Bore/Stroke...

[sinfestboy]

ok, 2 questions:

1)Is JUN's stroker kit good? are the pistons and connecting rods REALLY heavy duty?

2) I haven't seen the inside of an SR20det... is it safe to bore it out? and if so, how much?

I have this idea cooking up for a superSR20det... totally bombproof... nukeproof... MWAHAHAHAH!

probably not gonna happen though *shrugs*

[sinfestboy]

come on, somebody has to know!

[Cheater240SX]

Get used to it... no good info here...  Just people saying "my cars too slow" or "there's a funny sound coming from somewhere"

PLEASE!

[Jeff240sx]

LOL.
Dont wanna flame ppl here, but you seem to be asking for it.  First, you made a totally odd, off topic, and not narrow post, asking stupid questions about things you'll never do.
That said...
JUN's stroker kit for the sr20det are not good from what I hear.  The stroker kit will "unsquare" the Bore:stroke ratio.  This will not allow the revs to go as high, and make more torque than horsepower.
Also, you are taking a pretty strong, aluminum alloy block, and trying to bore it.  Pretty strong I say. but built that way for a reason.  At moderatly high boost, around 1 bar, the walls of the SR20 flex.  And they are thick enough to flex and not crack.
Then you bore it out, and Presto!, $3000 paperweight.
Finally, look at the pics of the top of a Nissan 2.4L and 2.0L engine.  The piston walls are so narrow, you wouldn't want to.
-Jeff

[rampid360]

If you want to bore things out...buy american.  Go get youself a nice Camero or Rustang and have at.   Japanese cars are built to Japanese specs, and tend to like running the way they were built.   American iron is pretty simple to work with...yet noone can get their 600hp Camaro to start in the morning for some odd reason.   Try it with your Sr20 and see what happens though.

[LanceS13]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from Cheater240SX on 9:53 pm on Jan. 28, 2002
Get used to it... no good info here... Just people saying &quot;my cars too slow&quot; or &quot;there's a funny sound coming from somewhere&quot;

PLEASE!
</td></tr></table><span id='postcolor'>
You're being pretty derogatory to have only been a &nbsp;member for 4 days. &nbsp;That's not a good way to build a reputation. &nbsp;

[WhiteS13]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from Jeff240sx on 4:16 pm on Jan. 28, 2002

Also, you are taking a pretty strong, aluminum alloy block, and trying to bore it. Pretty strong I say. but built that way for a reason. At moderatly high boost, around 1 bar, the walls of the SR20 flex. And they are thick enough to flex and not crack.
Then you bore it out, and Presto!, $3000 paperweight.
Finally, look at the pics of the top of a Nissan 2.4L and 2.0L engine. The piston walls are so narrow, you wouldn't want to.
-Jeff
</td></tr></table><span id='postcolor'>

What are the cylinder liners made of? &nbsp;Are they open face, or close faced?

[Jeff240sx]

WhiteS13,
I am pretty sure that when people do bore out the sr20det piston walls, they put an iron sleeve into it so that they can turn up the boost without overflexing the walls. &nbsp;I am also pretty sure that the cylender liners stock are aluminum alloy.
-Jeff

[oberkill]

SR's have iron sleeves stock from the factory and they dont start to twist until ~450-500 HP. I wouldnt run over 400hp personally but I have already been through one engine. The JUN stroker kit is the best on the market and you pay for that. There are years of engineering and testing plus its been in use in Japan for years. I would think if you are going to spend the money on the stroker kit plus the connecting rods you may as well get the liner kit as well. You will still need to have it align bored plus the money to get the old sleeves taken out and the new ones installed. JUN connecting rods and pistons are pretty bullit proof. I would take more technical questions to www.freshalloy.com as there can be alot of &quot;incorrect&quot; info put out here. Not saying that all the info is bad because that is far from true but for more technical info this is not your best resource.

Alan

['91 D21 beater]

sheesh, I seriously can't believe the number of crap info that gets passed on this forum... Some of you guys should be ashamed of yourselves.

SR20 is a close deck aluminum sand cast block with iron/nikelsil (sp?) cylinder liners. It's okay to take .5 to 1.0 mm out of it, but any more, it's time for resleeving.

The magic number as tossed around by Japanese tuners is 450hp, but there are a good # of SR (SE-R) folks that pushes much more than that on the factory sleeve.

As for the Jun kit, hey, it's good enough for their 8 second S14 Silvia. Need I say more?

[AJ]

he got deleted! lol... <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/sad.gif" border="0" valign="absmiddle" alt=':('> he knew stuff too..

[sinfestboy]

jeff240sx-- Actually, I (now) plan on openeing (or having a good shop do it) my sr20det before I swap it. Bored, stroked, sleeved, high strength valvetrain, the whole works. It should be about square and revving to 9k+. ofcourse, I'm gonna have to save up forever, and If I do it myself, I'm gonna have to wait till cousin comes into town (ASE certified Master blablabla) who has opened up and worked on many *nice imports, a couple **decent nissans in there.

*= 650 hp supra
** 500 hp maxima, 11 sec. 300ZX.

AJ-- who got deleted?

The jun kit is looking good <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

Fresh Alloy = my new heaven

Sorry if this question sounds dumb, but hey I've seen it posted and I'd like clarification. What do you mean by bore:stroke Ratio. How is it squared? I'm just trying to figure out, lets say for instance I have any given bore and stroke, how would I find out if it's square or not. Personally I haven't installed or used the JUN 2.2 kit, but I don't think they'd produce stuff unless it was good, they wouldn't get as well known as they are if they produced stuff that was just &quot;alright&quot;. Nothing wrong with more torque than HP either. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

[wherezmytofu]

bore &gt; stroke = high reving
bore &lt; stroke = mid range monster

stroking adds to the size of each cylinder by making them longer...in sum sense. this also adds stress to the engine becuase it actually adds compression when the piston is pushed higher in the combustion camber.

boreing adds to the size of each clyinder by giving them a greater radius. the only problem to it is that is thins out the cylinder wall, but a good sleeve will protect from problems.

boring + stroking = death, thinner walls from boring and extra pressure from strokeing makes this combo very very bad.!!!!!!!! just pick one