Broken valve...the curse continues

[Darius]

I was retorquing my head last week due to my head gasket insecurity complex. Everything was going good, my head bolts needed a quarter turn to tighten which concerns me a little, but everything else went as planned. I was turning my crank by hand to tension the timing belt when I heard a small metal on metal sound like a nut fell down and landed on my frame rail. I thought it was weird but kept cranking slowly....until no more cranky. I tried to back it up and could only back out 90-degrees and forward to the same spot again.

To investigate, I pulled my cams again and under one of the buckets on #6, the problem was revealed. I broke a valve...







I was pissed at first, but realized how lucky I was to break it by hand and not when I started the motor up. That thing would have jacked up my entire build. Now I'm in the market for a new set of valves since I am skeptical that the OEM valves will last much longer with stiffer valve springs and higher lift cams.

Are OEM valves forged? And how much stronger are Ferrea valves?
Modified by Darius at 12:48 PM 1/31/2007

[USMCgetsome]

dibs on the stock valves and take that money and use it towards the ferrera valves. werd!

[Yellow4g63]

how fast were you cranking it lol. never bent a valve hand cranking before.

[Chaos the Xile]

I;m not to sure if the stockies are forged... And does Ferrea make valves for the RB25??

[Sil240]

They do make valves for the BR25 & 26 none for us red headed step child Rb20's

They're MAD $$$$$$$

[USMCgetsome]

about $600 for the full set

[Darius]

KUILLIN_DRIFTER - If you're serious about the stock valves, drop me an e-mail and a fair price.

Yellow4g63 - I was turning it with my humongous 15-inch biceps so I probably mustered about 2 rpm.

I figure that while I have the head off to do a valve job, does anybody know off hand any shops that have ported/polished/flow tested the RB25 head? Hell, I'm already spending $900 on a new set of valves and their install and might as well upgrade the head to get the most bang for my buck.

I'm going to do some searching on SAU tonight because I know I have seen a thread with pictures somewhere.

[kouki-gymkhana]

Bastard! Why couldn't you have had this little misshap a week or 2 ago!!?? That way I could have picked up those stock valves from you for cheap. I just ordered (2), that's right TWO intake valves from Ferrea and it cost me $50!! Oh well...

BTW, if you are going to build the head properly, you might as well spring for the 1mm oversize Ferrea valves because they are the same price as the stock sized ones. If you are having difficulty finding a retailer, call Ferrea directly and they'll find your nearest one. The bastards wouldn't let me pick them up from the friggin' factory even though it's only 30 mins away from my house...

Good luck with the build. I still don't quite understand how you broke the valve though.

[Darius]

I found a few threads over on SAU that were interesting, but all lacked pictures since they were 3 years old. Sounds like quite a few guys do the porting/polishing themselves.

Here are some fairly lame threads;http://www.skylinesaustralia.c...9&hl=http://www.skylinesaustralia.c...0&hl=

This one is better;zerothread?id=128396
Modified by Darius at 3:02 PM 2/2/2007

[Darius]

haha sorry man! I should have broken it earlier for ya. I honestly think it was the higher lift and stiffer spring causing the valve to hit the seat harder and it simply fatigue-failed. That's why I don't want to replace just one valve, because I have $15K in the swap and don't feel like rebuilding it for the second time in 1.5 yrs.

[RB_Dreamin]

cant tell whats broken...

[Kansei240sx]

Dude....wow...that ****ing sucks so much ***.... Thats nearly as bad as the curse my friends RB20DET is going through right now, but it will be done sometime soon. But let this be a lesson! Dont screw with it unless its broken lol! Man.... i feel bad for you, i hope you find a deal on some valves.

[minivan_don]

unlucky !!!

man ... you got the worst luck ... hate to say it lol

keep us posted on the head work !!

[USMCgetsome]

u should have known better than to upgrade all items except the valves. Come on brother. You've invested tons of cash soo far you should have just done the valves. Email sent.

[Bluefire]

Breaking a valve like that is a pretty freakish accident and purely horrible luck under normal circumstances. I have done many many valvespring upgrades and other head stuff, and never once broken a valve. I am thinking there might have been something else going on here. maybe prior damage to the valve when the motor was running or maybe damage to the valve when the head was off... Did you possibly drop the valve on the floor or something?

-Bluefire

[eh?]

While you're at it dump that mhg and get a oem hg...

[Darius]

I've never heard of anyone breaking a valve because they upgraded the springs and cams, especially when mine are relatively mild. I did all my own install work, so I know that nothing was mishandled or muscled. It is purely a freak incident and I'm ecstatic that it happened in the garage and not when I fired it up. Otherwise, I would be writing a huge sob-story, for-sale thread instead.

KUILLIN_DRIFTER - I checked my e-mail this morning and didn't see any message from you ([email protected]).

[RB_Dreamin]

cant tell whats broken...

do your pictures show the damage? all i see are the retainers and keepers?

[Darius]

See how the second retainer from the right is taller than all the others? The others have the valve head on the other end to keep the spring compressed. That one doesn't, so the spring is unloaded. I can push it down with my fingers.

[RB_Dreamin]

ok i see that now.. your post said cylinder 5 but thats cyl 6, no?

[BoostFab]

I've never heard of anyone breaking a valve because they upgraded the springs and cams, especially when mine are relatively mild.

upgrading the spring will not break your valve. broken valves are usually happens when the cams and the crank not aligned correctly. if that's not the case, analyzing what caused a problem before you put in new valves

[Darius]

I tighten down the cams just enough to get all the caps on, then put the rear timing cover to align the cam with the timing marks. Then, I torque the caps down the rest of the way. The crank stays at TDC the entire time.

Thanks RB_Dreamin you are correct. It is cyl #6. I edited my typo in the original thread.

[Chaos the Xile]

ok i see that now.. your post said cylinder 5 but thats cyl 6, no?

Your right If I'm looking at the picture and seeing it as Daruis expalins it that would be the #6 cyl.

While you're at it dump that mhg and get a oem hg...

What would he want to swap the metal h/g for a OEM one?

[FAST-DATSUN]

let us see the valve when you get it a part, never heard of a valve breaking like that. Sure the spring did not break dropping the valve?????

[Darius]

Nope. You can still see the stem of the valve being held in place by the retainer clips in the picture. I will take pics and post them after I pull the head tonight.

[Sil240]

I tighten down the cams just enough to get all the caps on, then put the rear timing cover to align the cam with the timing marks. Then, I torque the caps down the rest of the way. The crank stays at TDC the entire time.

Thanks RB_Dreamin you are correct. It is cyl #6. I edited my typo in the original thread.

Rear timing cover??I have to re-set my cams this weekend, but i dont have the FSM on me right now.Which timing marks do you line them up with?Actually whats the procedure to set them.??

[Darius]

The FSM says you are supposed to install the cams with the knock pins rotated 15 degrees from horizontal (CW on the intake cam and CCW on the exhaust cam).

[eh?]

Your right If I'm looking at the picture and seeing it as Daruis expalins it that would be the #6 cyl.

What would he want to swap the metal h/g for a OEM one?

Because it's hard to get a mhg, especialy comectics, to seal properly. OEM gaskets are pretty damn strong and almost always seal correctly.

I speak from experience.

[Cornloaf]

They do make valves for the BR25 & 26 none for us red headed step child Rb20's

They're MAD $$$$$$$

i believe the n/a z32 valves are the same, which ferrea makes, correct me if im wrong

[Sil240]

The FSM says you are supposed to install the cams with the knock pins rotated 15 degrees from horizontal (CW on the intake cam and CCW on the exhaust cam).

Oh yeah thanks!!!I need to get a degree wheel from somewhere now.