Craigs New Datsun Sunny
- Thread starter craiGTi
- Start date
yeah
yeah pretty much, but its smoky on cold starts but also a bit at high revs, then again 150ml of oil ain't a lot for 500miles. also wouldn't mind knowing the exact c/r and bring it down a touch.
i can't win lol, if i take it all apart some think i'm stupid and hastey, if i don't some think i'm a clueless cowboy :lol:
have an idle issue that needs sorting, i adjusted my tps from 0.3v to 0.45v today as it should be, but myidles now at like 2k :wacko:timing obv needs doin but maybe i have an intake leak (although i've looked twice for one and can't see it) or maybe my tps or iacv is dodgy, but joe's sending me new ones to try, cheers joe
i can't win lol, if i take it all apart some think i'm stupid and hastey, if i don't some think i'm a clueless cowboy :lol:
have an idle issue that needs sorting, i adjusted my tps from 0.3v to 0.45v today as it should be, but myidles now at like 2k :wacko:timing obv needs doin but maybe i have an intake leak (although i've looked twice for one and can't see it) or maybe my tps or iacv is dodgy, but joe's sending me new ones to try, cheers joe
why if its built so badly and such a cowboy mess? it burns a bit of oil and the idle/comp thing might not be right
I never said it was
If the P2W clearance is correct then i cant see how they can have more or less blowby than any other piston
its a fact mate, dont know about "jury" ... forged aluminium pistons have a higher coefficient of thermal expansion
Steve
because forged pistons, while being stronger, are more susceptible to thermal expansion. the p2w clearances are bigger than std pistons. i'm' not convinced its why but there's a lot of ppl on the web sayin this is one of the cons of forged.
well yeh, thats a fact lol, but there seems to be some mixed stuff about the link to oil use/smoke when cold. makes sense though
Personally to get it right i would be stripping it apart and putting a new set of rings in and the cylinders honed again - just sticks in the mind of you said you have a rough feeling cylinder. Personally i wouldnt even start putting the engine back together unless everything is perfect. My mate built an old capri pinto engine, and one of the cylinders was rough, he thought it would wear in, It lasted 3000 miles and it ate his rings and wrecked the barrel. you want minimum friction in there, some people might think its ok, but do you think when nissan built these engines and if one of them was all rough they said fuck it? sent it out?? dont think so. you engine is to produce more power than a stock SR20, so think about it.
The Shells should be fine but just make sure you know which came off which,
As for the compression ratio, I wouldnt be going any higher than 12:1 to be honest, but its everyones preference and if you can get the fuelling right then perfect...
I can't comment on forged pistons, personally i dont see the point unless your going mega power, i hear the bottom end of a DE stock is good for 400bhp (wether there is any truth i dont know) so i feel any uprated pistons is pointless, I aint made my decision to use N1 pistons or SR16VE, on these facts its the reason i aint even bothered to research non-nissan pistons,
Like you said Craig, if you dont mind putting in the hours to get it right then its the best way, no point bodging a job, with silly little changes just becuase people want to see it ragged. take your time, make sure you check, double check, and triple check everything, Do the running in again, and back on the dyno.
The Shells should be fine but just make sure you know which came off which,
As for the compression ratio, I wouldnt be going any higher than 12:1 to be honest, but its everyones preference and if you can get the fuelling right then perfect...
I can't comment on forged pistons, personally i dont see the point unless your going mega power, i hear the bottom end of a DE stock is good for 400bhp (wether there is any truth i dont know) so i feel any uprated pistons is pointless, I aint made my decision to use N1 pistons or SR16VE, on these facts its the reason i aint even bothered to research non-nissan pistons,
Like you said Craig, if you dont mind putting in the hours to get it right then its the best way, no point bodging a job, with silly little changes just becuase people want to see it ragged. take your time, make sure you check, double check, and triple check everything, Do the running in again, and back on the dyno.
a forged internal engine will smoke when cold. probably even when a normal operating temp!
it will also sound rattly/clunky/terrible until it warms up.
just the traits. i told you before craig about the fully forget starlet i was following and getting painted by his blue smoke.
shit happens. just top it up regularly and enjoy the power at the cost of a little oil.
it will also sound rattly/clunky/terrible until it warms up.
just the traits. i told you before craig about the fully forget starlet i was following and getting painted by his blue smoke.
shit happens. just top it up regularly and enjoy the power at the cost of a little oil.
How does she feel though? Is there any loss on power.. what did it dyno at btw on initial mapping
Are you going to Jez next monday mate?
you seem like quite the expert
the cylinder wall wasn't rough, 1 of them had a mark/depression about 5mm long which you could only just feel with your fingernail, and i mean only just. with your fingertip it was as smooth asthe rest of the bore. It wasn't rough or raised up in any way and wouldn't be wearing the ring, it looks like it was done on initial startup by a slightly rough ring end.
I've also come to the conclusion that after 500 miles of 80mph odd motorway driving, and twisty,steep mountain roads under heavy load, to only use 150ml of oil and no smoke when driving warm it can't be the rings. I'm guessing it's either valve seals not quite swapped correctly, or a dodgy one, or just the forged pistons, expansion thing ross is confirming.
I'm not fussed about the 12.5:1 or higher, i have my secret weapon for that
as for forged pistons, i'm glad with the det i suffered in run in, i had stronger forged ones to put up with it, i wouldn't like to see the state of cast ones after detting its tits off like it did lol
cheers babez,wondered if anyone would actually mention the pics apart from liam pm'ing me lol. corwin was the one saying the thread was boring lol.
and yeh she forgave me
although the sore bumhole jokes didn't stop for a while :lol: