Boring out an SR20

[angus]

I was wondering if anyone had any experience with boring out an SR20?I was looking to find out the maximum amount that an SR20det could be bored out to.some help would be appreciated.thanks.

[Def]

Search online for the SR20DET Factory Service Manual. Should have manuf. specs for EVERYTHING in the bottom end. You'll need this if you plan on working on the internals to make sure it is put toghether correctly.

[Repo Man]

I have not bored an SR myself, however I can tell you would certainly be more complicated then boring an RB or CA given that it is a sleeved, aluminum block. I would have to look up the cylinder wall thickness to see what degree it could be bored.

If it were me and I had a large budget and I insisted on larger displacement (which I probably wouldn't), I would build my SR with a stroker kit. I think JUN makes such a kit. My personal opinion is that boring an SR block would be more trouble and expense than it's worth, but I'm no SR guru (not yet anyway).

What power level are you seeking? I'll move this into the SR section to further stimulate the thread. That was a Fredism.

[Dori Dori]

Be warned there is a nicasil coating on the cylinder walls.

[angus]

I wanted to avoid stroking the engine so that I wouldn't kill the rod/stroke ratio.This engine has to be reved to 9000rpms.

[I H8 UR DSM]

bye bye to hydrolic lifters...

[Repo Man]

I wanted to avoid stroking the engine so that I wouldn't kill the rod/stroke ratio.This engine has to be reved to 9000rpms.

I see. Why do you need to rev to 9k? And again, what power level are you looking for? If you're just needing to rev to the moon, have you considered a CA? Or do you already have the SR? More details man...

[Nathan]

CA's rev really well...but not as well as everyone thinks. The reason is that there is quite a difference in the displayed (via factory tach) rpms and the ACTUAL rpms. THe rev limit is actually factory set at something around 7500 if I remember correctly. However, on the tach you see it hitting in the 8000's. Not that it isnt a great revving motor because it is...certainly has a better valvetrain for high revving and with some upgraded valve springs, retainers, cams, balanced bottom end etc. I would not hesitate to rev to 9000. But an SR is NOT going to do it reliably without some additional valvetrain modification.

[Dori Dori]

I wanted to avoid stroking the engine so that I wouldn't kill the rod/stroke ratio.This engine has to be reved to 9000rpms.

Then the head should be your first attack point. The SR has rocker arms and hydraulic lifters. First off, as Jesse said, you're gonna have to kiss those lifters good-bye and get solid tappets (tomei, jun, hks, ect). That also entails getting cams specifically for those lifters. The rest of the head should be upgraded as well (valves, springs, retainers, ect). Some custom rockers...titanium maybe?...are definately in store for you too.

Good luck.

[I H8 UR DSM]

call MTS tuning, they have a roller kit available....$3000+. But yea, headwork, headwork and more headwork