'62 Monza convertible "Ralphie"

[66vairguy]

I forgot what cam you are going to use. If it is NOT stock, then you'll have to check for valve spring bind. A broken spring happens, but TWO on the the same engine at once is very suspicious. The Isky 260 will work with stock Corvair springs, BUT NOT the 270 or 280. They require special Isky valve springs.

Our club helped out a member whose Corvair kept breaking valve springs, rockers, AND LIFTERS! When the engine was torn down we found an aftermarket high lift cam and a bunch of bent pushrods.

Make sure your pushrods are not bent.

[Dennis66]

I'd have to double check, but I think it's a 260. I'm not married to this cam, my only real attraction to this cam is it's already "friendly" with the lifters. Jury's out until I check it with a dial indicator anyway. Probably get back to the head bolts tomorrow. Dennis

[66vairguy]

I'd have to double check, but I think it's a 260. I'm not married to this cam, my only real attraction to this cam is it's already "friendly" with the lifters. Jury's out until I check it with a dial indicator anyway. Probably get back to the head bolts tomorrow. Dennis

I've read that the Clark's Corvair 260 has a greater lift vs. the Isky 260, but I have not confirmed it. As you said, best to confirm.

BTW I have an Isky 260 in one of my 140HP engines. It really is a goer, but the idle is a little lumpy. My other car is a convertible and it will just be "boulevard cruiser", so I'm going to install one of the "304" reproductions cams in that 140HP engine for a smoother idle.

The "304" cam was developed for the 180 turbo engine to reduce overlap (not good during boost) and increase torque before boost comes on at lower RPM, yet the mild ramps and lift allow 6,000 RPM without valve bounce using stock valve springs - at least that's what I've read. I'll see how I like it.

[Dennis66]

The update: Got into it yesterday. Pulled both heads and cylinders 6, 5, and 4. Some observations: it is an Isky 260 cam. The upper head bolts took about 30-35 lbs to break free. The lowers were 20 to 25. There were no issues with the threads on the uppers (clean) I had made a picture of the cam in one of my early posts. It showed where they had beat the cam gear on. I commented about the quality of the previous engine build. I'll comment again. While the crank is broken and junk, the bearings I have removed are all scored. It is a miracle this thing ran and didn't spin a bearing. it must have been assembled by a caveman.
Some notes for anyone wanting to gain information from this:
First: head bolts are tightened in a sequence, and should be removed in a reverse sequence
Second: note the use of spacers on the head bolts in the picture. Simply short pieces of pipe to hold the cylinders in place for disassembly and NEEDED for reassebly as you rotate the engine
Third: you will want to have a few pieces of 3/8 I.D. plastic tubing for disassembly and reassembly. After removing the rod caps, place these over the rod bolts to protect against scratching the crank journals (I didn't bother here because I already know my crank is junk
Fourth: Note the picture with the magnet. Mr. Magnet is your good friend here. Those lower rod cap nuts tend to drop if you aren't careful.
Fifth: It goes without saying that you should be careful to keep everything in order as you disassemble so it all goes back in the right place. I used egg cartons for my rocker arms, lifters (when I get to them), and made block with drilled holes for the pushrods. Dennis

More pictures to follow.

Our friend "Mr. Magnet"

[Dennis66]

And some of the insides. Its obvious it had been running rich and using oil. I noticed on removal that most of the valve seats have been "peened", a procedure to tighten the aluminum around a valve seat.

And the last cylinder to be removed. Notice the scoring on the bearing shell, and wear down to the copper. This is why we emphasize CLEAN when assembling an engine - especially doing the bottom end.

Next step, removing lifters, pan, and separating the case halves.
Dennis
For some reason it loaded the head picture twice

[66vairguy]

Great advise on dissembling an engine. I've taken apart a few engines that were as bad, if not worse, than what you found.

One had "sat" for a long time (always a red flag as why did it STOP running). I found the rod bearings were all worn severely at the top and bottom, yet the rest of the bearing looked new. Then it occurred to me ---- I mic'd the crank and looked at the rod bearing and found they were standard bearings and the crank had been cut 0.010"!!!! That engine must have sounded like a barrel of rocks when it ran.

Oh! Cam gears. I have read a number of posts by folks saying "Just chill the cam in the freezer, then heat the cam gear and it just pushes on. BALOONEY!!! That aluminum cam gear will cool VERY fast after you heat it and you just end up broaching the gear with the cam and eventually it comes loose. I use the billet gear sold by Jeff at California Corvair, and have him install it. He uses a set up to keep the cam gear heated WHILE he installs the cam. I have not found anybody that has had an issue when Jeff installs the cam gear.

I bet those bearing were ruined by engine assembly lube. It is NOT meant to be used on rod and crank bearings, just use a good motor oil. I ALWAYS run the oil pump on an assembled engine to fill the galleries and lube the crank and rods (turn the engine while running the oil pump) the same day before I fire up a new engine.

New cylinder lower and upper gaskets compress. As you said do the torque via the pattern, but do it in increments of five pounds. Then after a day I recheck all the head nuts again.

Looks like your doing a good job. It will be nice to see it done.

[Dennis66]

Moving forward. Pulled the pan. The bolts were so loose that I could almost remove them with just a socket and my fingers.

. At least it's a nice finned aluminum pan. As I popped it loose, I was startled to see aluminum chunks fall out - I have been worried about the broken crank damaging the block. Turned out they were just teeth from the cam gear.

And here's a shot of the bottom of the block showing the pickup tube (for those who may not be familiar with it).

Next step is split the case and see the real carnage.

[Dennis66]

Funny how things come back to you. "Corvair mysteries". 1. Why do you put the crankcase bolts in from the passenger side? 2. What are the two 3/8 - 16 tapped holes on the bottom of the block with nothing in them for?
I'm now remembering from long ago that I was told that the 3/8 holes were originally for the assembly fixture when assembling the engine. Refer to the modified oil pickup picture.

Now the reason you would put the bolts in from the passenger side is so they drop in while the driver side is held in the assembly fixture. This also helps keep the oil dip stick tube, mounted on the passenger side, from getting bent if it is not removed first. (removal tip: with the pan off, give the protruding bottom of the dip stick tube a tap or two with something SOFT like a brass drift to dislodge it, then put a 5/16 bolt in the top while gripping it with cushioned pliers and twist to remove. The 5/16 bolt keeps the tube from getting squished.)
The carnage:

It broke right where they drilled to balance it. I don't see any serious damage to the block YET. I still have to clean it, and check closely, then fit the new crank and bearings.
Forgot to add: you have to remove the oil pickup tube before separating the block halves or using the factory fixture mountings.

[66vairguy]

Funny how things come back to you. "Corvair mysteries". What are the two 3/8 - 16 tapped holes on the bottom of the block with nothing in them for?
I'm now remembering from long ago that I was told that the 3/8 holes were originally for the assembly fixture when assembling the engine.

The consensus is the "tapped" holes were for mounting during machining. You should never swap case halves. The halves were machined together and should stay together as an unit. If one side is damaged, you should replace the entire block. Unfortunately Chevy did not identify matching case halves so if someone swapped one side you can't tell (assuming the same style). One fellow had a heck of a time until he finally figured out the crank bores didn't exactly line up and it was "pinching" the bearings and crank.

[66vairguy]

That bolt on the oil pickup bracket clamps one case side to the other. I've seen "gorrillas" break an engine case tying to split the cases because they forgot to remove that bolt.

The other issue is folks jack up the engine with a floor jack under the stock steel oil pan and it bends up the oil pickup unit so it is pinched. Not good for oil flow to the pump. The oil pickup almost touches the steel oil pan. Bend the pan, you bend the pickup.

[Project65]

Wow! That’s some serious carnage. You definitely don’t see that very often. I’m hopeful that the block is ok and you can rebuild it.

[Dennis66]

The progress continues: Yesterday, I got the cam gear off. Interesting note here, the cam gear that was beat up had a steel ring around the head. i figured it was some kind of locking ring so I wanted to remove it before trying to remove the gear. i tried adding a little heat and NO Budgee. Wouldn't move when trying to twist it with channel locks. After cooldown, I thought "I'll drill a hole and break it off. drilled a small hole and surprisingly, the ring moved. All I can figure is the aluminum must have expanded when I heated it and stretched the steel ring. with ring off, a little heat, a puller, and the gear is off (remember, the gear is junk - missing several teeth).
I cleaned everything up, light dab of oil on the bearing surfaces, set the cam in, and set up a dial indicator to check if the shaft was possibly bent. Its' fine with no movement at all.
Took 3 cylinders with pistons still in them to work today to clean them in the parts washer. Scrubbed funk off the tops of the pistons and they are .020 oversize. Combine that with the .010 undersize on the crank and bearing shells (all shot) and I figure this must have been a rebuild with a performance cam update. it is an Iskendarian cam.
Tomorrow, I clean up the other 3 cylinders, and eventually i will pull the pistons and check ring gaps. On inspection of the block for damage from the broken crank I discovered that the assemblers had put a thin coat of silicone on the WEB mating surfaces . They really didn't know what they were doing. Other than dressing a few small areas with a fine file, the block doesn't look al that bad. Next step on the block will be cleaning up all the casting flash and boogers that GM left behind when they built it.
[attachment=2]beat up cam gear.jpg
EDIT: note that the dial indicator is old, but it's a Starret and works fine. The yellowed lens is more clear than in the picture. Dennis

[Project65]

I’m finding this very interesting and hoping to learn about what’s involved with a rebuild.

I didn’t dare attempt rebuilding mine. Wanted to leave it to an expert. Hopefully some day I might get the chance to assemble one for myself. Keep up the posts and photos!

[66vairguy]

On inspection of the block for damage from the broken crank I discovered that the assemblers had put a thin coat of silicone on the WEB mating surfaces . They really didn't know what they were doing.
EDIT: note that the dial indicator is old, but it's a Starret and works fine. The yellowed lens is more clear than in the picture. Dennis

I never understood why folks put sealer on ALL the block halve sealing areas. It can keep the halves from seating properly. Only a couple small areas are not under a gasket and then only use a thin sealer at those areas as shown in the shop manual, NO silicon (RTV).

I would suggest bolting up the block halves with only the cam installed with some plasti-gauge. Even at the maximum tolerance it's good to go, unless you plan on going racing. The only alternative is a new block at this time.

Peening the valve seats was a popular "myth" at one time. So was heating the heads to a high temperature and freezing the seats in liquid Nitrogen. Neither proved to be effective. It's a simple issue of alluminum and the different alloy valve seats having different expansion rates. No matter how TIGHT you get the seats inserted, after a few thermal cycles (engine heads at operating temperature) the different expansion rates RELAX the tension (less tight) between the aluminum head and the seat. Only fix if greater contact area (deep seats) to increase the friction between the seat and head material. Of course if you badly overheat the heads, even deep seats will come loose.

A check to see if the heads were overheated is to remove the old head gasket ring. If there is a groove in the head were the gasket was -- the head was overheated. A minor groove is fine as a head rebuilder can machine it for a good gasket surface, however I've seen the groove as deep as 0.150" which requires a lot of material removal and you have to CC the chambers to makes sure they work. I got one set of heads with a pile of parts I bought. The heads work looked bad and the chambers CC'd to 11.5 to one compression!!! They went to the scrap heap.

[Dennis66]

Actually, I'm more worried about the crank bearing fit than I am about the cam. I plan to "plastigage" both. Yeah, a coat of anything, even thin, still adds space on an incredibly close tolerance. With a N.O.S. crank and standard bearings, all of that will be back to stock. I probably won't get to cleaning up or close inspection of the heads until the short block is all together. The peened valve seats may, or may not be a problem. Cross that bridge when I come to it. I have seen plenty of valve seats fixed by peening. Not my first choice, but I've seen it successfully done. I've also seen just as many valve seats knocked loose on aluminum heads from sloppy valve guides as I have from overheating. Interesting note about the head gaskets (rings). I really don't think this engine has been overheated (not THIS time). The amount of residue on the heads and tops of the pistons indicate it was running too rich, too cool, and or burning oil. Back in the day when combing boneyards for good Vega heads, I used to look for the ones that were all carboned up. That was usually a good sign that they hadn't been running hot. (for those who might not know, Vegas, the economical descendant of Corvairs, had an aluminum BLOCK, and a cast iron head that was known to crack if overheated. Usually, the aluminum cylinders scored or wore causing excessive oil consumption, and a one way trip to the boneyards. There are a lot more Corvairs around today than there are Vegas.)
Project65: Thanks for your comments too. yes, plenty of pictures for those who will be interested in learning about "rebuilds" - or overhauls. There are several different levels of "overhaul" / rebuild. I like to reserve the term rebuild for bringing everything back to minimum tolerance - be it oversize or all standard sized. Otherwise, I like to refer to it as "overhaul". In my aviation days, we had terms such as Zero Time, Major overhaul, and Top overhaul for different levels of repair. Dennis

[Dennis66]

Back to the Corvair project - a little. Had a few around the house and yard projects that needed tending to. Then there was "the boat". FYI, the boat needs to go away as it and the Coot ATV are being replaced by the Corvair. Boat needed some fiberglass work done, and my friend came over to get on that today. While he was grinding and glassing, I took a little time to pay attention to the NOS crank for my project. This is a new GM crank that went from GM to Clark's to whatever garage had this Corvair all those years since toe other crank broke. The car was last registered in 2005. It, and the new crank have been in storage from then, until some time in 2022. While the bearing surfaces of this new crank had been coated with grease when it was new, 15+ years of storage found a few places where the grease had been smudged, and the non coated parts had a light rust patina on them. Tuesday, ti cleaned everything up, polished the journals, and everything came out pretty clean. Here's the IMPORTANT part: After polishing, I was cleaning everything up. I was pushing little pieces of rag through the oil holes that run from crankpin to main journal. One came out with a little bit of rust stain on it - NOT GOOD. Today, I used a .22 caliber rifle cleaning rod and some 600 grit paper and thoroughly cleaned each passage. Then I pushed small pieces of clean white cloth through (much like cleaning a .22) until they came out clean. Then I used a toothbrush to apply and scrub in Naval jelly to all the crank throws and counter weights. Then a wire toothbrush to scrub the rust patina away. Then a washdown with cleaner to remove the excess naval jelly, then a thorough cleaning to remove any water, and cleaning all oil passages again. After all of this, the naval jelly residue left a few journals stained, so I will have to polish and repeat again. In the meantime, I oiled everything down to keep it from rusting again. This is humid, salty air Florida, and you can literally watch clean, untreated steel rust before your eyes. After oiling, I wrapped the crank in inhibitive paper and then wrapped all of that in the plastic bag. Hope to get those journals polished tomorrow.