no comp in cyl 1 after timing chain break

[HOOCH]

Ok so broke my timing chain the other day, car was at an idle when it happened and then i rotated it around by hand and everything seemed smooth didn't appear to have hit any valves. So i put new chain and what not re timed it and went to start it and nothing no fire, every once in awhile it would kinda fire but nothing!

I then did a comp test and got no comp in cylinder 1 and 140's in every other cylinder!

I find it rather weird myself because if it where bent valves then wouldn't the valves in cylinder 4 be bent as well? Because 1 & 4 are on the same plane.

So im curious to know if there are any possibility it could be? Any incite would be appreciated!

motor is SR redtop
hks 264 step 2s
BC valve springs

[yurisfriendevan]

maybe you got lucky and only had contact with the #1 cylinder. Once you pull the head you will know. Look on the bright side, you only have valves to replace in one hole.

[HOOCH]

maybe you got lucky and only had contact with the #1 cylinder. Once you pull the head you will know. Look on the bright side, you only have valves to replace in one hole.

Thats one thought but i thought if #1 made contact then so should have #4?? This is why im stumped

[jr_ss]

Cylinders 1&4 piston's cycle the same but the cam lobes themselves are at different cycles...

[Pandapants]

Cylinders 1&4 piston's cycle the same but the cam lobes themselves are at different cycles...

This.

My timing belt slipped while idling on my rb20 and I barely bent both intake valves in #3. Only 2 valves out of 24!!!! I got lucky.

You probably will too. GL.

[Antihero983]

Thats one thought but i thought if #1 made contact then so should have #4?? This is why im stumped

Well when you have the head off to do the valves, do a leak test on cyl 4 just to make sure they're still kosher.

[HOOCH]

Well when you have the head off to do the valves, do a leak test on cyl 4 just to make sure they're still kosher.

How exactly do you do a leak down test? With the head off? I've never done it.

But I did get the head off today and sure as suit both exhaust valves in cyl 1 were bent to shit! Put 2 lil markes in the piston but nothing that will cause any harm!

[jr_ss]

How exactly do you do a leak down test? With the head off? I've never done it.

But I did get the head off today and sure as suit both exhaust valves in cyl 1 were bent to shit! Put 2 lil markes in the piston but nothing that will cause any harm!

There are many ways to test for a bent valve. You can flip the head over after all shims/rockers have been marked to each valve of course and fill the chamber with fluid. If fluid leaks past the valve you obviously have a leak. Another way to do it, is put a seal around the intake/exhaust ports and pull a vacuum. If you can't pull and hold a vacuum, you have a leaky valve, however you could have bad valve stem seals and that would give you a negative reading.

While you have it out, you might as well go a head and put new valve stems seals on too. I would have a machine shop replace the valves and check #4 myself.