Group A specifications

[oldeskewltoy]

Often times when researching performance engines we here of Group A, or N2. These specifications, at least Group A, are based on the specifications allowed by the F.I.A. in the AE86 homologation paperwork. The AE86 homologation papers for the AE86 are; A-5179 (for the coupe), and A-5180(for the hatchback)


from the A-5180 papers.... 3 door/hatchback - here are most of the specifications listed....

1599cc max
minimum rod mass - 431 grams - length 122mm - big end diameter 43mm (so no 42mm cranks!)
minimum crank mass - 11540 grams
flywheel cast iron minimum mass - 7060 grams
55mm T/B
injectors in head (not in intake)
maximum valve lift - 7.2mm - clearances .2mm, and .25mm
number of intake manifold elements - 2 (TVIS plate and intake??)
exhaust cast iron
max intake valve diameter 30.7mm, 6mm stem
max exhaust valve diameter 25.7mm, 6mm stem
wet sump oil system

As I read it... that leaves a LOT of room for special machining, and head porting. It also has cam lift listed... but not durations.... no mention of compression ratios either.... no mention of adjustable cam pulleys either....

so if you are looking to build a Group A engine.... you begin with the proper specification

[turboae92]

This is very interesting.Oldeskewtoy do you have 4age bible??

[oldeskewltoy]

This is very interesting.Oldeskewtoy do you have 4age bible??

yes I do... the TRD pistons listed in the Bible were the basis for my piston design

[turboae92]

Can you share some of specifications on the parts that made n2 race cars, engine parts like camshaft lift, duration, compression, camshaft size, rotating assembly weight.

[oldeskewltoy]

Can you share some of specifications on the parts that made n2 race cars, engine parts like camshaft lift, duration, compression, camshaft size, rotating assembly weight.

many... think of a milder 9500rpm Formula Atlantic engine... O/S valve, 11.5 to 1 cr, 270 to 300+ duration - 10mm lift cams

[turboae92]

Thanks, about how much power they were making at the time??

[oldeskewltoy]

Thanks, about how much power they were making at the time??

205-210 hp @ about 9000-9500.

[turboae92]

Those are good numbers.Thanks buddy..