I've been working away on non-start issue after the heads on my 1992 f150 5.0 were rebuilt and I'm wondering if you folks would tell me if I've missed something...

Heads went to a reputable shop, and had a valve job, seals replaced, magnafluxed and 0.006" milled off to true them. Shop said no need to change pushrod length.

I reinstalled the heads with ford performance head gaskets that have 0.047" compressed thickness. My understanding is that this is 4 or 5 thousandths taller than factory. The pushrods were put back in their original positions, but since the rockers came back loose from the shop, I'm not sure that mattered. I lubed the ends of the pushrods, the guides and the rockers. The factory rockers were installed and torqued to spec. The Haynes manual pretty much just said "for roller engines, just torque them down." I replaced all intake and exhaust gaskets with felpro products.

So I reassembled the rest of the motor and it wouldn't start. I was able to coax it to run but it sounded like it was not running on all cylinders and would die. I removed a valve cover to ensure I'd set the initial timing on the compression stroke and watched the #1 rockers move while hand turning the engine. Eventually I checked the compression on #1 and found I had none... Initially with my finger, then with a gauge. I used a remote starter switch to bump the engine for those tests.

I'm at the point now where the only thing I can think to do is check the plunger depth in the lifters. The oil level is high from the engine being flooded, so I'll change it next. But I didn't think that would impact the plunger depth. Is there anything that jumps out as obviously wrong? I've read so much about setting up rockers at this point that I'm wondering if I should have ensured the non-adjustable rockers were installed while the lifter was off lobe...but that doesn't make sense to me given that they are not adjustable.

 

I'd pull the valve cover on passenger side (cylinder 1), and remove or at least loosen the rocker bolts for intake & exhaust so there's no preload on the lifter (pushrod is a tiny bit loose) and recheck compression. It sounds like you've got valves hanging open.

How long have you owned the truck? Motor ever been apart before? Sure, 0.006" deck off heads with 0.047" head gaskets should be fine but if someone's been in there, you only know what you measure. Assumptions...well you know what they say.

 

I'd change the oil. Diluted oil is hard on the engine. I had a non Ford once that diluted and would run like crap and then not at all as the oil got thinner, assuming the lifters couldn't pump up.

 

lifters not pumping up wont hold a valve open - are you still using a pedestal valve train or did you go chevy style with adjustable? if the lifters are flat it will still open the valves 60% of the way at least.

remove a rocker and use a bad pushrod to test for lifter spring pressure

 

Thanks everyone!

Heads have never been off the vehicle - I've owned it for a couple years and am the second owner. The original owner is an 80 year old relative. He had maintenance done at the recommended time intervals, since he barely used the truck over the past 10 years. The mileage was 78,000mi when I bought it. It's up to about 90,000 now. It's only had filters, fluids, brakes, tires and ignition work (plugs and wires) prior to my ownership. Was running before disassembly - work was to fix a leaking lower intake gasket. Everything else was "might as well while I'm in there..."

Will change oil before any other testing just to be safe.

Valve train is original non-adjustable. I don't have any extra pushrods on hand - should I pull the lifter to clean and inspect it?

 

Decreased both lifter preload on #1 and now have compression, so I've shimmed all the rockers 0.010" and we'll see how it goes tomorrow morning!

 

The shims did the trick! Had my daughter give it some gas while I I set the timing and we're back in business. Now to clean up the underside and confirm it was really just the intake gasket that was leaking....

 

Woohoo! That's good news.