I decided to do a quick tear-down and regasket on the 350 in my 68 camaro, I had the valves in the heads freshened up last year, checked the cam (one low lobe, nothing to bad) and aligned the cam-crank.

I have tried to start the car for a few days now, I'm getting around 50lbs of compression on all cylinders, which is very low, and can't seem to get any extra compression out of it. I've adjusted valves several times, tighter, looser, zero lash and "clacky" and haven't had any improvement, also rechecked and re-aligned the cam and crank.

Any ideas or suggestions? I don't have a leak-down tester handy or a spark checker either.

Even at 50 lb the engine will fire if has spark, compression and fuel.

threre is that 180* out thing to consider.

timing is set so the dot on the cam and crank are straight up, rotor pointing at number one.

50 psi, would be like runnign a 5:1 CR. is there an actual likely hood of the car getting a better compression or did I end up doing something wrong?

Should'nt the two timming marks be pointing at each other<cam pointing down and crank shaft pointing up> and could have the crank gear on the wrong degree mark!

pointing at each other is to fire #6, both pointing up supposedly fires #1 TDC... I checked the cam 3 times today to no avail. still 50 lbs

Edit: motor is a 30 over 74 350, wiseco flat top pistons with valve reliefs, stock iron heads (1.90 intake) edelbrock performer RPM and holley 650 cfm, ran great last year, and I'm really thinking that 50 PSI is way to low for this motor.

you are 180 out you need the cam and crank dots pointing at each other cam down and crank up you were mis informed about your setting

A couple things you can do as others have suggested.
With camshaft arrow/mark pointing down and directly over the imaginary centerline between the cam & crank, place the crank socket pointing directly in the middle of the chain slack. If they don't align/poin to each other, the cam or crank might be off a tooth or so. I have worked on a Buick 350 being three teeth off still collect 90 PSI of compression.

Advance/retard the camshaft a tooth at a time and take a compression reading for each tooth. The higher the compression, the right direction.

Fifty PSI in all cylinders? Correct head gaskets used? Torqued correctly?

Yup... Thats why it was hard to understand what could be wrong for them all to have such low compression... it wouldn't be so odd if one or a couple had low compression, but all of them?

I agre with ugot86d you were misinformed on you cam intall.. get #1 to top dead center and line up the dots.

you are 180 out you need the cam and crank dots pointing at each other cam down and crank up you were mis informed about your setting

#1 firing TDC on my engine was when both dots were pointing up

Assuming the cam was installed correctly - it sounds like it was. Cam dot down, crank dot up. (dot to dot) If you removed the crank gear during the freshen up, some of those buggers have 3 keyways on them and can be confusing. If you didn't remove the crank gear, disregard.

You are correct - when the cam is installed "dot to dot" it is ready to fire #6, not #1. Crank dot up and cam dot up is ready to fire #1 - so you got that right.

You are getting the lifters on the base circle as you adjust the valves, right? And you trust your compression gauge?

Assuming the cam was installed correctly - it sounds like it was. Cam dot down, crank dot up. (dot to dot) If you removed the crank gear during the freshen up, some of those buggers have 3 keyways on them and can be confusing. If you didn't remove the crank gear, disregard.

You are correct - when the cam is installed "dot to dot" it is ready to fire #6, not #1. Crank dot up and cam dot up is ready to fire #1 - so you got that right.

You are getting the lifters on the base circle as you adjust the valves, right? And you trust your compression gauge?

thanks for the info, when i tore my timing cover off, i was confused when i saw that, because i thought dot to dot should be firing on #1, until i did a bit of research, and this thread pretty much confused me

You can line it up either way. I always go dot to dot so that there is less chance for error. If it is 180o out, just drop the distributor 180o the other way. If the compression is low try backing the rocker arms off some and checking. It could be a valve tightened down a little too much.

There is some very confusing information here! When I install them, first verify that #1 piston is at top dead center. Then I line the dots so that the crank dot is straight up and the cam dot is straight down. Move nothing now until you install your timing cover and pointer. Verify that your pointer is actually pointing at 0* (some will point at 4* BTDC which is fine). You just might have the balancer that has the timing mark up near the 12 o'clock position at TDC. If so, mark your damper with a paint stripe at zero. Now, after marking 0, rotate your crank 180* and install your distributer to fire at #1 piston. You should now be good to go. From youir description, I suspect you have the 8" balancer with the timing mark at near 12 o'clock.

There is some very confusing information here! When I install them, first verify that #1 piston is at top dead center. Then I line the dots so that the crank dot is straight up and the cam dot is straight down. Move nothing now until you install your timing cover and pointer. Verify that your pointer is actually pointing at 0* (some will point at 4* BTDC which is fine). You just might have the balancer that has the timing mark up near the 12 o'clock position at TDC. If so, mark your damper with a paint stripe at zero. Now, after marking 0, rotate your crank 180* and install your distributer to fire at #1 piston. You should now be good to go. From youir description, I suspect you have the 8" balancer with the timing mark at near 12 o'clock.

Rotate the crank 360* - cam will rotate 180*

Rotate the crank 360* - cam will rotate 180*

Crap, now I am adding to the confusion! Thanks for catching that. I didn't mean what I said, I meant what I thought!

I agre with ugot86d you were misinformed on you cam intall.. get #1 to top dead center and line up the dots.

Nope. When they're dot-to-dot, it's at #6 firing position; when both dots are at 12 o'clock, it's at #1 firing position. :thumbsup:

Have you checked your damper to make sure the outer ring hasn't slipped? With #1 piston at TDC the timing marks should line up whether it is on compression or exhaust.

I actually now have the heads off the car, I'm changing the heads back out to the ones I had on the car last year.

I'm disregarding the compression tester, when the snap-on man comes by work next thursday, I'm swapping the bugger out. I'm also going to swap out my plugs and see if that'll get her running this sunday.

Edit: I re-set the timing with the heads off the car. #1 piston lined up with the deck of the block when I did it, cam pointing down.

Was it off?

the timing was actually dead on, I'm going with the compression tester was broken, talked to my shops snap-on dealer thursday and I should be able to get the tester back next week. I'm just going to put the heads on and try starting the car again.

The thing that tipped me off was that it's the father in laws tester and the gauge facing is cracked, and he was telling me one night that his truck had 65 lbs of compression on two cylinders... I'm thinking he dropped the tester after the first six. His truck is a Ford 390... so an extra fifteen lbs of compression sounds right to me.

I am quite sure I would be somewhat upset if I tore down an engine because of a faulty compression tester! As a matter of fact, I would most likely take a time-out, hang the tester on my back fence, and shoot the thing! Hopefully things turn out this time around.