Had some fun last night. My sister's former husband of 11 years (they divorced about a decade ago) is also the one person that can take the primary credit for my mania over small blocks. He guided me through the rebuild of a 283 when I was 15 (28 years ago this winter) and then rebuilt a 350 for me after I cracked a cylinder, bent a rod and ruined the crown of a piston after a screw found its way into my intake manifold from a carb rebuild.

Anyway, when I moved back to Ohio back in July '05, I stopped by his farmhouse in the country to say hello and to also show my '69 L46 to him as I was driving it that day. I'd mentioned that I was bringing the '80 L48 north that September and had valvetrain noise that I've been pursuing diagnosis and fixing of for a number of years. This past weekend, after driving to the city for some groceries and such, I stopped and he agreed to take a look at the car Tuesday (yesterday). It rained cats and dogs here last night but a tuning session with 'Mike' was something I hadn't participated in in much too long a time. So, I loaded the '80 with some cold beverages, fender covers, some mechanics gloves and, as an afterthought, a box of take-off rocker arms, push rods, locking nuts and pivot *****. I picked my brother Jim up and we cruised over. Jim was also an influence as he was into all makes of hot rods; starting with three Mustangs, then a 383 Barracuda and then a Red '69 396/325 Chevelle SS.

Now, Mike has the type of garage we all dream of having some day. Mike's brother Bob worked for Marathon for decades in their truck repair shop until recently. Mike had heard of a Marathon station that was closing a few years back and scored an in-floor lift, MASSIVE corner air compressor and other handy bits. He has also installed a propane fired boiler and steam radiators, insulated the walls and ceiling and poured concrete flooring in half of his LARGE metal building. Oh, he also installed a fridge with keg and tap through the door.

Mike has rebuilt and built more car engines than anybody I personally know. He started early with mowers, mini bikes and go-carts and logically progressed to car, truck and tractor motors. Watching him tune an engine is FUN at its most.

So, back to my story. I'd told Mike that I had this pesky valvetrain noise that has persisted through two sets of heads (rebuilt 882's and my current DART Iron Eagles). I've repeatedly tried rocker adjustments, and even resorted to cylinder head, intake, exhaust gasket replacement thinking it may be a leak. Mike first had me prepare the patient; he was there for the surgery and I was to assist. I moved everything out of the way (valve cover, hoses and wires) and he set to work making a couple passes through the left bank of rocker arms; the noise would not stop. We then took a look at the individual parts and got to discussing the different parts I have installed that may contribute to geometry issues (heads, intake, pushrods, etc.) and we got to discussing the pushrods in particular. I'd had a mechanic in Fla rebuild the engine back in '99 and we installed Sealed Power, one-piece hardened pushrods. I swapped these out for a set of ball-in-end summit push rods when I installed the 882's and then, with the DARTs, I swapped the pushrods and rockers for a fresh set of Summit brand hardened ball-in-end pushrods and rocker set. Mike suggested that the ends of the pushrods may be 'loose' OR perhaps there was a potential length discrepancy between the solid Sealed Power pushrods and the Summit pushrods. Digging into my take-off box, I swapped the one-piece hardened pushrods in and spun the lock nuts down on the rockers 3/8". Mike then proceeded to adjust the rocker arms once the engine was back to operating temperature. Voila, reduced valvetrain noise. Mike suspects the pushrods were not of equal length as he found it took almost a full quarter turn less with the replaced pushrods for the engine to show signs of distress (when turning the lock nuts down too far, it started to run rough). He took his time and adjusted the rockers until he was completely satisfied. I closed the patient up and we then proceeded to enjoy our cold beverages and talk about past engine projects, cars and good old times. Jim and I drove the vette home and valve train noise was no longer as evident as it had been. Once the weather clears/dries, I'll be taking the '80 back to Mike to replace the right bank of pushrods and a 'test drive'

So, it appears I had a pushrod length issue contributing to a persistent valve train noise (like a sewing machine but even noisier).

Thought I'd share.

P.S. Mike suggested I take two Flowmaster 40's and bring the patient back for a follow up.

 

good job , some times divorces seperate good people

 

interesting...