Cause of ticking

[maldotcom2]

Ok I just shot 100 PSI up the exhaust pipe and got under the car with soapy water. I found some leaks around the flanges which I have repaired with new gaskets, bolts and high temp silicone. The noise is still identical so it wasn't that. MACE, if I buy your CROW lifters do you have the specs for preload so I can determine whether or not I need longer/shorter pushrods?

Does anyone else have tuned length extractors? I'm wondering if this is amplified valve noise.

 

[MACE]

"Ok I just shot 100 PSI up the exhaust pipe and got under the car with soapy water. I found some leaks around the flanges which I have repaired with new gaskets, bolts and high temp silicone. The noise is still identical so it wasn't that. MACE, if I buy your CROW lifters do you have the specs for preload so I can determine whether or not I need longer/shorter pushrods?"
Yes that's not a problem

"Does anyone else have tuned length extractors? I'm wondering if this is amplified valve noise"
Before changing lifters I would try somehow physically mount this material to each header (or use exhaust wrap to a lesser degree)

ACL Race Series Heat Shield Material

This will dampen help in dampening the sound.

 

[maldotcom2]

Thanks MACE,

I'm pretty skeptical about sound deadening. That would be a band-aid fix. I'll probably have to take the plunge and get the lifters (yes pun). FYI I noticed while running the motor with the rocker covers off that there was bugger all oil coming out of the rockers. Some rockers had no oil after 10 minutes of running.

To the guys suggesting it's injector tick, I could try unplugging the Cam Angle Sensor and see if that changes it to a slower tick. My understanding is this sensor controls the sequential injection while CAS controls ignition? If my thinking is correct it should then pulse all injectors at once like the buick.

 

[MACE]

Thanks MACE,

I'm pretty skeptical about sound deadening. That would be a band-aid fix.

If there is an underlying mechanical problem then I completely agree with what you're saying.

However, if you had the same sound before the build, what could it be? I guess you can try changing the lifters and checking the injectors

Keep us posted

 

[maldotcom2]

Ok I put in a new set of Crow lifters and nothing has changed, when I first tightened up the rockers with the new lifters I counted 2 full turns from zero lash to hand tight (25 Nm?). I'm not entirely sure what the torque spec is on those YT cap screws but either way i'm looking at around 2 turns of preload at the moment. Too much?

I've taken it for a drive to run them in a little, i'll recheck the preload once it all cools and the lifters bleed off.

 

[Immortality]

I think it's a 5/16" unc bolt? 18tpi so the thread pitch is about 1.4mm or (0.056") per turn. so 2 full turns of pre-load would be about 2.8mm or 0.112" pre-load which is to much. Have you checked with Crow to see what the recommended pre-load is to suit there lifters?

From hand tight it's probably another 1/4 - 1/2 turn before the bolt is torqued to spec' so the pre-load would be even more

 

[maldotcom2]

By hand tight I mean nipping it up with a short handle Allen key. But it 2 turns sounds excessive, i'll have to recheck the exact amount of turns because I wasn't sure what the torque specification is on YT ultralites. Does anyone know?

I have noticed that the engine is now very smooth while cruising. No vibration, idle is much less lumpy, no popping on deceleration. Although top end power seems to have dropped off.

 

[Immortality]

the torque required is based on the fastener, so in this case i think MACE recommends 23Nm for there 5/16" cap screw bolts so the YT items would be much the same

 

[MACE]

We recommend 23 ft/lbs for the fasteners.

In regards to lifter crush 1.5-2 turns is what we aim for with these street engines.

In saying this though, if you feel that power output has dropped off top end you would have to log how that car is running, as you may be getting more effective lift (changing AFR's) or the valves might not be seating properly at higher RPM.

Regardless though that ticking is likely coming from your extractors, it seems

 

[maldotcom2]

Well as long as 2 turns is not risking bottoming out the lifters i'll just leave it and send the bastard to the exhaust shop. The car has landed on the extractors going over speed humps so maybe there's a crack that they could find.