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strange 572 crate hemi issue

corunna bird

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Hey guy's, haven't posted in quite some time. I installed the hemi in the challenger and was ready to fire it up and to make a long story short it would only turn over about a quarter turn. it is building like a hydraulic situation for some reason like the crank and cam are out of sync? remove the plugs and all is good put two plugs in it anywhere and it comes to a stop. the motor was run and dynoed and I did not touch it so I pulled the motor took front cover and timing chain off and the crank spins nice. removed the pushrods and the cam spins free valves open and close like normal and rocker shafts are all good. not sure if anyone ran into this just looking for some ideas.

thanks Bruce
 
That's too bad, expensive engine.
I assume all the plugs were dry, so in fact it is not a hydraulic lock? spins fine with no plugs so not mechanical interference?, unless it is the plugs themselves?. Does it turn over with plugs in but ignition and fuel disabled? You seem aware but be careful about bending valves with your cam disconnected or not timed.

Ideas,
Phone up the engine supplier.
compression check.
check cam timing.
weak starter or starting circuit.
Too much ignition advance
 
That's too bad, expensive engine.
I assume all the plugs were dry, so in fact it is not a hydraulic lock? spins fine with no plugs so not mechanical interference?, unless it is the plugs themselves?. Does it turn over with plugs in but ignition and fuel disabled? You seem aware but be careful about bending valves with your cam disconnected or not timed.

Ideas,
Phone up the engine supplier.
compression check.
check cam timing.
weak starter or starting circuit.
Too much ignition advance

thanks for the reply. well I did drop a little oil in each cylinder and rotated it once and awhile while waiting for the car to be done. no mechanical interference just compression have a high torque starter tried direct with heavy cables but quarter turn and that's it. Funny thing is the motor was definitely run and dynoed and I touched nothing . removed chain and push rods crank rotates nice cam turns with your fights nice , no sticky rockers and valves open and snap shut so nothing bad there. it has a 3 keyway bottom sprocket but I put it were it was so I'm kinda stumped.
 
Hmm. Can you checked the cranking compression in a few cylinders, one cylinder at a time. Starters can sound like they are working hard but hardly have cranking torque. Perhaps something is funny with the starter/ flywheel or inside the starter so when it meets a bit of resistance it kicks over somehow and jams? If you have 2 plugs in it, is it possible to turn over by hand with a breaker bar on the crank bolt, a rotation or 2?
 
Probably hydraulicing on the oil you put down the cylinders. No need for that. If the engine is going to set for a while you can remove the rockers to shut all the valves so no moisture gets in.
 
Whoa! Your removed the timing chain and spun the crankshaft and the camshaft? Are you sure you now have retimed the cam correctly? Before removing the chain did you try to spin the engine on the starter without the ignition on? It could be the timing advanced too much. Before you removed the timing chain did you try to rotate the engine with a wrench on the crankshaft? What is the compression ratio of this hemi? We've built hemis where the compression and lack of leakdown would make it feel like it locked, and if we waited a few seconds the compression pressure would release and the engine would then rotate again.
 
Whoa! Your removed the timing chain and spun the crankshaft and the camshaft? Are you sure you now have retimed the cam correctly? Before removing the chain did you try to spin the engine on the starter without the ignition on? It could be the timing advanced too much. Before you removed the timing chain did you try to rotate the engine with a wrench on the crankshaft? What is the compression ratio of this hemi? We've built hemis where the compression and lack of leakdown would make it feel like it locked, and if we waited a few seconds the compression pressure would release and the engine would then rotate again.

yeah it seams like there is zero leak down. if you wait a Second it moves freely. it's not like it's crazy compression 10/1 . motor definitely was run and I have touched nothing just dropped it in the car it has a quick time bell and a high torque starter and McLeod twin disk which is all good . there is no intreference with anything just a compression issue for some reason. tried two starters with same results. Really not sure never had an issue like this before
 
Probably hydraulicing on the oil you put down the cylinders. No need for that. If the engine is going to set for a while you can remove the rockers to shut all the valves so no moisture gets in.
I see your point. Really just put a small amount in there but who knows maybe enough to cause me this issue . I have rotated the motor by hand using a ratchet. there is compression for sure maybe to much for the starter with the oil film there not sure
 
Someone didn't drop a nut down intake
Those starters will turn over 13:1
 
If the dyno operator didn't have a problem, I'd say it's your starting system or potentially your timing curve (too much initial). Did you do a starter draw test? Are the cables getting hot? What is the inital timing set to? What are the cylinder pressures?
 
If the starter and ring gear are too tight the amperage will spike on starter and first cylinder it see will stop it
 
If the dyno operator didn't have a problem, I'd say it's your starting system or potentially your timing curve (too much initial). Did you do a starter draw test? Are the cables getting hot? What is the inital timing set to? What are the cylinder pressures?

yeah I tried two starters hooked direct to the starter with welding cables. I did not touch a thing with the motor except for putting a little oil in the cylenders and i rolled it over once and awhile that's why I'm thinking the oil has something to do with it. might have like total seal rings or something. for sure it has been run you can tell. juse wondering what would be the best way to get rid of the oil?

thanks everyone for your help

bruce
 
If the starter and ring gear are too tight the amperage will spike on starter and first cylinder it see will stop it
well I looked at the flywheel and clutch for interference and found none. it has a quick time bell housing first time I dealt with one of those so not sure if anyone has had any issues with them or not.

I do have a factory bell I could install and try just to eliminate that I suppose
 
wondering what would be the best way to get rid of the oil?
Pull all the spark plugs. If with the plugs out, the starter will spin the motor over, will tell if no mechanical issue. And, at same time will push out any excess oil. Think it would have to have a bit of oil on top, to make it hydraulic.
If you haven't already, turn the motor by hand first, before using the starter. Hope you got the timing chain back on, timed right.
 
Pull all the spark plugs. If with the plugs out, the starter will spin the motor over, will tell if no mechanical issue. And, at same time will push out any excess oil. Think it would have to have a bit of oil on top, to make it hydraulic.
If you haven't already, turn the motor by hand first, before using the starter. Hope you got the timing chain back on, timed right.

yeah everything is back exactly the way it was. no mechanical interference at all. I did remove the plugs and rolled it over to try and blow it out but as you know with a hemi the starts to flow and runs back into the plug holes. it just builds so much pressure I'm thinking it has to be something with cam to crank timing like valves that should be opening are out of sync somehow.

thanks for the reply and help
 
Try a small tube and a vacuum pump to suck the oil out
 
Might have too much oil. Try necking down your shop vac hose to a tube that will fit through the plug holes. See what you can draw out.
 
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