No Compression

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you have a timing set wear out and jump a tooth or more

Or to try to further explain, timing chains stretch over time. In addition some engines originally were equipped with an alloy top sprocket with nylon? some sort of plastic /phenolic teeth. These used to troublesome, as the plastic wears down and the chain gets even MORE loose. Not sure if slants used 'em or not

Evidently they did, one of these blasted things:

timing-gear.jpg


There have been cases in many engines, not just Mopar, where those damn things "lost their teeth" and stopped an oil pump---breaking parts, such as the cam gear. This happened on a a 351 powered LTD II I got really cheap "back then."
 
Or to try to further explain, timing chains stretch over time. In addition some engines originally were equipped with an alloy top sprocket with nylon? some sort of plastic /phenolic teeth. These used to troublesome, as the plastic wears down and the chain gets even MORE loose. Not sure if slants used 'em or not

Evidently they did, one of these blasted things:

timing-gear.jpg


There have been cases in many engines, not just Mopar, where those damn things "lost their teeth" and stopped an oil pump---breaking parts, such as the cam gear. This happened on a a 351 powered LTD II I got really cheap "back then."

yea those plastic gears suck, but never have seen one on a slant
 
yea those plastic gears suck, but never have seen one on a slant
I hate those gears. We were told they were made so the engine would run quieter. Actually they were made to cu cost. You don't have to machine the plastic gears. Were real trouble on fords.
 
I hate those gears. We were told they were made so the engine would run quieter. Actually they were made to cu cost. You don't have to machine the plastic gears. Were real trouble on fords.

think the mid 70's and up SBC ran them to... POS's
 
after taking all the advice from you guys I tried MMO in all the cylinders let it sit for a week.
It did not do anything to boast compression. Still zero in five cylinders and 30psi on number six. So I then tried another suggesting to pull the rocker rail to see if it was a timing issue still no change in compression. So I am still going back to my original guess that its possibly the head gasket. Is there a way to check that? I appreciate all the help in advance guys.
 
I doubt very much it is a head gasket. Unlikely a head gasket would cause "0" compression in that many cylinders. I'm betting cam timing issue.
 
So the valves are all moving when the engine is cranking?

If not I would say you have a broken crankshaft
 
I removed the rockers to rule out the timing. This would in sure the valves are closed during compression stroke. The crank being broke is probably not the cause...I have a little compression in #6 and the crank is still turning the crank gear and timing chain. That means the crank is turning all the cylinders. I am probably going to pull the head next and do a better inspection from what i can see. Or see if the local pay and pull has a running slant six.
 
Now that you have the rockers off and all the valves closed, apply air to the cylinders one at a time. If you get air out of the tail pipe, bad exhaust valve. Air out of the intake and carb, bad intake valve. Air out of the valve cover area from the crankcase, bad rings or hole or crack in piston.
 
So the valve are all moving when the engine is cranking?

If not I would say you have a broken crankshaft

really?

I removed the rockers to rule out the timing. This would in sure the valves are closed during compression stroke. The crank being broke is probably not the cause...I have a little compression in #6 and the crank is still turning the crank gear and timing chain. That means the crank is turning all the cylinders. I am probably going to pull the head next and do a better inspection from what i can see. Or see if the local pay and pull has a running slant six.

when you removed the valve cover and removed the rocker shaft, did you take a level and make sure all the valves are on the same plane? you didn't describe whooshing from the exhaust (exh valves), intake (intake valves), or crank case (rings or guides)... i im thinking you stuck a bunch of valves which is not uncommon if it was over heated...
 
Moparkid that's what I'll do before pulling the head pull out the compressor and attemp to see if I have leaks. It trips me out that 5 out 6 cylinders are completely out. What amount of pressure should I apply with air I was thinking about 100-140 psi?
 
Moparkid that's what I'll do before pulling the head pull out the compressor and attemp to see if I have leaks. It trips me out that 5 out 6 cylinders are completely out. What amount of pressure should I apply with air I was thinking about 100-140 psi?

no need to put in air... you know they are no sealing, just need to figure out why. check the valves are i stated and if they check out then you'll use 100psi on a leakdown tester. the gauge is like a %. so with 100psi in it what ever your leakdown is with be a % of 100 so it makes it easy.
 
Often when an engine sits, the valves stick. A used small block I picked up was like that. I tapped the top of each valve with a hammer until it popped up. You must remove the rocker arm assembly first (easy) and first spray each stem with WD-40 or similar. Another guy seconded my comment that it is extremely unlikely that a bad head gasket could take out 5 cylinders, so spend more time diagnosing before you pull the head and probably waste a lot of time.
 
I added a dose of 100psi to all the cylinders and air was blowing out the carb on all of them. So i tap the valves with a rubber hammer to see if they were stuck they moved and still continued to blow air out of the carb on all cylinders. No air at all out the exhaust. So your right guys...not the head gasket. So what would cause all the intake valves not to seat properly. Maybe the previous owner never adjusted them I guess. But I would think that it had to be getting some compression when parked 13 years ago.
 
I should probably try and treat the valve stems with some sort of lubricant seeing that they still look dry from sitting and even though I changed the oil and added mmo to the cylinders I don't think the valves have got much oil on them.
 
I added a dose of 100psi to all the cylinders and air was blowing out the carb on all of them. So i tap the valves with a rubber hammer to see if they were stuck they moved and still continued to blow air out of the carb on all cylinders. No air at all out the exhaust. So your right guys...not the head gasket. So what would cause all the intake valves not to seat properly. Maybe the previous owner never adjusted them I guess. But I would think that it had to be getting some compression when parked 13 years ago.

well my only guess is that the valves are for some reason bent causing the valve not to seat.

did you check to see if all the valves are level? if the intakes are lower than your looking at something keeping the valve from closing, whether it be a bent valve or carbon build up, or seat issues.
 
After taking a real close look and putting a straight edge over the valves i noticed that the valves are not level at all and also the oil seals are mostly all broken into pieces. most have drie rotted over time. So that's the culprit. Thanks guys for helping narrow it down with the fun of online diagnosis. Question is what do i do now. I guess i will start at the junk yards.
 
After taking a real close look and putting a straight edge over the valves i noticed that the valves are not level at all and also the oil seals are mostly all broken into pieces. most have drie rotted over time. So that's the culprit. Thanks guys for helping narrow it down with the fun of online diagnosis. Question is what do i do now. I guess i will start at the junk yards.

Pull the head, check everything out (bores, pistons and rust) and have the head rebuilt if everything else looks good.

Keep in mind engines you buy at the junk yards are also old unless it has been rebuilt.
 
Well if it jumps enough teeth and bends some valves, THEN it will be zero

im not sure if its an interference motor or not stock, i dont think so though, .200 in the hole, .021 thick head gasket, valves are at least another .200 if not more. stock cam lift is something like .421 before lash if i remember LOL

After taking a real close look and putting a straight edge over the valves i noticed that the valves are not level at all and also the oil seals are mostly all broken into pieces. most have drie rotted over time. So that's the culprit. Thanks guys for helping narrow it down with the fun of online diagnosis. Question is what do i do now. I guess i will start at the junk yards.

dont be surprised by the seals being gone

now is a great time to have the head milled .090, enginebuilder 1.7/1.44 valves installed and blended, also install some new BB mopar valve springs.

Pull the head, check everything out (bores, pistons and rust) and have the head rebuilt if everything else looks good.

Keep in mind engines you buy at the junk yards are also old unless it has been rebuilt.

been there done that! bought a PNP motor and had 2 spun rods! learned my lesson!
 
Not likely the valves hit the pistons. No need for BB valve springs, with a stock or mild cam. I run 340 springs with dampers on my 170 and can turn 7,000 without vave float.

My sugestion is to put the piston at TDC, and remove the valve springs on that cyl. Remove the old seals, and put MM oil, Kroil, or something like that, on the valve stems. Use a tap handle on the valve stem and rotate the valve as you push and pull the valve, to free it up. If the valves free up install new seals and reinstall the springs. Do each cyl the same way.

If you do need to pull the head, then I would suggest milling the head while it is off. Raising compression ratio is the best single thing to help a slant.
 
Guys you all have been great and do appreciate the tricks of the trade. But after Moparkid starting talking about the bigger stainless valves 1.7/1.44 and the bigger springs i looked on ebay and they both can be had for a hundred bucks. But then i stumbled on a rebuilt head the same cast number as mine and I made a offer and I got it...I think the gentle men was nice enough to knock a hundred off his original asking price. Hopefully its as nice as he says it is. no guarantees of course but he through in the head gasket as well for 265.00 shipped
 

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So now i guess i am moving on to head removal and installation. I have some vacation time next week so if and when that head gets here its game time. I got to get this tired fish started back up.
 
I still suggest checking the cc's of the combustion chambers, and milling the head if it has not already been done. Do the measurements on the block, once the old head is off, and mill the new one to get about 8.7-9.0 to 1
 
Pulled the head was previously rebuilt in 85' parked in 99' ran for 14yrs sat for 14 more rebuild has .30 pistons and there's no telling what else was done but there is a stamping for the rebuild on the front of the head. Everything cam apart easy hopefully goes back the same. I pulled the exhaust/intake manifold as one. Can it be assemble back the same? What else should I be looking at while this top half of the motor is open? The timing mark on balancer is dead on TDC on cylinder 1. So the timing chain was done right which is good i was worried. I will pull the distributor later on and see if it is facing number 1.
 
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