[Cam Timing Fix Contd]: head/cyls removed, 2 bent valves...

[Dave_A]

I had a valve cover bolt bust off. So I had to take the head off.
This resulted in me busting off the 4 exhaust bolts...

I plan to have these professionally removed, so as to avoid damaging the head.

The cam bearings don't look burnt out or damaged, and everything inside seems to look ok (with the exception of what's mentioned in this post)...

While I was at it, I also pulled off the cylinder block to take a look at the pistons....


1) What should I look for WRT ring, piston, and cylinder condition?

2) Any suggestions as to where (what kind of shop) I should take my head to get the screws extracted?

3) It also turned out that I have 2 bent valves (exhaust valves), which have made a nice shiny mark in the top of the piston head. The rest of the piston surface is covered in some sort of deposit, either rust, soot, or both... Is any of this a problem, should I try to 'clean up' the piston heads, etc...???

4) How do I know how much damage has been done WRT the bent valves (I know I need new exhaust valves, but what else might be wrong? The valve-bending ocurred as a result of trying to re-start after a stall, not as a result of engine operation)...

5) Are valves easy to replace, or should I have that done for me too??? If they are easy enough to replace, what parts must I order, and which ones can be re-used???

6) Is there anything else I should consider doing while I have the head & cylinder block off???

[SqDancerLynn1]

First I would take the head completely apart and have it abn the barrell cleaned/ bead blasted make them look like new. Have the valve guides checked, Lap the valves if needed, replace the bent valves, replace the valve stem seals. I would have the cylinder miked If it is within tollerances,I would hone the cylinders and put new rings in the motor. Put it all back together Let the machine shop deal with the broke studs if you are unsure about removing them

[Dave_A]

Well, I took the head in to my local shop yesterday...

They're working on getting the stuck bolts off...

They're also going to take the valves out (no extra charge) and tell me if I need new guides... They also quoted me $30 to hone both cylinders...

How hard is it to change valves? From what I understand, I need a tool to compress the springs, and a feeler guage to find out what size shim-plates I need...

Anything I'm missing here????

[cbxchris]

Since I can`t see how bad your valves hit the piston when you get the pistons and block ready do this. Lets just say you bent valves on #1...put the pistons on the rod on #1&4 with only the top ring on. Bring your pistons to top dead center...are they the same...good way to check for a bent rod. I dropped a valve last year in a hayabusa and found a bent rod this way. Personally I would surface the head and cylinder to make sure they are flat. Hope everything goes well!

[Anonymous]

How hard is it to change valves? From what I understand, I need a tool to compress the springs, and a feeler guage to find out what size shim-plates I need...

It's not too hard to change the valves. You will need either to buy or make a valve spring compressor. If you don't have it on hand already, get some grease to hold the valve collets in place while you release the spring.

Michael

[Dave_A]

Since I can`t see how bad your valves hit the piston when you get the pistons and block ready do this. Lets just say you bent valves on #1...put the pistons on the rod on #1&4 with only the top ring on. Bring your pistons to top dead center...are they the same...good way to check for a bent rod. I dropped a valve last year in a hayabusa and found a bent rod this way. Personally I would surface the head and cylinder to make sure they are flat. Hope everything goes well!

I have valve-strikes on both pistons (2cyls, 2 valves per cyl), in both cases it is the exhaust valve that hit... So if one's bent, they're probably both bent...