Thread: bent pushrod help!
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09-09-2004 05:29 PM #1
bent pushrod help!
have a 428 cj with a bent pushrod. the engine was rebuilt and is still new. i do not know what type of cam. the heads have adjustable rockers and the pushrod has a cup on the top end. i need new lifters too cause they are the only thing that the engine shop left in when it was rebuilt. the valves "float" around 4000. my questions are what type of lifers and pushrods should i use if i keep the adjustable rockers.
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09-09-2004 09:10 PM #2
Well I'll keep the thread going for you a little longer on your first post. I really know little about the 428 CJ except that that is a desireable engine that ought to be fixed. If the valves floated at 4000 rpm they may have just had old reused springs, very tired springs. The first question is whether the bent pushrod also bent a valve. The first thing I would do is have a compression check to find out if the valves are sealing and check for a bent valve where the pushrod was bent. If the valves are OK then the next thing to do is to replace the springs with either new stock springs or performance springs. There should be a Ford Motorsports catalog at a number of sites including Pep Boys shops which offer racing parts for the Ford big block. As far as I know you will have to remove the heads to change the springs and that would be a good time to have the valves refaced as well as replace the springs. Lifters can't be that expensive so it would be a good idea to replace the lifters too. All of that assumes the bottom end of the engine is in good shape wrt bearings and rings. Well there other people on this Forum who have expert knowledge of the big block Fords so I will kick this up to the top of the thread list and hopefully one of them will give a better answer. Welcome to the Forum, there are some real experts here, but they have to sleep sometime(??????).
Don Shillady
Retired Scientist/teen rodder
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09-10-2004 07:40 AM #3
I am trying to recall the exact engine in the T-roadster Tech1 had, but I believe his engine was similar and he should be able to make helpful comments at the highest level of expertise. For me I would be in anguish to have such a good engine with bent parts so I hope there is no damage to a piston or a bent valve as well as a pushrod. After all, something was out of sync to bend the pushrod and I think you will have to take off the heads to examine the pistons as well as the valves. If you do not get any further response, I suggest you look up Techinspector1 in the members list and send him an e-mail message for help.
Don Shillady
Retired Scientist/teen rodder
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09-10-2004 06:34 PM #4
Great answer Tech1! I followed the development of the 332 and 352 up to the 390 but at that point in history I got involved with VWs and did not know where the 460s originated. So you are saying that one of the possibilities is a tight valve guide? That would bend a pushrod but not push a valve in at the wrong time so the damage may not be more than the pushrod. That would be good except there may be others. I had a tight guide in a rebuilt MG midget engine and the fix was to thread a piece of rope in through the spark plug hole, compress the spring, remove the keeper and spring and then attach a 3/8" drill chuck to the valve stem and spin the thing with lubrication until it "wore in". That was not my idea, it was done by the MG shop guy. The rope in the cylinder held the valve up while the valve was being spun. Actually he overdid it because I then experienced some added oil consumption, probably down around the valve stem. Therefore if this approach is used it should only be done a little at a time until the valve is free. Do you miss the T-bucket Tech1? Anyway your comments are valuable!
Don Shillady
Retired Scientist/teen rodder
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09-10-2004 07:14 PM #5
Well good luck with the new project Tech1, I know well the empty garage syndrome. I have gone through it selling a '40 Ford convert, swept the garage clean and within a month I had found a badly rusted '29 roadster body and frame, but it was far worse than the '40 I had just sold! Well let's hope the originator of this thread only has minor damage and your comments should help him. For your new project you can do that in Arizona where it seldom rains, but last Monday we had 12 inches of rain in a few hours here in Richmond! I wonder how I can get a roadster top with side courtains that can add the curtains quickly in our weather environment, but maybe my roadster will only be a car for special occasions, we shall see.
Don Shillady
Retired Scientist/teen rodder
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09-12-2004 09:30 AM #6
thanks for all the help guys. i fould the build sheet on this engine and the heads were reworked with new springs, locks and retainers. new guides hard seats and all is well. the 428 has less than 1000 miles on it since it was rebuilt in 91 by then kuntz and kraft. new everything balanced and blueprinted .030 over. the only thing they didn't replace were the lifers. i replaced all the lifers and the one that caused the damage is seized up. i hope this will be the end of that problem. the motor is very tight with 10.5:1 and extremely strong. well over the advertised 335 hp for a 428cj.
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