500 damaged rockers

[pete500]

1996 500 20.000miles. Removed the rocker assembly both sides today. Found the hardened steel inserts in the alu-rockers, the part pushing on the valve, to be damaged on several of the rockers. It's broken off hardened steel-parts around/near the hitpoint in the valve-stem. On one of them there were digging marks from the stem. Anyone observed anything like this before? Over-rev? Valve float? Low oil-level? Have to replace this, anyone having experience with Yealla Terra roller-rockers? pt

[Boosted Ls1]

I'd discover then cause if at all possible. YT rr's are very well made

Boosted.

[topsparks]

This is caused by the very stiff valve springs TVR use,according to Rob @V8D,he use's the slightly softer double valve springs from Realsteel and on my 5.5 I have used group A rockers off an Sd1 which have larger shafts and steel rockers.You can get hold of steel rocker arms that fit the standard shafts from V8 Tuner for about £85 a set which I have got to go on my 5.0 liter engine going into my Land Rover !
I had this happen to my old Griff ,the pad did't shatter but if is does it can totally f**k the engine.

[shpub]

There are also some gruesome pictures in the bible as well. Steel rockers are the way to go.

[Podie]

Quinny said:

The best solution is to go for solid steel rockers and do away with the pads all together.

[siwes]

I would refer you to my earlier post ticking Griff
this is due to incorrect clearence settings your valves are not the same height.
while you have the rocker shaft off put a straight edge along the valves and check the heights
I bet your engine was ticking quite loud before you didmantlet it

[pete500]

Yes, it was ticking, but not alarming. Yes, the valve stems differ in height - by 0,2mm approx. Two of the rockers are damaged like the picture in Steve's bible, ed 2 page 52, giving an extra gap of 1,5mm....! And I suppose the sump is full of hardened pieces There were none preload-shims in the setup, and this is, as far as I know, the first time the engine is dismantled. pt

[Boosted Ls1]

The aluminium rockers make the valve train lighter. I've never used steel rockers or felt the need to. Is your valvetrain/cam very aggressive?

Boosted.

[shpub]

You might want to check the cam... mine also needed replacing. Not sure what caused the problem but it looked like no preload had been done when the engine was rebuilt before I got the car.

[pete500]

Everything standard 500... 20.000 miles, regular oilchanges every 6.000 miles - Mobil 1. Know the car had some serious highspeed driving at Autobahn by previous owner - 280km/h (175miles) spoken. Will install a H404 complete kit with lifters and springs, together with either steel rockers and adjustable pushrods or Yella Terra Roller rockers - if I can find a source. pt

[Boosted Ls1]

YT will sell to you direct if you use a credit card

Boosted.

[red griff 500]

Is it only a ticking sound that lets you know about this fault, or are there other symptoms?

[pete500]

I had no idea about this. Removed the manifold because of coolant leak at rear of engine. Was sure that gasket between head and block were leaking, observed the cracked rockers when I removed them.
Cause of leak was that the bolts holding manifold against heads were almost loose!! Vibrations combined with course treads and no locktite I suppose.
Top gaskets and cylinders in sterling condition.pt

[siwes]

I had the heads off the engine , new valves and seats new springs , then took the heads to a machine shop and had the valve stems machined ground to ensure they are all the correct height.
Checking the clearences when the heads are back on the engine is at best bloody hit and miss. bent and flattened welding rods, you could never say this engine is state of the art
New cam and rocker and arms and the engine now sounds as it should , for how long is anyones guess.

[pete500]

For your information, new H404 installed together with new lifters and a the new springs following the set. BUT I did one interesting observation: The new springs are 6% stiffer than the old ones - witch were told to be the overly stiff originals… Perhaps they set a little bit over time so they in fact are equal. According to Kent’s catalogue the installation height is 2mm less than my original, increasing the forces even more, but I’m not going to do that mod. Hopefully my new Yella Terra Roller rockers will not break as the original rockers did. pt

[David H]

Hi Pete, let us know how you get on with the H404. I have one it mine now but don't drive it for a while yet, I'm always interested to hear what people have to say about it.