A little oily but not terrible. Did you test compression first? Because it is impossible to tell just by looking if either the valve guides or rings are passing any oil. When you say you inherited this car, who owned it before you? An elderly relative that may have been lax on oil changes? I still say for it's age that is in petty good shape.
So I just primed the engine. Put a guage on the oil sending unit and checked to make sure oil was getting through the rods. After a little work and pushing some 18 guage wire through a few they all eventually got oil flowing. Pressure was about 60 psi with drill motor. But the I got worried there would be a bunch of devri between the cylinder heads so I decided to go ahead and pull them before I did a compression check.
Ya, I got it from my aunt. She always wanted to restore it and drive route 66. She always had it garaged but hadn't started it in at least 25 years. So hopefully the enginecis still good minus the parts with coolant sitting forever. Like the water pump.
Unless you care about aesthetics i wouldn't worry about it. The clamping force of the other 5 bolts is more than enough to hold a bellhousing or transmission to the block. Besides the cost to repair by welding and re threading would out price the cost of another block.
I did that repair on a 301 Turbo block. I placed a grade 8 bolt in the threaded hole with the head on the engine side, the shaft sticking towards the trans side. Then I welded it in place. Welding cast iron is tricky. If you can or know a buddy that can do it, then make the repair. What I do is use an acetylene torch to melt and flow the iron where I need it. The block is a huge heat sink so I use a very large tip to get the area I need melted. When the metal turns yellow/white it can flow. I use the torch pressure to push the molten metal around where I need it. You can even use a cutting tip to goose the molten metal around. You are not trying to weld the steel bolt to the cast iron block, but rather re-forming the iron around the bolt to hold it in place. You can use a broken chunk of iron as filler. If you are not comfortable with that an alternative is to braze it in place. Cast iron does braze easy with a flux coated brass rod. You still need to get it very hot but brass melts at a much lower temperature than cast iron. As bigchief said one bolt doesn't matter all that much but I prefer to have at least something there to secure the transmission.
Thanks for the info fellas. Unless I get bored before my timing chain housing gets here I'll probably just leave it as is. I'm pretty crappy at welding and if it's tricky it can only end badly.
"I'm pretty crappy at welding " That is why I suggested brazing. Before I had real welding equipment I had a Sears Solid-Ox torch. You burned a rock-like pellet in a tube and it gave off oxygen. Combined with propane it got pretty hot. I sucked at welding too, but brazing was what this thing was best at. My wifey dropped a huge cast iron skillet and busted the handle off. I used a flux coated brass rod to braze the handle back on. That was almost 50 years ago and the handle is still in place. You don't need to melt the iron, but just get it hot enough so the brass melts and flows into the cracked part. It's a good skill to know.
While I have everything torn apart, how can I tell if I need to replace the timing chain? Car has around 85000 miles don't know if it is the original chain. It seems to have quite a bit of slack. Probably an inch and a half.
The cost of the equipment and the skill needed to do the repair exceeds the cost of another block. Yea if the timing chain has that amount of slack its time for a new timing set.
Looking at it again, I see another way. Do you have a big bench vise and a BFH? Why not fabricate a strap of 1/8" steel, maybe an inch wide, and bolt one end to that oil pan bolt, or the block drain bolt, and the other to the oil filter adapter bolt? Work the metal and have it bend over to the broken part with a hole in it so you can have a nut/washer on one side and the bolt on the other? I can be as shadetree as they come but it beats changing blocks.
Hello again. So I replaced the timing chain, housing, and water pump today. Decided to hook up the starter and a battery to check the compression in the cylinders. Below is a picture of how the engine sat when I dud it. No covers, no manifolds, ect. Didn't think any if that stuff would make a difference but it's very possible I'm wrong. Not sure excactly what all boxes needed to be checked before doing that test. And not sure what good compression should be. But here are the numbers I got.
Those numbers are not good. It is not so much how high the numbers are, but rather that they are all relatively the same give or take 10psi. So even a tired motor with 120 in all cylinders would be a good running engine. Did you clean up the combustion chambers, piston tops, and use a new head gasket? Properly torqued? Did you remove all the spark plugs while testing? Now the thing is to squirt some oil in each cylinder one at a time and see if the numbers change. Being on a stand, you can rotate the engine so the bank being tested it perpendicular to the ground. That way the oil will not puddle at one side but rather fill all around the rings. Squirt motor oil into the spark plug hole, then test the compression. If the pressure goes up, the rings are bad. If nothing changes, the valves are bad. The oil will temporarily seal the rings but not the valves. Sitting that length of time some rings may have rusted stuck causing the low compression. Did you adjust the valves? That cylinder with 0 says to me a valve is hanging open or there is a broken part causing the no compression. Using the Pontiac jam nuts all you do is torque each rocker nut to 20ft lbs. The lifters are self-adjusting so good oil pressure is a must.
Ok, so I cleaned the piston top real good and used a new gasket. As far as the combustion chambers, they all looked clean and smooth so I didn't do anything to them. I did remove all the spark plugs but didn't squirt oil in them or have it rotated perpendicular. I can try that this afternoon. So as far as adjusting tge valves goes, I messed with them, lol. So I watched several videos, none of them made it as simple as tighten to 20 ft pounds. Some said tighten until there is drag on the rod then go one flat. Saw another guy tighten until he couldn't turn the rod and the he would go a fullv3/4 turn on the jam nut. Spin the balancer 99 degrees and repeat until he couldn't spin them at all while tet another individual tightened them where none if the rods would spin then backed it off till they did. So I ended up somewhere in the middle. I tightened them till there was drag spinning them and then added a flat. Looks like I'll do some adjusting and retesting later today. Thanks for the knowledge
Ya know, now that I think about it, I looked at the bottom half of the engines cylinders and the were pretty smooth. But never paid much attention to the bottom side of the top except to scrape the crust off and wipe it down. Guess I need to pull the heads back off. Can you only use a head gasket once? They ain't cheap.
So I got back home, re torque everything, shot some oil in the spark plug hole and got 1 90 2 90 3 90 4 100 5 0 6 110 7 100 8 120. And the I started experimenting with that cylinder a little bit ,because why not, lol. And I noticed if dropped the torque on the forward rodto around 5psi it actually got a reading of 30. Encouraged and fascinated, I took the rocker and rod out all together and got 120 psi. Now I'm sure to the more knowledgeable folks like yourself your probably like "well ta, obviously, not [censored]". But I don't comprendre. It would seem like that information would help narrow down the problem. But damned if I know what it tells me.
these engines are 54+ years old and at that point should have had a few valve jobs and a rebuild. If not it needs one. Piston rings loose tension and the piston ring lands in the pistons get worn out and you add cylinder wear to that which makes various compression in cylinders different.
That is quite an improvement in your numbers. The oil sealed up the rings and made a big difference. Remember you are waking up a tired old engine that sat for many years. I know what you mean by all the weird rocker nut adjustment procedures. That applies to engines that have solid lifters or poly-locks. But a stock Pontiac uses a bottle neck stud and a jam nut. The jam nut gets torqued to 20 ft lbs and it 'jams' against the bottle neck. After that once the engine is running the lifters self adjust via the oil pressure and bleed-down hole. When the lifter is on the baseline of the cam the oil pressure fills it through that tiny bleed hole. Once the cam lobe lifts the lifter off, the oil hole is shut off, oil can't be compressed, and the lifter becomes 'solid'. It really is 'set it and forget it' but the jam nut is supposed to be one use only and be replaced every time. I just torque them 5 lbs more each time but that only works a couple of times. Head gaskets are supposed to be one use only. But since the engine was not run, I think you can get away with re-using it. But since everything was cleaned and torqued properly I would not touch it. There is nothing you can do in there without taking the entire engine apart. I would get it running first to give the rings time to loosen up and re-seal. Either you have a tired old engine that needs a complete re-build- or it just needs running time to shake off the cobwebs. I have saved two 400's that were completely filled with water right up to the carburetor. Talk about rusty rings! But they are both running tight and strong now. That is a story for another time but shows you not to toss in the towel just yet. Loosen all the rocker nuts, re-torque them to 20 ft lbs, then spin the engine with the starter and no plugs in. The lifters should self adjust and your valves will open/close properly. Then re-test for compression.
You guys are the best. I think my plan is going to be since I already have it out and on a stand I'm going to dug a little deeper on the inside. Hopefully I will be able to tell more. I don't mind giving it a valve job, new rings, stuff short of having to take it in to be machined. I would like to get it running and hope that the one cylinder gets with the program. But the thought of it staying at zero and having to pull the engine again isn't real appealing. So I'll rip into it. More photos to come. If I haven't said it, thanks for the help
There are only two ways that cylinder would be at zero. One is a valve hanging open. If it sat long enough in the open position it could be rusty and stuck. The other is a broken piston or ring land. I am sure you would have noticed a broken piston. I had an engine with broken ring lands. It was a 1967 Firebird 400 HO. A high compression engine, but someone drove it on cheap gas and detonation cracked most of the ring lands. I only knew because I spun a rod bearing on a 1969 GTO 400, and I had to pirate a complete piston and rod from the '67 into the '69. Almost all the pistons were broken. So check those valves for proper adjustment and I bet that cylinder will came alive. In other news I found this video of a guy using an acetylene torch to repair an engine block.This is exactly what I was speaking of. Block repair
Well holy hell. Went and had some lunch. Came back. Spun it over, 120 psi fully torqued. Might be time for a maker's mark and 7. So I guess I'm onto re-installing the manifolds. Anything I need to look out for oh wise one?
Nostradamus worked on cars? I thought he predicted the future? HA HA! I am only good at remembering the past , and learning from it. I have been playing with Firebirds for almost 50 years. When I got out of the ARMY in 1975 I bought my neighbor's 1968 Firebird hardtop, OHC-6, automatic. It was my daily driver for 16 years. I learned a lot on that car, had 6 different engines, and converted to manual transmissions. At the end it had a 400 4-speed. It literally rusted out from under me, that was my favorite car ever. So that cylinder came alive? Excellent! As for the manifolds, just clean up the gasket mating surfaces, chase the threads in all the holes, put a little schmear of RTV around the water crossover holes, and use a torque wrench, and always use anti-seize on anything exhaust related. Over the years I have learned to upgrade exhaust bolt to stainless steel, with anti-seize on the threads, you will be glad you did down the line. A note about rings- to have new rings be worth the trouble you need the cylinders to be bored and honed. There is a ridge at the top where the rings did not touch and it needs to be removed, cylinder walls checked for taper and roundness, pistons cleaned and checked for skirt wear. That usually means oversize new pistons fitted by a shop to get the specs correct. Trying to hone a cylinder with a honing tool on a drill is not the way to go. That is something racers do between runs on cylinders that are almost perfect to begin with. Plenty of people do it and say it worked out great. Our rule-of-thumb is that if hand-honing was good enough to get proper ring seal, the cylinders were so good they didn't need touching to begin with. I know we all like to do something once and be done. But with hot rodding in general, and especially old cars like these, sometimes you need to try something out, and if it doesn't work, take it all apart and try something different. It's just part of the 'fun' of old cars. .
Hey buddy, got a question. Well maybe a couple. I was looking at the exhaust manifold and one has some really deep pitting going so was considering replacing rh side. Along with the pitting, the heat riser valve doesn't move very freely and i think the heating coil spring won't open the valve. The casting number is 9779328. Which matches to 66-68 gto and 68 firebird. But not a 70 Tempe. Wonder if it was taken originn motor. Also, how necessary is that valve??; thankt
HOLY FRIGGIN' MOLY!!!!! You can work on my engines anytime!!! It's beautiful!!! If the pitted manifolds bother you coat them with EASTWOOD stainless steel paint. Looks great, lasts a long time. Exhaust manifolds are not cheap. So the heat riser valve is a flap that closes when cold, forcing all the exhaust from that side, up through the intake manifold exhaust crossover, and out the other side. That warms up the intake/carburetor so the fuel atomizes faster and it runs better. Once it warms up it opens and the exhaust goes out each side as normal. Racers delete it but street cars need it. If you leave it in the open position the intake will eventually warm up but in chilly weather it will run rich and crappy until it does. Oil it up and loosen it. If the spring is shot you can replace it. Same for the THERMAC heated air cleaner. It warms up the intake air so the fuel atomizes faster. Take note: once the THERMAC air cleaners were installed, carburetors were jetted to work best with the heated intake air [approx 100°] so delete at your own risk. Since my cars are used all year, I add a thermostatically controlled vacuum switch to shut off the THERMAC after the engine reaches 90°. I only do that in the summertime. In winter I need all the heat I can get. A better idea is the EFE valve used on later engines [Early Fuel Evaporation]. It has a vacuum motor to close the flap and it releases when the engine gets to operating temperature. I added that to our 1968 Buick LaSabre. The heat riser had rusted so badly I added a late model EFE by welding it into the pass side exhaust head pipe. It worked great. If you stumble across a later exhaust manifold with the EFE, you might want it. It has a flat flange that takes an EFE valve between the manifold and the head pipe. But the pipe won't work without the EFE because of the flat flange. That EFE is VERY expensive and hard to find so make sure it is on the manifold. Man, I'm drooling over that engine. Well done!! .
Well thank you sir. I'm nit afraid to get dirty obviously. The reason I asked about tge putting is some articles led me to believe it was due to rust and if they were deep could be expecting a failure from it. So in you vast experience, have you swapped a lot of engines? I'm just wondering hiw much I can put together on the stand before it makes it to hard to get back in. Obviously it's a lot easier to work on on the stand but has to come a point where shuts just in the wY. Curious your thoughts. Thanks
The exhaust manifolds are pretty thick. They are expected to rust and pit. The only time I would replace them is if there was a serious crack or hole. And even then I would use the acetylene torch to repair it first. We just spent a LOT of time looking for some later exhaust manifolds for my buddy's 1980 Trans Am. He had headers that rotted out so I convinced him to go back to the stock manifolds. We were super lucky to snag a set of 1977's but the EFE valve was missing. THAT will be an expensive long search. I have been swapping engines since I was old enough to hold the flashlight for my Dad. I learned much as well as many new curse words. I put the engine/transmission in as a single unit if I can. Working in my driveway that is easier than trying to put the trans in later. I leave off the distributor, carb, starter, alternator, all sensors, all brackets, all cables, and wires, anything that can and will get hung up with 800 pounds swinging from a hoist. Usually the exhaust manifolds can be on but sometimes they catch on the engine mounts. Be ready to remove them if they do. Of course the radiator must be out, trans cross-member can be in but I loosen the bolts in case it needs to be moved for clearance or fitment. I also often find that the legs of the hoist hit the lower control arms. So I place the front wheels on two thick planks. That way I get a precious couple of inches clearance and I can still roll the car forward and back while dropping the engine in. I would rather move the car than the hoist with all that weight dangling from it. You are moving right along and I am envious. I am working outside and it has been raining and cold. I have been busying myself trying to rebuild a tilt column down my basement.
Ya, the workshop does make it easier. Far from climate controlled but throw in a 185000 torpedo heater and 10 gallons of diesel you can stave off the cold. I'm definitely glad I asked you, I was getting ready to start putting the starter and things back on.. unfortunately ran into a snag.(wife). Got pulled off to put a gutter on the workshop to catch rain water and still gotta build a raised flower bed this weekend. Did you ever use chiltons or factory assembly books? Looks like a lot of good info, but pricey. Thanks OS&U
Chilton is a waste of time. Get the 1968 Pontiac Factory Service Manual. It has been reprinted and is going for around $50. Even less used on Fleabay. The 1968 Fischer Body Service Manual is also a must. It covers the convertible top system better than the FSM. With these two books there is nothing you can't do on the Firebird. A little harder to find is the 1968 Diagnosis Manual. It explains systems in more detail and makes it easier to track down troubles. Luckily for us these books have been re-printed and are very available so it is easy to have the important information right at your fingertips.
Sounds good. I ordered the factory one. But until then I need your expertise again. Suprise suprise. Is the starter pinion supposed to stay out? Online I have read that it will stay out if the engine doesn't start. Have also read it should retract after you stop turning the ignition. I've tried no shim. 1 shim and 2 shims. Pinion Always good stays out. So I don't know if is a problem or functioning correctly. Thsnks
Last edited by Oly; 03/27/2301:46 PM. Reason: Typo
No, it should retract. That is what the starter solenoid does, it extends the drive pinion to engage the flywheel ring gear, and makes contact between the battery cable and the starter motor so it runs. The little wire that comes from the ignition switch activates the solenoid. There is a big spring inside the solenoid. The innards may be gooey from age or even broken. It comes apart pretty easy just don't break the solid copper wires in there. Or get a new one. GM used the same one for about a hundred years. When we were poor we would rebuild the solenoid for next to nothing, and just flip the big copper washer over. As for the starter/ring gear gap, I think it is .020" engaged and it should not be touching. But it is difficult to extend the starter gear and check with a feeler gauge. That is what the shims are for and I have never seen a good starter fit without at least a couple of shims. By me we have an old timey auto-electric rebuilder guy and he is just fantastic. His stuff will outlast the car. I never buy a rebuilt stater or alternator from a chain store. Good move on the FSM, you will be delighted with the information.
So I'm out here now playing around with it. With two shims, one thick one the thin. It still sticks. So experimenting I took one of the shims from the hood didn't use the others and put just the one shim with the bolt closest to the engine so it kicked the starter out a little more instead of down. It doesn't stick anymore and still turns the flex plate but it doesn't sound right. Doesn't sound like it's trying to turn the motor over. Just a flat sound without the rrehhh rehhh sound. Lmao, pretty sure that's an official term.
That shim canted the starter away on an angle? Something is not right. It should only take a couple of shims to get the right contact. How about the drive gear? If you pry it out does it snap back in? If so it is OK. I had a similar problem but the stater was an aftermarket high torque unit. It NEVER fit right even though is was spec'd for a Pontiac 400. We ended up getting a new one which worked fine. We never did figure out why the bad one did not fit. Did you pry out the drive gear and test the gears for .020"?
So by shimming one side was the only thing that seemed to give me more space. Just adding the two shims left the teeth with no gap. It seems like the shims just push it down instead of out. I guess since it's round it technically doing both. But I should make sure I'm following you. When I say pinion I'm talking about the gear that shoots out and spins the flexplate. Am I calling them the wrong things? What are you referring to when you say drive gears,
Yes, same thing. Was this starter on the engine all along? Did you ever try to spin it before it was off? When you were spinning the engine to test the oil and compression, did it mesh correctly or not? The only time I have come across this is when changing parts that were from something else. Do you have another starter to test with?
It's the same starter that came on there. I replaced the Solenoid. I never really thought to check when I was doing the testing. The piston would fire, the flex plate spun so I assumed all was good. It very well could have been stuck in the engaged position then too. If I hit the terminal to only fire the piston, it returns ok. Just when it engages the flexplate and spins it does it get stuck. It's the only one I got, no spare
