Guys,as per topic..i wonder what is the maximum RPMs for Nissan A Series standard/stock engines? What is the Max RPMs with free gear and with gear engaged?
(i've looking around but couldn't find any info in the net )


A12 = ? rpm

A14 = ? rpm

A15 = ? rpm


Many Thanks.

for stock engines, about 6400 rpm.

for A12 GX stock engine, about 6700 rpm.

If you fit aftermarket valve springs they will all rev to 8500 rpm. The A15 can rev as high as the A12.

thanks ddgonzal for the infos.

my rebuild a14 only can rev up to 6800rpm (gear on),

actually i'm expecting at least 7500rpm when this engine is fitted with double valve spring,twin Mikuni 40PHH and fully balanced internal parts.



What am i suppose to do? and where should i start to check the failure (if there any) that stoping it from revving more that it should?

or is it normal regarding of the engine's performance?

Thanks.

if its working fine up antil then maybe the fule pump cant keep up?

ROConnor,i'm not sure about that..the engine is fitted with the standard a14 ac fuel pump..is there any possibilities that the fuel pump cant keep up?should i change to electronic fuel pump?

but i've read that a14 ac pump (2.8 - 3.8psi) will working fine with this carbies and even for a hot street A14..

Thanks.

I had the same problem with mine when we would race in Japan. Would only Rev out to 6500-6800. I upsized to twin 44's and it solved the problem. Not getting enough air flow. Maybe if you just change the choke size, but not really sure.

silvia-specr,this is what under my twin Mikuni 40PHH right now:-

Main Air Jet #210
Main Jet #120
Idle Jet #57
Pump jet #40
Choke #32

Is the combination is not matched with the engine's need?

Get a pressure gauge onto it at max revs under load... if it drops at these revs then you need a pump that will flow more fuel. If not it could be multipule things like cam timing ignition timing etc.

how to be sure that the cam timing is in the perfect order?any other symptom to detect this?



thanks.

all engines differ, when i ran the 44's it was
main air 210
main fuel 150
idle 57.5
pump 45
choke ? i don't remember
this is how it ran good in the USA
In Japan it was this
main air 200
main fuel 130
idle 52.5
pump 40
choke ? still don't remember
same motor, just relocated to a different part of the world. I have heard of people removing the chokes complely but I still don't know???? Trial and error!!! with no fatalities....