Hi new here so I hope I'm posting this in the proper category.i picked up a old 1973 f100 to play with when I have time. It is kind of a mutt truck it is a 1973 supercab that had a long bed that is now cut to be a short bed. It has a 351m engine and 4 speed out of a 1979 truck and the front clip is a 1979 that I converted back to the round headlight 1973 front end. When I got the truck it had not been started in 3 or 4 years. I got it to start and then started to finish the welding on the bed and other stuff . The other day I fired it back up because when I first started it I noticed a tick and wanted to address it. It ran but was back firing so I decided to pull the covers and check it out. I found 4 bent push rods all on the intake side. Not sure what to do next part of me thinks stuck valves the other part thinks timing chain jumped. Don't know much about the 351m. What would you recommend for the next step?
Thanks

 

The 351M/400 is the same as any other engine except better. Lots of untapped potential.

Don't think it would be the timing chain but if she sat for a spell, she could use some lovin'.

Ok...were the bent pushrods all on the same bank? Stock pushrod length is 9.5". Could they have been changed?

The next step would be to check the cam lobes......pull a couple lifters - #1 exhaust and #2 intake are the easiest....remembering their respective locations. Take a straight edge or the side of the other lifter and lay it across a lifter's foot. You're looking for a slight crown in the middle. If you see daylight in the middle, the cam and lifters are pooched. Daylight on each outside edge is fine.

Oh, and welcome to FTE....good guys here.

 

It was 2 , 4 , 6 and 8 intake. 2 and 6 were off the rocker because they were so bent. I was thinking of just changing the cam before this because of the reading I had done on the 351m spring lift problem with aftermarket cams. Im almost sure its all stock but If I have to fight with the 400lb intake to check the lifters I should probably just do new cam,lifters,springs and chain don't you think? I have the non rotator cap springs on it now. Can you recommend a good spring to run with a little bit bigger cam? For the timing chain all I have to do is get one with 3 key way setting and set it dot to dot straight up with the cam at 6 o'clock the crank at 12 o'clock and the key way straight up and down to get rid of fords 4 degree retard ? Do you have any recommendations for these parts?

Thank you

 

Actually, you don't have to remove the intake to get at the lifters. just yank the right valve cover and <POOF!>... you're looking down a nice hole to remove those lifters.

Did you take off the exhaust rotators or did you get the vehicle like that? Generally, the exhaust rotators are replaced with new retainers when an aftermarket ("bigger") bumpstick is installed.

If someone installed a cam with a lift more than 0.480" and used the stock valve springs, the stock valve springs will coil bind....they weren't made for that much lift. Not all the time, but most of the time. New springs are a must with a healthier cam, in my mind. I wouldn't put an engine together without them.

Let's do some troubleshooting first, just to be sure, ok? Pulling those lifters is an easy job. I took out and replaced all 16 in less than an hour not too long ago. The most troublesome was #8 cylinder.

I'll gladly give you my opinion on a cam/lifters/springs, timing gears, etc.....but just to check, yank those two lifters and check 'em.....? Mebbe there was some broke valve springs....coil bind....hard to say...but 2, 4, 6, 8, and all intake?

But,......yes to all your questions, you're correctamundo!

 

Ok will do and I will let you know my findings. Thank you- what tool did you use to get the lifters out ? I'm not sure why there are no rotators I did not do it. I don't think they are there at least, ill post a picture.

 

Yeupp, you're right...no rotators. Interesting.

I used an extendable magnet to grasp the lifters, with a screwdriver to help. A pick would work with a 90* bend at the end if you can hook onto the little wire keeper. The magnet worked fine for me.

Good luck.

 

First, welcome to FTE!

Second, I'll just kibitz as you guys are doing well.

 

Um, you can't get the lifters out through the head!

 

Yes, you can. Been there, done it. On an M block, that is. FEs, 385 series, no.

 

The stock M/400 heads have nice big openings where the pushrods come through, instead of narrow channels. You could easily thread a tool down in there and extract the lifters from the lifter valley. I think it might be more difficult on an older engine where the lifters might have some mushrooming or some sludge buildup keeping them from sliding freely out of the bores, but it is physically possible.

 

Why not just simply replace the bent push rods and see how it runs? You want to verify engine condition before modifying it don't you?

 

@ FILTHY BEAST So I pulled the lifters and they looked ok to me I will attach some pictures.




@ KULTULZ I have new pushrods on order I just wanted to see if I was missing anything or if there was something I could do to prevent the new pushrods from bending. I don't like not to be able to figure out why something happens, Just wired like that I guess. The truck does(did,I took it apart) run ill put a link to the video maybe you can hear something the only thing is you can not hear the ticking from the pushrods hitting the side of the head

Thank you

 

If you used the framing square as shown in the picture you might not get a good reading....did that lifter "rock" side to side a bit? I'll throw up a picture when I can....the best way to do check the cam/lifters, and the way I do it, is to put the lifters together such that they make a "T". Better visual. At least they came out without a problem, no?

I heard the ticking in the video....if you have her back together before I post a picture of the cam/lifter check, attach a vacuum gauge to manifold vacuum....what does it tell you? You could try whacking (with a brass drift pin) the offending valves to see if they move - on the valve stem, NOT on the retainer! Don't want to have the keepers flying off in all directions!

You could pull a few plugs - on the offending cylinders and look for what they're telling you.

From the second picture...that lifter's foot doesn't look healthy.....

I'll be baack.....

 

This lifter (above) is pooched...along with the cam. Note the light shining through the middle...where a crown should be.



Good lifter and cam....note where the light shines through - on the edges - indicating a crown in the middle

 

I could be wrong of course but I still don't see how to get 335 series lifters out through the head. I'm trying to post a pic.