Thread: V8 valve springs

Certainly a bent valve, from whacking around on the piston.
Did you by any chance install a high lift cam?

Regards Philip A

G`day ,

few yrs back , 4 ltr short new crated 8.23:1 , std composite elring 10 bolt gaskets 3.5 heads but machined to have 21cc chambers . Heads don`t have stem seals like yours so the guides are shorter that end , so valve could drop further . Cam a little higher lift than std .

During the run in period it broke a valve spring , bought new springs , fitted without removing heads , all good but i may have been very lucky .
.
Couple of yrs back replaced 10 bolt composite for 14 bolt composites which are thinner so as to raise the compression a bit more and when apart the piston top was unmarked .

Don`t throw odd things out , the spring is broken in 1 place at 4 1/2 coils and 2 1/2 coils .

The piston top should show the initial strike and also if the valve has broken ( but i guess the camera wont show that side ) the stem guides are very brittle and harder than alloy also and if the valve dropped that far , what i`d more expect the bits to be . When you have the head off have a look at both valve runners they will probably be pitted also .

I guess you know what a broken ring and piston top look like ? is it similar ?

Peter

The quick look I had showed ball pein hammer type marks all over the top of the piston,,
I wouldve expected sharp half moon gouges if a piece of valve head was bouncing around in there,,

so, these things just break springs?
randomly?

Have you had a good look at the spring ?

I've broken springs in a 351C, but only because whoever did the heads installed springs that were damned near coil binding at full lift.

I eventually dropped a valve, IIRC it was a year or two later but I was organising new bits for a new engine at the time anyway.

Also broken a spring in the race car, it was a bad spring, there was a stress raiser when you had a close look at the wire.
Probably installed a new valve, can't recall ?

Originally Posted by Pedro_The_Swift

so, these things just break springs?
randomly?

I`ve seen mention of 2 in V8 Rovers , yours and mine .

Stem guide is rounded so could possibly , valve pieces i`d expect to look like broken ring .

Chamber should be marked as piston

Maybe something was dropped/left in the inlet on reassembly , like a dowel

Guessing games forever , when apart should be obvious

This is the first time I have ever heard of Rover V8 engines breaking valve springs..

My original 3.5 ran for 33 years and 345,000km with no problems in that regard, but mine is but one example.

Now I know that not all Rover V8 parts these days are OEM, some are utter rubbish so it pays to be careful.

Were the valves springs that broke OEM or aftermarket, and if the latter, which brand?

Ron.

They are dead stock,, just over 100K old,,