What causes burnt valve/valve seats and high combustion chamber temperature.

[Minaj]

I asked the builder was specs he set the valve lashes to, he said to kelfords spec. It runs kelford 103lb springs.

[EJ20T]

Yeah hes always going to say that right? Has anyone measured the vavle length yet? What conditions was the engine run under? High egts effect engines run under constant load like boats or planes more than automotive engines. If u had valve temps that high the exhaust manifold would be white hot

[Minaj]

 EJ20T said:

Yeah hes always going to say that right? Has anyone measured the vavle length yet? What conditions was the engine run under? High egts effect engines run under constant load like boats or planes more than automotive engines. If u had valve temps that high the exhaust manifold would be white hot

Yup, no one has measure it yet, the whole engine has been stripped except the short block. Car get's driven once a week and only has done 7 runs down the 1/4. Other driving is just city and normal cruise driving.

[Minaj]

 Minaj said:

More, I'll have a look when I get home.

One is 2 degrees and the other is 5 degrees

[Minaj]

Here are some photos.

[Minaj]

[Minaj]

Also forgot to mention, the valves have deformed, like the face of the valve is not flat, it's mushroomed in.

[Rosssub]

Still thinking the exhaust cams have been dialled in wrong, pistons kissed the valves at high RPM. Bending the valves slightly causing them to leak, then burn the seats out.

[EJ20T]

With how little running its done I would agree with rosssub, the valve hasn't been uniformly on the seat causing combustion gas to flow at high temp and speed past it. This is unlikely a extreme egt failure. Normal valve burning doesn't result in piston damage

[Minaj]

Not only the exhaust valves have kissed the piston, I think one or two intake valves have also kissed the piston. Have a look at the picture of the pistons on the previous page, you will see 3 marks where the valves have kissed the piston. Cam timing was maintained and everything lined up.

[Minaj]

Just got the heads back from another assessment I got done, another thing which they noticed is that some of the intake and exhaust valve had a lot of clearance When we opened the valve, we moved it side to side and found a lot of clearance in the intake and exhaust (some had more clearance and some didn't).

[EJ20T]

The guides are worn? That can be a cause of valve burning, the reason I went for manganese bronze guides.

[boon]

I pulled down a 200000km motor recently and the valves looked healthier than that.

The valve deformation blah blah to make it trash the piston like that is pure BS.

The motor was assembled incorrectly, if the person who assembled it continues to deny this I would either take them to the disputes tribunal or if the money involved is more than the maximum I'd be straight off to the District Court with a statement of claim or whatever they call it.

[Minaj]

 EJ20T said:

The guides are worn? That can be a cause of valve burning, the reason I went for manganese bronze guides.

it has bronze K Liner valve guides.

Edited May 20, 2015 by Minaj

[Minaj]

 boon said:

I pulled down a 200000km motor recently and the valves looked healthier than that.

The valve deformation blah blah to make it trash the piston like that is pure BS.

The motor was assembled incorrectly, if the person who assembled it continues to deny this I would either take them to the disputes tribunal or if the money involved is more than the maximum I'd be straight off to the District Court with a statement of claim or whatever they call it.

Yup, I'm going to see how things progress tonight with the builder and makeup my mind after. I've already got my reports done and it's not looking good his way.

[SpeedySub]

Sorry but I have no helpful info, just a question regarding Photos 3 and 4 on the first page. They show marks in the combustion chamber around the valves and spark plug, was this caused during engine operation or from trying to get stuck valves out? it seems strange to have damage there. Also in the same photos it looks like the combustion chamber looks a little oily on one side compared to the other chambers is this anything to do with your issues?

[Minaj]

 SpeedySub said:

Sorry but I have no helpful info, just a question regarding Photos 3 and 4 on the first page. They show marks in the combustion chamber around the valves and spark plug, was this caused during engine operation or from trying to get stuck valves out? it seems strange to have damage there. Also in the same photos it looks like the combustion chamber looks a little oily on one side compared to the other chambers is this anything to do with your issues?

The pictures is of the motor apart, I have not touched anything. Nope, nothing to do with the issue. The issue here is a dropped intake valve and all exhaust valve seats burnt and some exhaust valves burnt.

[pedro]

 SpeedySub said:

Sorry but I have no helpful info, just a question regarding Photos 3 and 4 on the first page. They show marks in the combustion chamber around the valves and spark plug, was this caused during engine operation or from trying to get stuck valves out? it seems strange to have damage there. Also in the same photos it looks like the combustion chamber looks a little oily on one side compared to the other chambers is this anything to do with your issues?

One of the exhaust valves has got a segment busted out of it and it has rattled around in the combustion chamber..Wonder where it ended up ?

[SpeedySub]

 pedro said:

One of the exhaust valves has got a segment busted out of it and it has rattled around in the combustion chamber..Wonder where it ended up ?

That would explain it, now I look at the photos again. Didn't put 2 and 2 together.

[boon]

 pedro said:

One of the exhaust valves has got a segment busted out of it and it has rattled around in the combustion chamber..Wonder where it ended up ?

A good look at the turbo's turbine wheel would tell you whether it got slurped up the up-pipe or if it's still chilling out in the headers somewhere

[hijacka]

Bugger hopefully you get it sorted in the end man sounds like a expensive piece of machinery! .. yes there is not much leg room before the valve touchy touchy the top of the pistons.

[hijacka]

Bugger hopefully you get it sorted in the end man sounds like a expensive piece of machinery! .. yes there is not much leg room before the valve touchy touchy the top of the pistons. fwiw i remember reading crawford? or someone like that do adjustable tensioner bolts for the tensioners to pull in the slack from machined blocks and heads etc

[Minaj]

 boon said:

A good look at the turbo's turbine wheel would tell you whether it got slurped up the up-pipe or if it's still chilling out in the headers somewhere

Turbo exhaust wheel is also buggered.

[Minaj]

Bump

What causes warped heads ? I know overheating does but anything else?

[SpeedySub]

 Minaj said:

Bump

What causes warped heads ? I know overheating does but anything else?

Im guessing incorrectly torqued head bolts?