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1963 PV544 rat rod

I almost did a spit-take when I saw the price of that kit. I'm sure it's worth it if you're doing some very exacting restoration that, for some reason, doesn't adhere to stock configuration but does to OEM Volvo parts?

FWIW, the PV is a very light car, I don't really see a need for a brake booster. The braking force for pedal force is about the same as it had with the drums, maybe takes a little more of a push. But nothing too strenuous.

I'm sure you could fit WIlwoods on it, it all comes down to making a bracket that bolts onto the spindle (the small reddish metal piece in the kit - the holes are in different spots vs. a 122). Other than that, whatever fits on a 122 would fit on a PV.

FWIW If I were doing it now, I wouldn't be bothering to put 122 brakes on. They're nothing special, and they're getting harder and spendier to buy if you need to replace a rotor or a caliper. Find something more modern and vented and common.
 
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And after not doing anything with this for about a year, since the 245 was apart and getting al LS'd up But now that's done so it's the PV's turn again.

Not much, but today I took the head off. #3, the cylinder with the low compression (leaking into the crankcase) looks fine from up top, no marks on the cylinder walls. But it ever so slightly oily, unlike the other 3 cylinders.
IMG_20191124_143558-1036x1842_zpsqcpwg9ts.jpg


I didn't feel like pulling the motor the rest of the way out today, so I just poured some motor oil in all 4 cylinders to see if #3 leaks it past the rings more quickly. hint: it almost certainly will.

Still not sure what I'm going to do. I'm assuming that #3 has cracked piston rings, or perhaps a broken piston, like last time.
1) Quick/dirty swap with one of my 3 'good' pistons from last time, rebalance, reinstall, vroom vroom. The drawback is that both sets of pistons have been thrashed enough for one of them to fail, why put them back in to see which one is next?
2) Get some custom rods and forged pistons. Something that can actually survive the sort of revs I enjoy using on this motor. LIght weight, revvier, zoomier, still goode olde pushrod B20.
3) There's a 16V turbo motor sitting in the garage - taken out of the 245 to make way for the LS. The blingy intake and exhaust manifolds it has certainly won't fit (Nathaninwa intake is wide at the front, same with the RSI front mount turbo manifold), so something else would need to happen
3a) Use my old log manifold to keep the turbo where it might fit in the PV, and use a shortened 16V intake that will fit inside the tapered hood
3b) Go old school and put a pair of DCOE's on the 16V, still get those induction growls (and fuel smells, lol)

No clue which way I'll go, really.
 
JohnMc said:
And after not doing anything with this for about a year, since the 245 was apart and getting al LS'd up But now that's done so it's the PV's turn again.

Not much, but today I took the head off. #3, the cylinder with the low compression (leaking into the crankcase) looks fine from up top, no marks on the cylinder walls. But it ever so slightly oily, unlike the other 3 cylinders.
IMG_20191124_143558-1036x1842_zpsqcpwg9ts.jpg


I didn't feel like pulling the motor the rest of the way out today, so I just poured some motor oil in all 4 cylinders to see if #3 leaks it past the rings more quickly. hint: it almost certainly will.

Still not sure what I'm going to do. I'm assuming that #3 has cracked piston rings, or perhaps a broken piston, like last time.
1) Quick/dirty swap with one of my 3 'good' pistons from last time, rebalance, reinstall, vroom vroom. The drawback is that both sets of pistons have been thrashed enough for one of them to fail, why put them back in to see which one is next?
2) Get some custom rods and forged pistons. Something that can actually survive the sort of revs I enjoy using on this motor. LIght weight, revvier, zoomier, still goode olde pushrod B20.
3) There's a 16V turbo motor sitting in the garage - taken out of the 245 to make way for the LS. The blingy intake and exhaust manifolds it has certainly won't fit (Nathaninwa intake is wide at the front, same with the RSI front mount turbo manifold), so something else would need to happen
3a) Use my old log manifold to keep the turbo where it might fit in the PV, and use a shortened 16V intake that will fit inside the tapered hood
3b) Go old school and put a pair of DCOE's on the 16V, still get those induction growls (and fuel smells, lol)

No clue which way I'll go, really.
Click to expand...
I vote 16v turbo.
 
Dang man. I wondered where this car had been. I really loved the built up push rod thing you had going on, but a carbed 16V would be pretty rad too. I'll be excited to follow along with any of the paths you chose!
 
Weather has almost decent yesterday, so I pulled the motor out.

I'm a bit confused as to what's wrong with it at this point. It def. has low compression in #3, and a shadetree leakdown test (just stuck an air hose onto the compression tester hose) was blowing air out of the block breather.

But so far - the bore and top of piston looks perfect, no surprise. But the weird thing is that pouring stuff in #3 and #4 shows a very similar draining time. I poured a few ounces of gas in each one (pistons leveled vs. each other, poured to the same level) and they both took the same amount of time to drain dry - and it was about an hour either way. About the only other possibility is a headgasket leak from the chamber to one of the block oil drains. But I looked it (Cometic MLS) over *carefully* and didn't see anything that looked even faintly iffy.

Ah well, it's already out, head's already off, might as well pop off the oil pan and pull #3 piston and see what it looks like. But I an out of motivation yesterday and just put evrything back in the garage.
 
Well, that's weird. This was the last time, years ago:
P5202490_zps8296cdeb.jpg


And this is what I just pulled out #3:
IMG_20200201_140437_zps8q69idlh.jpg


Pretty much the same exact issue as last time. WTF?
 
How would you feel about switching to a non-overbored b20?

Edit: Something tells me the ring land issue may correlate to the high revving combined and high CR.
Edit2: Core shift?
 
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Same hole as last time, same failure, almost exactly.

I've got a few options.
1) I could put one of the 3 good pistons from last time back in and slap it back together
2) I could get some custom forged pistons that might hang together better, maybe with some longer rods?
3) 16V motor swap
 
That can come from rings butting together at the gap when they have insufficient gap and receive too much heat. In fact, that is the most common reason to see that. Was it over heated?

What you are seeing definitely will not be solved by precisely duplicating the parts in some new whiz-bang material. *If* you were to achieve resolution via an install of new pistons, it would most likely be due to the rings having more gap. (Forged pulls heat away, and is more impact resistant than cast, but not by enough to matter here).

That also can be detonation. PV's are not quiet vehicles. If it were pinging, are you sure you'd hear it? Is your timing curve/fuel choice combo sufficient to give you a safety margin? Is your fuel curve up high and under load one that gives you a safety margin?
Dyno, if noise and/or a lack of mechanical sympathy prevent solid "yes" replies? You are way way away from stock parameters.
I am aware of your modified chambers (broad/shallow) I don't claim to know for certain if they are more or less detonation prone than other's builds. Sub 130 cranking gives one peace of mind that cyl pressures aren't excessive, but your combination comes up on cam... so pressures under load, @ around peak RPM, could be extreme.

Lastly whatever Freudian thing you get out of shopping for longer rods. STOP. You want stock or shorter (length or ratio) for what you are doing. Namely, building a cylinder pressure (and therefore octane) limited street engine. Ask John Kaase, Bischoff, the late Swedish fella, or any of the guys that competed in the Engine Master competition in its heyday. You have 1.81 ratio- they won using 1.44 in one example.
If you were going racing at Bonneville and had unlimited fuel octane, then maybe... even then probably stock is excessive.
 
That's what the guy at the machine shop I use said last time - butting ring gaps. And it's been many years, and I don't recall the specifics, but I know I gapped the rings somewhat loose this time around. Can't remember the gap I used, but it was on the loose side for a non-turbo engine.

This wasn't ever overheated. But I do drive it pretty hard. But just 'normally aspirated' hard.

And I do occasionally hear some pinging, even with all the noise. I was under the impression that pinging in a non-turbo car, as long as it was fairly rare, wasn't much of a thing to worry about. Just an occasional light sprinkling of pinging at higher RPM's. The piston crowns all look unmarred, not pockmarked like the forged pistons I pinged to death in the wagon.

I certainly don't know what I'm talking about when it comes to rod lengths. I was just going by what JohnV touts - longer rods and pistons with the pins closer to the crown for less rocking. Also - the geometry of a longer rod per stroke gives a tiny bit more 'dwell' at TDC and BDC?

If I end up reusing one of my old pistons I'll def regap all the rings again on the 'very' loose side. It does certainly indicate I'm doing something wrong to have the exact same failure twice in a row. I'm not really keen on making it 3 times.
 
After not thinking about this much at all, I decided to go quick and dirty with it, and stick one of my leftover pistons from the last time one broke. I replaced all 4 then. I'm just going to take them all to the machine shop to have the one piston installed (interference fit on the wristpin, I can't do that at home), and get them balanced.

And then check, recheck, regap the rings and make sure they are NOT tight. Loose, like for a turbo car. Like they say, gap the rings too lose, and you'll know it. Gap them too tight and everyone will know it.
 
It just wouldn't fit well in the PV. I couldn't use the superslick RSI front mount exhaust manifold, or the superbling Nathaninwa intake. And I might need to remove the heater since it's bulky and hangs out on the driver side of the engine compartment.

And I'm just feeling lazy - it's really easy and cheap to slap an old piston in it and slap the B20 back in the car. It's all sorts of fun with the snorty old pushrod motor and 165-ish hp.

That car would probably be pretty scary with 250-ish hp.
 
JohnMc said:
After not thinking about this much at all, I decided to go quick and dirty with it, and stick one of my leftover pistons from the last time one broke. I replaced all 4 then. I'm just going to take them all to the machine shop to have the one piston installed (interference fit on the wristpin, I can't do that at home), and get them balanced.

And then check, recheck, regap the rings and make sure they are NOT tight. Loose, like for a turbo car. Like they say, gap the rings too lose, and you'll know it. Gap them too tight and everyone will know it.
Click to expand...

Y u no haz freezer and oven? Lay a towel on the workbench support piston with 2x4s, heat piston to 275f, freeze pin overnight, quickly drop pin in and let cool. To remove, heat assembly to 325-350f, smack pin out with a wooden dowel.
 
Maybe I'll try disassembling one of the old pistons and see how it goes. I have two of them.

The interference fit is on the connecting rod small end - I guess what you say would work - just heat the rod (instead of piston) to 275 and chill the pin (I have a deep freeze).

I think I forgot to mention - one weird symptom from this time around is that the bad piston is a little stiff on the wristpin. The other 3 - move easily. The one with the chip, #3, does move, but it's very noticeably stiffer.
 
Although won't the machine shop take them apart to balance them anyhow - so they can weigh the con rod big ends and small ends separately.

I've rebuilt it in the past both with and without a machine shop balance, and the factory tolerances can feel noticeably buzzier at higher PRMs.
 
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