Need help, timing jumped, bent valves??

[turbolover10]

Just wanted to update and say thanks for the help. I ended up having to get the head rebuilt but all is well now.

 

[xchrisx]

sorry to thread jack, but how do you replace valves if they are bent?
I have a 96 n/a and the intake valves are bent, I know this because when replacing the timing belt the cam was very stiff and after putting everything together and timing it correctly, the car wont stay started and smells terrible and basically well wont start but i had a feeling i bent the valves because when driving the belt came off and skipped a bunch of teeth which is why i did the belt in the first place.

 

[bryanwheat]

You can't usually just replace the valves. The guides will probably be cracked, and will need to be replaced. If the guided need to be replaced than you will have to have the seats re-cut also so that the valve is concentric to the seat.

 

[bullettdsm]

You can't usually just replace the valves. The guides will probably be cracked, and will need to be replaced. If the guided need to be replaced than you will have to have the seats re-cut also so that the valve is concentric to the seat.

Actually, you CAN usually replace just the valves. We have done a multitude of these with just replacing valves (I'm guessing 15 done by me personally). Guides were fine, The problem with the design on these cars is that it doesn't take much to bend a valve when it is hit at an angle by the piston.

As for how to do it, you will have to remove the head and take it to a machine shop where they can check it out (or get a replacement head). They can determine what valves are bent and if, by any chance, you need to replace the guides. They will seat the valves etc. for you.

MB

 

[bryanwheat]

Most Every 420a head that i've put rebuilt that had bent valves i had to replace a few, to all of them. They aren't usually real visible, some i've seen with a chunk broken out and some are just a tiny hairline crack.

 

[Shake_Zulla]

Actually, you CAN usually replace just the valves. We have done a multitude of these with just replacing valves (I'm guessing 15 done by me personally). Guides were fine, The problem with the design on these cars is that it doesn't take much to bend a valve when it is hit at an angle by the piston.

As for how to do it, you will have to remove the head and take it to a machine shop where they can check it out (or get a replacement head). They can determine what valves are bent and if, by any chance, you need to replace the guides. They will seat the valves etc. for you.

MB

Where do you stand on checking out the pistons Mark? If I was in the op's shoes I would be getting those looked at.

 

[bullettdsm]

Where do you stand on checking out the pistons Mark? If I was in the op's shoes I would be getting those looked at.

Honestly, it depends on the parameters of the thread jacker. If he's got a car that let a belt go at 7k and the valves are all smushed, then he has no choice but to check the pistons. If he has a belt that let go at regular driving/idling and he pops the head and just has some small valve marks on top, he will need to make a decision. Does he want to roll the dice that there was no damage (as in internal cracks etc.) to the piston?

In the case where you just have some slightly bent valves, the chance of them being cracked is pretty slight. I would have no problem recommending that he go ahead and fix the valves/head and put her back on with a visual inspection of the pistons to see if there are multiple hits and gouges.

MB

 

[flipinit25]

Horrible problem i think i set my 420a motor 180 degrees off i fixed it i am wondering if i might of bent any valves if any info i would love to know also i have spark and fuel and it wont turn on ive even sprayed starting fluid in the intake and nothing cranks over its a fresh new crank and pistons and rings i just dont understand it