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Alright, been waiting to ask this question. First of all I have been searching not only this site but a general google search and can't seem to find the answers, so here it is: I have a 3 part question, and I'm sure someone's ***** wanna dog out the new guy to the forum, so have at it. Basically My background is a Chevy SB builder, that tried out the Honda thing. I have been sadly dissapointed with the honda blocks, and ran across a "square motor" (the sr20det) with equal bore & stroke. Which is to me a gold mine, and the main reason I'm interested in a 240sx. However;
1) What is the stock limits of the DET, basically if the stock turbo was infinately able, what part of the lower end (given ARP head bolts and a HKS or Cometic head gasket) would go first?
2) If that same block was fully built, (as in top of the line rods, pistons, total seal ductile iron rings, bal & blup'ed, crank micro-polished the works), at what point would the stock cyliders blow out (supposing serious boost)? Also I would have the static compression to 9:1. I know most honda's give out at 15 lbs and that's even running proper A/F and timing to limit any detonation.
3) Wondering what brands you folks see as the top of the top for rods, pistons, sleeves, valves (& beehive springs?) w/titanium works.. Also is there a spacific aftermarket crank that's worth the money, or do you recomend to just flycut & knife edge (w/micro-polish) the stock one??
Alright, well, that's it for now, and I know it's a novice question for you nissan folks, but I sincerely appreciate any answers & suggestins. This site seems to have some compitent folks, that's why I came here! Thanks again, and look foreward to see what you have to say. Best wishes all.
1-The Nissan hypereutectic cast pistons usually fail first on the ring lands. The rods and crank can support >480 crank hp just fine up to ~8,000rpm.
2- I have heard the DET tends to fail the sleeves at about >480crank hp if consistently asked to do so.
3- Rods (Cunningham of Pauter). I have had bad experiences with sustained high rpm using Crower (big end splay by 0.0001" on the cap). Pisotns (JE, full stop). Sleves (dunno). Valves (Ferriera or however you spell it) (Get a high port head with larger sodium filled exhaust valves - more info in tech sections). Crank (Crower or Farandon in the UK).
Farandon is about GBP 1400 and look and work like heaven. They build for a big sector of the UK series'.
You would be hard pressed to break a Nissan Forged Steel, full counterweight SR20 DE, or DET crank. If you spin one up and find it more than 1g out of ballance, I'd call you a liar.
Main Oil gallery is about 1/2" (13mm). It feeds nicely to the big ends and mains and the crank is fully cross drilled. It supplies the head as well and there is a problem here. Nissan overdo the oiling to the head, reduce the size of the oil control orrifice to the head (sits in the block). I have never broken an oil pump, but I know people who have. Condemn the oil bypass port in the oil heater casting (if your DET has it). Run a good Oil Cooler.
Change the oil pan, make one or buy one with a baffle trap door arrangement around the pick up.
Use Tomei's Main Studs, they effectively dowel the caps into place with perfect machining on the stud shank.
If yoy feel the need, pilot dowel the caps onto the block (like on a rod). The SR tends to yield the block half of the bearing cap over time from the caps "walking".
Keep the big nasty looking super heavy crank pulley, you can make 6hp with 0.001 psi increase in boost pressure.
Head work...........tom, dick or harry........whoever makes you feel comfortable.......the flow bench don't lie.
Cams, Tomei, if not, Tomei, if you still cant get them then use Tomei.
Bee Hive Springs......No.......stick to the Jap crap, good old progressive or linear rate dual springs.
Go to a sold lifter valve train. Build it from the OEM's or buy from Tomei (one piece). Make or get the Tomei Rocker Stoppers as well.
Under drive the waterpump, the SR pump cavitiates >6000rpm.
If you do it right, the SR will take awsome punnishment. Block for block more so than an open deck Honda.
I'm surprised you've known anyone with a failed oil pump. That thing is so bloody stout I figured it would take a nuke explosion to kill it.
I don't know if JWT makes cams for the RWD SR20, but if they do, I'd consider them heavily. They have done a lot of cam development with a guy who does cam development for a lot of race teams at the top level of professional motorsports.
Oiling is an issue for the SR20. JWT sells modified bearings for improved oil flow. They should be considered a must for a high end build. Personally, for a high end build I don't think I would consider doing so without an Accusump if you plan to spend any time at all on a race track.
I don't think you'll have to worry about the bores failing with an SR20. There have been some pretty outrageous engines built. I don't know what the record is, but I remember reading about a 700 bhp version.
__________________
George Roffe
91 SE-R (well modded)
84 944 SCCA ITS race car under construction
http://www.nissport.com
Hello again,
I want to say thank you "Bigtoe" for your most complete answer, that was damn near poetry! If anyone else has any brands, or just suggestions I'd be glad to hear them.
As far as what my goals are? Well, I don't know how to answer that, No set HP #'s, and no real boost #'s. I'd suppose it'd be fun to tool around town on the weekends at about 15lbs, maybe 250 hp ish, and be able to crank the boost (and fuel map) up to shoot, (what's a rediculious number) ~ 30 lbs maybe, for drag racing once and a while on the track... I'd just like to build a fun weekend toy that's all..I am a serious car hobbiest, and fascinated with building engines that perform extremely well. I hope that's a decent answer for you. I'm ***** run for now, but thanks again Bigtoe...
well the record on a rwd stock motor is around 579whp
you can leave it stock and make 450 all day long.
But if you are looking for more use arias or je piston's
cunighamm or pauter rods. Also get a comitc metal head gasket
and if you want to run over 20 psi get head stud's just to be sure.
crack shaft is almost bullit proof.
well then you dont need to build anything other than the ARP studs and a Cometic gasket. the stock bottom end should be ok up to 25 lbs. im not sure how different the RWD sr20 is, but the internals are comparable to a BB no? so like bigtoe said, you are good way past 400hp. i believe the stock bottom record is 524whp? but thats just a record, nothing reliable or consistant.
Black '95 200sx SE-R Turbo Lowport 286whp/245wtq 12.306 @ 113.55
White '92 NX2000 All Stock.
White '92 NX2000 Automatic, stock, not moving, and FOR SALE <---- Click for Pics
Quote:
Originally Posted by BORNGEARHEAD
It's pathetic the amount of people in this country that believe all the bullsh*t being spewed out the mouths of Bush, Cheney, Rove, Rice, Snow, oil companies, lobbyists, etc.
Alright folks,
Seems I have under-shot the engins capabilities... In the event I build the motor with the forementioned parts (being built as stout as can be) what would you folks speculate the capabilities of that block (eg. redline, boost limit, ect.) I assumed you would say 30lbs is ludacris however if the block/bottom end could handle more for short runs, I would probably be inclined to do so.. To all the replies, thanks for the info, I'm taking notes.. ;-) (Can't seem to source Tomei parts yet ***.)
Any body know who made the AEBS Head Studs for the SR20. I have these, but when I called AEBS for some other stuff they now have Tomei's Head Studs.
I bought my motor form a guy who killed it with 30psi and a 100shot NOS. On all four pistons the primary ring lands were broken. The bore was near perfect with about 0.0002" taper at most. Crank was perfect, so were the rods.
What's these JWT special bearings? The GTIR drilled Mains and the 19mm Rods?
The 19mm Rod Bearings will not fit the Standard Rod (Ben Pila at JWT) because of the lock tang configuration. And I bought the drilled Mains, funky looking and useless unless your Main saddle can supply the full drilled segment behind the bearing shell (Like on the Cosworth BDG's etc). I visualise those holes are going to disturb the hydrodynamic boundry layer unless they are supplied with pressure from the main oil gallery.
Yeh, I have seen two cracked outer segment oil pumps, agreed it's not as frail as Honda's though.
one word of caution about going really big turbo... you'll lose a lot of everyday driveability. I'd consider 300-325whp an area where you'll still get good spool and response.
__________________
Khiem
'96 SE-R.... boost, brakes, suspension, etc... sold
'05 Evo
'05 CBR 600RR
Hello again,
I want to say thank you "Bigtoe" for your most complete answer, that was damn near poetry! If anyone else has any brands, or just suggestions I'd be glad to hear them.
As far as what my goals are? Well, I don't know how to answer that, No set HP #'s, and no real boost #'s. I'd suppose it'd be fun to tool around town on the weekends at about 15lbs, maybe 250 hp ish, and be able to crank the boost (and fuel map) up to shoot, (what's a rediculious number) ~ 30 lbs maybe, for drag racing once and a while on the track... I'd just like to build a fun weekend toy that's all..I am a serious car hobbiest, and fascinated with building engines that perform extremely well. I hope that's a decent answer for you. I'm ***** run for now, but thanks again Bigtoe...
not true I have a big turbo and get boost before 2800rpm. if you build your set up right your fine
Well, it's all relative. With the current cooler weather in Florida (ya know 60-70 degrees ), I'll be at 10psi by 2800, and that's about as high as I go anyways. Of course, my peak HP is probably about 200whp less than yours or so
Geo's absolutely right, at the moment I'm doing some research and verifying which route I want to go with a potential engine build. I wish some people I knew would research things before they just jump in the water head first. Seen alot of blown engines in my last couple years. Also gettin' tired of fixing them for friends.. I'm still saying thanks for the imput, and hope you (Geo and others) aren't offended by my researching a topic. Take care all,
Geo's absolutely right, at the moment I'm doing some research and verifying which route I want to go with a potential engine build. I wish some people I knew would research things before they just jump in the water head first. Seen alot of blown engines in my last couple years. Also gettin' tired of fixing them for friends.. I'm still saying thanks for the imput, and hope you (Geo and others) aren't offended by my researching a topic. Take care all,
-J
I would say if you're doing research, give the specifics of your goals both short and long term. You came in asking about a build as far out as can be. Turns out your goals are 250 hp. There's a lot of info here, but you should ask what you really want to know. If you don't, you could end up wasting money. For instance, up to about 400 bhp you don't need to replace the rods. There are enough 400 bhp SR20s around running the stock rods to know this is not a problem. The stock rods are forged and pretty stout.
What you will need for a mild build or a mid-level build will be different from what you will need for an all-out build.
I have been sadly dissapointed with the honda blocks, and ran across a "square motor" (the sr20det) with equal bore & stroke. Which is to me a gold mine, and the main reason I'm interested in a 240sx. However;
), I'll be at 10psi by 2800, and that's about as high as I go anyways. Of course, my peak HP is probably about 200whp less than yours or so 
