bending pushrods
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Joined: Feb 2005
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bending pushrods
I have a 72 ford 1/2 ton.360 2v auto.The truck sat for a long time while i was rebuilding the trans. (12 to 18 months).After finishing the trans and reassembling everything I drove the truck for a few miles.Trans seems to work fine but the engine keeps bending pushrods.It seems to only happen on the left side of the engine (1,2,3,4).I dont understand why this is happening.Nothing else has been done to the engine since the trans was rebuilt.Somebody told me that bad gas would leave deposits on the stems and guides of the valves and cause them to drag and possibly bend pushrods.Somebody please help.
Post Fiend
Joined: Mar 2004
Posts: 6,056
Likes: 8
From: Union, Washington
OK, first 1,2,3,4 cylinders are on the right (passenger) side. Usually when this happens the valve stem will hangup or the lifter pumps up to far and will not bled down, so the valves bounce off the piston top and the weakest link (the push rods bend) fails.
Cargo Master
Joined: Feb 2004
Posts: 2,046
Likes: 164
From: Central Texas
Bear's theory could be right, but I would bet that the cause is bad, old fuel. I have seen this a number of times, especially on FE's for some reason. Old fuel will migrate into the valve stems while it's running and the varnish will bind up the valve.
This happened to me after I rebuilt a 390 for a 60's T-bird. The owner never thought that 3 year old gas would be an issue...it was. Same exact thing happened on a 360 for a 75-ish Pick-up.
Clean the old gas out, spray carb cleaner on the valve stems and give it another go.
This happened to me after I rebuilt a 390 for a 60's T-bird. The owner never thought that 3 year old gas would be an issue...it was. Same exact thing happened on a 360 for a 75-ish Pick-up.
Clean the old gas out, spray carb cleaner on the valve stems and give it another go.
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Post Fiend
Joined: Dec 2003
Posts: 6,658
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From: "Islander"
If you had bent pushrods from sticking valves you would have dead cylinders, fishy being the whole right bank. Take a rubber or plastic hammer and thump each valve to see if they unseat and snap closed freely. Rockers free on their shaft?
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Elder User
Joined: Nov 1999
Posts: 796
Likes: 3
From: Anderson Northern Ca
Bad Gas
Had the same thing happen on My 73 F-350 -390.I bought the truck which had not been started and completely warmed up for 3 years.The engine never got hot enough in those 3 years to cause the varnish to heat up enough to stick to the valves and guides.Well I drove it home 30 miles and shut it off,came out in the morning and started it and bent 10 pushrods.It took us many hours to free up the valves,drain and clean the gas tanks and lines.Then after we thought we had it all clean we started it up and bent 4 more pushrods.Clean everything as good as you can!
"bowties in the rearview mirror"
"bowties in the rearview mirror"
Cargo Master
Joined: Jul 2003
Posts: 2,328
Likes: 14
From: Colorado
Hey guys, my friend is having some woes with his 428:
His motor was running strong for a long time then one morning he started it up and it bent 3 pushrods, 1 on one side and two on the other side. He tore it apart and had lots and lots of slop in the timing chain and pretty much just assumed that was the cause. He checked the pistons, no damage, no cylinder ridges so he decided just to do a top end on it. So he was wanting a bit of freshening up so he bought Performer RPM aluminum heads, intake, recommened Edelbrock cam (cant remember number) and edelbrock lifter kit.
He put it all back together and broke in the cam, then drove it around the neighborhood and all was well. Parked it, went out to start it the next day (cold) and sure enough (clunk clunk). Took off valve covers to find 4 more bent pushrods. ANY ideas on what could be causing this?? Thanks!
His motor was running strong for a long time then one morning he started it up and it bent 3 pushrods, 1 on one side and two on the other side. He tore it apart and had lots and lots of slop in the timing chain and pretty much just assumed that was the cause. He checked the pistons, no damage, no cylinder ridges so he decided just to do a top end on it. So he was wanting a bit of freshening up so he bought Performer RPM aluminum heads, intake, recommened Edelbrock cam (cant remember number) and edelbrock lifter kit.
He put it all back together and broke in the cam, then drove it around the neighborhood and all was well. Parked it, went out to start it the next day (cold) and sure enough (clunk clunk). Took off valve covers to find 4 more bent pushrods. ANY ideas on what could be causing this?? Thanks!
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Cargo Master
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Ford Parts Specialist
Joined: Nov 2006
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From: Simi Valley, CA
Originally Posted by ceetwarrior
Anyone got any suggestions? Lifters? Different length pushrods in wrong spots?
B8AZ-6565-C .. Pushrod ~ Use with solid lifters ~ 1966 Police Interceptor: 9.345" / 9.355" o/all length ~ 1 oval and one cup type end.
C4TZ-6565-B .. Pushrod ~ 1966/68 (all exc. P/I) before change L/5. 9/62" o/a length.
C8AZ-6565-A .. Pushrod ~ 1968/70 after change L/5. 9.59" o/a length.
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C8AZ-6500-A .. Hydraulic Lifter ~ Used 1966/70
Last edited by NumberDummy; Dec 9, 2007 at 02:57 PM.
Cargo Master
Joined: Jul 2003
Posts: 2,328
Likes: 14
From: Colorado
We think its not an original 428. We believe it was a 360 turned 428.
Cam: Edelbrock 7106 Intake Duration @ .050, .236
Intake .572 lift
Exhaust .572 lift
Heads: Edelbrock Performer RPM (preassembled of course) cam is recommended for heads (seems a little high on lift).
Valvetrain: Stock non-adjustable rockers.
Cam: Edelbrock 7106 Intake Duration @ .050, .236
Intake .572 lift
Exhaust .572 lift
Heads: Edelbrock Performer RPM (preassembled of course) cam is recommended for heads (seems a little high on lift).
Valvetrain: Stock non-adjustable rockers.
Cargo Master
Joined: Apr 2004
Posts: 2,574
Likes: 4
From: Golden, CO
Originally Posted by ceetwarrior
Heads: Edelbrock Performer RPM (preassembled of course) cam is recommended for heads (seems a little high on lift).
Valvetrain: Stock non-adjustable rockers.
Valvetrain: Stock non-adjustable rockers.
Just going off memory, .572 is more lift than the stock valvetrain can accommodate, and that is without shaving the heads or deck. My guess is that your bud will need to get an adjustable pushrod to determine the length he needs, and order that length pushrod.
I'll let the older dogs chime in now...
Needsmorecoffee.
Joined: Oct 2004
Posts: 3,624
Likes: 2
From: CT
Even tho Edel lists a .600 lift with those springs I'd be leary of that and their quality. You might be getting coil bind with that .572 lift and the stock springs. That with a mismatched pushrod might be getting him in trouble. Getting a set of adjustable rockers would solve the different pushrod length problem. And I'd suggest looking into the springs matched for the cam. Just a few thoughts.
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
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From: Simi Valley, CA
Originally Posted by ceetwarrior
We think its not an original 428. We believe it was a 360 turned 428.Valvetrain: Stock non-adjustable rockers.
The same specs apply.
Early 1968 360's (and 390's) installed in trucks used the C4TZ pushrods till the change: L/2. After change L/2, 1968/76 360/390's used the C8AZ pushrod.
Last edited by NumberDummy; Dec 9, 2007 at 04:25 PM.
Cargo Master
Joined: Jul 2003
Posts: 2,328
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From: Colorado
hey Hypoid, thats kinda what I was thinking. He needs some 1.76's. I have a brand new set of DSC adjustable assemblies, early FE finger drip rails, and pushrods (for my build)... we'll probably end up putting it on and trying it out. But he doesn't really want to spend the extra $$300-400 to buy it all from me!