[deanbradford]

Anyone got any ideas as to what this strange metallic sound might be on the right side. It's not an air leak or fan rubbing as I had taken the fan belt off to test. Newly built engine runs great on the test stand but a bit noisy.

 

[Mr.Whippy]

Sounds like metal to metal rubbing. ??? maybe.

Did you check the ring gaps prior to build ?

Dave.

 

[lukej]

I'm thinking tight piston pin or piston slapping?

How you'd go about diagnosing it I really don't know, maybe run it with no1 plug out then no2 see if you can narrow it down.

What did the engine come apart for? What's new with it?

 

[deanbradford]

Did check the ring gap and all seemed good. Engine has run around 2 hours without this issue.

Had to rebuild the engine after recently CB Performance cam follower and FK10 SC1 failure. Engine has now new FK10 and new Scat lub a lobe followers. Cam burn went well using the running in oil I think Lukej recommended.

All was well then I readjusted my rocker shaft clearances to 4 thou and it started to make this metallic sound. I plan on swapping over the rocker shafts to see if the noise moves over to the left side. If not maybe it is a tight wrist pin. Can you still run if it is and hope that a bit of wear will sort it out or will it get worse if not sorted?

 

[lukej]

Ah yeah, I remember!
Glad break in went well.

Good shout on moving the rockers around, worth checking none of the pushrods are rubbing, also, check all of the rockers move freely if you're swapping sides.

IF it is a tight pin, I've no idea if it'd get better or destroy something... assuming the engine is still out of the car, it's probably worth pulling the head off the 1/2 side.

 

[deanbradford]

I'm pretty sure it's not a tight wrist pin as I got them through the piston to a point where they slide onto the rod a bit (may be half way) and then tap them through. They were tight on the piston but with a rubber hammer managed to tap the pin home ok.

 

[lukej]

Sounds promising then.
Were you running an Fk10 last time? Same rockers and pushrods?
Is there any chance you have a valve kissing the piston? Maybe you left some cylinder shims out on the 1/2 side? Or coil bind? Or retainer hitting the guide boss?

 

[deanbradford]

Installed another new FK10 and same rockers and push rods. Just turned the engine over slightly with a wrench on the pully nut and there was a very slight metallic click sound as if something freed up. Possible rocker shim heating up and sticking although gaps seemed to ok. Swapping rocker shafts over should confirm that.

 

[lukej]

Possibly wrist pin popping out and pin hitting the cylinder wall?

Hope its as simple as the rockers, keep us updated

 

[deanbradford]

used Teflon buttons so no fear of that.

 

[lukej]

Awesome :hangloose

 

[deanbradford]

Swapped the rocker shafts over and adjusted a couple for side clearances. Metallic noise seems to have gone.