the intake valves Dont close at or near TDC , if it does --180* offi have been fighting problems with my 524 w/ a broken key @ crank gear, after fixing problem i went to the track and had major timming issues shooting fire thru exhuast and carb. First, i thought i had broken another key, but after teardown revealed the timing chain and key were intact. Assuming i had probley bent some valves when the key had originally broke i began a second teardown, removing the pass side head showed no bent valves no contact of any kind. At this point i'm baffled.... Since i put a Summit Billet Roller chain in when i had fixed the broken key i called summit to inquire what could be the problem with the timing. The tech person advised me that i had installed the Dizzy wrong???????..i had installed the Dizzy the same way i had always instsalled it with No. 1 [email protected] stroke rotor facing 1 on the cap. when i had re-installed the cam after the first tear down i lined up the 0 mark on the crank gear @ 12:00 and the dot on the cam gear @ 6:00, installing the cam "straight up" at this point No. 1 cylinder was @ TDC on compression stroke and i dropped in the dizzy. According to the tech person i was 180 off. he then advised me to turn the motor over (while i had the head off, watching the lifter movement) until i saw the intake lifter moving up and then all the way down which brought the No. 1 up to TDC again. At this point the piston is @TDC and the intake valve has just closed (not quite on the full base circle of the cam) and here is where he said to install the dizzy. i re-installed the dizzy and when i get the new head gasket tuesday i will see if the motor runs properly. At this point i really have no explination of why the cars timming is being such a problem and am willing to try it this way. the tech guy said that the timing mark on the cam gear should be at 12:00 and the timing mark on the crank gear should also be at 12:00 when the dist is installed. My question--- is this all in the timing chain assy i got from summit. the timing chain i had in there before was not set up like this and i wonder if the summit billit chain is different from all the other chains out there? has anybody else run into this before?
X10!!!SUMMIT, what a bunch of idiots.
the intake valves Don't close at or near TDC , if it does --180* off
Exactly!!! Intakes CLOSE when the piston is done making it's DOWNWARD travel! The cam is 180* out. The exaust should be closing at TDC. I've never heard of timing the cam gear at 12 oclock, the dots always were next to each other.......I could be all wrong here but all the BBF's that I've done, if memory servs, were next to each other......And be sure you gas check the other head too.
critter is definately onto something here, the last guy i knew that recently bought summit's steel billet timing set had similar issues, he also bought their balancer, and rockers, etc.....he had nothing but problems with this engineAre you using an SA timing set? If so it's probably machined wrong.
