Slant Six Forum :: A long story, but I bet you can help me

While disassembling the head and taking the bolts off in the correct order

The lash should be .012 intake & .022 exhaust.

Quote:

While disassembling the head and taking the bolts off in the correct order

You said you re-used the timing chain. Did you leave it installed, or remove it and then put it back on? If the latter, how did you degree the camshaft gear?

Some will recommend you use a degree wheel every time, but that should be close enough to get it running. At this point I'd suspect either your valve seats or your rings.

Do you know why this engine was non-running in the first place? Can you do a leakdown test and follow the noise to see where the air is coming out? If you already have the head back off, you can check both sides with liquid like DD suggested.

I'm thinking I didn't lap the valves correctly so I disassembled again.

Valve seats and piston rings it is

Author:	Bethom1989 [ Tue Mar 30, 2021 5:22 pm ]
Post subject:	A long story, but I bet you can help me
1965 / 170 Valiant 1) Disassembled a non running engine down to taking the head off (took the bolts off in the right order) along with the manifolds, water pump, timing chain cover. 2) Cleaned EVERYTHING. Head, rocker arms, rods, nuts, bolts, etc. 3) Reassembled and set TDC. 4) I have a new coil, fuel pump, alternator, water pump, spark plugs, wires and a rebuilt carb (Holley 1920). 5) Tried to start. The best I could do was a backfire through the carb. I tried BTDC, ATDC...every combination under the sun. Getting fuel no problem. Nothing. 6) Decided to check compression pressure on each cylinder. By just using a remote starter, I got a couple 30 psi's and a couple 0's. Only one of the 30 psi's was holding pressure. I'm thinking I didn't lap the valves correctly so I disassembled again. 7) OK...HERE'S MY QUESTION. While disassembling the head and taking the bolts off in the correct order and when I loosened the second to the last bolt (#2) a good deal of anti-freeze exiting through the gap between the engine and the head around cylinder 6 and 5. WHAT HAPPENED? I'm guessing that the engine didn't fire due to coolant in the cylinders. Warped head? Your takes? Thanks!!

Author:	Rick Covalt [ Tue Mar 30, 2021 5:40 pm ]
Post subject:	Re: A long story, but I bet you can help me
Quote: While disassembling the head and taking the bolts off in the correct order No correct order in disassembly that I know of. Still not sure from the post how far apart you had the engine? Did you have bottom end apart or just the head removed Did you put a timing chain in? Are the valves adjusted too tight and hanging open? Thus no compression

Author:	Bethom1989 [ Tue Mar 30, 2021 6:15 pm ]
Post subject:	Re: A long story, but I bet you can help me
Just down to the head. Used existing timing chain. It was within "taut" specs. Valves were moving freely while cranking. Lashed them at .12 and .22 for a cold engine. I would have re-lashed to the manual specs when it had a chance to warm up.

Author:	Doctor Dodge [ Tue Mar 30, 2021 9:27 pm ]
Post subject:	Re: A long story, but I bet you can help me
The lash should be .012 intake & .022 exhaust. Some coolant will spill-out of the head when it is removed, even if you completely drained the cooling system. Be sure to blow or vacuum the coolant out of the cylinders to prevent rust. Carefully check cam timing by degreeing-in the cam. Check valve sealing and ring sealing by pouring some solvent into the chambers / cylinders. If the solvent drains thru quickly, you have a sealing problem that needs to be addressed. DD

Author:	Bethom1989 [ Wed Mar 31, 2021 1:20 am ]
Post subject:	Re: A long story, but I bet you can help me
Quote: The lash should be .012 intake & .022 exhaust. Yeah...that's what I meant...012 and .022 I'm gonna drain the oil this morning and I bet I'll find quite a bit of coolant in it, maybe a ton. I feel pretty good about the timing. Re-lapping the valves and checking the piston rings might be the answers. I really didn't want to get into the crankcase though. Never pulled an engine before.

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Author:	Bethom1989 [ Wed Mar 31, 2021 6:27 am ]
Post subject:	Re: A long story, but I bet you can help me
Quote: Quote: While disassembling the head and taking the bolts off in the correct order No correct order in disassembly that I know of. Hey Rick, It was my understanding that if you didn't take the head bolts off in a correct order...working outsides to insides, bottom to top...you would end up with a warped head.

Author:	Dart270 [ Wed Mar 31, 2021 8:31 am ]
Post subject:	Re: A long story, but I bet you can help me
Disassembly order is unimportant, and it is very hard to warp a Slant 6 head. I have never taken a head off and then put it back on and had it not seal (using a new composition head gasket). My guess would be the cam timing is off. In other words, the timing chain may not be installed correctly. My first thought was not having the valves adjusted and you mixed up the order of rockers, but you check that. Also, if you vigorously cleaned carbon off the piston tops and junk fell down between the pistons and cyl walls, you can score up the cylnders pretty badly. Hard to see your compression would be so low on so many cylinders, though. Lou

Author:	SpaceFrank [ Wed Mar 31, 2021 9:38 am ]
Post subject:	Re: A long story, but I bet you can help me
You said you re-used the timing chain. Did you leave it installed, or remove it and then put it back on? If the latter, how did you degree the camshaft gear?

Author:	Bethom1989 [ Wed Mar 31, 2021 12:32 pm ]
Post subject:	Re: A long story, but I bet you can help me
Quote: You said you re-used the timing chain. Did you leave it installed, or remove it and then put it back on? If the latter, how did you degree the camshaft gear? By lining up the dots on the crank and cam gears.

Author:	SpaceFrank [ Wed Mar 31, 2021 1:18 pm ]
Post subject:	Re: A long story, but I bet you can help me
Some will recommend you use a degree wheel every time, but that should be close enough to get it running. At this point I'd suspect either your valve seats or your rings. Do you know why this engine was non-running in the first place? Can you do a leakdown test and follow the noise to see where the air is coming out? If you already have the head back off, you can check both sides with liquid like DD suggested.

Author:	Bethom1989 [ Wed Mar 31, 2021 3:46 pm ]
Post subject:	Re: A long story, but I bet you can help me
Quote: Some will recommend you use a degree wheel every time, but that should be close enough to get it running. At this point I'd suspect either your valve seats or your rings. Do you know why this engine was non-running in the first place? Can you do a leakdown test and follow the noise to see where the air is coming out? If you already have the head back off, you can check both sides with liquid like DD suggested. I figured it would be close enough to get it running as well. Valve seats and piston rings it is. I'll have to wait till the weekend. The PO said he couldn't get spark and that's why it would not start. I figured I could at least get spark and he seemed like a good guy and was shootin' straight. I thought I bought a 1964 with a 225, like the ad said. I instead got a 64 body with a 65 170 in her. I already have the head off. Thanks for the input!

Author:	Rick Covalt [ Wed Mar 31, 2021 5:54 pm ]
Post subject:	Re: A long story, but I bet you can help me
Quote: I'm thinking I didn't lap the valves correctly so I disassembled again. What did the pattern look like when you lapped them? Quote: Valve seats and piston rings it is I'd hold off until I had more info. Something doesn't sound right here. Zero compression? Valves can look pretty bad and not have good sealing and still have some compression. I would have squirted some oil into cylinders and checked them again before removing the head.

Author:	DusterIdiot [ Wed Mar 31, 2021 6:14 pm ]
Post subject:	D
D

Author:	Dart270 [ Thu Apr 01, 2021 6:19 am ]
Post subject:	Re: A long story, but I bet you can help me
Valves or rings need to REALLY bad to have 0-30 psi cranking compression. I still think it's cam timing. Try backing off the valve lash another 0.020" on every valve and see if cranking comp goes up. It sees you took the head off, so now it will be harder to diagnose w/o hooking up a degree wheel to check cam timing. With head on and the valves not connected to the cam (no valve gear/pushrods), you will know right away if the rings or valves are leaking badly when you turn it over with a wrench. Lots of resistance = valves and rings at least decent. Lou

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Author:	Bethom1989 [ Thu Apr 01, 2021 7:50 am ]
Post subject:	Re: A long story, but I bet you can help me
Hey guys. Thanks for all the great suggestions. I really do appreciate your help. I've had a personal setback on working on the Valiant until some time next week. We have moved my mother-in-law (dementia) from one nursing home to another and it's been exhausting to say the least. Trying to figure out the car and making sure my wife and her mother get what they need during this move will be too much to do together. I'll circle back with you all some time next week. In the meantime, please keep your suggestions and comments coming. They really help me learn about this crazy engine I've come to love.