· 475RWHP 449TQ and climing
I had great compression like 180 across the board with a 1.2mm metal hg. I had a new oil pump with 8k miles on it. Every thing ran fine then when driving at 60mph knock occured. Well after taking the engine apart with the great Chevyeater we discovered that the oil pump drive shaft was the culprit. The bushing in the front where it bolts to the block was out of spec and worn. This caused the shaft to move forward and backwards causing the pully drive gear to erode to the point where the shaft no longer was spinning with the engine. The pully turned but the shaft itself was rounded off and it did not turn with the pully. Thus oil pressure dropped a bit then just let loose and started knocking from lack of oil. :dunno: All of the bearings, and mains were fine except rod #1 which the bearing was fused to the crank. The crank other than rod jounal #1 was micro polished in perfect condition after inpsecting it. Chevy gave me a 7m crank which is 10 over and polished ready to assemble, with clevites, and arp rod bolts, and all rods recut and sized!This down period has allowed me to sell of all that I had to get a gt4088 and go foward facing intake so it was a benefit in a way. Hopefully the ffi pics will be up in a week or so, since I am still waiting for my fabricator to finish it. Wow did it look sweet when I saw it. Sooo..... Look out for worn oil pump drive shaft bushings that is on the front of the shaft where it bolts to the engine. Make sure that after it is bolted to the block that there is no play or backwards and forwards movement! For some of you 7m beaters this is not a 7m is a knock felon thread. It merely is to show that if one thing is done wrong when doing the engine at any stage of the game knock will and can occur. You must be very dillgent when doing a rebuild.