s13 sr with broken rockers... what other surprises can it have ?

[alesserfate]

looking at buying a motor from my buddy

its an s13 sr blacktop that he miss-shifted 4th into 2nd and blew up rockers on

besides broken rockers, what other disasters can it be hiding ?
could the valves have hit the pistons-is that why rockers break ?
could over-revving destroy rod or main bearings ?

i was planning to pull the head, change to metal headgasket/studs, and change the rockers.. bad idea ?

any experienced input would be appreciated thanks.

[steve shadows]

looking at buying a motor from my buddy

its an s13 sr blacktop that he miss-shifted 4th into 2nd and blew up rockers on

besides broken rockers, what other disasters can it be hiding ?
could the valves have hit the pistons-is that why rockers break ?
could over-revving destroy rod or main bearings ?

i was planning to pull the head, change to metal headgasket/studs, and change the rockers.. bad idea ?

any experienced input would be appreciated thanks.

THe camshafts could be badly scored and the cam journals in the head could be damaged beyond repair which means you might need a new head, you might also have little tiny pieces of metal in your oil system. I wouldnt take the motor unless it was free, or maybe super cheap, 100 bucks or less.

Unless it was only like one rocker and it was very minimal damage etc

[dubtastic]

You are taking chances by rebuilding the top only. 4th to 2nd can easily spin a bearing. I don't even know if that engine is worth a compression test.

Agreed no more then $100. Tear it completely apart. If you rebuild, Rocker Arm Stoppers are cheap insurance.

[johngriff]

You will need to re-shim for sure.

Check this out.

RPSport SR20 Valve Shim Height Tool (http://www.rpsport.net/vsht)

Biggest thing to look out for in engines w/broken metal in the oil system is metal particulate in the oil pump/bearings. Take the lower end apart and inspect thoroughly!

John

[rioredstang]

We race a NX with a SR and my buddy has did the same thing twice. He has been lucky though and not bent any valves. We did pull the pan and check for debris, while I had the pan off I took a magnet from a transmission pan and JB Weld to the bottom of the pan. After the season was over sent the head to machine shop and found valve springs were weak. Replaced springs and no valve float yet.

[codyace]

Scattered rockers wouldn't scare me. Happens all the time to more people than we all realize. The bigger concern to me, is making sure you find all of the shims and retainers...easter egg hunting for them is a PITA at times as they can scatter everywhere.

Make sure the cam looks ok and that everything looks good though, and you should be good. Oddly enough, the rockers usually just fall off nicely and no harm no foul. Every once in a while you'll see rocker arm soup on a track car, but rarely at best.

Heck I know of a few guys who track every other weekend that spit rockers yearly without issue too...just how it all works ya know? On the same statement I know of a few local guys who also have played yahtzee with them and ruined their head.


I'd throw the rockers back on (assuming you can refind the shims) and see how she runs/do a leakdown.....from there just go at it. If you're going to put a HG and studs in it anyway, then it's a moot point as you may as well tear it out and just go over everything anyway ya know? If you are just gonna keep it on a stock turbo/stock power, then I'd do what I decribed earlier and say fuggit. Often times people make a bigger deal out of an issue than it needs to be.

[steve shadows]

I would mostly be concerned with how many broke.

If it's only a few pieces that broke that you will be ok, but if there was catastrophic failure of several of the rocker arms I would be a bit more wary.

It is actually pretty common to throw a single rocker arm, under high revs whne using rocker arm stoppers and bouncing off a soft cut limited at say 8500 rpms, I did it a couple times! haha- just swapped the bad rocker arm out with a new one, used some fine grit sandpaper to clean up the cam lobe and I was on my way

[alesserfate]

Thanks guys, heres a quick re-re of what I'm planning to do with the motor:

I have a car with aftermarket turbo, pfc, injectors etcetc, makes 380 wheel and the old longblock finally let go, I have it running good with: apexi metal hg, studs, greddy ras, and hks cams- for internals.

I know this motor he has was mint, running stock, it broke more than one rocker, but didnt make a rocker 'soup' lol (i know exactly what you're talking about).

What I want to do is grab it, pull the head, put in my headgasket/studs, some new rockers, my hks cams and greddy ras.

The only thing that's stopping me is if the reason the rockers broke was also possibly valve hitting piston and shooting up-breaking rocker, then I don't want the motor because that could mean bent valves or fucked rod bearings.

This motor would cost me around 200$ CAD, I'm planning to sell him tein superdrifts for 1000$ or 800$ plus motor.

To be honest, I don't think I'm gonna grab it, I've had enough fuckery with swapping things back and forward already lol. Thanks for all the input again.

[johngriff]

For that cheap I would pick it up, if its only a few rockers, and they didn't break apart its worth it.

[sacco sideways]

i broke 6 rockers once and it was a pain in the ass.... they grenaded inside my head into a million peices and i had to replace my head, well idk if i had to but i didnt take the chance of having baD VALVES..

[codyace]

I would mostly be concerned with how many broke.

If it's only a few pieces that broke that you will be ok, but if there was catastrophic failure of several of the rocker arms I would be a bit more wary.

Exactly. If there is Rocker soup, then it ca just stay there. Even then it still *could* be fine, but even I wouldn't want to find out.



It is actually pretty common to throw a single rocker arm, under high revs whne using rocker arm stoppers and bouncing off a soft cut limited at say 8500 rpms, I did it a couple times! haha- just swapped the bad rocker arm out with a new one, used some fine grit sandpaper to clean up the cam lobe and I was on my way

1 or 2 off for sure it's usually something silly hehe. When I first got my car I did this. Thankfully from FWD land I knew what went wrong.

[jspaeth]

Out of curiosity, what are the preventive measures (if any) one can take to make sure this DOES NOT happen?

Are stiffer springs and Ti retainers enough to ensure this doesn't happen for modest RPM levels?

Obviously, there are many variables (cam lift, etc, etc.) but assuming you don't mis-shift or over rev the engine, from your experience (experienced guys), when do you typically see this happen?

I am running HKS Step 2s (12 mm intake 11.5 exhaust lift) with BC springs and retainers (single spring, but a spring test on FA showed that they were better than nearly every brand out there except Ferrea---> $$$) and currently have my redline set to 7800 so that the momentum of the engine when I let off the clutch never takes it over 8000.

Also, I have RAS...which I know John doesn't like.......

Should I be fine for the most part?

I ask this in the general sense, bc obviously, anything can happen even if your setup is safe and some freak incident occurs.

[johngriff]

The two important factors I see are:

Shim matching, to time the rocker arm striking both valves at the same time, this way the rocker is not "wobbling" off @ high rpm.

Rocker arms following the cam reliably, meaning not floating. Difficult thing with the SR is that you can get float on the valves (valve spring weakness), and the HLA's (hla weakness), but I am investigating HLA designs as we speak, and looking to produce an uprated set for racing applications.

[codyace]

IMO the biggest issues for rockers to spit are from over revving. The Same track cars I speak of that spit them, often times don't even measure the shims...lay em back in, and go out and race.

As long as you don't jam 2nd when looking for 4th, you should be ok.




but I am investigating HLA designs as we speak, and looking to produce an uprated set for racing applications.

It's to bad we can't adopt the RR style ones to rev reliably.

[johngriff]

It's to bad we can't adopt the RR style ones to rev reliably.

RR Style? I would like to know more.

I was noticing that the B13 SE-R HLA's have a much longer piston (the hla rides the piston) than the S13/G20 style HLA. They are also much better constructed as far as the mechanical seal. I am looking into "how/why".

[codyace]

RR Style? I would like to know more.

RR = Roller Rocker. 99+ FWD SR20's featured roller rockers/HLA's in their cars. However these motors also do not rev as high as others, and you don't see companies really pushing that design for higher RPM power. One would think a roller valvetrain would rev higher, but again, you never see these being converted over to older heads

You also can look at VVL heads, which feature shaft mounted rockers
(ganked image, as I don't have one of the actual rockers, just the cams)
http://media.photobucket.com/image/vvl%20rockers%20picture/sr-starlet/P1010142.jpg, but I'm pretty sure this style can not be adapted to non VVL heads.


Either way, I would love to see a better HLA that isn't solid...I drive a street car, and do not want the hassle of Solids.


I was noticing that the B13 SE-R HLA's have a much longer piston (the hla rides the piston) than the S13/G20 style HLA. They are also much better constructed as far as the mechanical seal. I am looking into "how/why".

I do remember someone saying that running B14 ones are supposedly 'the best', but I am unsure as to why as I've never personally looked into this. It is interesting however to watch part progression and assimilation through SR20 variations and years. I mean, one side of me says 'well if they changed it in later yeras, it's for good reason'...but in the same regard, who's to say that the newer design is really *better* than the old design?

For example: Very common to see mix/match SR20 parts in FWD crowd. 4cw VVL cranks well net more power, yet they are unreliable. B15 rods/pistons and valvetrain are lighter than B13 and B14, and you see many 'stock' racers adapting these parts to cars...just crazy to see comparisons

[johngriff]

I just snapped this photo, its older point and shoot so focus isn't great.

We notice in the picture, that first the lock ring for the S13 is made of a softer metal, and only locked onto the bottom with 3 compression points.

The SE-R lock ring is stainless, and compressed tightly all the way around the HLA lower body.

Next is the HLA Piston. The S13 is broken up into two parts, while the SE-R is a single unit.
S13 Combined Weight w/spring clip: 14.9G
SE-R Weight w/spring clip: 16.6G

Finally the springs, the S13/G20 Spring is made from the same black metal as the associated locking upper ring. The SE-R Spring is stainless.

S13 spring is also smaller gauge wire wound to make up the spring, total shorter height (could be from advanced wear) and fewer windings.

SE-R Spring has larger gauge wire wound, stainless, and maybe a half turn more windings.

Pic: Enlarge it in firefox, its a large picture.
http://www.rpsport.net/img/hlacomp.jpg

[jspaeth]

John, sorry if I missed it, but do the SE-R HLAs drop right into an S13 head then?

Are the outside diameters the same? Height? If not, what else needs to be modified if anything?

[codyace]

John, sorry if I missed it, but do the SE-R HLAs drop right into an S13 head then?

Are the outside diameters the same? Height? If not, what else needs to be modified if anything?

Yes, they drop right in. It's what I used.


John: Again, it's much like my post. Interesting to see why and how they changes such basic parts.

[steve shadows]

LOOK AT THESE GUYS!

giving away the whole farm

[codyace]

LOOK AT THESE GUYS!

giving away the whole farm

"been playing with SR20's longer than you've been able to drive"


;) Just teasing of course.

[johngriff]

I don't know about giving away the whole farm.

But obviously, if we were going to compare the OEM's view of the S13 engine vs the SE-R engine it would be this:

The S13 engine is a mass production, mass market engine to provide entry level performance, to entry level enthusiast who CANNOT AFFORD A Z32.

The SE-R B13 is a low production, CLASS RACING ENGINE, whose major components must be geared towards cup racing, for minimum production standards of associated classes, purchased by Specialized enthusiasts for cup car racing.

So the differences we see in t hat B13 engine are most definitely for some type of competitive advantage when compared with Mass Market SR20 Variants.

Now I have some nismo documentation on B13 cup cars and HLA's that takes to improvements even on the SE-R models.

About me worried about comparison for the sake of profit, even if I made these, the demand still will not be enough for me to have lost anything on open source info.

[codyace]

Another thing that Is odd for me to see, is the differences between the two variants, and how they progressed on both sides of the pond. N/A and Turbo.

B13, in a 'general' sense is similar to S13, intakes and all.
Now when you look at Avenir and Bluebird motors, they are also very similar to Redtops.

B14 and s14 however are nothing alike, with the VTC stuff going on, but share similar intake manifold design. FWD Turbo DET's were still much like B13/Redtop/W10 style

Now when yuo get to the B15/S15 you get all sorts of wackyness going on Again, B15 SR20 (and p11) all have the roller rocker business going on, yet S15 doesn't (similar to s14).

(I don't even compare GTiR motors to any of the above, as they were simply homogulation motors with the best of the best parts).



I guess my main point would be, It would be interesting to see a W10 HLA persay, compared to the Redtop and B13....

[codyace]

About me worried about comparison for the sake of profit, even if I made these, the demand still will not be enough for me to have lost anything on open source info.

Thats the thing...those who will even want to learn more about it, already have half a brain on them. I can totally see your point of view here.

[steve shadows]

True, but it's definitely worth it to re-shim and to upgrade the whole lifter to B!3, not just the spring

[jspaeth]

True, but it's definitely worth it to re-shim and to upgrade the whole lifter to B!3, not just the spring


Well That's why I asked above if they are drop in.....I will probably never pu them in, but just out of curiosity, I wonder how it effects the rocker.

Is the B13 HLA taller than the S13 one?

[johngriff]

Well That's why I asked above if they are drop in.....I will probably never pu them in, but just out of curiosity, I wonder how it effects the rocker.

Is the B13 HLA taller than the S13 one?

My measurements is that the external specs for the B13 are identical, and Cody seems to be running them successfully in his RWD SR.

I feel sorry for the OP, me steve and cody have turned this thread into a Mensa meeting.

[S13 curtis]

there is probly galges in the pistons.

[codyace]

My measurements is that the external specs for the B13 are identical, and Cody seems to be running them successfully in his RWD SR.

I feel sorry for the OP, me steve and cody have turned this thread into a Mensa meeting.

Yea I'm running them now, simply because I had a low milage set of them before even working on my current (well, same as always) engine. Pat himself sent me his shim tool (custom steel) to play with, and all went in as spec and perfect (had a bunch of shims to use as well). Works pretty good so far....even changed valvesprings without worry (not that it should)

Mensa meeting lol. I'm to barbarian for that stuff...you guys are the smart ones! haha. I put things in without testing lol!

there is probly galges in the pistons.

Why would that be? the rockers have nothing to do with the valves....and even if it did 'jam the spring' there still is plenty of room.

[Firestorm]

hey guys, i just thought i'd hijack this thread instead of opening a new one.

heres the deal, someone offered me a clean zenki with a S14 SR20 which had a rocker arm slip off and damage the camshaft on the intake side. the car is a real bargain and the chassis is in a real good condition so i'm tempted but i wonder if the rocker arm could've caused some serious damage.

here are some pictures, showing the damage:

http://666kb.com/i/boiyr72zdu2p668aq.jpg
http://666kb.com/i/boiyroxm0hc6sk802.jpg

as you can see, part of the cam lobe broke and the valve retainers are scored and i think the HLA is broken too. i could easily fix the damage but honestly i'm worried about debris in the oil system and i would feel better pulling the engine and rebuilding it but then the car wouldn't be such a bargain anymore ;)

would be great to hear some different opinions about the damage so i can decide if it's worth it or not.

[steve shadows]

does it drive?