so I have and engine noise Ive had in my cuda for probably 10 yrs I cannot seem to figure it out. gave up till I freshened the engine up now it bothers me. first I am a trans and engine tech for dealer I build engines and transes every day for 30 years. master tech at a dealer. of course not building 440s anymore but I know how to build and diagnose engines this one has me stumped. first the engine was a .030 440 stock forged crank and rods trw forged dome pistons the infamous 509 purple cam stick valve train single plane intake hooker headers. mallory dist only use the car nice sunny days and spends 5 months in winter hiding so only gets 3k mi per year on it. never burns any oil plugs always looked great. holley 850 hp 4spd 390 gears. of cource with that cam driveability under 3k sucked but loved the performance. the noise sounds similar to road knock but its not. tried stethescope cant pinpoint it tried killing cyl 1 at a time makes no difference. you hear it loudest standing center in front of car or leaning over engine. but only low at idle if I raised idle to 1100 or more it does away. I can hear it low rpm driving to my trained ear most people riding in car dont hear it. Its kind of a thump sounds like crankshaft speed not cam speed. I replaced fuel pump etc made no diff. so I gave up on it and just drove it. last year I had an oil filter failure and all of a sudden low oil psi so I took engine out and time to rebuild. great Ill find the noise now right?
decided to upgrade some stuff while its apart so had 2 machine shops check pistons after I mic them skirts had no wear on them cyl measured ok only thing I found wrong in engine was 2 and 3 main bearings scared up and crank. not spun just beat up looking. that bearing failure happened that day never had an oil psi problem till that day. doubt that was the noise but couldnt find the noise.
so new build stealth heads had mild pocket cleanup 3 angle valve job new springs to match cam and retainers with 10 deg locks. new cam higher lift mech cam but shorter dur 235 dur 540 lift. using push rod length checker obtained correct push rods and roller rockers. cloyse double roller so whole entire top end of engine is brand new. lower end crank machined .020 .020 clevite bearings rods resized arp bolts. pistons machine shop cleaned up etc arp main bolts oil system mods opened oil holes center 1/2 pickup melling high vol cam bearing rotated with left oil galley plugged .010 hole in plug full time oilling to heads through tubing with a .045 restrictor. 11:1 comp motor runs awesome drive ability even allot better than before thraction is a huge problem now. however after all that the freaking noise is there and now it bothers me casue I never found what it was. so did all the diag again you can hear it in stethescope in the center of oil pan or valley pan you cannot hear it in heads or block really take pow steer belt off no diff take main belt off and you can hear a diff. it again only at low rpms. so I changed water pump and made no diff. cant hear it in WP housing or timing cover or fuel pump shes tucked away for winter so I figure it has to be piston slap because I did not bore it this time. but I would think if it were slap you would see some evidence in the piston skirts. so I am ready to give up and drive it and ignore it again.
no I build a 451 stroker motor for my brothers 32 plym this motor received full treatment brand new everything piston rings bored the works. his has elect fuel pump he has my ported 452 heads his has same kind of noise.
so I tried for the hell of it listening with a screwdriver to the ear trick and noticed I hear in in the number 1 intake runner what seams really loud could it be some kind of intake reversion or something maybe num 1 or 3 cyl since intake ports are kind of shared very wierd noise has me stumped now. seems to have no effect on performance or dive abilty anybody out there have a similar experience?
decided to upgrade some stuff while its apart so had 2 machine shops check pistons after I mic them skirts had no wear on them cyl measured ok only thing I found wrong in engine was 2 and 3 main bearings scared up and crank. not spun just beat up looking. that bearing failure happened that day never had an oil psi problem till that day. doubt that was the noise but couldnt find the noise.
so new build stealth heads had mild pocket cleanup 3 angle valve job new springs to match cam and retainers with 10 deg locks. new cam higher lift mech cam but shorter dur 235 dur 540 lift. using push rod length checker obtained correct push rods and roller rockers. cloyse double roller so whole entire top end of engine is brand new. lower end crank machined .020 .020 clevite bearings rods resized arp bolts. pistons machine shop cleaned up etc arp main bolts oil system mods opened oil holes center 1/2 pickup melling high vol cam bearing rotated with left oil galley plugged .010 hole in plug full time oilling to heads through tubing with a .045 restrictor. 11:1 comp motor runs awesome drive ability even allot better than before thraction is a huge problem now. however after all that the freaking noise is there and now it bothers me casue I never found what it was. so did all the diag again you can hear it in stethescope in the center of oil pan or valley pan you cannot hear it in heads or block really take pow steer belt off no diff take main belt off and you can hear a diff. it again only at low rpms. so I changed water pump and made no diff. cant hear it in WP housing or timing cover or fuel pump shes tucked away for winter so I figure it has to be piston slap because I did not bore it this time. but I would think if it were slap you would see some evidence in the piston skirts. so I am ready to give up and drive it and ignore it again.
no I build a 451 stroker motor for my brothers 32 plym this motor received full treatment brand new everything piston rings bored the works. his has elect fuel pump he has my ported 452 heads his has same kind of noise.
so I tried for the hell of it listening with a screwdriver to the ear trick and noticed I hear in in the number 1 intake runner what seams really loud could it be some kind of intake reversion or something maybe num 1 or 3 cyl since intake ports are kind of shared very wierd noise has me stumped now. seems to have no effect on performance or dive abilty anybody out there have a similar experience?
