4AGE rally engine specs - thinking out of the square

[V-Na]

But Bermy's thread "Long rod 4A or how to destroke a 7A" got me wondering if there is other option outside of the square.
Thoughts?

Outside the square you say, what about over(the)square?

67 mm stroke + long rods = 1381 cc high revving 4A which satisfies the rules for Class P1 (1400 cc)?

[rallysprinter]

... 1381 cc high revving 4A which satisfies the rules for Class P1 (1400 cc)?

Ummm. It's bad enough trying to drag 1050kg around with the torque from only 1600cc. I think I'd pass on having less torque, but I like the left field idea though.

[oldeskewltoy]

CAMS, the governing body has just released a bulletin, today, in relation to the regs for PRC, that I currently compete under, that allows the substitution of a 20v 4AGE for any car that had a 16v 4AGE.

http://docs.cams.com.au/Regulations/...PRC%202014.pdf

So, this is now a further option, and attractive in that I could remain in class P2, under 1600cc and probably have better performance than yhe big lift 16v.

Any estimates in the cost of getting a blacktop 20v into an Ae86, assuming it doesn't need a rebuild? I would keep the haltech ecu and loom and sell off my 16v parts I've accumulated.

You don't need big lift to make power in a 16V 4AGE...... I'm making 145whp (165-170 @ the crank - same as a blacktop) with a mostly stock* smallport 16V - all internals except wrist pins, cams, and valve springs are stock Toyota parts... the head is ported. Oh... although the cams are aftermarket, the cams and compression of my engine are not more extreme then what came in the blacktop from Toyota

And here is a VERY in-depth largeport build that plants over 140 whp on STOCK AW11 management (stock ECU) with a few tuning aids - http://www.mr2oc.com/showthread.php?t=468649



Ok, now to your question... you CAN'T assume the blacktop will not need a rebuild! There is something about the oil flow, or temp in a blacktop head that leads to sludge development... I've seen far more sludged blacktop heads then all other 4AG heads combined! If you shop well, and have a bit of luck you may find one that doesn't need anything.

Ok, lets assume you found one that isn't in need of a rebuild - besides the engine, you will need some way to convert the cooling system to rwd application. This can cost as little as nothing if you have a machine shop @ your disposal... OR could cost over $1000. Besides the cooling system you will need to convert the distributor to either run @ the front instead of the back... OR using an OBD based 4AF oil pump housing...




convert the ignition to something like a wasted spark system.


I can't help you with your specific costs because I'm in 'merica (America) so the buy-in for the blacktop is likely much different. Typically a blacktop sells for about $1000-$1500 in the USA.

Not sure if this helps.... best of luck

[rallysprinter]

Thanks for the detailed information Dan, ill read that thread too.

After researching 20v vs modified 16v over the last 2 days, I'm leaning towards continuing my 16v build and remaining in the P2 class. The cams are the only major decision to make on that front. I'm looking for an increase in the mid range, but maintaining the usable rev range, so my thought and supported by a few desktop dyno calcs suggested dropping back the duration but increasing the lift would provide the required result.