For those still following this thread lol, I am in the process of reassembling the engine. Rod number 6 was the one that spun, luckily it did not wipe out the crank it only took out the bearing.



I got the block cleaned, deglazed, and the crank polished. Machine shop measured all 8 rods and found that rod 6 was .0015” smaller than the other 7 (it was also a reman rod). Got that fixed, I’m happy with the new clearances, and I’m getting ready to put this engine back into the truck now.



I got a new cam as well. Switched from the comp 20-745-9 XE to the Hughes SER0814ALN-14. Shorter duration but higher lift, supposedly will help with low end torque and efficiency. I measured my pushrods and with the comp I measured 6.76” zero lash, but with the Hughes I’m measuring 6.805”. Would this make sense?

The cam from Hughes also came with new springs and retainers so I upgraded those (now I should be able to bump up to a 6000rpm hard cap). Why I would ever need to? Good question. But I CAN now, for shenanigans sake.

 

Here’s the carnage if anyone is curious.

 

The hughes cam is likely a re-grind, so, slightly smaller base-circle on the lobes.....

 

Did it actually spin? The tabs look good. I had one spin and it had no tabs at all.

 

I don’t think it actually spun, it seized up. The guys at the machine shop measured everything and all of the rods were in spec other than rod 6 (the culprit), it was .0015” undersized I believe he said.

The bearing though shrunk? It wouldn’t clip in at all to the rod or the cap, it would just fall off.

 

Got the engine all put back together and she runs. I did the break in for the cam even though you really don’t need to with a hydraulic roller, but what harm could it do.
75 psi oil pressure at 2200rpm consistently, no weird noises, and no forbidden glitter in the oil after the first drain. Surprisingly high idle vacuum, 23 inches or so at 700rpm, seems a bit high to me.

I have not moved the truck yet, I ran it for about 20 min for the cam, changed the oil, and let it idle to do a walk around. There is still quite a bit of valve clatter, it’s symmetrical side to side so it doesn’t sound like an exhaust leak and it’s rhythmic it’s not random. I do have the Hughes 5007 lifters which I hear are often louder on a fresh build and will quiet down over time, and will be louder than stock style. They want a bit more preload than stock, I measured 6.81” zero lash and put in 6.9” pushrods, which is in the range they recommend for iron block iron head magnums.

This new cam idles very cleanly too. There is a bit of a lope, but it’s still very tame. I’ll post a video here. And ignore the belt squeal in the background lol, belt got soaked in coolant and sounds like a dying pig.

 

Another update. Truck drives great, sounds great, I did put in longer pushrods (6.936”) giving me a preload of .126” (right in the middle of the Hughes recommended preload). There’s still a small tick but I think it could at this point be a bad rocker. Anyway, I have a question about PCV.

I just did a first WOT pull up to 5500, and now my front main seal is leaking a tiny bit. Not a lot, but enough to bother me. I have a new Pioneer balancer, and a new pioneer timing cover, as well as a fel pro gasket. The way I installed it was by loosely starting the timing cover bolts, then fully installing the balancer to pull the seal and the cover where the snout wanted it to be, then torquing down the timing cover.

My PCV system however is “half” setup? I still have the valve going to the manifold and it’s pulling vacuum, but because I have a 14” open element filter I don’t have the breather side hooked up to the intake, it just vents to atmosphere. Is it possible that at WOT when vacuum drops to basically 0, the pressure is building in the crankcase (rings I’m assuming are not fully seated yet) and it’s pushing past the seals?

I am also running a filter relocation as I think I’ve mentioned before, and due to this I’m running about 7-7.5 quarts of oil in the system as that is what gets me about halfway between the two lines for full on the dipstick. There’s about 6 feet of 10AN hose between the stock filter location and the new bracket, so I just filled it up to the point it said full (after priming the system), but I didn’t want to go too crazy. Could this be related to my issue?

 

Do you have a breather filter of some sort on the PCV??

 

Yeah, I have the normal PCV fitting on the passenger valve cover hooked to manifold vacuum, and the driver side pcv filter is there it’s just open to atmosphere right now. I’m waiting to get the part in to hook a hose to it from my air hat.

 

If it is drawing filtered air, that is all that is important. That's the intake side anyway.

Your tick might be an exhaust leak as well....