings, gaskets, headgasket, bearings, etc - where to buy? What type? Part no's?
5. Lighter flywheel - brand, price etc
6. ARP stud kit? Where to buy? Price?
7. New oil pump/gears? Just in case. Where to buy? Price?
8. New water pump - Where to buy? Price?
9. Full rotating assembly balance. Who in Vic?
10. Reco head. Port n polish. Reface/lap valve seats etc.
11. New cams thinking around 264/264 in/ex or 272/264, max lift to suit std shims -Suggestions where to buy and prices?
Already have adjustable cam gears in a box somewhere.. Who can tune/dial these in in melb?
12. New valve springs - aftermarket? Where? Who?
13. ??? Anything I am missing.

I am of the opinion I would like to keep rotating mass to a minimum, i.e keep the bigport crank and Conrods etc.. I would like to see it rev really fast..

I am very mechanically inclined so I can do the assembly and weight matching of components myself etc. Have rebuilt euro motors before..
The only thing I would prefer to outsource is block and head machining, cam tuning and rotating mass balancing.

All of this is anticipation of a further upgrade down the track including itb's and aftermarket Ecu etc. But at the moment it would need to run on stock management.

The other thing I would like to know is standard head and block deck dimensions, I.e. If this motor has been rebuilt before I want to be able to check how much as been machined..

Please feel free to comment ≠)
Thanks in advance too!

[tottacrolla]

13. ??? Anything I am missing.
Bigport + t-vis
Fwd cut n shut to rwd plenum

Is this a FWD TVIS manifold, does it say 'TVIS' on it ?
Generally it is the smallport inlet that is modded to run RWD so are you sure you have a bigport engine ?

[pro86]

Yep its definitely bigport with tvis, and tvis badge on top of plenum, the shut is facing the firewall, the throttle body flanging is welded to the right side of the plenum looking into the intake, therefore towards the front of the engine bay in my ae86. I reckon it's either an early Mr2 or ae82 tvis bigport twincam? which ever would be the right configuration?

[Matt]

James from autosurplus can sort out the bits for you.

Piston wise aim for 12:1 or there abouts compression, but personally if you were happy with performance I'd check out the existing ones and re-use if they check out
Cams : Poncam
Rings: I use hastings
Bearings: ACL race if you can find them, otherwise King bearings is what i use
Headgasket: TRD ( Sq Engineering - Sam Q has them in stock usually)
Oil Pump: run genuine ( Sam q will also have stock)

Check your engine number doesn't begin with 7A as you may have a 7age motor if the flywheel has 6 bolts or the real early 4ages had them too but is worth checking anyway.

[pro86]

Thanks Matt.

The block is definitely 4A numbered and the crank is 6 bolt I remember checking when I changed the clutch.

To help with raising compression and for the sake of reliability I would prefer new pistons, but I'm a at a loss as to which ones would give me adequate comp increase, lighter and stronger than existing stock ones, and fit early rods?

It's funny when I think about the Fwd bigport plenum cut n shut mentioned by tottacorolla - all I can think of is this is a very early rwd conversion 4age, probably before there were many rwd plenums around / available in this country..

[Matt]

Arias and wiseco are two brands of piston that come to mind.

It'd be interesting to see exactly what you have there in terms of the block. Being a 6 bolt crank limits the flywheel choices available but whatever you do don't run an aluminium flywheel , have seen stress cranks in the fidanza ones after not all that many track kms.

[Matt]

The cut n shut comments stem from a while back where you could buy cut n shut manifolds for $60 exchange. Rwd manifolds still fetch > $200

[Jimmee1990]

Supertec make pistons off the shelf to suit 18mm pins, and would be the most affordable also.

If you were happy with the standard engine, my suggestion would be a standard rebuild to standard specs, just add a 0.8mm TRD head gasket and some mild 256 type cams. Keeps everything that's good about the standard setup and just makes it all just that bit better. After 150,000km you will definitely need to bore the block for over-size pistons though.

No point using race type bearings or ARP anything except maybe rod bolts if yours are stretched, totally unnecessary for a mild engine build. 6 bolt crank in a 4A-GE from factory is a myth, it will be a 4A-C or 4A-FC bottom end that's had 4A-GE pistons fitted to it.

[pro86]

Thanks for the input guys.

Matt - I'm not keen on an aluminium fly to begin with so I'm safe there. Not really even keen on aluminium front pulleys etc, I remember hearing things over the last few years about crank stress/failures possibly to do with aluminium pulleys - THIS IS AN IM NOT SURE STATEMENT SO DONT BURN ME IF THATS ALL BEEN RESOLVED LOL.

Jimmeee - I guess my crank origin is now in question. I'd certainly like more info to certify the myth? And how to tell 4ac VS 4age crank differences if any?
Also according to Billzillas Web, two quotes:
"The total variants of the 4AGE are, to the best of my knowledge -
- Very early big port TVIS 16 valve, with black lettering & 6-bolts holding the flywheel on."
&
"- I have also heard that there was a very early (1983) and now rare 4AGE TVIS FWD that had black lettering on the cam cover, but the main difference is that the crank only has six flywheel bolts verses all the other 4AGE's that have eight and so it looks like it has a 4A-C single-cam type crankshaft."

All so interesting......

[Jimmee1990]

I've had a look at a pre-production 3 rib bigport 4A-GE development engine, and it had an 8 bolt flywheel. As well the genuine parts catalogue listing nothing but an 8 bolt part number. That myth I suspect was created so some dodgy people could build a slapper motor out of left-overs, and Billzilla's site is full of wrong and mis-information and shouldn't be treated as a bible by any means.