Engine Knocking After Fresh Build

Calvin Martinsky · Apr 4, 2020

I just finished rebuilding my engine (Anderson B31 cam, .030 Over Forged Summit pistons, The crank was ground, all new bearings and rings, new 1.6 crane stud mount rockers, gt40p heads with upgraded springs, explorer intake, 42lb injectors) and installed an on3 70mm Single Turbo kit. It was hard to start at first, but after adjusting the timing, got it to fire up. The engine ran perfectly (minus being too rich at first until unplugging the MAF sensor because of the wrong table, still needs a tune, but it ran much better with the MAF unplugged temporarily) for a little while, until we put the car on the ground after coolant was bled to test drive, the engine started knocking pretty badly. I relashed the valves with no avail. After putting the car back in the air and starting it with a buddy under there feeling around, the knocking was equally as bad on the transmission, oil pan, and valve covers. We unhooked the clutch cable thinking a misaligned clutch could've been the issue but that didn't solve the issue. Stumped, we pulled the engine out of the car and took the oil pan off. Nothing really caught our eye, but the rods moved side to side on the crank slightly. So then we took off the lower intake to check the top end, didn't find any problems.

I'm pretty much out of ideas at this point, has anyone had a similar problem, or can point me in the right direction of what the problem could be?

evilcw311 · Apr 4, 2020

Post a video to let us here it.

Sent from my iPhone using Tapatalk

Calvin Martinsky · Apr 4, 2020

evilcw311 said:
Post a video to let us here it.

Sent from my iPhone using Tapatalk

ttocs · Apr 5, 2020

damn thats one of those "POLICE AT THE DOOR" knocks...

01yellercobra · Apr 5, 2020

Pull the rod and main caps. Hopefully there isn't too much material taken off. If so you might get lucky and only need to clean the crank with some emery cloth. What was the oil pressure like at start up?

Calvin Martinsky · Apr 5, 2020

01yellercobra said:
Pull the rod and main caps. Hopefully there isn't too much material taken off. If so you might get lucky and only need to clean the crank with some emery cloth. What was the oil pressure like at start up?

I wish I knew, since I used the on3 turbo kit, I used a fox oil pressure sending unit which didn’t read on the gauge. I primed the pump out of the car and the oil flow was very strong coming out of the oil feed for the turbo.

Calvin Martinsky · Apr 10, 2020

I ended up figuring out the problem, failed rod bearing, I was lucky and bought a new pair for the rod and threw it in, bearing measured good. All put back together now and running great!

96blak54 · Apr 11, 2020

Sweet! Im glad the fixed turned out positive!

Is their a better video of it running? Or better yet....how about a video of it pulling? We all like videos!

Calvin Martinsky · Apr 11, 2020

96blak54 said:
Sweet! Im glad the fixed turned out positive!

Is their a better video of it running? Or better yet....how about a video of it pulling? We all like videos!

I actually need one more thing, the car isn’t tuned yet due to me not having the correct transfer function in my computer for my MAF. I’m running a SCT BA5000 MAF. I’ve spent the past few days searching for the transfer function for that MAF, with no luck. It would be greatly appreciated if someone could provide me with that, or point me in the right direction of where to find it!