Where is my compression and vacuum??

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Guys, if the engine runs smooth but lacks power, it is not an ignition issue. I've never seen an engine run with the distributor 180 degrees out. In every case I've seen through 40 years of tinkering, this is impossible. You're claiming that an engine will run when the spark for each cylinder is occurring on the exhaust stroke. What may happen in that instance is popping and stumbling, not an engine running and idling on it's own.
We all want to help when a member has trouble but some people that respond are completely clueless.
I had a Duster with a 318 that ran smooth but wouldn't peel out on dirt. That engine had a timing chain replaced before I got it. The cam sprocket was 3 teeth off retarded.
Yeah...it idled great and ran but it was s-l-o-w.
 
junkyardhero said:
true on the pressure, but they'll run 180 out. not well, but it'll make a go of it.

the "ah-ha" moment comes when you've cranked the unit around until the VC hits the firewall and you think: hmmm... i don't remember that....

anyway, is it just my thinking that 90psi cranking compression is dreadfully low?
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No, they will not run 180 "out"
 
Did someone mention "are you sure" the valves are actually opening and closing AKA something wrong in the valve train HOLDING the valves OPEN or cam so flat they really aren't opening, etc........Does it have oil blowby, indicating poor ring seal?

You have FOUND the area of trouble.........very poor compression. Use air/ leak test to try and find WHERE the compression is escaping. Apply air into the cylinder at TDC and listed "to where" it is coming out.......oil filler, exhaust, carb, and radiator
 
67Dart273 said:
Did someone mention "are you sure" the valves are actually opening and closing AKA something wrong in the valve train HOLDING the valves OPEN or cam so flat they really aren't opening, etc........Does it have oil blowby, indicating poor ring seal?

You have FOUND the area of trouble.........very poor compression. Use air/ leak test to try and find WHERE the compression is escaping. Apply air into the cylinder at TDC and listed "to where" it is coming out.......oil filler, exhaust, carb, and radiator
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The valves are moving for sure, and they close fine. A leak down test says no blow-by at the valves and ring leakage is good at less than 10%. All signs point to the cam being installed incorrectly. I will know more when I get it out and on a stand.
 
halfafish said:
The valves are moving for sure, and they close fine. A leak down test says no blow-by at the valves and ring leakage is good at less than 10%. All signs point to the cam being installed incorrectly. I will know more when I get it out and on a stand.
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You started 6 hours ago you ain't got that thing on the engine stand yet!
Did you go in and take a nap or something?!....
 
Why pull the engine again ?
The rear main is accessible and the cam timing can be checked in place as well.
 
Just went back to the first post in this thread. Is this engine a 1982 hydraulic lifter engine? With non adjustable rocker arms?
 
Kern Dog said:
Why pull the engine again ?
The rear main is accessible and the cam timing can be checked in place as well.
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The Young Jedi should've degreed the cam in the 1st place, so that's what should be done now, working in a D-series truck I can't recall what kind of room for a degree wheel there is.
 
Charrlie_S said:
Just went back to the first post in this thread. Is this engine a hydraulic lifter engine? With non adjustable rocker arms?
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Read the link in the 1st post, think He went mech. & OCG cam.
 
Slant sixes are difficult and clumsy to install and remove.
 
Charrlie_S said:
Just went back to the first post in this thread. Is this engine a 1982 hydraulic lifter engine? With non adjustable rocker arms?
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Yes, it's a juice head but I swapped in solid lifters, rockers, and cam.

Killer6 said:
The Young Jedi should've degreed the cam in the 1st place, so that's what should be done now, working in a D-series truck I can't recall what kind of room for a degree wheel there is.
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The young Jedi did degree in the cam, but by all appearances screwed something up. A slant in a truck is a no-go for getting a degree wheel in, and also a no-go to replace the rear main seal in place.

Kern Dog said:
Slant sixes are difficult and clumsy to install and remove.
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Yup. I'm WAY too old to be standing on my head trying to degree the cam in place. There's just about no room to work anyway.

I bid you gentlemen a good evening, while I head to the shop to pull the engine.
 
My machine shop buddy tried 3 sets of gear sets and none of them the dots aligned. We degreed it and it was perfect so the dots on the gears were off. They were half a gear off so one could easily have selected the other side and gotten it a tooth off if not degreed. Not sure what was going on with slant gear sets a few years ago.
 
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