help - i screwed up on my v8 - advice needed Options

[jimkelly]

last week we determined that some of my oil leak problem was 4 bolts holding my carb intake to the heads, so we applied sealant and 3 stopped leaking. on Saturday I thought i'd address the last one that did not stop leaking, so not only did I add sealant to it again, I decided to use a longer bolt because the other 3 were longer. I used a 1.5" bolt but it turns out the other were probably 1.25", the max that should be used. so anyway, monday go for a drive but power is weird, I figured it had to do with engine being cold and I just changed the fuel filter and thought maybe there was some starving going on, but 30 minutes later I decided to go back home and figure out what was wrong. anyway, yesterday I pull the valve cover off to find a cracked valve rod that I retrieved from the head with a magnet on a stick but I had to remove the intake to put the lifter back in the head. anyway, it is all back together but it revs ok in neutral but under load it is either valves or knocking. what you think? anyway, why does a guy with so little mechanical prowess own a 914, who the hell knows. i'd like to think the noise is due mostly to timing cause I of course had to pull the distributor. and I never put a tdc mark on my flywheel or crank balancer, need to, asap. I first thought it was vacuum advance problem but vacuum is pulling thru hose.


https://www.youtube.com/watch?v=tfKEa1-W0XQ


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[rick 918-S]

The good thing: Your working on the most common V8 engine on the planet. The second good thing is they are easy to work on.

Start systematically. You can first check the valve lift with a simple metal ruler. First check to see you have not set the lifter too tight. At bottom dead center see if you can just spin the push rod with your fingers. I think you can go 1/4 turn tighter but don't take my word for it. I haven't built a Chevy for 30 years. Check the internet sites for SBC engines. Just leave the pushrod as is for the test.

Next rotate the assembly through one revolution. Measure the amount of travel from the bottom of the motion to the top at the nose of the rocker.

Then check another exhaust valve and compare. Who cares if your not dial indicator accurate. With the intake on you will at least know if you have enough of a difference to dig deeper into the engine. Lifter or cam.

Ya, Another thing. Watch the bolt that can come in contact with the push rod for the mechanical fuel pump. That will wreck a cam also.