55 Pontiac 287 Cranking Noise after top end job?

Hey Hamb!
Hope everybody had a great Christmas and is looking forward to an awesome new year.

I need some quick help figuring this one out.
I've got a 55 Pontiac Star Chief, with the 287.
I recently had the whole top end apart, had the heads rebuilt (bad freeze plugs), new head gaskets, etc.
Just got it back together today, and I'm not sure whats going on.

This thing cranked easily and fired immediately before taking it apart.
Now that its back together, I try to start it, everything moves as it should, but it seems like it is not cranking full speed, and I just get a random backfire.
(didn't change timing and all plug wires are in correct place).

Here is a video I just took of the noise trying to start it:



It sounds like it's straining or something binding while its turning. However
I didnt touch the timing chain, or anything in the bottom end.

I'm wondering though, could the starter be crapping out? Maybe it had no problem cranking the engine with the old bad head gasket, but now with new gaskets the compression is higher and it has trouble?

All the head bolts are torqued to 95lbs per manual, and all rocker nuts are at 15lbs per manual.

What am I missing here!??

Thanks guys I really appreciate it!

Evan

 

Ck firing order its on the intake,ck compression sounds like valves are open.

 

I will go double check the firing order. Should be correct as I didn't touch the distributor and marked all the plug wires before I removed them.

How could the valves be open? Wouldn't it crank easier if the valves were open rather than sounding like its straining now?

 

bttt

 

In 55 only the pontiacs had adjustable rockers like a small block chevy. 56 and newer you just torqued them down. Bring up #1 to TDC back off the nuts till you can just spin the pushrod with your fingers then tighten 1/2 turn and continue every 90degrees through the firing order, This should get it started so you can adjust them running.Hope this helps

 

Thx Buds56, you were right. Loosened em up and its almost going now. Back to the garage...

 

Like my bro said - you were dead on Buds.
Thanks for the advice.
I just set all of the rockers with the valves closed, and it cranks just fine.

Still don't have it starting though. It'll kinda pop a little, its close, but I can't get it running. Whats next...

 

i used to adjust my rockers on my 55 while it was running never had a problem. billy

 

I would make sure each valve is closing when cranking now, its possible you collapsed the lifters when they were tightened down before and they have pumped themselves back up with the latest cranking, other than that possibility, I'd check the plugs for gas fouling. Hope this helps

 

I am having trouble finding out what my compression for each cylinder should be on my 287. does anyone on this thread know what a good compression reading should be? I have 2 @75, 4 @ 60, 1 @ 55 and 1 @ 40. thanks for any help on this.

 

If the valves are adjusted correctly. You should have much higher compression. At around 90 PSI the cylinder will barely fire. You probably want to see 125 PSI or higher and no more than 10% difference between cylinders.

 

May have bent some valves that is very low compression.

 

ehhhhhhhh...you guys are aware this thread was submitted in Dec of 2009, right? I doubt the guy even has the same car now. If he does, it's either fixed or the motor swapped.