Imagine that...all that drama and just now pulling the pan. Where's all the engine experts from earlier? Lol
I've seen piston to head contact on bored F motors, if the combustion chamber is not enlarged. It'll sound exactly like rod knock, and won't always be consistent. I doubt IP would over look that as I know theyve had CP make piston with outter diameter reliefs for that exact reason. Nevertheless, something to inspect.
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Hey man, I own a business and am a father to two young kiddos... I don’t have time to wrench every weekend.

Nevertheless, I’ve been building cars for 15 years now and have never heard the sounds like this thing made. It literally sounded like a bolt was loose and jumping around inside the valve cover. I couldn’t believe I made it home with the motor still running that day and am shocked that the pan came up clean.

 

Bad knocking but no metal anywhere? That is very interesting. Next step would be to pull the head and inspect the cylinder walls?

 

I'm going to do a compress/leakdown test this week/weekend to see what happens. I dont even know what to expect at this point, haha.

I can't imagine the engine making noises like that and no evidence of anything afterwards.

 

Hard to see if piston crown hitting combustion chamber is the issue here with head on,maybe a cam down the plug hole.

 

This is what it'll look like, If it's actually the problem. And tbh, it'll clearance itself.

 

Yes but it would do this and make noise outside of 2,500-3,500 rpm though, right?

I would think it would make a racket all the time if this were the issue.

 

Not necessarily. I've seen it perpendicular to the piston pin as the piston rocks on it, but piston doesn't rock above a certain rpm.

Just scope it. You'll be able to see it, if this is actually a problem.

 

So it's the cylinder head/gasket.......

I did a leakdown tonight with the header detached from the head. Obviously motor was ice cold but here are the results:

CYL1: 60% leakdown with air coming from exhaust valve, cyl 2 spark plug hole, cyl 2 exhaust valve

CYL2: 60% leakdown with air coming from exhaust valve and cyl 1 plug hole

CYL 3: 30% leakdown with air coming from exhaust valve and cyl 2 plug hole

CYL4: 15% leakdown with air coming from exhaust valves and cyl 3 plug hole

Interestingly enough, I did have the radiator cap off during the test and didn't have any bubbling or anything of the sort from the cap, although I am running a sideways radiator so it's about triple the capacity of coolant and with so much pressure escaping through the plug holes and exhaust valves, I assume I didn't have enough to bubble the coolant. The car does not use coolant, blow white smoke, anything like that.. BUT I did notice in the week or so leading up to the track day that after running the car hard my radiator hoses seemed pretty pressurized. I attributed that to the up-rated rad cap that came with my sideways radiator.


I've long suspected this head wasn't 100%, but inline pro rebuilt it and said it was good to go on the first engine build I did with them. It was part of their refresh signature series "package".

The previous owner made some posts on s2ki from 10 years ago stating that the car shut off at a redlight, wouldnt idle correctly, etc. He said he took the car to a "shop" where they found some "valves screwed" and fixed it. When I first took this car to inline pro, they found sunken exhaust valves and botched machine work done to the head, so they machined in new valve seats on I believe all the exhaust valves.

Now, I've had the TCT rattle since I bought the car. I've replaced the TCT with a Billman TCT, never fixed it, then Billman sent me a revised TCT, didnt fix it, then Inline pro put in their "race" TCT, still hasn't fixed the rattle. On the 3rd engine build from inline, I requested they replace everything timing related with new OEM parts, which they did... still didn't fix the rattle.

I believe I have a head that's been milled to out of spec. With the previous owner machine work and inline pro milling the head during their rebuild, AND my TCT issue not going away... I highly suspect my head is out of spec, timing off a bit, and obviously now the head is warped/gasket/something.... If this is true, this could be the cause of all of my engine issues right? With timing/compression different than what inline/tuners are expecting, then the cylinders would be heating up beyond expectations causing the pistons to expand and score... right?

 

It is sounding like there is something wrong inside the cylinder head that is causing your rattle, or "knock" which is totally possible, and it is time for a new head.