Hi all,
I guess this for folks more familiar with 351C than I am. The engine was bored .030 over and mains .010 by a reliable machine shop. I'm new to the 351C. The rockers are non-adjustable but when i torque them down, I still have .075 to .100 clearance between rocker and valve when rotate to the base lobe. Not on all the lifters. Some intake, some exhaust. When i run the engine I can hear the lifter noise(I've broken in the engine per normal; it was pretty loud and I didn't notice). Now am trying to determine why there is lifter noise. I didn't notice this until after the break-in (used high zinc oil) The cam/lifter are new matched set from Summit (RV cam) I re-used the push-rods and stamped rockers from orig '74 engine). Machine shop agreed, they showed little wear. Compression is great; it's just I can't lash down the valves! Could my lifters have failed? I know they make .060 longer pushrods but that won't work. Some lifter are really loose. About 6 out of 16 are loose..
The exh/int push rods are same length from what i measured so i don't think i mixed something up. The stamped rocker arms have either a 1, 2 or 3 number embossed on them. Is there a difference? There's no correlation i can see. I might have to pull engine and take it back to machine shop to see what happened. I've only run it for about 10 min in the truck (after break-in) before I noticed the noise. I know, should have caught it earlier but i thought. cool, non-adjustable, just torque them to spec...sigh. Oil pressure is good , 25 at idle; up to 70 ish when i rev.
Any debugging suggestions? I guess i could put a dial indicator on the rocker to confirm lift per the cam spec. Frustrated, engine starts and seem to run well except this clatter. Something's not right.

Just looking for some informed opinions. Best regards.

 

Well, something's not right
You re-used the pushrods and that's okay, but are any of them worn?
Same with the rockers and the fulcrums, are any of them worn?
It's possible that the pressed in rocker studs have started pulling out of the heads
It may be time to inspect the cam lobes and the lifters, if all the rest checks out okay

 

Wiped cam lobes are all too common these days.

 

Was 2023 when I did my lower end bearings, etc I let the lower end drain over night, and I had the oil pump out, even oil galleys drained. I didn't want oil in my face is why I let it drain, I was doing it "in the truck" lying on my back. I had put the cam and lifter set in back in the 1980s (was a Crane Fireball cam, but is same grind as the Edelbrock Performer-Plus camshaft #2172 sold now-adays), the lifters were quiet in 2023 before the job. I never even took the valve covers off, but with the oil pump out and me removing bearing caps, etc , there was nothing preventing a slow emptying of oil ways.

After it was all done, after I poured 7 quarts in, I turned it over on starter to see oil pressure.

Oil pressure was great ..... but some of the lifters had drained, and those parked on lobes had compressed some as the galleys had drained. I had lifter tick for a long time that day, certainly more than 10 minutes, but gradually it quieted. I had removed the plugs to more easily turn the engine over with a breaker bar. See this thread here.

 

Thanks for the input. I did some further digging tonight. I pulled the valve covers and plugs and cranked the engine over and some of the problem rockers definitely don't deflect as much as others. Drained the oil and have fine metal whiskers on the mag plug; not excessive, The engine only has an hour on it after machine work. I tried to use a dial gauge to try and measure lift but didn't really work out, don't have a good base. The problem is I don't know if it's the lifter or cam. I checked a few rockers where the pushrods were loose and they weren't egged out; they looked ok. I had run it for about 10 minutes, i would think that would be enough time to allow the lifters to pump up but perhaps not based on feedback. The engine had been sitting for 5 or 6 months between cam break-in and this initial firing while installed in the truck. I'll probably pull the intake and check a few lifters. I've done a few engines and have never had this prob. I guess all i can do is explore and try to get to root cause.

Does anyone know how to check a hyd lifter once it's removed from engine? Just taking it slow. Thx for the feedback and suggestions.

 

When you pull the lifters, do not mix them up. Make a organizer to keep them in order since you done broke them in. I made one from a 2x4 with 16 holes drilled in two rows of 8 using a 1" wood spade bit, then cleaned it, screwed and glued a bottom on it, labeled one end front, polyurethane-ed it, 50 years ago, still got it.

How did you break the cam in. You call this an initial firing, but that was when the cam was broke it.

Lifters can be pumped when out of the lifter bores, you can use a pushrod to push the center down, oil will come out then. When out of the bores, they pump freely. In the bores, they will hold oil a long time. You'll be looking for wear pattern on the base and the cam lobes them selves.

 

I would run it with the valve covers off, and see if the problem rockers have pushrods that spin
That is the problem with cams that wipe lobes out
The angle on the camshaft lobe must match the lifter" crown", and that iis the problem these days
If those angles do not match, the lifter and pushrod will not spin
That wipes out the non spinning cam lobes in about 20 minutes

 

This is correct and while everyone likes to blame the materials/lack of hardness what I've found is that problems with the way the camshaft and possibly the lifters are ground are very common. The cam for a 351C like other Ford small block engines is ground with two different tapers 1/2 of the lobes taper right, the other 1/2 taper left. Total taper across the lobe should measure about .002in 1/2 inch. This means that there should be about .001 across the lobe on each side. Otherwise without this taper the lifter will not rotate and this causes the friction to go way up and it wipes out the cam.

There could also be problems with spring bind etc. Sometimes this can happen on some but not all of the lobes so check it out. 351C has a high rocker ratio so even a short duration cam lobe can get a pretty good amount of lift. Early 351C "lug" style rockers can have interference at around .525 lift.

 

@Greyner123,

We’re sorry to hear about the issues you’re running into. We’d be happy to take a closer look and help get this sorted out. Please shoot us a PM with your order/invoice number so we can review the details and assist further.

 

If the cam is gone so are the lifters. Sorry.

 

For sure. and I would toss them if I just accidently "mixed them up" while inspecting them, if broke in, even if the cam was OK.

 

Alot of good input. Much appreciated. i modded my dial indicator so i could screw it into the valve cover bolt holes. I took some measurements; see photos. None of the lifts are correct. Of course the lifters aren't pumped up but where I was expecting at least .45, i was getting .2 or .3ish. i took a close up pic of my re-used lifters. Im going to pull the the cam. I was reading alot in Tom Monroe's book. Can anyone confirm that Ford made a conn rod change in the 351C's to +..060 inch pushrods? To something longer than 8.4" (which mine are). Won't help my situ but I'd like to make sure i've got the correct pushrods when i redo this. I guess the bottom line is about half the lifters cannon be torqued to remove looseness at TDC of the given cylinder.

Someone asked about break-in. I used high zinc oil, ran for 25 min at about 2500 rpm. Have done this a few times with other engines; no issues. The engines all had adjustable lifters. I got too careless with this non-adjustable setup. Break-in was on an engine stand and seemed to be ok. It's my inexperience that kept me from doing a post break-in detailed checkout on the stand before I installed in truck. Anyway, i'll update all when i pull cam and lifters.. Thx again for all advice. There was a suggestion about checking for rotation; i'll try that tomorrow after work. FYI this is a mild rebuild w/ 351 2V heads, keeping the manifolds, Edel Perfomer ink and 650 vac sec carb.

 

Mine is the other 351 in the "C family", the 351M. I have two copies of Tom Monroe's book so to keep one near. Mine was/is a Crane "Fireball" (.484"I / .510"E / 282* / 292* / 112*) ...and it was put in over 35 years ago. I'd say it and the all metal timing set has 60K or more miles on them now. I used new stock lifters with the cam, and my truck's original non-rotator valve springs then. I stood there in front of the truck running over 2,000 rpm with water hose showering the radiator for 20-25 minutes at least. In about 1990 I burnt a valve (I was messing with timing and carb jetting on a trip to increase gas mpg), it was missing, I needed it running, so I got a set of heads off of a '79 T-bird (it was gonna be scrapped anyway, got wrecked), took them to a shop for rebuild & was gonna use new non rotator springs (but by luck the T-bird heads had been rebuilt, they had 16 new guides and 8 new exhaust valves and the right springs already) ... swapped them on one afternoon after my shift. Laid my original heads in trunk of that T-bird to go to the crusher as weight. Performer 400 & Holley #1850 and distributor quick advance kit. Uses exhaust manifolds, no headers.

 

Hopefully it is just some collapsed lifters, which is all too common with the made in China/Mexico lifters. I only use NOS made in the USA Sealed Power or Johnson HT900's or TRW VL35's. All the TRW's will be USA on the Sealed Power's be sure the box says made in USA. There are usually some on e-bay. I highly recommend Driven assembly grease for the lobes that stuff sticks and will stay there. The last 351c cams I got one form Howards and one from Bullet came with a pack of that stuff.

 

By the way you most likely have a 351M as Ford didn't put the Cleveland in trucks.