Thread: think tank - vqman's N/A Big Cam SR23DE Build 92x86

Exactly. When boring the motor you help the size and flow but pistons speeds and dwel stay the same.... so basically staying the same but more power.... basically.

so what about people getting N1 cams, that were designed for SR16, its interesting that they were designed with a different stroke in mind, but are still working great with 86mm stroke of an SR20..

SR16 stroke is what, 82mm? I can't remember, i've read it somewhere before.

there you go, vqman. the compression needed for the "lopey@idle" 184c's. with a screaming top end to boot. no block boring or head work required

i may have finally been convinced to go VE...

i had no idea that the higher
compression would result in lopey idle..

with 12.5:1 compression would i need stronger head studs?

i don't even know where to begin googling to look for an explanation on how the compression affects "lope"... with a small cam... (the cam obviously isnt the only thing that affects idle)

Ben PM'd me (not wanting to point out my failing to understand on here), i appreciate that Ben, or the thought at least...

The higher compression will not result in the lopey idle, the cam profile will.... I believe on a stock compression engine the idle will be even lopyier or not even be able to idle below probably 1500 rpms and stall sometimes even then but I have not tested it so sr20Gti-r should be able to answer that question better as I believe he has tested it. The higher compression should help the idle be more tolerable and driveable while making more hp rather than less than stock cams (or so I believe since I haven't gotten my hands on the 184c's yet). Correct me if I am wrong in my assumptions please. I am glad you have finally seen the light VQ, you will not regret it.

As far as the head studs, you shouldn't need them as 400whp boosted applications can hold up quite well on stock head bolts, so once again, more money saving and quicker build time equals more time to enjoy your vehicle. Are you going to go aftermarket pistons, n1's or sr16 to attain your desired compression ratio? Do you have E85 available? If you do I would run the sr16's unmodified. I have seen people run them on 93, which with the 184c's should be able to net you a lower dynamic compression ratio hence keep a good timing map with higher than 12.5:1 on 93 or e85. If you don't want to chance it, just run the n1's and tune tune tune.

I see that someone else pointed out my previous post but I'll leave it up anyway. I would probably if it were me, get 88mm 12.5:1 or 13:1 depending on fuel, have the stock sleeves bored and do that as it won't cost that much for the machine work. Again, completely unnecessary for your goals but the way I look at it, while its apart, why not? Ecconomics wise, a N1 or sr16 piston and a good 4 to 1 would be just fine and get you to where you want to be. I would ditch the budget header and invest in a 4 to1 regardless as it was not designed for bigger than N1 cams.

What can I expect about the static compression ration with SR16 pistons (non-N1) in my sr20 RR ?

12 to 1 compression.

Ben Fenner had me right.