Fresh B20 engine tapping mystery

Cam / lifter break-in on flat tappet cams can be hard on the cam with heavy-duty or double springs. Hope that's not your case.

sksmith said:

Cam / lifter break-in on flat tappet cams can be hard on the cam with heavy-duty or double springs. Hope that's not your case.

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Well, I hope so too. How could that be in the first 2 hours of running the motor? If that's the case, that cam would be on its way to a perfect circle by now. I am hoping that it's rockers, but I also suspect that I will have to pull the head to get an answer. At least it's not bottom end knock. Top end repairs are at least accessible without having to do a full teardown.

Take the valve cover off and inspect the valves and springs for anything out of the ordinary. Are all the valves the same height? Are there any broken springs? Are all the guides sticking out of the head the same amount? Can you wiggle any of the valves? Then crank the engine with the ignition disabled and see if they're all opening the same amount. A flat lobe will be obvious.

hiperfauto said:

Take the valve cover off and inspect the valves and springs for anything out of the ordinary. Are all the valves the same height? Are there any broken springs? Are all the guides sticking out of the head the same amount? Can you wiggle any of the valves? Then crank the engine with the ignition disabled and see if they're all opening the same amount. A flat lobe will be obvious.

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Will do.. Clearly, there is something wrong and I will see it. So when I see it, this head comes off. I mean, no matter what, there is no 'fix' for this without pulling that head. Broken anything means I gotta get it repaired. Trust me when I say that sending it back to J Parker is out of the question. I was just happy to get it back at all. So, hopefully it's nothing special where I will be sending it off again. Stinks, because I have other projects to get to. This was supposed to be wrapped up 2 months ago. Thanks again for your help.

Hate to say this but John Parker is sketch on his work. He used to be really good, but has really fallen off. Doesn't deliver parts, half assed jobs, etc. I have a few friends with pushrod motors that sent him things with extremely mixed results. Check everything like Hiperfauto said. Sad. You should have received a working product.

hiperfauto said:

A flat lobe will be obvious.

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Yep, by the time it's flat enough to make a noticeable driving issue, it's BLATANTLY obvious. No need to measure, it will stick out like a sore thumb. Unplug the coil, take off the valve cover, crank it round and round a few times.

If you measured the lifts carefully, you might get lucky every once in a blue moon and catch a lobe in the middle of going flat, but that's usualy a fairly short amount of time. Once the finish is gone, and it's worn past the hardened surface, it just carves on through the rest of the lobe like buttah.

centason said:

Sad. You should have received a working product.

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Agreed. That was my last time trusting John. I gave him chance after chance. This last time he contacted ME. It was almost like he was apologizing for making me wait forever last time. He kept following up until I agreed to send the head to him. Then, as before, I had to start calling him, threatening legal action, the police, etc. That wakes him up from email blackouts, but then it's a blackout again for weeks. Pity, really a super nice guy on the phone and seems to know endless amounts about performance Volvo. But then there are guys like hiperfauto who actually write back and seem to care AFTER you get off the phone. Imagine that, a vendor who cares about your business? Just really liked the HSR carbs John sells. They just work amazingly well and, after my experience with the stock carbs, I welcomed modern carbs gladly. I think John is just swamped with work and racing projects. I mean, like 5 years of backlogged work. But needs cash to keep the lights on, so takes a job here and there to keep money rolling in, but really cannot reliably carve off time for killer piece work. That's my $.02. I'm with you, cannot recommend anymore.

Only took me a year to get the head I have, but it was back when his work was still legit. Sad to hear his quality has gone downhill as well, but not totally surprised.

hiperfauto said:

Take the valve cover off and inspect the valves and springs for anything out of the ordinary. Are all the valves the same height? Are there any broken springs? Are all the guides sticking out of the head the same amount? Can you wiggle any of the valves? Then crank the engine with the ignition disabled and see if they're all opening the same amount. A flat lobe will be obvious.

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Results:
No cam lateral or longitudinal wiggle. I got that right I guess
All valve stems about same height, within 1-2mm across all
No visible broken valve springs, caps, keepers, mushroomed stems, looks clean. Looked for 5 minutes for even a hairline crack
Can't rock or wiggle any valve spring/valve
Rockers not great but fine for running, no cupping
Compression:
#2,3,4 115-117 psi dead on, DRY
#1... 30,60,90 (usually ~30) psi on multiple tests DRY
Add teaspoon of oil, NO CHANGE

So, this means the #1 or #2 valve , which is where the tapping is coming from, is not seating right?

Sounds like that head is coming off...

You could do a leak down test to see which one is leaking, but basically you're pulling the head at this point anyhow.

centason said:

Hate to say this but John Parker is sketch on his work. He used to be really good, but has really fallen off. Doesn't deliver parts, half assed jobs, etc. I have a few friends with pushrod motors that sent him things with extremely mixed results. Check everything like Hiperfauto said. Sad. You should have received a working product.

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This.
There's much better machine work to be found locally, even from a Napa machine shop.
It's a cast iron 4 cylinder, it's not rocket science.

Update:
Got a set of nice reconditioned rockers from hiperfauto. The car idles much better, but sadly the clacking/tapping is still there. I would have been shocked otherwise, but they had to be replaced in any case. Adjusted to precisely .41mm +-.01mm. I think I roached out the cam. During the break-in. I ran the car for 5 minutes at 1500 revs with ZDDP additive and redline assembly line on everything. But maybe because of the dual springs, it needed more.
I'll check the movement with a dial indicator, but I'm pretty sure that's what's up. If I had a stuck valve or dropped seat, I'd see other problems I think. It runs fine, plenty of power, just clacks like hell.
You can hear it in the cabin. And the fact that it gets progressively worse over time too. So, I think it's worn lobe(s)

Anyone have a cam recommendation for carbs? This was a new Crane cam from J Parker. With new lifters and rods.

Is there any chance you have a cracked exhaust manifold? Or a bad gasket?
I had the exhaust gaskets go out on my 740 and I swore it was something much more serious.

Maybe you could do a smoke test.

No personal experience with performance valve springs, but I've read that you should break in the cam with standard valve springs. Also, you should run the car at 2000 RPM's for 20 minutes, using a break-in oil with ZDDP, which it sound like you did.
After 20 minutes, change the oil & filter and drive lightly for 500 miles, then repeat the oil & filter change.
That sucks, man, hopefully not a flattened lobe.
I'm going to be changing my cam and having valves, new springs, etc. sometime this summer. I'm going to use standard valve springs though.

Schneider cams has some good looking numbers, I've never used one but when I decide to nut up, I'm going to have them run me a custom order for moar boost

Update:
I found the WORST thing you can find in any motor - or anything for that matter... Absolutely NOTHING.
Solvent leakdown: zero loss
Valve springs, caps, base washers intact, not broken
"" guides, intact, stable, nothing loose
"" seats, intact, no evidence of loose anything. No cracks or nicks even.

Pushrods look new, no visible bending, but will roll each one.
Lifters show zero wear. They look new on the bottom, no dishing, no gouging or galling or any wear. One had the tiniest little abrasion, maybe during break-in something moved through there
Head gasket show no signs of compression chamber leak, coolant leak.
Manifold gasket shows no signs of exhaust leak. Exhaust leaks sound like ticks in my experience, this is a rapping, clacking.
No sign of piston slap, walls look good, cross hatch still there. A bit too much carbon is all I found. John P had sent me bigger mains, and the AFR was at 12:1 for the first 50 or so miles, I dropped them back and now get 13-14 at cruise, 14.7 at idle.

Is it possible that the cam is wrecked but there is no visible damage to the lifter faces?

I was really, really hoping for a positive answer. Something bad that jumped right out. This thing makes a HELL of racket. Could it be the alternator or water pump clacking all the way back to the #2 cyl vavles?

blackbird939 said:

One thing I noticed. They had upgraded to steel timing gears. The cam gear did not require pressing. It slid right on, into the key. I torqued it to 105ftlbs I think, per the spec in my 71 manual

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Hmmm. I know failing fiber gears could sound like a rod knock. Fooled me once.
Not sure about the steel gears.

^That must have been a really worn out gear!
That worn out usually they'd backfire on me and the ignition timing would be all over the place until it finally wouldn't start/blew out the map grenade/k-jet boot.

One thing I found today, that I doubt matters, but..

A member on this post suggest that I look for cam movement, lateral in the cam bearings. I said there was none. But now, with the head off and no tension on the lifters, there IS a bit of play. About 1mm or so, not much but something.
Also, spun the water pump and alternator, not coming from there. That is all tight. The alternator is a bit long in the tooth, but not tapping. at least when spinning freely.

I did not replace the cam bearings as this motor was 'rebuilt' 3K miles ago. I have the paperwork. The cam bearings were replaced then. The cam felt smooth when sliding in, but could it be worn out and flexing in the middle bearing?

I guess I have no choice but the pull the whole motor and start over. The head does not seem to be likely the culprit although when I used the stethoscope, the tapping seemed to be coming RIGHT from the 3rd valve (#2 intake). It was LOUD and clear there with the rocker cover off and running. You could feel the clacking, not just hear it. Pity because this car was not a weekend thing, it was my son's daily driver and he is moving out to go to college in the morning. Guess it's time to pull it out and start a full teardown - 2 weeks after the last one. Something is bad in there.