Kachess
TY 4 Stroke Junkie
I re-shimmed my intake valves on my 03 rx1 (11000 miles). Slapped it back together, spun it, checked compression, fired it up, and "clunk". Timing chain jumped the intake cam sprocket and bent no. 1 cylinder intake valves. I haven't removed the head but I can see the caps are not up.
First of all, is my head shot or can I typically just replace the valves? How about bent rods?
Secondly, I realize I should have checked the cam to make sure it spun freely, or as freely as they turn. I was carefully to not overtorque the camshaft keeper bolts. What may have gone wrong? I've done it before on this sled and one other, and not had this problem.
First of all, is my head shot or can I typically just replace the valves? How about bent rods?
Secondly, I realize I should have checked the cam to make sure it spun freely, or as freely as they turn. I was carefully to not overtorque the camshaft keeper bolts. What may have gone wrong? I've done it before on this sled and one other, and not had this problem.
grizztracks
Tech Advisor
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You should be able to replace the valves. With the head off check the pistons, valve guides, and valve seats for damage. If they're Ok buy some lapping compound and lap the new valves so they're properly seated. When you get it back together rotate the engine by hand until the chain tensioner takes up all the slack. I use tie straps on the cam gears to hold the chain in place when I rotate the engine. You have to keep repositioning them as it rotates but normally after one rotation the tensioner will remove any slack in the chain.
http://www.ty4stroke.com/viewtopic.php?t=90826
http://www.ty4stroke.com/viewtopic.php?t=90826
Kachess
TY 4 Stroke Junkie
The pistons and head look OK so I ordered new valves. My concern is the intake camshaft does not turn freely. I cleaned up the journals with 600 grit Emory cloth and the shaft still sticks in the journals. The shaft doesn't seem to sit all the way down in the journals, or the caps. You have to force it in, and almost pry it out. The intake cam shaft seems to rotate freely. Is my head shot?
grizztracks
Tech Advisor
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- USA
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- FX Nytro RTX, RS Vector, SR Viper RTX SE
I'm not sure if the cams have the same diameter journals but if they are can you swap the two cams to see if it's a bad cam or the head causing the problem? The cams should sit down in the journals without forcing them and rotate freely. Are you sure you don't have a burr on the cam or journals?
Kachess
TY 4 Stroke Junkie
The cam definitely sticks in the journals. I'll hit some more with emery cloth. This is the second time I've had my valve clearance on cylinder four close up to zero so that the intake valves won't seal when the engine is cold. Once warmed up I have compression. I can't imagine what make the clearance close up but I wonder if it is connected to way the CAm is sticking in its journals.
