400m problem
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Joined: Dec 2002
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From: chicago burbs
compression test, that hasn't gone away. if there is a broken valve spring the more you run it the more chance you're taking of total disaster. locate the problem cylinder and pull the valve cover to inspect what's goin on. i just found a broken spring on a head i'm working on, i didn't catch it until i was about to bag the head after having apart & back together twice but man i'm glad i saw the edge of the crack. being on an engine in the chassis you'll have to look listen smell touch taste feel those springs REAL GOOD to be sure there's no crack, hopefully since there's a valve hanging open it'll be easy to spot and easy to fix
if you find a broken spring and a hanging valve don't F with it unless you have that piston to TDC so the valve can't drop into the cylinder, even better feed a piece of nylon rope in through the plug hole before you get the piston to TDC. the piston and rope will hold the valve securely to the top.
it could also be a broken valve stem, if it is hopefully the broken edge is holding the valve from dropping all the way in... that's what happened in this pic and is why you don't want to run it more than you have to before you find the problem
if you find a broken spring and a hanging valve don't F with it unless you have that piston to TDC so the valve can't drop into the cylinder, even better feed a piece of nylon rope in through the plug hole before you get the piston to TDC. the piston and rope will hold the valve securely to the top.
it could also be a broken valve stem, if it is hopefully the broken edge is holding the valve from dropping all the way in... that's what happened in this pic and is why you don't want to run it more than you have to before you find the problem
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Joined: Nov 2008
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From: wyoming
igniton stuff.
on the ignition hope hes not between contacts in distrib and causing it to fire wrong cylinder. I do believe hes possibly got a weak spring or something. Just went through this with a older engine 400. I run a phaseable rotor in my MSD for fine tuning my rotor. 
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From: chicago burbs
boy i'm getting soft here, your post just tripped my grey matter
it's happened to me a couple times and many others as well... the distributor drive pin can be broken and causing the out of time issue. sometimes the pin is broken but not visible externally, the pieces are still holding in the gear & shaft but not in the right place, the only way to check it is to try to drive the pin out with a 1/8" punch and you may as well replace the pin regardless at that point anyway
also very possible that the pin broke internally and 'caught' again when it came around 180* out. set the engine to TDC on the firing stroke using the 'finger in the hole' method, pull the dizzy out and check the dizzy gear drive pin. if it's damaged, use a 5/16" - 1/4" drive socket to check to see that the oil pump driveshaft turns counter-clockwise. either be very careful not to drop tools into the engine(it'll happen) or use a piece of tape to keep the socket and 1/4" to 3/8" adapter from falling off the extension. the oil pump driveshaft should turn easily with no resitance until you try to turn it fast, then you should feel it build oil pressure
it's happened to me a couple times and many others as well... the distributor drive pin can be broken and causing the out of time issue. sometimes the pin is broken but not visible externally, the pieces are still holding in the gear & shaft but not in the right place, the only way to check it is to try to drive the pin out with a 1/8" punch and you may as well replace the pin regardless at that point anyway
also very possible that the pin broke internally and 'caught' again when it came around 180* out. set the engine to TDC on the firing stroke using the 'finger in the hole' method, pull the dizzy out and check the dizzy gear drive pin. if it's damaged, use a 5/16" - 1/4" drive socket to check to see that the oil pump driveshaft turns counter-clockwise. either be very careful not to drop tools into the engine(it'll happen) or use a piece of tape to keep the socket and 1/4" to 3/8" adapter from falling off the extension. the oil pump driveshaft should turn easily with no resitance until you try to turn it fast, then you should feel it build oil pressure
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From: chicago burbs
that's kinda my point though, there's no benefit to fixing everything that's not causing your problem, it's called diagnosing
the compression test will tell you if it's a mechanical problem, checking/replacing the 25 cent roll pin will confirm either way and not hurt your pocket
if it's not the module you're still not running and $20 lighter. maybe it's the magnetic pick-up in the dizzy? $$ nope... maybe it's the coil? $$ nope... ignition switch?
you can probably rent a compression tester and/or a valve spring compressor if you need it at the part store. if you need a spring or 2 i'll send ya a couple, i have a few extra hangin around. it's pretty simple to change a spring in the truck
the compression test will tell you if it's a mechanical problem, checking/replacing the 25 cent roll pin will confirm either way and not hurt your pocket
if it's not the module you're still not running and $20 lighter. maybe it's the magnetic pick-up in the dizzy? $$ nope... maybe it's the coil? $$ nope... ignition switch?
you can probably rent a compression tester and/or a valve spring compressor if you need it at the part store. if you need a spring or 2 i'll send ya a couple, i have a few extra hangin around. it's pretty simple to change a spring in the truck
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Joined: May 2011
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From: Wrights community
Is there a way to check the magnetic pick-up? coil? while the motor is in the truck? How do I go about changing a spring? And thanks for the offer. How much$? How hard is it to replace a rocker arm or put one back on? I have read about working on the 400, just haven't gotten inside of it yet. The only inside motor experience I have is re-ringing a dirt bike.(wasn't hard, but timing with the cam, crank, and pulse generator is what was)
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From: Wrights community
I got a guy that worked at Ford up north for 30 years coming to help. If he has to, he can take it home and rebuild the whole Hoover DAM thing for me. I am willing to let him do it, my pockets, not so much, but it leaks oil out of the front crank seal, so...yeah.
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Joined: Dec 2002
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From: chicago burbs
here's a couple pics from yesterday, if you did a ring on a bike you can do a valvespring with a little good guidance, a short piece of nylon rope and this tool
OTC Tools 4573 - OTC Large Valve Spring Compressors - Overview - SummitRacing.com
each rocker is held on by a single bolt, no adjustment, just torqued to 20-25#. if you don't have a torque wrench that means not very tight, just so it doesn't come loose
OTC Tools 4573 - OTC Large Valve Spring Compressors - Overview - SummitRacing.com
each rocker is held on by a single bolt, no adjustment, just torqued to 20-25#. if you don't have a torque wrench that means not very tight, just so it doesn't come loose
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Joined: May 2011
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From: Wrights community
well the guy is not here, he should have been here today @ 3:30 pm. So, I'm gonna call him tonight and see if he said today or tomorrow. If he said tomorrow, I will just let him rebuild it and not worry about it being in my yard for a while. I would do it myself, but I don't have time. I got football, summer basketball, jobs, and a girlfriend. So do ya'll recommend the rebuild kit from TMeyer, inc. or go OEM style(as in cast pistons etc)?
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From: chicago burbs
i recommend troubleshooting the problem before spending a penny on parts
a couple thou later you can be sitting on the same problem but it's your $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
i doubt very few here or anywhere else would not recommend Tim
i believe Tim handles Hypereutectic and Forged pistons, Hypereutectic are usually cast but i've seen 'Forged Hypereutectic' advertised somewhere before
Hypereutectic is a term that describes the ratio of components (metalurgy) of the alloy used to make the pistons. a Hypereutectic alloy is more brittle than a Eutectic alloy(standard cast) but holds dimension better so they run tighter clearances
alloys for 'classic' Forged pistons are different yet, more maleable and less dimensionally stable so they run larger clearances, they can take anything and survive where a Hypereutectic would crumble
a couple thou later you can be sitting on the same problem but it's your $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
i doubt very few here or anywhere else would not recommend Tim
i believe Tim handles Hypereutectic and Forged pistons, Hypereutectic are usually cast but i've seen 'Forged Hypereutectic' advertised somewhere before
Hypereutectic is a term that describes the ratio of components (metalurgy) of the alloy used to make the pistons. a Hypereutectic alloy is more brittle than a Eutectic alloy(standard cast) but holds dimension better so they run tighter clearances
alloys for 'classic' Forged pistons are different yet, more maleable and less dimensionally stable so they run larger clearances, they can take anything and survive where a Hypereutectic would crumble
Posting Guru
Joined: Nov 2008
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From: wyoming
thats a cobrajet head!!
here's a couple pics from yesterday, if you did a ring on a bike you can do a valvespring with a little good guidance, a short piece of nylon rope and this tool
OTC Tools 4573 - OTC Large Valve Spring Compressors - Overview - SummitRacing.com
each rocker is held on by a single bolt, no adjustment, just torqued to 20-25#. if you don't have a torque wrench that means not very tight, just so it doesn't come loose
OTC Tools 4573 - OTC Large Valve Spring Compressors - Overview - SummitRacing.com
each rocker is held on by a single bolt, no adjustment, just torqued to 20-25#. if you don't have a torque wrench that means not very tight, just so it doesn't come loose
Senior User
Joined: May 2011
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From: Wrights community
well rebuilding it ALL would solve any and all problems. I had compression checked, and none at all. I am getting it rebuilt, all the way. New cam, valves, cylinders honed, IDk bout boring yet(if I do, .10 over), pistons, rings, plugs, etc.