timing

[Irishbleueyes]

you would need to get a leak down tester to see if you have worn guides or bad valves etc

[OrrieG]

Originally Posted by Irishbleueyes

no, while the engine is runniung just back the timing down till the vacuum gauge stops jumping. that should put your timing at maximum at idle. now for full advance timing turn the timing dial till the balancer zeros while revving at 3000 rpm. that will tell you what your total timing is. should be about 32 to 34. if not, your distributor will need some recurve work.

This is the easy check, then the leak down for valve issues. Hopefully timing off just a bit.

[1project2many]

Hopefully, but I've seen that reading before.

[yoshi]

I started the engine & turned the dizzy but it made little difference to the needle in the vacuum gauge. For some reason I suddenly thought it maybe worth checking the temperature of the headers. My temperature gun registered 115 deg for cylinders 1, 3 & 5 150 deg for No. 7. 315 deg for No.2, 290 deg for No4, 270 deg for No.6 & 62 deg for No.8

[yoshi]

Looks like problem found

[1project2many]

That's a bad sign. It takes a *bunch* of pressure to do that. And combined with the broken starters and unusual timing readings, I have a feeling about what's going on. Something is definitely binding, no question, but the mystery is why? There are plenty of reasons, and this list might cover some most likely to least likely possibilities

1) Improper valve adjustment. If someone tightened all the rockers all the way down they will bind.

2) Improper cam installation. If a valve is open while the piston is on the rise, you'll get a crash.

3) Improper valve guide clearance. If the valve siezes, even temporarily, the rocker and pushrod can suffer.

4) Improper valve spring travel for the cam. If the springs prevent the rocker from opening you'll lose the pushrods and rockers.

5) Improper valve clearance inside the combustion chamber. Wrong pistons, heads / block shaved too much can cause an issue.

Check all the pushrods and all the rockers. Be sure to remove the pushrods and roll them on a flat surface to look for bends. Also look at the height of all the valves with the rockers removed. They should be very close, as in, if you place a straight edge across the valves they're should be no significant gaps between any valves and the straight edge. If there is only one damaged rocker/pushrod then you are lucky. It's possible that the valve was adjusted improperly. If there are many damaged parts you've got some investigating to do.

Glad you've found the problem, but the work is only beginning.

[OrrieG]

Hopefully, it is just the rocker, valve looks ok. Dropping a cylinder will definately affect the idle!

[yoshi]

What I found when I lifted inlet manifold

[OrrieG]

Mix and match remanufactured block??? If you pull the lifters make sure you keep them matched to the cam lobes... I once pulled the intake off of a used donor engine and found a well soaked rag sitting in the valley.

[yoshi]

Rods are different

[1project2many]

Different ends are ok. As long as they are the same length you're fine.

With the intake removed you can turn each pushrod and watch for the rocker to wobble side to side or the center of the pushrod to show signs of bending. Even a slightly bent pushrod should be replaced.

[yoshi]

Difficult to tell if length was different

[1project2many]

True. If they used a pushrod from an engine with a factory roller cam there would be a significant length difference.

The top and bottom pushrods are factory flat tappet and factory roller tappet.

[imjeff]

I missed the history on the motor. That would be helpful. It doesn't look like a new motor and with different pushrods I suspect it's been rebuilt? If this is the case you can rule out a lot of the causes listed above. It didn't suddenly run out of clearance after running for ? years. The more common causes I've seen for broken rockers and bent pushrods resulted from higher lift cams without adequate slots in the rockers. You rev it up, bust the rocker by banging the slot on the stud, and bend the joining pushrods due to high cylinder pressure (rocker no longer opening the intake valve). You can also get enough pressure from timing waaaay out of wack. Can you give us a little history on your motor?

[yoshi]

Bought from a bloke locally he'd had it for a few yrs only turning the engine by hand. He was told by PO that engine had been rebuilt with a wilder cam. I managed to track down & speak with him myself, he had a guy called Nick Dann do all the work on it & when money ran out he pulled it & sold it. No paperwork or receipts.
Valves seem intact, there's another one like the straight one above fitted to No.6 exhaust all the rest are the same type as the bent one. The damaged one above came from No.8 inlet

[OrrieG]

I would not consider reusing the existing. New are on ebay for less than $30, summit has them for $32. Ebay has an international shipping program where the seller pays to send it to the US forwarding center at the US rate, then it is forwarded to you. I don't what arrangement they have with the PO but I have used it and it is legit. I sent an item to Brazil that would have cost over $30 international shipping for around $7 US rate.

[yoshi]

Re using the existing?

[OrrieG]

You have one that you know is bad, I would not trust the rest, replace them.

[Irishbleueyes]

Yoshi heres another article that helps explain timing, its really good.
I know it says pontiac but it still applies to all our slow burn early heads.

[yoshi]

Thanks for that, lots there to read. Finely got it started again after fitting new parts & breaking a spark plug. Problem I have now is a ticking sound coming from that rocker cover. Gonna remove the cover & start the engine & press down on each rocker to see if it makes any difference

[yoshi]

I can hear a clicking sound coming from the right hand side around no.2 cylinder
Its clicking about 2-3 times per second, hopefully you can hear it
https://m.youtube.com/watch?v=d77h8t...&persist_app=1

[OrrieG]

I can't get the link to play.. If it is a clicking probably just a lifter a little out of adjustment, if I remember right turn cw until they stop clicking, then half a turn more (when running and warm). I have an old set of valve covers with the top cut off to keep oil off the exhaust manifolds, heads, block, etc.

[yoshi]

Try http://youtu.be/d77h8tTZTkY