stalker26

So a few weeks ago I broke my timing chain.... I found out that I have probably bent some valves to go along with it.. but I wont know that until about wed when the mechanic has the timing chain back on and checks the valves. Now this being said.... I was wondering what I could do since the mechanic is already going to have to mill the heads, what else could be done, relativly inexpensivly to make more performance. ANY IDEAS?

Neumonic2002

What is done to the car or is it stock?

glenB

Your statement makes no since. If he's pulling the heads, why wait to determine valve damage? This can be done prior to replacing the timing chain and should have been part of a complete diagnosis.

Sounds like your tech is double dipping the labor

What is relatively inexpensive?

hungryhippo

take it somewhere else. a leak down test can be done as it sits and will tell you if any valves are bent.

timd38

If they can't tell if the valves are bent when they take it apart, take it to another shop.

old motorhead

Even if you did bend valves, milling the heads is kind of way down on the list of things that may need to be done. Bent valves can be diagnosed without removing the heads. A simple (and cheap)compression check can give you a clue whether you need to dig deeper. Valve springs can then be removed on suspect cylinders to see if the suspect valves move freely and/or rotate. Heads may or may not need to be removed. At least that's the way I'd approach it.

LEAVINU

Assuming this car is cammed if you snapped the TC, correct?

stalker26

My car is bone stock. And He is going to check the compression before takes the heads off.... but from everyone that iv asked, they automatically assume that I have bent valves.

stalker26

Anyone have any ideas?

johnodrake

Head and Cam - at least. If it were me- H&C and all forged, stroker.

Vito.A

Depending on the RPM conditions when your chain broke will depend on how many valves are bent. Sometimes it is the cam gear bolts or dowel pin shearing and it will skip a couple of times before breaking. Either way, some of the valves are left hanging and the pistons then play tag with them. You could have from 4-16 valves bent. Worst case is a valve head breaks off and breaks up the cast piston and then the connecting rod thrashes the block.

I would do a leak down check on all 8 cylinders before tearing it down. You will have to back off the rockers to get the valves closed as the cam is no longer being turned by the crank.

While you have the heads off you may want to change the cam and add a set of headers.

glenB

He needs to do a leak down test, not a compression test ...

z51vett

They all drive foreign cars and yes you break a timing belt or chain on a foreign car and you bend the values. Ls engines may or may not bend values.
z51vett

stalker26

everytime I ask my mechanic about a cam. He says that we would have to pull the engine to do that. Is this true?

Pack Leader

If you back off the rockers to close the valves, you can hook up an air hose with an adapter to the spark plug hole. With air pressure applied if you have a bent exhaust valve you will hear the air leak from your tail pipe, same for the intake you'll hear it from the throttle body. You can do this pretty fast on all 8 cylinders.

No need to pull the engine for a cam swap, find a different shop. My 02 centavos.

stalker26

how would you change the cam without pulling the motor?

AORoads

the way this is going I hope you have a lot of money. this is sounding very expensive....

Pack Leader

Stalker, sent you a PM on camshaft. Hope that helps.

Finja

Not completely true. There are non-interference motors........I have made good money off people like you haha........some turbo cars will not bend valves because there is enough clearance......I find those that think thats whats wrong, by it for cheap, replace belt and sell....

Anyways, on the LS motor there will most likely be at least a few bent valves......unless the chain popped with the motor not running

Finja

Pull radiator..........