1963 PV544 rat rod

Probably my favorite car at the Midsommar meet, and I enjoyed very much driving it a few laps around the parking lot. Makes me want one bad! John, you leaving the parking lot sideways with tires smoking was a nice show too.

Nice little bit of progress John!

I've actually been running a Cometic on the B20 for a couple years, had good luck with it, even with winding it to 6500. Motor's only 9.1:1 though, not the insane:1 yours is with that head.

I do hear ya on those damn 3-bolt gaskets though. Aside from the alum ones in there now, nothing held up. Given mine will see boost, I'm not going to worry about pulling the Clifford header off, fixing the leak in the collector, and putting a v-band on it, just not worth the time and hassle.

I never got around to replacing the 3 bolt collector on the old header until the flange on the header it bolts onto actually cracked off. At which point it was either weld on a V-band or pitch the header. If' I'd seen the $64 header then I'd have replaced it, but I was still thinking the cheap crappy ones were $200 (which is what everyone else sells the Patriot brand header for).

I just wanted to skip the hassle this time around, and use V-bands from the start.

I've been using Cometic's in the 245 with great success, not a single issue with leaks, drips, combustion leaks, blown gaskets, nothing. I just had this big bore copper HG sitting around the garage from the last time I worked on the engine, and thought I should at least give it a try. I gave it a nice spray of Permatex copper spray-a-gasket (hard to get an even coat when you spray copper paint onto a copper gasket, it all looks the same...) and torqued the head bolts a little over spec.

I'm a bit embarrassed to say why I didn't use the copper HG last time. But (ahem) - the directions said to give it a thin coat of Permatex Copper gasket sealer, and without thinking much, I grabbed a tube of this stuff I had laying around the garage:

and smeared a thin layer over the whole headgasket. Didn't think that through very well. Sure, it's 'Permatex Copper' - but not the very thin spray on paint stuff, the thick silicone based stuff. Anyhow, even with the hedbolts torqued to spec, the layer of silicone was enough to gap the block and head slightly apart, and instead of a nice steel block/copper HG/steel head metal to metal to metal combustion chamber seal, it had a layer of silicone in the mix. Basically, on the first drive I made it about halfway down the block before a massive cloud of steam came out the tailpipe.

Deeeeerp. I just found a conventional big-bore Elring and hastily fixed it last time. Just thought I'd give it another try this time and see if it works any better with all the silicone scrubbed off and a coating of the proper sealer. It's possible that it might weep coolant, or ooze oil, or be annoying in some manner, so I'm ready to order off the Cometic 92mm gasket on a moment's notice.

Did a little more work today. Not much. Mostly just getting the roller rockers situated on the head again I took a few pics of them before they get hidden under the valve cover again. It's a set of KgTrimning roller rockers, with an aluminum bridge in place of the 4 little pedestals the stock rockers sit on.

First, a shot of the olde stock rockers, don't mind the dust.


Does the shaft flex under the loads of high lift cams, double valve springs, high rpms? Dunno. But the KGTrimning bridge supposedly supports the shaft on all sides of the rockers, and prevents flex and vibration.



I took a few measurements. The rocker shaft seems to be the same diameter (.855") between the stock and KGTrimning shaft. I think the KGTrimning catalog says the shaft was modified somehow, my Svenska reading isn't really good enough to decipher it.




I measured the height that the shaft sits above the top of the head. The stock pedestals are 1.04" tall. The bridge is .92" tall. In theory, this is good for higher lift cams, lowering the shaft puts a more equal amount of angulation on either side of level for the rocker. Otherwise, all the added lift on a high lift cam would come via the rocker going farther past horizontal (assuming same base circle). Which wouldn't be good.

Some pics of the rockers. They're in pairs, with subtly offset rollers for the valves, and adjusters for the pushrods. Are these custom ordered like that? Or was it very craftily ordered as a sort of stock-ish part from something mainstream and domestic? Dunno. There are a variety of shaft mounted rockers from domestic cars. Even some shaft mount conversions for engines that normally have stud mounted rockers. There's no clue on the rockers where they came from, no part numbers, no company names.



The bridge sits directly against the head, and reaches out to the valve cover mounting surface. Which means it needs to seal without a gasket. So smear on some Indian Head Shellac (I seem to have better luck with that than silicone), setting it in place, and positioning it with bolts. I also glued my rubber valve cover gasket to the bridge, I'll leave the top of that dry against the valve cover itself. I nestled the valve cover on to hold it all in place as the shellac dries.


I might use the 'VOLVO' valve cover this time. I've had the no logo post Volvo warning IPD cover for a while, because it seats the valve cover gasket a little better. But my older Volvo logoed cover is cooooooler.

Took it for the first drive back together today. And... the damn copper gasket is not holding compression. The temp gauge was jumpy on the drive, went back home and took the cap off and a steady flow of vapor rolled out of it as it idled. No white fog out the tailpipe, but it's obvious a fair amount of compression byproducts are making their way into the water jacket.

Ordered a 92MM bore .036 Cometic for it. Head comes off again this weekend. Just like the last time I tried to use the copper HG. Only that time I'd obviously done something wrong. Ah well, I'm just glad Cometic sells big bore B20 HG's and I don't have to try to track down one of the very hard to find 92MM Elrings.

If you got some basic dimensions off those rockers I could probably figure out what domestic application they are from, if any.

Cometic big bore HG came in yesterday, bolted it all back together.

And upon first start up now the header is leaking form the center ports? Makes a chuffle, I can feel it. Erg, I'll order two manifold gaskets and double it up.

Drove it to work chuffle and all, no weirdness with the temp gauge this time. Cometic:1 - copper HG: -2. I don't think I'll bother trying to use it a third time.

EDIT: Moved this thread to projects and restorations from 'maint and non-perf'. It's not really a great project thread for the PV, but it's all I got.

With the wagon finally getting back together and working well, my #2 pending car issue got a promotion to #1 - the PV's motor.

It's a B20E block, bored to 92mm. It uses some B21FT pistons on B18 rods, with the wrist pin bushings removed and the 24mm B21 wrist pins interference fit (the B18/early B20 engines have 22mm wristpins). It has an R-sport stage 4 head, one of my lucky ebay finds, but in a prior use it was shaved down to a ridiculous degree - that's why I'm using B21Ft pistons - I need the cc's in the dish. It has an Isky W81 cam, old school high rpm cam. Probably something with a more modern lobe shape would work better, but the Isky's are at least cheap. SBC lifters and tubular pushrods pushing a KgTrimning roller rocker setup. It has a pair of DCOE 40's with 36mm chokes on the intake, and a cheap 4:1 header and a 2.25" exhaust on the exhaust. A Crane optical ignition box running an MSD 6A box running an MSD Blaster 2 coil for the zaps.

All in all, it seems to make about 150 hp at the rear wheels, based on the weight and trap speeds in the 1/4 mile. Which is pretty fun in a 2200 lb car.

The motor was built about 20K miles ago, since then I've had a minor issue with cams, with them only lasting about 10K before a lobe goes flat. The lifter/lobes are the weak spot on the B18/20 (other than the fiber timing gear - I have steel Penta/B30 gears). They don't like high rpms, stiffer valve springs, taller cams that much, and in this case it gets plenty of all 3. I rev the piss out of it regularly because it's fun, it has double valve springs, and the cam lift is pretty high plus the roller rockers have a higher ratio, increasing the pressure on the lifters.

But that's not the problem it's currently having. Last spring it started to get a little blowby. And it started to loose a little power. Nothing too bad, but I stopped driving it to make sure I didn't let a small problem turn into a bigger one. But then the wagon had to get rebuilt (tiwce - since I derped out and missed the cracked cylinder wall the first time, oy vey) - and then it needed a new head gasket, all in all, I haven't really had time to take this thing apart, until now.

So I did a compression test. Very clear indication of problems: 160 psi on 1, 2, 4. But only about 80 psi on #3. The plug on #3 looked very slightly different as well, just a little bit sootier.

I obviously should have done a wet test here, bot for no good reason I didn't, I instead whipped the head off.

But instead of seeing clear signs of the cause, it's a bit of a puzzler. The bores on all 4 look great. No signs of lines or rub marks on #3 which would indicate a broken ring. The HG does not show any real obvious signs of leaking, but it's a Cometic MLS, and I sort of think they won't show much unless it's a pretty serious leak. The head seems to show some signs of irregular sealing around the bores - the lines left behind by the Cometic vary as they go around.

The intake valve is also darker on #3, not sure what the problem is there.

At this point, presented with fine looking bores, and a very slightly iffy looking HG, I'm leaning toward leaving the bottom end in place and alone, but I'm starting to regret not doing that wet compression test, to verify that the rings aren't leaking.

As a distant second best shade tree test, I rotated the motor so all 4 pistons were equal height, and filled the cylinders with oil. I'll let that site for a while and see if #3 drains any faster than the others. If they stay the same, I'll just assume that it's OK.

So far, it looks like a very light head skim, a valve job, and a new HG.

It's a treat working on the PV, there are so very few wires and hoses to deal with, the head comes off in about 15 minutes.

Swap in some beehive valve springs, a lot easier on the rest of the valvetrain. They can work wonders with pushrod engines.

Interesting puzzler.

You mentioned you noticed some blowby -- what symptoms? Excess crankcase pressure? Oil consumption? Only could see that being related to HG if the HG blew between the combustion chamber and the pushrods...

Could it have cracked a compression ring? How hard is it to get the pan down in the PV? If it were me, and it weren't too hard, I'd probably want to pop that #3 piston out and see if there's anything happening there that the condition of the bore is not making obvious. Your oil test might show something but if you can get the piston up for a visual, seems like that might give more complete answers.

JohnMc said:

little blowby...compression test....But only about 80 psi on #3. The plug on #3 looked very slightly different...just a little bit sootier.

Click to expand...

Any chance compression/oil rings were lined up incorrectly?

If minor cylinder ridge, and if hone marks are still present and decent, I'd just pull three out and inspect...and re-install with new rod bearing.

The oil is dropping very, very slowly in all cylinders, but noticeably faster in #3. Looks like I'm going to pull the motor and take the pistons out.

I had just noticed an increase in crankcase vent fumes, I didn't really drive it enough past when I noticed that to see if it was using oil.

I don't think the rings were lined up incorrectly - it's worked perfectly fine for something like 20K miles.

The block has a visible difference where the rings run and the top edge of the bores, but there's not enough of a ridge to feel with a fingertip.

With any luck it will just be a broken ring, if the piston is hosed it seems like I'll have to get a custom set - non-oversized B21FT pistons do not seem to be available anywhere any more.

Finally got around to pulling the motor out of the PV.



The head was already off, so I took the pan off and took the piston under suspicion of shens (#3) out. I was expecting to see some broken rings. I was initially confused because all 3 were intact in looked to be in good shape. The ring lands looked good too, no looseness or slop.


Then I looked a little closer and... whoa. Chunk of the piston is split out. It's a weird sort of damage. A 'flake' of the piston is separated, parts of the ring land above ring #2 as still connected, and the #2 ring was keeping this piece in place. Sort of. I've never seen anything quite like that on a piston before.



Well, a little JB weld on the piston and right straight back in it will go!

Nah. Some rtv outta do the trick.....whose making b21 pistons these days? Johnv?

Looking at those pistons, I don't think they're turbo. They look more like the low compression B21A pistons.


B21FT (pic stolen from jack)



B21A

Hmmmm... That does seem to be the case. Maybe my CR has been a little higher than I thought it was? It runs fine on 93 octane though, so I might as well replace them with the same thing.

I guess I need to look for some standard size (92mm) B21A pistons? I wonder it they're any easier to find than the B21FT pistons seem to be.

Here you go.

I have +.020" pistons if your block needs to be bored.

Thanks! I found a single piston on eBay: http://www.ebay.com/itm/Volvo-Brand...r_Truck_Parts_Accessories&hash=item27e1916cd1

But it doesn't seem like a very good idea to replace one, although the other's only have ~20K miles on them.

The block looks very good, plus it's an overbored B20 to begin with, I'm not going to touch it. Bearings looked good on the only one I've looked at so far (#3). Lifters all looked good too. Dunno, I'm half tempted to just stick the single new piston in it (after balancing it with the other pistons).

Check the other pistons. They may have cracked ring lands too.

If you really do have B18 rods this would be a good time to swap them for some B20 rods. They're thicker where the beam meets the big end, an area where they are known to fail. I suspect you may already have them, since they haven't already broken with the heavier B21 pistons. Can you post a pic of the rod?

Changing 1 piston is done all the time. It will make the motor last longer if all the pistons weigh the same, so I suggest sticking with the same brand of piston which appears to be Mahle.