4age Piston Ring comparrison - BP SP 20V

[blair]

Car - hachi

motor - 16v Bigport Head on 20v Silvertop Bottom.

use - dori

problem - Don't know what to order

occurs/started when - I found information that confused the shit out of me.

personal situation -
I've been sussing out Piston rings, and everyone i've spoken to says that SP and 20v are the same.
Yet, Road and Track who build pretty serious engines list 3 different types!

PISTON RING SET, 1.2 TOP, 1.5 CENTRE, 2.8 LOWER. 4AG 16VALVE 89-91
PISTON RING SET, 1.2 TOP, 1.5 CENTRE, 3.0 LOWER. MOST 4A 20V
PISTON RING SET, 1.5 TOP, 1.5 CENTRE, 2.8 LOWER. 4AG TO 1989

ACL only list the ones for 1989 onwards (SP im presuming) as the ones for SP AND 20v!
do people just get the 1.2,1.5,2.8 and wing it without the extra .2mm?

If not, does anyone know if ACL DO the 3.0's if this is even correct? and a P/N please?

Blair xo

[Sam-Q]

well I didn't know there where two types of lower ring, I need to look into that.

However the bigports had 1.5mm twin top rings. Everything later on had a 1.2mm top ring and a 1.5mm secondary.

[blair]

Yeh i realise that sam, and was under the impression from all the forums that all 4a's share the same 2.8mm lower oil ring.

However, when you find Solid information of listed parts/specs from a reputable engine builder it throws a fairly massive spanner in the works! lol.

Hmm, i shall find a 20v Manual?

[blair]

Another thing, does it even matter that much? haha!

[ke70dave]

yer id say it does matter.

you want everything to be sealed perfectly, especially since everything else will be brand new.

what does the engine builder suggest? ie what would he do if you didnt know anything about it?

i think i have a 20v manual at home, in pdf.

[blair]

True. Havent actually spoken to them, might ring them now actually...

had a look at the manual just before, only seems to mention ring gaps and tolerances etc not the thickness?

hmmf.

[Sam-Q]

lets skip the bullshit, I will measure a ring for you later out of a silvertop

[blair]

Yeh thats what i'm gonna do cause i have the old ones sitting at home aswel, will measure at about 5:30 when i get home tho, and i'm trying to order engine parts ASAP so wont be til monday at this stage

[Sam-Q]

haven't found my silvertop parts yet in the jungle but I measured a 7afe at 3.0mm how that's any good for you I don't know

[blair]

Conclusion to this thread:

4age 20v Silvertop Rings ARE 3.0mm (measured PERSONALLY)

So, anyone buying them through ACL according to their website, is getting the wrong rings.