|08-05-2010 07:38 PM|
|bbcguy140||but like every one else said it dont matter where the rotor ends up at #1 cause all u need to do is just change the locations of the wires. i just prefer to have #1 in the factory location it makes it easier to put the wires on|
|08-05-2010 07:33 PM|
|bbcguy140||wow man that looks pretty bad would definately affect compression. and no the valves will not fall into the engine if u take out the rockers and push rods cause they are held in by retainers that are held into a groove machined into the top of the stem held by the pressure of the spring. youd need to take the heads off in order to get the valves out. so dont worry about loosing the vaves into to engine. and the best way ive found to get the distributor lined up in the factory position for #1 is to get the engine to compression. and i always line up the mark on the balancer with the 0 mark on the scale. that is where the piston is all the way up in the cylinder. then i pull the distributor and line it up with the number one tower on the cap then turn it counterclockwise back just a little before #1 then drop it in the hole and twist it clockwise a little till the gear lines up then it will be lined with the correct tower. then i bump the starter to get the oil punp shaft lined up till the distributor falls down all the way then ur golden. after all that i normally get the engine back to tdc on #1 to double check the alignment. its never failed me. so give it a try. sorry about the wordiness of this but it takes alot to explain|
|04-15-2010 03:06 AM|
Stock GM rockers and valve springs are not compatable with high lift cams.
Long slot style rockers are required. Replace all the push rods and all the rockers.
Valve spring compressed coil clearance at full lift and retainer/seal guide boss clearance at full lift must be verified.
First you need to verify the actual cam lobe lift of the cam that is in the motor. Don't assume the cam in the motor is the specs shown on the cam card. Measure the cam lobe lift off the push rod with a dial indicator. .320" The lifters must be inspected for wear.
The cam and lifters are probabily trashed now too.
I'll bet you will need a new cam+ lifters + long slot rockers+ pushrods+ correct springs+retainers and seals.
Do not use gasket sealer on the rocker cover gaskets. It is not nessessary and the sealer ends up stuck in the engine oil passages blocking oil flow.
Engine bearing damage, cam lifter wear and noise etc etc etc.
Who ever put this motor together is a hack.
|04-14-2010 07:12 PM|
|04-14-2010 02:49 PM|
|Forza1||How straight do the push rods need to be? I rolled them over glass, and one will need replaced for sure. The other two roll pretty smoothly, but if I get eye-level with the glass, I can see a slight(hair thick) bend to them. Should I replace them?|
|04-13-2010 01:30 PM|
OK, gotcha, thanks. I spoke to a cylinder heads shop yesterday and he wondered what could have caused it, he suggested maybe a valve binding. However, I read if you don't de-burr the oiling hole in the pushrod cup, it can lead to cracking. Plus they look like older rockers to me. It's my only car so it's kind of a chore getting to the parts store but I will keep everyone updated.
|04-13-2010 01:19 PM|
|04-13-2010 01:17 PM|
|richard stewart 3rd||the slot that the stud comes through|
|04-13-2010 01:03 PM|
|Forza1||By "rocker slot", so you mean rocker arm? Or is this a specific part of the rocker arm? I've never heard the expression before.|
|04-13-2010 05:55 AM|
|04-13-2010 02:55 AM|
I know the car needs valve seals, and I'm wondering if I should just get a cam kit for $350 and change my cam, rockers, lifters, timing chain, push rods, seals, etc... I don't really have the tools for precise measurements and clearances.
|04-12-2010 06:52 PM|
|04-12-2010 05:57 PM|
|richard stewart 3rd||
Look like GM rockers, A guy at work had this happen all the time 67 chevelle 396, just unbolt the rocker & replace it, roll the push rod on a piece of glass to be sure it's straight, & make
sure it's not clogged also.
|04-11-2010 01:36 PM|
Well I found out the cause of the weak compression on the passenger side, and so the plot thickens...
So on a whim, after I set the crank and rotor today, I decided to pop the valve covers before I buttoned things up. The drivers side looks fine, but it looks like 3 pushrods on the passenger side pushed through their rockers. I attached a pic below... Can anyone ID these rockers by looking at them? I guess I'm going to need to replace the pushrods too. If I unscrew the rocker arm, will the valve fall into the cylinder? What's the procedure for this?
Thanks everyone for your help so far!
|04-11-2010 06:48 AM|
the .320 lift is lobe lift, multiply it by rocker ratio to get valve lift (.544)
BTW that looks like a relatively conservative cam for a big chevy.
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