Need help diagnosing these noises

[ArdWrknTrk]

Knock sensor

Edit to add, link to FTE: https://www.ford-trucks.com/forums/1565706-351w-block-question.html

Bearings look normal. 🙄

How do they feel if you run your fingernail across them? It's hard to tell things on my phone.

Perfectly smooth, nothing to catch a nail on.

The pic looks fine to me. As long as they aren't rough.

My screen protector sees dirt and greasy fingers every day (night?) when I log VIN and registration numbers for calls, so it's not even close to pristine. 😆

[ArdWrknTrk]

Knock sensor

Edit to add, link to FTE: https://www.ford-trucks.com/forums/1565706-351w-block-question.html

Bearings look normal. 🙄

How do they feel if you run your fingernail across them? It's hard to tell things on my phone.

Perfectly smooth, nothing to catch a nail on.

What does your aftermarket efi use for a knock sensor?

[Pete Whitstone]

What does your aftermarket efi use for a knock sensor?

 

The ProFlo 4 has no provision for a knock sensor, unfortunately. I guess it just runs a fairly conservative tune.

[ArdWrknTrk]

What does your aftermarket efi use for a knock sensor?

 

The ProFlo 4 has no provision for a knock sensor, unfortunately. I guess it just runs a fairly conservative tune.

My understanding is that it's still a speed density system that allows for updating the lookup tables so you can use cams with more duration and/or tighter LSA's.

Are you using an Edelbrock cam as part of a package?

Did you put it on the Dyno before & after install?

Are you able to share a single TPS with whatever tranny controller you use?

[Pete Whitstone]

My understanding is that it's still a speed density system that allows for updating the lookup tables so you can use cams with more duration and/or tighter LSA's.

Are you using an Edelbrock cam as part of a package?

Did you put it on the Dyno before & after install?

Are you able to share a single TPS with whatever tranny controller you use?

It is a speed density system, yes. You can update tables and such but I really didn't buy it to do any tuning with it, I just wanted it for drivability reasons over the carb I was running.

The engine currently has a stock cam in it, but while it's out I'm putting in a very mild upgrade.

I did not put it on the dyno either before or after. I did not have an expectation of a horsepower upgrade.

There is a single TPS which is shared with the trans controller, via some kind of doubler thingee sold by the trans controller people.

[Pete Whitstone]

I will try to cleanly collect some fluid and see if it has steel in it.

I did try the "bolt the starter on and spin the TC" test. It was inconclusive, no noise was made like the noise in the videos, but the starter could only spin it about as fast as it does when starting the engine, I thought it would spin a lot faster without the drag of the engine on it.

So I continued with engine teardown. Took off the intake manifold and took out all the rockers, pushrods and lifters. Did not find anything unusual. But while I was doing that, I noticed a little clump of blue painters tape that I had shoved in a hole at the back of the block to paint it. Here is the hole, on the passenger side (block is upside down, oil pan facing up, in this picture).

It was open but for the tape that was shoved in there. I squirted some brake cleaner in there and it seemed to drip out of the crankshaft, only a few drops, but it made me think that passage might be open to an oil gallery. So I pulled the nearest main cap and rod cap to see what those looked like. Here they are:

Now, there has always been a small oil leak somewhere, I thought it was rear main seal. And then after pulling the engine and finding oil higher up, thought it might be a poorly sealed rear china wall. But now I'm wondering if this thing had oil coming out of it.

If it did, it had to be minimal. It has always had good oil pressure on the gauge (30-60 depending on cold/hot/rpm) The truck could drive thousands of miles and not go a quart down. And it could not have been coming out of there under any pressure at all, or it would have blown the tape wad out long ago.

So I don't know if this is anything or not. I pulled the rest of the main bearing caps and looked at the lower bearing shell, they all looked similar to the one in the picture. I have not pulled all the rod caps but I did verify there is no real clearance gap on any of them (like you would expect a rod knock to produce).

So what is that port? And what are the thoughts on those bearings? The truck has maybe 8-10k miles since rebuild. Do those bearings look consistent with that amount of miles?

Thanks!

OK found the problem. I had pulled all the main caps and 1 rod cap, and they looked fine. Today I went down the line and pulled all the rod caps. The 3rd rod from the front had a spun bearing. While the bearing looked bad, the crankshaft looked worse.

The crank looks very chewed on, I'm not sure it can be undercut and cleaned up.

I'll have to take some measurements. But I'm looking at stroker kits too. Unfortunately as far as I can tell those all use oversize piston bores so I would need block machining to make that feasible. Still weighing my options.

In the meantime, what would cause one bearing to spin while the rest look fine? I measured everything when it went together, and used plastigage to double check. So i don't think it was too tight, but I could have missed something. Thoughts?

[ArdWrknTrk]

OK found the problem. I had pulled all the main caps and 1 rod cap, and they looked fine. Today I went down the line and pulled all the rod caps. The 3rd rod from the front had a spun bearing. While the bearing looked bad, the crankshaft looked worse.

The crank looks very chewed on, I'm not sure it can be undercut and cleaned up.

I'll have to take some measurements. But I'm looking at stroker kits too. Unfortunately as far as I can tell those all use oversize piston bores so I would need block machining to make that feasible. Still weighing my options.

In the meantime, what would cause one bearing to spin while the rest look fine? I measured everything when it went together, and used plastigage to double check. So i don't think it was too tight, but I could have missed something. Thoughts?

Was the crush good when you assembled the engine?

Did you plastigauge all the rods? (I missed your final statement (after the photos)

The only other thing I could think is a lack of oiling to that one rod.... or sometimes stuff happens. 🤷‍♂️

The Pro-Flo seems an awful long way to go to fix a carburetion problem.

Id be throwing a lot more cam in it if I had a roller cam (from an Exploder?)

[Pete Whitstone]

The only other thing I could think is a lack of oiling to that one rod.... or sometimes stuff happens. 🤷‍♂️

Doesn't the rod journal get oiled by the oil galleries that zig-zag through the crank? I don't see how the journals on either side can look fine and this one be bad, but I'm not sure of the exact oiling path. When I rebuild the engine all those passages got cleaned with brushes similar to gun-cleaning brushes.

The Pro-Flo seems an awful long way to go to fix a carburetion problem.

I wanted FI and I didn't think assembling all the parts for a 30 year old factory system was going to be feasible or cost effective or easy to troubleshoot or have much support.

Id be throwing a lot more cam in it if I had a roller cam (from an Exploder?)

I don't want to give up low end torque so I can have a higher HP number higher up, where I really don't spend any time. It's more of a work truck to me, not a hot rod. Mileage is bad enough already (10-11) so I'm not going to be wringing its neck very often. My cam selection was pretty conservative, 213/219 @ .050.

 

[Pete Whitstone]

I'll have to take some measurements. But I'm looking at stroker kits too. Unfortunately as far as I can tell those all use oversize piston bores so I would need block machining to make that feasible. Still weighing my options.

Rough measurements with dial calipers show that the damaged journal is about .040 smaller than the undamaged ones. I think the crank would have to be turned .050 or possibly .060 to clean up. The only advantage to trying to save this crank is that I won't have to have the reciprocating mass rebalanced. Just the machine work for undercutting the journals.

New cast cranks from Scat are running around $400, then of course that would have to be rebalanced.

Stroker kits can be had, but they all require oversized bores, so major machine work there, plus they need to be balanced (I think, not sure). Lotta money to spend down that path.

The truck is my primary form of transportation, although I have other vehicles. So I don't really want it down for too long, which if I went down the stroker path I bet it would be. I'll have to see what kind of timeframes the machine shop is quoting.

[ArdWrknTrk]

The only other thing I could think is a lack of oiling to that one rod.... or sometimes stuff happens. 🤷‍♂️

Doesn't the rod journal get oiled by the oil galleries that zig-zag through the crank? I don't see how the journals on either side can look fine and this one be bad, but I'm not sure of the exact oiling path. When I rebuild the engine all those passages got cleaned with brushes similar to gun-cleaning brushes.

The Pro-Flo seems an awful long way to go to fix a carburetion problem.

I wanted FI and I didn't think assembling all the parts for a 30 year old factory system was going to be feasible or cost effective or easy to troubleshoot or have much support.

Id be throwing a lot more cam in it if I had a roller cam (from an Exploder?)

I don't want to give up low end torque so I can have a higher HP number higher up, where I really don't spend any time. It's more of a work truck to me, not a hot rod. Mileage is bad enough already (10-11) so I'm not going to be wringing its neck very often. My cam selection was pretty conservative, 213/219 @ .050.

I didn't mean to suggest that oiling passages in the crank are blocked, just that one bearing may have smeared and/or shifted.

Something caused that one bearing to grab and spin.

Cams aren't only about high rpm horsepower. (I have an RV cam in my truck and it doesn't do nearly as well as the stock cam did on top (with a straight up timing set)

But I can put 2 ton in the bed, or 12 ton on a trailer and hardly know it's there, except for starting on a hill.

If I had FI and the ability to tune it I'd be looking for a lot more than I'd get from a stock SD cam.

Most strokers I know of are 408 (.030 overbore, 4.00 stroke) and it really doesn't make sense to spend that kind of $$$ to get a dozen bags of concrete at Home Depot.

Have the crank turned on the rod journals and fit whatever undersize bearings you need.