I recently built my block using Wiseco 9:.0:1 .04 86mm pistons using eagle connecting rods and a 4g64 crank. My head has BC titanium valves (stock measurements), springs, and retainers.

Timing was dead on and it sounded like the valves were tap dancing on the pistons. It made a horrible noise. The block was built by a local shop and everything was done perfectly. The head was built last summer and ran perfectly fine with the stock pistons.

Took the head off and checked out the valves and pistons, it looks as if they were tapping slightly on the corner of the dish where it allows for valve clearance. We only let the car idle and never drove it. The valves have no damage other than the slight marks from tapping the pistons. No bends or anything.

Because of the stroke change, should I opt for a thicker head gasket? If so, what size? The block was not machined much at all, just enough to clean the surface.

Sorry for the novel. Thanks in advance for any suggestions or opinions you guys have.

 

Any chance someone put the pistons in backwards? Meaning exhaust side reliefs under the intake valves?

 

not sure i will check that, also the messed up thing it that it hits really bad on one piston and it hardly hits on the others

 

Here are some pictures of the clay test we did. This is cylinder 2. The indents are from the exhaust valves. The other cylinders had slight indents like the intake ones on this piston. I am guessing this was causing the noise we heard. I cut away some clay to check the depth, but I didn't have an accurate measuring tool to get a number just yet.





Only these 2 valves are having a clearance issue. None of the valves are bent (I just checked them and did a quick valve job this weekend). Timing was then checked after I turned the crank by hand and it was dead on. We have a 1.5 mm head gasket that we are going to try, but I just hope there isn't some underlying problem.

I checked the pistons and it doesn't look at all like it is 180 degrees the wrong way, but I will spend more time checking it out to be 100 percent sure.

 

wrong valves? maybe the two in the cyl. are just longer?

and the piston in backwards sound like something to check

 

I'm 100 percent sure the valves are correct. It is a new set of BC valves and I had them all next to each other when I took them out to check for bent ones. I'm going to check the pistons asap and go from there.

Only problem with the pistons being backwards is that these valves would still go as low as they are going. If the piston was backwards, it would still indent the clay just as much. I'm also going to mess around with the head itself and turn the cams to see what the heck is going on.

 

to get a proper measurment for PTV clearance you need to do this. Go buy some tootsy rolls, leave them in the wax wraper, place 1 over each valve releif, put the head gasket and head on and torque down. After that roll it thru a rotation and then take apart. Once you get back down to the tootsy rolls, be very careful when pulling off the piston, and place them in the freezer for a few hours. Once they get hard, you can cut them in half and get your measurment (still keeping them in the wrapper.)

Once you finish you can have a nice sweet treat too!

Did you have the head milled or did you have the block decked at the time of rebuild or at any point before? The most you can have milled off either (total) and still run a stock head gasket is .030 (asuming you are not running high lift camshafts)

 

well good luck man and deff. let us know my motor is on the stand now for a build and 2.3. is what im looking at to.

 

I would get that head checked to for bent valves. It is not always possible to see stuuf like that with the human eye. They might not completely seal on the valve seat.

 

I've done this before with clay, but seems like tootsies would be easier when frozen. The head was never touched. It may have been cleaned up, but not enough that would take anything off to cause this.

The problem is, it is ONLY these two exhaust valves in this cylinder. If the head or block was milled off too much, the other valves would indent the clay just as much. The intake valves in this same cylinder are only leaving a slight indent (like the rest of the valves in each cylinder).

As I said in an earlier post, I already had the valves out. I removed every single valve and none were bent. They were installed perfectly.

I water tested them before removing them and it had no leaks. I also water tested several different ways after putting it all back together. No leaks whatsoever.

I am going to take these two valves back out and see what is going on with them, but when I had them out before, they were perfectly fine. I had them lined up next to the other valves when checking. Spun them all in a drill and ledge tested them. These things are perfectly straight.

 

The tootsie roll thing is an awesome tip, I will keep that in mind! The valve releifs are diffrent from on side of the piston to the other so this could be your problem. No way you can mix up intake and exhaust cam right? Did you order the pistons for a stroker?, the pin height of the piston is different for the stroker application.

 

I noticed you have aftermarket cam gears, you sure you have the dowel in the right whole. My came gear had two wholes, one was correct and one was like 90 degrees off I think for an eclipse. I am really intrested to see what this is, Its odd because its only one cylinder, Although my car jumped time once when the tensioner pulley slipped and it only dropped one cylinder. No valves got bent or anything, just driving along then all of a sudden subie mode. Towed it home put it back in time ran like a champ??

 

Back from the dead. Curious on what headgasket was used. I´m building my engine with 86mm pistons and the OEM gasket extends a tiny bit into the cylinders.