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Unfortunately, moving the trans rearward 3/8" will not disengage any drivetrain. It would have to go back farther than that.
I would wait a few more days and see if somebody brainstorms your issue. Truely bizarre.
Dropping the pan for a "look-see" is a whole lot easier than pulling the engine. Maybe something will jump out at you inside the crankcase.
Unfortunately, moving the trans rearward 3/8" will not disengage any drivetrain. It would have to go back farther than that.
I would wait a few more days and see if somebody brainstorms your issue. Truely bizarre.
Dropping the pan for a "look-see" is a whole lot easier than pulling the engine. Maybe something will jump out at you inside the crankcase.
Good Luck
I’d also pull a couple rod and main caps while you have the pan off to see if the bearings give you any clues.
While you may ultimately have to pull and dismantle the engine, maybe you could very the valve train is really operating as it should. You might want to consider pulling the plugs again since you said it spins freely without them in place. Then remove the valve covers and have a friend crank the motor over while you watch the rockers and valve stems plunge and return to a fully seated position.
Plugs in...no rotation...plugs out...rotation. That makes me wonder if the air has no place to go. Pumps don't like blockages.
Good Luck and don't loose heart. You will discover the cause sooner or later.
Hey everyone i got a update of course its not a good one or one im happy about but i need to move forward.
pulled the motor, that was fun, ill need a engine leveler when it goes back in.
started to dissemble and check to see if its able to crank over as i go (still locked up)
i got 2 pistons out and i still cant crank the engine over, (heads off)
the rod bearings have some wear. pics attached.
i got to get the rest apart and ill update again.
thanks for everyones time and comments
Hey everyone i got a update of course its not a good one or one im happy about but i need to move forward.
pulled the motor, that was fun, ill need a engine leveler when it goes back in.
started to dissemble and check to see if its able to crank over as i go (still locked up)
i got 2 pistons out and i still cant crank the engine over, (heads off)
the rod bearings have some wear. pics attached.
i got to get the rest apart and ill update again.
thanks for everyones time and comments
That rod bearing got dry and scrubbed past the babbit into the brass......my fear is you will find worse looking ones as you go.
ok. got the engine down to the bare block.
the crank was what was holding it back.
a wear line down the mains, and most rod wear towards the back near oil pump.
i had 60 pounds of oil pressure while this engine was running.
what causes this? when the engine was assembled it rotated nicely.
crank is 20/20 already and needs work after this,looks like ill be ordering a eagle crank.
since a machine shop is in my future, what will it take to put a roller cam with around the same specs as the stock 427/390 specs? never ran a roller cam but always wanted to.
engine is 30 over and the cylinders look great still
cam pulled out very nice and all but number 5 exhaust lifter came out of the block without a fight.
ok. got the engine down to the bare block.
the crank was what was holding it back.
a wear line down the mains, and most rod wear towards the back near oil pump.
i had 60 pounds of oil pressure while this engine was running.
what causes this? when the engine was assembled it rotated nicely.
crank is 20/20 already and needs work after this,looks like ill be ordering a eagle crank.
since a machine shop is in my future, what will it take to put a roller cam with around the same specs as the stock 427/390 specs? never ran a roller cam but always wanted to.
engine is 30 over and the cylinders look great still
cam pulled out very nice and all but number 5 exhaust lifter came out of the block without a fight.
I suspect the journals were not square.....
Oil pressure can look just fine and the journals can scrub themselves to death.....
What were the main and rod bearing clearances?
You need .003+ and .002+ on a BBC and that is the minimum....I like .0035 and .0025 respectively.....
I would have this block line honed.
Also....inspect the cam bearings and their clocking....
If going roller....please do yourself a favor and put a real cam in it.....the 427/390 cam had pathetic specs and just about anything else you put in there will make more power.....if you go with a roller that small it defeats the purpose of even having a roller....
A roller will need a roller spring setup....
I recommend Scat over Eagle right now.....used to be the other way around but I have built three Scat crank engines in the last 6 months....the cranks and rods are beautiful and on the money with STD. Bearings....
Eagle cranks almost always run fat and almost always need X bearings for proper clearance....and they don't sell them that way unless you buy direct and specify them....
Without knowing the full history of this engine from 2011 to 2023 and not being able to put a visual eye on the teardown I can only speculate so I will do just that. This engine at startup did not get or got very little oil to the crankshaft.
The first thing I want to know is why the crankshaft was not getting oil regardless of what the oil pressure reading was, my first inspection point would be the cam bearings and how they were clocked during installation. You said the crank was 20/20, I would measure the crankshaft and installed bearings to see if they were correct for this setup.
On a side note, there are still a number of good used STD/STD or NOS GM 3856223 (6223) crankshafts on the market. I have built a few 427's in the pass and always used GM cranks so I can't speak to any of the aftermarket cranks.
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i would think the cam bearings were in wrong or the crank didnt get any oil from the pre start oil priming or it just didnt have and assembly lube in it....Since its apart i would have it cleaned and everything check by a machine shop. when I built mine I checked and double checked all the clearances. Im kind of into that sort of thing so I actually enjoyed the time playing with micrometers and gauges.
as for the cam definitely spec one for 500 hp. you will be suprised how hard it is to stay down to 500 hp in todays market. As for pricing you will need
cam
lifters (the best ones you can get and they will be about $700 or higher...get bushed bearings not needle bearings)
springs
roller rockers for the spring diameter size
retainers for the spring diameter size
retainer locks rated for the spring pressure
shim kit to get the spring stack height correct or pay the shop to set up your heads. If you have stock cast heads they will have to be cut for the springs anyway so get them set up properly. I would go with a good set of aluminum heads because its going to be the same price or higher at this point...dont bother with the GM aluminum heads from the 69/70s
rocker arm studs
cam retainer or cam spacer. Since its in the shop and the big blocks have the provision for a retainer have the shop drill the retaining bolt holes and set it up fo rit. Buy a cam that has the retainer recess.
roller cam pushrod for fuel pump
correct hardened distributor gear
valve covers to fit this stack or a valve cover shims at a minimum
add the machine shop fees in
I may have missed something.....
go to summit and start a wish list for just these parts and see what the total is....you are not going to like it
right now my thinking is buy a scat crank. whats the thought cast vs forged?
pick a roller cam, any suggestions? im looking for a good running smooth engine over speed.
take to the machine shop and have it all cleaned and gone through.
Thanks
right now my thinking is buy a scat crank. whats the thought cast vs forged?
pick a roller cam, any suggestions? im looking for a good running smooth engine over speed.
take to the machine shop and have it all cleaned and gone through.
Thanks
If you're going to drop that much coin pay the extra and have the machine shop break it in on a dyno.
Heres a update on the engine issue.
I tore the engine apart and took it to the machine shop. bought a new Scat Crank, had everything balanced, checked, new freeze plugs, cam bearings, they did a hone and cleaning.
i kept the hydraulic flat tappet cam, I did wanna go roller but i had this cam already.
assembled engine,
reinstalled in car set timing at 10btdc
Broke cam in 25 minutes at 2500 RPM.
engine never got over 210 degrees. runs great so far.
im still on the center carb only, gotta set timing, dwell and then start introducing the other carbs and go from there. so far the second round is going good so thats my update.
im curious on what everyone recommends for my initial timing, ive read everywhere from 4-12 BTDC. specs are: 69 427 with tri power. stock style cam, stock heads, and i think it was .250 dome on pistons. this car was not a tri power car, but i found a NOS one and know it will take time tuning, should be fun. pic attached right after i got engine installed.
i used the eastwood chevy orange quart and hardener and sprayed with my auto paint gun. very nice paint and laid great.
