revving the LS
 

i just got a good deal on an LS block and it got me thinking. i know you can rev the ---- out of b18c's and b18c5's. do i have to do much to my LS to be able to rev it like those. i plan to build for 15psi daily and 20psi on occasion, but i would also like to rev it if needed or if it makes power up high. does anybody know the weak link between LS and gsr/itr?

Re: revving the LS
 

Rod bolts, rods, no block girdle, oil pump, and the head doesn't flow anything close to a b16 or b18c head.

Re: revving the LS
 

rev it to 7k and enjoy the long stroke

Re: revving the LS
 

Id say the weak part of a LS is the Cams/valve springs. I have a set of re-grind cams in my LS and it makes a huge diffrence, I now have a bent valve because the stock springs didnt like the cams and 8,000 RPMs.

Im sure JD will chime in and tell you everything on a LS is golden :P

Re: revving the LS
 

so, with balanced h beam rods, arp bolts and a gsr/itr oil pump could i rev it to 8k?

Re: revving the LS
 

The weak link is the rocker arm design - they are not retained by a shaft and are prone to go flying off at high rpms a la SR20DE(t). The SR20 boys have an interesting widget that limits rocker motion and helps hold them in place, we don't but it doesn't look difficult to fab, but I'm pretty disinterested anyway *yawn*.

Long story short, if you have one or two or more rockers that like to pop out when adjusting valves, those are the ones that will be wanting to pop free at high rpms. Replace the seat and arm combo with a different unit and reap the goodness. Nice middle of the road NA cams and stiffer springs (turbo cars like stiff, NA does not) and rev to 8000K with power increasing all the way there and you're golden. Most decent cam setups will leave you with ability to make power at 8500+, and most LS heads will do 8500 all day long, but you've entered the territory where the rocker arms start flinging free on some people. 95% of the time you just "lose" a cylinder and have to fish the rocker back out, and reinstall, and everything is peachy. Sometimes it gets wedged in somewhere and munches some bits, usually pretty cheap to fix although you sometimes need a diff head, but there is a chance you'd drop a valve and toast the motor.

You're either completely wrong or none of those things matter anyway, I forget which. Seriously. I just don't feel like all the typing it'd take to correct you.

Re: revving the LS
 

thanks for all the info. that is pretty interesting stuff. the head isnt going to be a problem though. i plan to put a vtec head on. most likely a b16 head. i hear they are the best and i dont have the money to do my own testing on that so i will hope for the best

Re: revving the LS
 

I hear hp/liter rules, yet big displacement RWD V8s with live axles still rule the street. Shows how much what you hear is worth. But, they have a point, if you're shooting for over 750 whp, or want a faggot NA engine that is death slow, you really should get rid of the poor flowing LS head. :y

B16 head flows exactly the same as GSR, people keep handing out Alaniz flowchart that shows OMG 1 CFM!!!11 difference for a very tiny portion of headflow vs lift graph like it means anything. Anyone who knows anything sees two lines drawn over top of each other. B16 doesn't have the straight drop down on the backs of the intake valves, the port bends and that causes turbulence, so the flow quality is worse than GSR, yet you "heard" B16 is better so I must be wrong. ??? God, it sucks to not know what I'm talking about. :'(

LS bottom end, all stock parts, isn't going to want to rev as high as the B-VTEC stuffs, but 8500 is not a problem if you remember you can fold rods compression downshifting just like B18C at 8500+, only a little easier. Big ends on the B18C are overbuilt, there are no rod bolt problems on LS they don't spin bearings they break across the beams, but you also "hear" that LS rod bolts suck. Girdles don't do anything but suck power, you never see one on a big power build at the top tier level; the block and crank likes to flex a little and isn't going to break from the flex, at the 500 whp level there's 10-15 caught up in a girdle holding engine straight which materialises to heat/friction in the bearing area. Just let it flex.

Everything is a trade off, have you heard that before? For a compressor-limited situation (turbo engine) the turbo dictates how much power you make, and until such time as your stock head restricts things (750+ whp, like, OMG) then there is no reason to run a V-Tec head. However, you can run one if you want, just be aware what the trade off is. Your trade off is money to get approval when you pop your hood, in which case you need to be posting engine bay hots to HT's Appearance forum.

Re: revving the LS
 

Id say a LS head and GSR head are around the same price. After u buy cams and spring for the LS its about the same price and results.

Re: revving the LS
 

Strange, I have a lot less in an low overall milage + 8K since machine shop cyl head with Crower billets and valvetrain than the run of the mill high mileage half slopped out GSR head that needs to go off to the machine shop sells for.

Re: revving the LS
 

Ok so u found a good deal, but someone else probably already has what like $600 into it.

Re: revving the LS
 

LS turbo for life? ;)

Re: revving the LS
 

yep 8)

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Me too. I'm too cheap for all the high dollar VtAK stuff.

Re: revving the LS
 

for now i am gonna use an ls head that i found with IM for $100. my reason for the vtec head was for high revving. i was unaware that the ls head had the capability to flow what would be needed. my final goal in this build is 400whp so it sounds like the ls head will be plenty along with the ls block i have.

thanks for all the info Joe, i am an open minded person and i was just stating what i have heard hoping to either have it confirmed or hear something better like you did. maybe just try to tone it down a little. i have hated b series engines for years cause i didnt want to jump on the bandwagon like every other club going fag i know where i live. but i bought this Ls since i figured i could make more hp and have a little more reliability than a 400whp d series

Re: revving the LS
 

I've personally never had too much luck revving the LS heads past 7500, and neither have a few of my friends. Once and a while I might've crept up to 7800 on accident (usually first gear or 2nd at wot and 14psi ;) ) and the rocker arms held, but as an everyday thing I personally think you should look into a way to keep them in once place...like the sr20 setup that JD's talking about.

Re: revving the LS
 

yea, i should have added that into my post. im gonna do some research on the SR20 thing and then see what things look like when i pick the head up this weekend

Re: revving the LS
 

I've seen a bunch of cars doing 8000 rpm no problems. TurbodEG has revved 404'd LS head to 8700 and never had problems. I think he was just real damn lucky, tho, I wouldn't even try. :l

No, I got everything at cost. The Skank2 IM was a good deal, though.

Re: revving the LS
 

so, i did a bunch of searching and i cant find much info on the sr20 rockers. all i can find are "lash killers" but the pics are really small and never pictured in an engine and no information about installation. does anyone know where i can find info on the rocker mod. if the LS head will flow to 8k then i will just make something to fix the rockers and not bother with vtec. i would rather spend the extra money on something other than i a head i dont need

Re: revving the LS
 

I would like to know more about this also. I have searched for hours and can't find ----. Is the a upgraded rocker that I can just buy??? I can't seem to find that much info on the LS rockers at all.

Randy

Re: revving the LS
 

Wow, first five links on first google search, guys.

http://www.tougefactory.com/shop/images/498.jpg
^^^ $69, whoopty.


http://www.sr20forum.com/archive/ind.../t-119852.html

http://www.240sxmotoring.com/grroarmsts13.html

http://www.nissan-parts.com/Merchant...Category_Code=

http://www.optionimports.com/hksroarmsts1.html

Jeez, guys, I understand gearheads not being entirely comfortable with wires or software-->electronic hardware-->mechanical interfaces utilised in tuning so I don't mind helping out some, but every damn one of you should be able to find common as dirt parts sold everywhere. :3

Re: revving the LS
 

Thanks JD!!!
I was looking for honda ----. I didn't even know what the hell sr20 motor came in. I'm just a dumb v8 guy that likes playing with little cars.

Randy

Re: revving the LS
 

Sorry, then, the screenname screams Honduh kid. I have patient domestic friends who hold my hand and explain V8 things to me when I need the help.

Are you one of the wierd engine swap Starlet guys?? Name seems familiar.

Re: revving the LS
 

I guess you can call me honda-dumb. Here is a little about my backround. I grow up playing with rc cars behide my father's trailer during scca pro racing. Then I got older and started racing karts. The last couple of years my ribs were about to fail due to the stresses put on them. I had about 3.5 bad crashes where they broke. I got very sick of not being able to sleep for weeks on end.
I went up to a local machine shop to hang out with a long time friend. He was showing me some pistons for a Honda icerace car. Well come to find out I knew the guy from when I was a kid. He worked on some Can-am teams and formula car teams, now him and his wife are out iceracing.
I knew this is something that I had to try. I bought a 84 crx HF because it is the lightest of them all. I welded a cage and new floor in to the car and went racing. My first dyno run was at 68 horsepower. Slow as hell!!! Well by the end of that year after head swaps-header and weber carb, I was up to 98 horsepower( I swear that ew4 wasn't ported).

Next year I did something a little different. I did a turbo-carb setup. It was pretty cool. The most power that I made was 232 in 3rd gear. Ran that for a year.

Now for this year, I am doing a b18a swap, with turbo. I think the boys are in trouble because this thing should be fast. I don't know ---- about tunning a honda, or what fails, or what to look out for. I don't have anywhere to test this fine peice of machinery other then our chassis dyno. So I read forums looking for info to save me time. I only drive this car 8 weekends in a row during Janurary and Feburary. I don't have time to learn inbetween weekends.

I also have been working at my father's shop since I was about 12. It's the only thing that I know. Built v8 engines, helped in building racecars, built brake and suspension packages, cooling is very important in road racing so I know all about that. I went to school for welding and machining. I'm out of patience on welding because we have a full time welder now. But if he is busy or is sick or something, I still can flip down a helment and get the job done.

When racing this car, I have to scream the engine in 2nd and 3rd gear, because we run a super tall studded tire. The trannies suck for this, their is too much gear spilt, so to drop in the powerband again, I have to run these up in the 8000 rpm. Not just for 10-14 senconds but for a 8 hour weekend. By the way I am on a budget!!!

Randy

Re: revving the LS
 

Holy ----!

Re: revving the LS
 

LOL

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thats crazy ----. i have seen that ice racing on tv. i live in FL so i wont be joining in

thanks for the links joe. i searched a few times and couldnt come up with much. i think i could make something like that. it looks pretty simple. i will be picking my head up this afternoon so i can get a look at things and start planning

Re: revving the LS
 

Yeah, I think using a quality spring steel and tempering it correctly is the only secret.

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DId you see the Monster Garage on ice racing? I was in there running 2nd place right behide a very fast rally SRT-4. Until a 27 cent part failed, the main power wire going to the starter broke off and hit my SS line feeding my turbo. Then the fire happened.

Randy

Re: revving the LS
 

Can you host video on youtube or something, link here?

Re: revving the LS
 

I really like this thread. ;)

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If it wasn't for the fact that oil gets squirted out of them into the rockers, I'd say maybe trying to actually bolt the back ends down to keep them in place. Maybe have the rocker points machined out, threads tapped and then drilled through the centers to keep the oil flowing some how. The way they pivot just makes things a pita. Spring plates would probably be the easiest way, something to hold the ball-end of the rocker down tight at all times.

Re: revving the LS
 

A vid of some Turbo Iceracing action would be sweet.

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I don't even have a tape of the show. I had to drive about 1 hour to even see it on tv. But this year I will make sure I get some racing on tape and yes I will post it.

randy

Re: revving the LS
 

do you have any pics of the car. i would like to see it

Re: revving the LS
 

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[IMG]http://i29.photobucket.com/albums/c255/iceracercrx/passing.jpg[/IMG

Here are some pictures of last year. Yes that is a charge pipe coming out of the hood.