1.95 Yella Terras, 5 years later valve springs finally gone..... upgrade springs !

[vxcalais_01]

After 5 or so years daily driving, my car stopped on the freeway and would not start again. On inspecting the engine, the springs were gone on the left head. It in turn caused the gasket to go.

To Yella Terras credit they do recommend a spring upgrade, so i advise all to do so if possible. My engine will not feel the same knowing that the YT's are not on them anymore hehe.

2 recoed heads and gaskets later, i may put them up for sale or reinstall them later on.

All in all still a fantastic product, but follow their advice.

[PRAVX II S]

Personally i would go 1.9 yella terras.
They lasted a while though you got good usage out of them.
Any pics of the damaged spring

[Pub247]

Sounds like a typical case of what happens when you mod a car shit breaks. Do it once do it right comes to mind

[monkeys437]

Was that with stock rev limit? When I got my YT 1.9's they told me to fit stiffer springs if I was going up to and over 6k RPM. Ive got the stock rev limit on mine and ive done 60k with them so far so im hoping I wont have the same issue as you

[vxcalais_01]

Yes stock REV limit, only other mods were extractors etc. Is a daily driver and i put them on around end of 2006. I was on Monash Freeway and it just ran rough all of a sudden. Got towed home, thought it was leads and plugs, Saturday would not start anymore. I havent got picture picture but i was shown them. Rockers in perfect condition, but at 280,000k's springs probably had it. It happened on the exhaust valve, so shut the chamber and caused the gasket to blow out. Just imagine the spring with no more compression and the top half loose hehe.

YT are correct all the way, they always recommend the spring upgrade but they can work without. 5 years i reckon i did pretty well hehe. I got quoted $400+ to do the heavier springs etc but as i need my car on the road, the head work etc is all i could do at the moment. Nothing to say they wont go back on again, but as i dont kow the history of the springs on this set of heads, i will sell them. They are still in perfect condition, no nicks etc.

[monkeys437]

I had my heads pulled off and checked over about 2 years ago when I had the LIM gaskets done. At that stage there was probably 25k of use with the 1.9's. The valves and guides all checked and they were not bent or overly worn so i'm hoping i wont have any issues. As far as I can remember most of the issues ive seen with roller rockers have come from the higher ratio stuff like the 1.95, 1.98 etc so fingers crossed ill be right

[vxcalais_01]

monkeys ,you are correct, 1.9 is probably best for longevity, i remember early in the piece some recommending only 1.85 etc..... I did my LIM about 3 years ago or so, and yeah, everything was good as well. Like i said, it just happened suddenly. Like some slight missing, then all of a sudden the engine shakes and runs on 5 cylinders. You can just imagine what happens when your on a freeway and a spring breaks, stopping that valve from working hehe. It was mentioned to me that if it was an intake valve spring that went, i may have been ok and maybe just needed a spring change. But the exhaust valve spring went thus sealing it and when the chamber ignited, the only was it could go was through the gasket hehe. It possibly may have been valve bounce etc as the springs tired, since 2 were cracked on the one head. Lucky a valve didn't drop and crack the piston top.

Now i have a set of lovely looking YT 1.95 rockers to look at hehe. I will post pics of them as testimony of 5 years use of a great product. They look brand new, no wear etc.

[TI3VOM]

Why not put them back in your car? 5 years and the springs have just failed, the springs most likely would have failed regardless of the YT rockers.

I have some mixed ratio 1.9/1.95 rockers in my car and I have had them for the past two years, I have had the shift points changed to 6000RPM and my car sees that fairly often, my engine has 256,000K's on it as well and have done around 40,000K's with them in.

[vxcalais_01]

I will have to leave them off for at least a year or 20,000k's as i have warranty on my heads etc and would only cover if i upgrades springs etc. Then i didn't want dramas with chain tensioners and so on. I have a sentimental relationship with my YT rockers hehe.... it was the first thing i ever did to my car by myself apart from an oil change. Now its a different story.

Love your ride by the way.......what are the Powerdynes like ?

[TI3VOM]

Fair enough mate,
The charger is not in yet as I want to get an intercooler and maybe some bigger injectors.

[vsv6dude]

monkeys ,you are correct, 1.9 is probably best for longevity, i remember early in the piece some recommending only 1.85 etc..... ..............

Now i have a set of lovely looking YT 1.95 rockers to look at hehe. I will post pics of them as testimony of 5 years use of a great product. They look brand new, no wear etc.

VX

Sorry to hear about your vehicle. I recall throwing out in the discussion the 1.84 ratio was optimum as measured by Zoomer on the ZZPerformance site so that there is no chance of valve float occurring.

The 1.84 ratio matches the upper limit of the spring capacity for the Buick V6 3800 according to Zoomer.

My mechanic (an ex engine builder) steered me away from the 1.84 HRR, he suggested I do CAI, CATback exhaust, manifold insulator, 82 deg thermostat stuff that doesn't impact moving parts and is within capabilities of the ECU. Not worth risking for 7 to 8 kws.

Yella Terra do make a 1.84 HRR for ZZperformance.

To keep things in perspective 280000 kms that's pretty good for an engine.
How can you know or predict which parts are due to fail. So don't be too hard on yourself.

It really spells out when you upgrade a part of an engine you need to take into account all other parts that may have a stress increase due to the mod and upgrade them as well. One small example is when superchargers are bolted onto standard engines without upgrading or strengthening other components including the gearbox.

My next mod if the stock headers failed for my VS V6 is the HM headers.

All the best.

VSV6

[vsv6dude]

After 5 or so years daily driving, my car stopped on the freeway and would not start again. On inspecting the engine, the springs were gone on the left head. It in turn caused the gasket to go.

To Yella Terras credit they do recommend a spring upgrade, so i advise all to do so if possible. My engine will not feel the same knowing that the YT's are not on them anymore hehe.

2 recoed heads and gaskets later, i may put them up for sale or reinstall them later on.

All in all still a fantastic product, but follow their advice.

Hey VX

Just a thought.

If you had installed the OEM modded rockers like MACE or ZZP say the 1.98's HRR that claim to preserve the valvetrain harmonics would this have prevented the valve spring failure. It seems it indicate that?

[2cap]

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[acarmody]

Hey VX

Just a thought.

If you had installed the OEM modded rockers like MACE or ZZP say the 1.98's HRR that claim to preserve the valvetrain harmonics would this have prevented the valve spring failure. It seems it indicate that?

The springs will still fail eventually. The fact is you are compressing them more than normal, which will make them wear out faster. When they fail is completely different on every vehicle. Some will fail soon, some will last for years.

[vsv6dude]

So what is the upper limit for high ratio for rockers that would prevent spring failure in the long term 1.84's
(ZZP claim 1.84 is the maximum ratio before valve float occurs is a guide or is it all springs will eventually failure)

[monkeys437]

YT told me 1.9 were fine with the stock rev limiter. Any higher revs needed stiffer springs

[acarmody]

So what is the upper limit for high ratio for rockers that would prevent spring failure in the long term 1.84's
(ZZP claim 1.84 is the maximum ratio before valve float occurs is a guide or is it all springs will eventually failure)

All springs will die eventually, its just a matter of when, not if.

Are you after rockers for your VS? Well your VS springs are pretty damn old now, and if I were in your shoes I would change them when you get some rockers. The price of new springs is pretty cheap (MACE sell them for $180), especially compared to the possible damage of a spring failure.