Help with 68 580ck 188d popping back through intake

a1cnc · Sep 27, 2020

History on this, I recently bought this not running. It had sat for ~2 years supposedly and drove to where it was. Engine turns over but it seemed like it sounded like 1 or 2 cylinders were weak when turning over. Got it home and found 3 bent push-rods and 2 stuck valves. Replaced the push-rods, freed the valves and now 3 seem ok but 1 seems to be popping back through the intake. I re-adjusted the valves also to .014" on all per the manual. I am thinking next step is pull the head. I noticed there are no timing dots on the idler gear which someone replaced at some point. Thinking the next step is pull the head. 1st picture at top dc by timing mark on crank, 2nd is 8 before dc
Any suggestions greatly appreciated

mEl · Sep 28, 2020

If you are talking about the gear between the cam gear and the injection pump they were never marked, the metal thing on the bolts is a pointer that when it points to the right marks on each gear indicates correct timing as far as basic gear to gear timing, final timing is obviously done by shifting the pump position in its slots with the flywheel at the 8 degree mark, you should be able to isolate the bad cylinder by starting it and feeling the heat on each exhaust runner at the head.

a1cnc · Sep 28, 2020

Yes the Idler gear is not marked. So that's normal good. In my first picture I am at TDC on the crank mark and the dots are pretty well lined up with the pointer. in the
second it is 8 btdc on the crank mark and the dots are not as well aligned. Is that correct or am I possibly off a tooth?

mEl · Sep 28, 2020

Do not worry about the 8 degree deal. If the pointer and the dots are in register that is a separate complete issue from the advance from TDC marking. It looks to me to be timed properly by the gear position in relation to the pointer. in neither picture are they precisely lined up but I believe would be with a minor turn of the engine. Once the front cover timing is determined to be right the cover can be reinstalled and then the 8 degree adjustment made if necessary.

a1cnc · Sep 28, 2020

Guess I know what happened now. #1 liner is cracked too. I hope the block isn't cracked. Am I going to have to pull the engine to find out or would it usually be evident
once the liner is out?

mEl · Sep 28, 2020

(quoted from post at 15:33:14 09/28/20) Guess I know what happened now. #1 liner is cracked too. I hope the block isn't cracked. Am I going to have to pull the engine to find out or would it usually be evident
once the liner is out?

<img src="https://www.yesterdaystractors.com/cvphotos/cvphoto57552.jpg">

<img src="https://www.yesterdaystractors.com/cvphotos/cvphoto57553.jpg">

<img src="https://www.yesterdaystractors.com/cvphotos/cvphoto57554.jpg">

Where is the liner cracked, usually if the engine has been froze it cracks between the sleeves, we had some breakage back in the day on early engines. Where is the liner cracked, can you send a pic of the cracked area?

a1cnc · Sep 28, 2020

I will have to get a picture tomorrow, it's dark out there now. It cracked from above the piston in the picture all the way to the top on the left side from the operators seat.No crack in the block visible.

I also noticed there seems to be a threaded plug on the lower backside of the injection pump that is out of the pump. Looks about 1" diameter. I will pull the pump
tomorrow and see what that is about.

My newest money pit oh boy!

a1cnc · Sep 29, 2020

Here is a picture of the crack. It goes half way down the liner

mEl · Oct 1, 2020

That is a rare crack, seen very few like that, We had sleeve cracking early in the 188 series engine but it was normally a radial crack at the counter bore level. A little later Case redesigned the block and went to a bigger top of sleeve dimension too give better sleeve seating and the radial crack deal kinda went away. We did many block mods to use the wider sleeve but it has too be done carefully as the top of the block has to be milled down far enough to cut the original a little deeper to have a totally fresh seat. If over done the valves will hit the valve reliefs on the pistons. I have seen valve impressions in the pistons after many thousands of hours but don't recommend that obviously!

Help with 68 580ck 188d popping back through intake

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