hello, I have a 455 in my 65 skylark. So far this is what the car is setup like 71 455 with unknown history, Turbo 400 with unknown history ford 9" narrowed 31 spline with 350 gears and auburn posi disk brakes. The 455 has no stamped numbers on the deck, So im assuming it has had work done to it in the past. Im running an 850 Quadrajet, aluminum intake, HEI, MSD 6AL, TA Headers, 2 1/2 dual exhaust. The engine runs good, Oil pressure when hot is about 30 at idle and i believe around 60 at freeway speeds. Compression test is 135 to 145 range. Vacuum is steady at idle and at RPM. I have not done a leak down test on it yet. Cam is unknown. One concern I do have is when hot and at idle, I can hear what sounds like valve train rattle when I give it a little Throttle and let off, The sound (rattle??) come up when the engine is decelerating. I have no idea what that means if anything? worn rockers? lifters? No issues?? My question is now what? is there anything that could potentially be an issue that should be addressed? Id like to put a cam and TA aluminum heads (edelbrock??) on this block. Do it all at once. This is a treet/ strip car. Only really driven in the summer. I have not ran it at the drags since the new rear rears/Posi, and getting the timming/ carb dialed in. I would welcome any advice I can get.
I assume this rattle you discribe is while driving which is not good! If the Vacuum advance is hooked up to the Dizzy unhook it and and plug the hose, then drive the car and report back if the rattle is gone. I would not run the car at the strip until I found out if and how the motor was rebuilt no matter how good the motor may perform for you now unless you want to be possibly rebuilding the short block at the same time your bolting on new heads!
It isn't that unusual to have a little valve train noise. IMO, people make a big deal out of it. The only time these engines were silent was when they were new and bone stock. It is good practice to check everything valve train related, rockers and push rods are first. It's an unknown history engine, so you need to check everything. Do one thing at a time, doing everything at once is begging for trouble. The good news is it makes good oil pressure and vacuum.
Thank you for that. How do you suggest I inspect the rockers and pushrods? Is it simply by removing and visually checking for wear? Disassemble the rocker shafts? Or is there a measurement that can be taken? When I plan to install a cam I was going to replace all the pushrods lifters and rocker assemblies with T/A stuff. Just for piece of mind.
Unbolt the rocker shafts from the heads. Visually inspect the shafts for galling where the rocker arms rotate. There are nylon buttons that hold each rocker to the shaft, it isn't unusual to find a few broken. Pull each push rod and inspect each end. Roll them on a flat surface to check for straightness.
Thank you. I'm feeling confident about the health of this engine and it being able to handle some interior modifications for power. Without changing compression ratio I think cam and heads is all I can do to get more out of it. Torque converter?
The cam choice is a big determining factor for whether an engine needs a higher stall converter. Not all do. Look at the power range of the cam. A converter that is too loose gets old really fast on the street.
If the engine is running good, i think I would turn my eyes to the trans. Maybe a refresh, shift kit and a converter.
