My 'mera GX 1.6
- Thread starter RAJackson
- Start date
Woooo GA powaz :lol:
so since the GA18 is dead in the water i have a spare engine.
so last week following a conversation with frank i took the intake cam out of said enging and stuck it in a box and sent it to birmingham where magic was performed
the result
Geoff at autosprint took my puny 222deg 7.5mm lift cam and made it into 8 lobes of 260deg 10mm lift fun. (JWT aint got shit on this)
magic innit
so last week following a conversation with frank i took the intake cam out of said enging and stuck it in a box and sent it to birmingham where magic was performed
the result
Geoff at autosprint took my puny 222deg 7.5mm lift cam and made it into 8 lobes of 260deg 10mm lift fun. (JWT aint got shit on this)
magic innit
i think the GA,s suffer the same problem as our CG,s, where the seat dia/throat of the exhaust side is so puny that you cant get any gains from more lift (ie, you could open the valve by a huge 2 inches but that little throat wont let any more fuel/air through)
so i think without bigger valves, exhaust cam gains are relatively small
(and a 2mm headskim to restore the compression lost by the extra inlet cam duration will pay more dividends
)frank
the cam base circle was taken down 2.5mm to allow a second OEM shim to be put under the bucket to keep the clearance in check.
i could get shims that take up the stock clearance AND the ground off clearance but they would be 5mm thick and have to be machined custom as nissan only do up to 3mm
both cams are a weakness on the GA.
i'll get the exhaust done in the not too distant future, but cash is short, you know the feeling
nice work mate... how much did the re-grounding on the cams cost???
i think the GA,s suffer the same problem as our CG,s, where the seat dia/throat of the exhaust side is so puny that you cant get any gains from more lift (ie, you could open the valve by a huge 2 inches but that little throat wont let any more fuel/air through)
so i think without bigger valves, exhaust cam gains are relatively small
(and a 2mm headskim to restore the compression lost by the extra inlet cam duration will pay more dividends
frank
thats what i meant.. the exhaust valves are shit.. so whilst its great to stuff more in getting it out is the problem. id put money if you had 2 GA16's one with standard inlet one with a cammed inlet but the standard inlet had bigger exhaust valves the exhaust one would win..
the CG intake cam mod you were on about looks a great place to start!
but N/A engines have to "draw in" air tho eh raceworks, so the inlet needs all the help it can get (hence the bigger inlet valves, relative to the exhaust ones)
whereas the exhaust gasses are physicly pushed out by the piston
the nissan 1348 CGA alpha (101hp) engine had a better inlet cam (236deg/8.32mm lift, but the exhaust cam was tamer (214deg/7mm lift) than a stock one (222deg/8mm lift) (and it had higher compression, and a tubular exh mani)
frank
cost me £130 including postage both ways for the intake cam.
not sure its possible to do it on an SR20 as it has rockers, GA is bucket and shim
Not a bad price eh
ya its a bonus that i have robs old engine cause the Valve Lash shims i need are £6 EACH from nissan and i need 8 per cam. so its saved me a bit of money.
just need a torque wrench thats getting delivered tommorow with cam switching VVL love. (failing that YD22 love)
