Finally changing the timing chain and gear on my stock 1968 350 PP motor which was long overdue . Also replacing the leaking oil filter mount and adding a T/A booster plate . Removed everything in the front of engine that needed to be removed with no issues. I was surprised how loose the chain was and determined it was a full tooth off . Spoke with someone today that said 1 tooth could retard the timing 18 degrees. Is that possible ? The motor ran smooth and had reasonable pick up previously but with the new chain I should notice more p/u . Also what should my timing be set at and by what RPM should it all be in by ?
How many teeth on the upper sprocket? Lower sprocket stays the same because it's attached to the crank and the balancer. Is the pointer pointing to zero at TDC, sometimes they're off, or the balancer slipped slightly (rubber) Count the teeth on the camshaft gear, divide 360 (degrees) by that number. 360 divided by 18 = 20 You have to divide the number by two, because the cranks turns 720 degrees when the cam turns 360 degrees. Check this thread: Power timing your V8 Buick
Valve timing and Ignition timing ARE TWO DIFFERENT THINGS. Valve timing is the timing of the VALVES in relation to piston movement. Ignition timing is the timing of the SPARK in relation to piston movement. The crank turns the cam via the timing chain. The cam turns the distributor. If there is excessive slop in the chain, you won't have a steady ignition timing mark when you look at it with a light.
If you were off a tooth, I don't think it would've run nearly as well as you described. They can get pretty (surprisingly) sloppy and still work.
Yes. 65 odd fire v6 and 75 odd fire v6 . Sounds like a 10 speed bike when you go to shift gears and it’s caught in between gears. Only with more rpm .
Decided to pull the intake to clean up a little. Was talking to a few friends about the benefits of swapping the stock intake on a stock ‘68 350 motor . Besides the obvious weight savings, is there any performance gains to be realized . Besides dual exhaust ( no headers ) pertronix ignition it’s as the factory intended. If any benefit , which manifold ? Too hot for the convertible so taking my time painting. Also what intake gasket do you recommend?
If the rest of the engine is stock, leave the iron manifold on. Weight savings is the only thing you'll gain with the aluminum intake at this point, and less pain on your back installing/removing. Use the Fel-Pro steel bathtub intake gasket. Use RTV on the end rails, trash the rubber end seals
Just got my Felpro gaskets today , with exhaust manifolds , no intake , and the wiring harness tucked out of the way the dirty work begins. Begin the degreasing cleaning up and might as well clean up the fasteners/ bolt holes. Anyone use the POR exhaust manifold paint ? Eastwood is out of stock on many of their paints for 2 months I’m told. Should I go with the spray can or apply with the foam brush?
What size tap / die do I need for the engine fasteners with 9/16” heads ? My tap set’s largest SAE tap- die is 1/2”- 20 . Went to 2 of my friends to borrow one and theirs is also 1/2” 20 max size . Strange that 9/16 would not be included in complete sets as older American cars 9/16 is one of the most common sizes .
Any hardware store should have a gauge/sizing tool for hardware. As you discovered they are NOT measured by the heads.
