Could it be a leak at the carb spindles? Check in between the carb's barrels where the spindle enters and exits using a hose as a stethoscope. The carbs can leak air timed to the cam stroke. Weber's are notorious, apparently, and what is a sharp chuffing noise can sound awfully like a loud clicking noise.
If you’ve had to re-torque the heads it could be a head to cylinder leak – do those 104’s have a fairly narrow sealing face? But that sounds mechanical to me, rather than a gas leak. Light, like a tappet. I think I’d be pulling the cam followers before trying to remove the heads in a car park. And you could poke your fancy borescope thing down the hole and have a look at the cam.
I haven't lost or gained any tappet adjustment since new. I've got as far as everything done except the stuff under the rocker cover, I haven't jacked up the van or lowered the engine or drained the oil. So far so good.
Pretty quiet in the engine bay on the vid? The sound is loudest underneath but not at the exhaust ports. I'm praying @77 Westy is wrong about the cam connection, anything cam would cause me a bit of a logistical problem.
Sorry, hard to tell from a video, in my defense, if it is an air leak the sound can travel. I can certainly hear your noise
Don't ask me, I'm out of my depth! It looks like it's been blowing in pretty much every direction to me, but the sealing surface is shiney and clean. If this was a stock type-4, just re-fitting the head would probably cure it. Think I need to do lots of measuring, I have a 300mm vernier somewhere... I stopped to eat, I'll go and measure the deck in in minute. I'll cobble something up to roughly cc the head when I've done contemplating it in this natural state.
Haha, I thought you'd enlighten me! I agree it looks like its blowing doesn't it. How else does the carbon and muck land there? Fast work!
I always get a bit fretful of these bigger bores and the way the barrels thin down and how they encroach into the head bolts. The chap who built my Bug engine used 90.5, said he wouldn't advise 92 on a street car, not for longevity sake. I might be tempted to up the crank next time, but I am hoping that's some way off.
I can’t add anything to the obvious - it’s been leaking especially #2 if RH or #3 if LH. but what caused those divots (or is just a bit of dirt?) in the sealing face of #4 (or #1)? And I’s still remove the followers.
Have they been machined to clear the valves? What has happened to the top photo, it looks like it's interfered, possibly? What I am missing?
