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Norm,
The engine under discussion here is a low compression engine. (8.75 : 1 )
120 to 130 PSI would be a normal cranking compression pressure.
The thread you referenced, discusses a Starfire high compression engine. ( 10.5 : 1 )
Yes, I agree that the pressures vary too much to call it " good ".
Last edited by Charlie Jones; April 11th, 2024 at 11:06 AM.
Too bad you didn't do the compression test when you started.
Then you wouldn't have to pull the engine twice.
Oh well, at least it will be easier ( and cleaner ) to remove this time.
Shoot a shot of oil in the low cylinders and see if they come up.
If they do the problem is rings.
Remove all the plugs before performing the compression test. No benefit fighting the compression of seven other cylinders when you're only interest is to measure compression in one cylinder (at a time) - the battery & ignition system will thank you.
Something to consider here is that the engine has sat unused for however long, and the lifters, even the best of them, have a tendency to leak down, (collapse), and sometimes it can take a while before they pump up again even with oil pressure. The issue is usually due to sludge or carbon build-up inside the lifters that is difficult to "cure" short of removing them and disassembling and cleaning, or just replace them with new. I've been going through your thread since I've also got a 64 ragtop with the 394 and slimjim transmission. I need to do this same thing with mine, since I've never heard it run and I have no idea who did the so called "overhaul" and what was actually done. I got this one, and a spare, from my dad who got it from the original owner after he lost interest in it. I'd like to know what you find out when you pull it out again. Something that I've ran into with old Cadillac engines that have sat for a long time is the wrist pin drying out and what oil does get splashed up there isn't enough to get between the pin and piston. I've had 2 engines just begin to knock like hell when I fired them up after sitting for years. One was a '72 472, the other was a '77 425 that my father in law had and quit driving due to his age.i know you didn't want to pull the distributor out, but it might have been a good idea. You can drive the oil pump with a drill to prime the engine and pump up the lifters and prelube the bearings prior to starting it.You also mentioned that you don't know what the oil pressure is. When you turn on key but don't start it, did the oil light come on? It should. If not, you wouldn't know if you lost pressure or not.Just for test purposes, I'd use a mechanical gauge on it. The idiot light doesn't tell you anything until it's too late anyway.Good luck with your engine, I wish you the best. Rick
Last edited by Cadman-iac; April 18th, 2024 at 06:03 PM.
Something to consider here is that the engine has sat unused for however long, and the lifters, even the best of them, have a tendency to leak down, (collapse), and sometimes it can take a while before they pump up again even with oil pressure. The issue is usually due to sludge or carbon build-up inside the lifters that is difficult to "cure" short of removing them and disassembling and cleaning, or just replace them with new. I've been going through your thread since I've also got a 64 ragtop with the 394 and slimjim transmission. I need to do this same thing with mine, since I've never heard it run and I have no idea who did the so called "overhaul" and what was actually done. I got this one, and a spare, from my dad who got it from the original owner after he lost interest in it. I'd like to know what you find out when you pull it out again. Something that I've ran into with old Cadillac engines that have sat for a long time is the wrist pin drying out and what oil does get splashed up there isn't enough to get between the pin and piston. I've had 2 engines just begin to knock like hell when I fired them up after sitting for years. One was a '72 472, the other was a '77 425 that my father in law had and quit driving due to his age.i know you didn't want to pull the distributor out, but it might have been a good idea. You can drive the oil pump with a drill to prime the engine and pump up the lifters and prelube the bearings prior to starting it.You also mentioned that you don't know what the oil pressure is. When you turn on key but don't start it, did the oil light come on? It should. If not, you wouldn't know if you lost pressure or not.Just for test purposes, I'd use a mechanical gauge on it. The idiot light doesn't tell you anything until it's too late anyway.Good luck with your engine, I wish you the best. Rick
Rick, I have the engine out and disassembled. Visual inspection, I see oil in the rockers, and the valley. I didn't notice if the oil light came on when I turned the key- pretty dumb of me, because of course it should. I thought about a pressure gauge and new sending unit, even if only for test purposes. Heads look really good, and I'm told they were done. Local shop can do the block next week- cam bearings, hone/bore the cylinders, new freeze plugs. He says he can provide the numbers I need to order the bearings, or he'll provide them so I know they're right. We're still in the talking phase, but he's highly respected as an engine builder locally, and booked out 6 months with builds. He's going to do my block between builds just because I guess he wants to help a guy who wants to do the build himself? Most of these guys really want to help from my experience- and quick cash is always a good thing in business.
Dave,
Are you putting in a new cam and lifters?
When you disassembled the engine, did you put the lifters in order somewhere so they could go back on the same cam lobe?
If you didn't, you will need to buy a new cam and lifters.
The reason is that a cam lobe and a lifter face "wear in" together.
Switching lifters around on a cam can result in galling and rapid wear.
Wiping out a cam, and filling the rest of the engine with "shrapnel".
Dave,
Are you putting in a new cam and lifters?
When you disassembled the engine, did you put the lifters in order somewhere so they could go back on the same cam lobe?
If you didn't, you will need to buy a new cam and lifters.
The reason is that a cam lobe and a lifter face "wear in" together.
Switching lifters around on a cam can result in galling and rapid wear.
Wiping out a cam, and filling the rest of the engine with "shrapnel".
Hey Charlie- yeah, I tagged every lifter and push rod, and every piston and connecting rod. I was very meticulous about it, each piece was done one at a time, tagged... everything. I laid out the head bolts in sequence in a box and put it aside, by the torque sequence in the book. That said, the camshaft shows wear and the lifters too, so they should be replaced. Lifter foot is concave, and the cam shows wear across the entire top of the lobe. Pistons are scored along the skirts, and the machine shop strongly suggests boring the cylinders out like .030 over and using new pistons and pins.
My next big question is whether I should go with a mild performance camshaft (I think I will) and the higher compression pistons- I think I'll let the dude at the machine shop guide me on that one, but I'd like to use the Super 88/Starfire 10.5:1 pistons. You can see the wear pattern extends all across the top of the cam lobe, and down the sides. The lifter feet are concave
Piston skirts are scored, and the machine shop wants to bore the block .030 over and use new pistons. I might go with the higher compression pistons.
Yeah, that Cam's good life is over.
Of the three types of pistons shown in an earlier illustration, only the 10.25 to one compression pistons are available now.
They are available from Egge, Fusick, and Kanter.
To my knowledge, the 8.75 and 10.5 pistons aren't made any more.
Fusick sells Starfire camshafts and Camcraft cams will grind any cam you desire.
Yeah, that Cam's good life is over.
Of the three types of pistons shown in an earlier illustration, only the 10.25 to one compression pistons are available now.
They are available from Egge, Fusick, and Kanter.
To my knowledge, the 8.75 and 10.5 pistons aren't made any more.
Fusick sells Starfire camshafts and Camcraft cams will grind any cam you desire.
My guy in Ware comes highly recommended- the machine shop. He builds motors, he's booked out until October, or so he says. He's going to do the block for me, and since he's doing the bore, he's ordering the bearings, and I would think the pistons and rings. I'll have to ask him about the camshaft- but he's doing the block so that includes the camshaft bearings. I'm lucky to have him. Otherwise, I'd be waiting months for a good machine shop to do this work for me. I spent all day on everything else- I've got nothing to do now until Edgar Machine in Ware Massachusetts (shameless promo) does the magic. If he had a website I'd share the link...
My guy in Ware comes highly recommended- the machine shop. He builds motors, he's booked out until October, or so he says. He's going to do the block for me, and since he's doing the bore, he's ordering the bearings, and I would think the pistons and rings. I'll have to ask him about the camshaft- but he's doing the block so that includes the camshaft bearings. I'm lucky to have him. Otherwise, I'd be waiting months for a good machine shop to do this work for me. I spent all day on everything else- I've got nothing to do now until Edgar Machine in Ware Massachusetts (shameless promo) does the magic. If he had a website I'd share the link...
How does the engine run ?
I replied in another of your threads about cams. Kinda confusing when you have several threads started and same questions are asked. https://www.camcraftcams.com/
I replied in another of your threads about cams. Kinda confusing when you have several threads started and same questions are asked. https://www.camcraftcams.com/
The engine doesn't run- not now anyway. It's torn down. And sorry about the different posts, but some things feel like a "general question" to me. Going forward, I'll stick to this thread. I have a shop that is taking on the machine work for me. He agreed to do the block between his bigger builds, so he's going to clean it, magna-flux it, replace the freeze plugs and cam bearings, bore the cylinders and hone them and set me up with correct pistons for the new bore. He's going to check the crank for wear and for round, and polish it, provide the main and rod bearings. I'll buy a new camshaft and lifters, a new oil pump too. I've got to complete the build. I expect to have everything back in the barn by the end of next week- I guess I'll see how it looks then.
I don't like feeling like I have to trust him to do it right, but if I want a builder to build me a complete engine I won't have the car on the road in 2024. No one reliable near me can do the job before October. It's madness that a person can't get an engine built in less than 6 months time- it makes me think there's lots of money to be made if you can build engines. Not too many people are doing it anymore, I guess. So it is what it is- dude says he'll do the machine work on the block, the rest is up to me. I'm okay with that.
I'll tell you how it runs when I'm done. It's just money and time, right? camshaft with the block behind #1 piston, there's 7 more pretty much like this one laying on an old towel
Iv ran into that exact same discussion on my project build. I had the thought of using Starfire/98 10.5:1 pistons in my 394. Unless you have access to 93 Octane gas with an octane booster or racing gas, I would advise against it. The motor would have to be detuned in order to run okay with lower octane gas. Charlie and a few other stated to me it just isn't worth it also because race gas is far and thin across America. I ended up going with 10.25:1 pistons using 93 Octane and no booster. Plenty of power and 91 is achievable if i just adjusting timing.
Also all those piston brands are great! I was originally going to go with EGGE but due to budget restrictions, I went with Rebuilders Choice Pistons out of Boonton, New Jersey. Great Pistons and knocks off a little on price.
Iv ran into that exact same discussion on my project build. I had the thought of using Starfire/98 10.5:1 pistons in my 394. Unless you have access to 93 Octane gas with an octane booster or racing gas, I would advise against it. The motor would have to be detuned in order to run okay with lower octane gas. Charlie and a few other stated to me it just isn't worth it also because race gas is far and thin across America. I ended up going with 10.25:1 pistons using 93 Octane and no booster. Plenty of power and 91 is achievable if i just adjusting timing.
Also all those piston brands are great! I was originally going to go with EGGE but due to budget restrictions, I went with Rebuilders Choice Pistons out of Boonton, New Jersey. Great Pistons and knocks off a little on price.
Kanter lists PST2179 and PST2180. I'm thinking the 2179 is the piston I want, it says it's for the 394 2 bbl engine. It does not specifically list the compression ratio. Do you know which ones you used? Also, I'm guessing these have full floating wrist pins, which don't need to be pressed. The tech guide says if the pins are properly fitted, they should slide in place with a little hand pressure, and fall out under their own weight.
Unfortunately I bought my pistons in 2020 and eBay cant re-pull the listing. I got them with shipping for about $520. I have a picture from the listing but the picture is pretty small. They had a black RC label and they were 0.30 over. They were cut to match OE 10.25:1 pistons. you could always call RC & ask what's available. Here are the only 2 picture I have of the pistons
The block is in the machine shop since Friday, "Eddie" (as I'm calling him) said he'd probably get it done this week. Edgar Machine in Ware is doing the work- so I call the guy Eddie. He never actually introduced himself, or handed me business card, so I'm just going to call him Eddie. His office is full of heads- if they were shrunken, he'd be a world class witch doctor. But they're rebuilt heads waiting for customers to come pick them up. His shop has engine blocks everywhere in various stages of completion. Eddie said he'd clean mine, and magnaflux it, check the bore and the deck and tell me what he thinks. I need camshaft bearings, and he said he'd plan to do those and the freeze plugs. Other than that, it's likely that the block needs the cylinders honed, and not much else.
I'm looking over the pistons to see if I really need to replace them. Rods look good, Eddie is going to polish the crankshaft, and again, if it needs more, he'll let me know. If I want to drop some money (just because) I can ask Eddie to bore it out .030 over and buy new pistons. It's not a bad idea. That would mean I have a block that been cleaned and magnafluxed, decks certified flat- or milled- center bore certified, cylinders bored .030 over, new camshaft and cam bearings, new lifters, new main and rod bearings, new rings and pistons, new oil pump... that's a pretty complete engine build for something I do mostly in my barn. It's good money spent- to bore it .030 over and get new higher compression pistons, but that's up to Eddie. I wish I really knew his name...
So nearly a month later- block is back from the shop, Edgar Machine (his name is Dave BTW, Dave Edgar), and I got the crankshaft ground by Steve Dutcher up in Greenfield. Dave Edgar was able to do the block between other jobs but told me he couldn't do the crank for at least 3 weeks. Steve Dutcher was able to grind the crank for me- again, between other work. These guys are in demand!
So the block is tanked and magnafluxed, new freeze plugs and cam bearings, cylinders are honed so I can reuse the old pistons. If you're doing a rebuild on a 394 you'd be wise to check availability for parts. I found only certain sizes were available. I was able to use .010 mains and standard rod bearings, but I think I might have found the last set of standard rod bearings and piston rings in existence. Pistons were only available at .020 over or more. These engines being 60 years old, most of them have already been worked a time or 2, so standard bearings, rings, pistons... there's not a lot of them left out there. You'd be wise to bore the cylinders out to .030 over and grind the crank at least .010 just because that seems to be sizes for rings, pistons, main and rod bearings that are available.
That was my experience anyway...
I measured the pistons with a caliper, and I'm confident the piston to cylinder wall gap is under .005. Ring gap is around .025 mostly. I was hoping for better, but I guess honing the cylinders pushed them out a couple thousandths. I spent a lot of time cleaning the pistons, and the ring grooves. They look good I think. I checked all the bearings with plastigauge, they're all at .002 or better. Torqued the mains to 110-120, except rear main, at 140. Rod caps torque at around 35-40 ft lbs.
I've got a new camshaft and lifters. I have to give the oil pump a good once over. I might have to order a rebuild kit and that would suck because I've really getting tired of waiting for parts. Exhaust manifold is *****. I've got to replace at least one of the studs and that's going to suck. I honestly don't know how much success I'm going to have with that, and again- there isn't a machine shop within 100 miles that even wants to answer the phone.
I have the crankshaft and pistons in the block. Spent the day on it. Wife wanted to go to some lousy craft fair this afternoon so I had to quit, but I was at my end anyway. We met up with friends and it was fun, even if the food trucks sucked and most of the craft stands were selling soy wax candles, redneck tee shirts and knit hats in June.
Here's some pics... of the motor, not the craft fair.
That's how it looks tonight
those are the original pistons. It took some work to clean them up but they're in good shape otherwise
Not sure how much you can see, but I already rolled the beast upright and it's heavy with the crank and all the pistons back inside.
A view of the lifter valley sans lifters and push rods...
new camshaft. The timing set is new too. I thought the cam lobes would be polished. WTF do I know?
Heads are on the bench. I'll give them a good going over, but they're supposedly already done, and the look that way too.
Today- oil pump. I took it apart and decided there's nothing wrong with it, so I replaced the gasket and put it back together. I installed the camshaft and timing set, and the heads. I used 2 pieces of threaded rod in the widest bolt holes to act as guides and they just slid into place. Torqued them down, and the rocker assemblies, but DOH! I need push rods. I should have just ordered them when I ordered lifters and the cam- dumbass. I cleaned up the timing cover and the oil pan, but for a tube of RTV gasket sealer I could install them both and put the motor back in the car.
I'll order push rods tomorrow, and paint everything. I still have to solve the manifold thread issue.
I set the valve covers and valley pan in place as dust covers for now.
Block looks good...
...from behind too, but I'm an *** man, so yeah...
I converted the points to an electronic pick up, which required setting the distributor free play. The air gap on the pick up has to remain between .010 and about .060, and the free play was much more than that. At first, I cut the enclosed shim like a circlip so I didn't have to drive out the pin on the drive gear. I installed the distributor and I found I had to turn the oil pump shaft with a wrench to get the distributor to drop in. I got it put together and bolted up the oil pan, then I had second thoughts. What if that "circlip" came loose inside the engine? And why was the oil pump so hard to turn that I had to use a wrench on it? I took it all apart. I found the oil pump gears were binding on the cover because I used gasket sealer rather than an actual gasket. I have gasket paper so I cut my own gasket for the oil pump cover and I found it provides just the right amount of clearance so the oil pump spins freely now.
Also, I was able to drive out the pin on the distributor drive gear. I used a sheet of 22 gauge steel I've had around since my last motorcycle build to fabricate a couple shims- basically, I made a couple really thin washers out of 22 gauge steel. That set the free play to around .020, maybe a little more, but it also set the max air gap on the ignition pick up to about .030, maybe .040. Little details that probably saved me a world of hurt later.
Front cover is already on the motor now, so I set the pulley at 0 degrees and with the valley pan out I can see the camshaft indicates #1 cylinder is at ignition and the piston is at TDC, which helped me set the distributor properly so I can do the fine tuning once the engine is running. Oil pan is back on, distributor is installed, and I primed the oil pump as best I could.
I previously installed the heads and torqued the bolts, but I had to install new lifters and push rods, so I had to loosen the rocker shaft bolts to get the push rods under the rockers. I re-torqued the bolts and poured assembly lube and a solid quart of motor oil over the whole thing. So we have new lifters and push rods, new camshaft, installed the rocker valley pan and the rocker covers.
Next, the manifolds. Exhaust manifolds are a bit rough so I used a bit of gasket sealer (the orange stuff, high heat for exhaust manifolds) and torqued them down to around 25 ft-lbs. I put a stud on the passenger side rear, where the trans dipstick and vent bolt onto the manifold, just to make it easier. That's where it sits tonight.
Tomorrow I hope I can clean the old gaskets off the intake manifold and install that, give everything a good looking over, clean off the greasy fingerprints and touch up the paint. I have to paint the fan shroud and the fan, there's a pulley I still have to paint, and I want to spend some time with the breather cover. That has to look special. With any luck, I'll drop the motor back in on Thursday- I have meetings all day Wednesday.
Here's some pictures. Everyone loves the pictures...
Some details... new spark plugs installed, new bolts in the manifold...
You can see the magnetic pick up in the distributor here
Oil filter mount and pressure sending unit, and that rear manifold bolt is a stud now, making it easier to attach the transmission filler tube and vent.
That's a new damper plate.
Block and front cover were repainted, the fuel pump is a thing of beauty, but you'll have to take my word on that for now
I really think I got it right this time... but I won't know for sure until it's in the car, and I start it up.
Last edited by davek1661; June 10th, 2024 at 05:45 PM.
You might want to add an oil pressure gauge line now while you have access to the back of the motor. I installed a tee so I would still have the light. It's no fun getting your hands down in there when it's all back together.
Looks really good, you did a nice job. Looking forward to hearing it in the engine running video.
Does the cam gear teeth for the distributor pull down on the distributor shaft ? Or does it push the distributor shaft up when its running ?
I'm going tp say it pulls down on the shaft, because the cam spins clockwise and the distributor is on the right side. I didn't think about, I just tried to follow the instructions. My understanding is there needs to be at least .010" end play to allow for thermal expansion, or the distributor might bind when it heats up.
The engine is in the car. It's a lot more work when you do it by yourself. I had a couple pry bars and a piece of pine all jammed in at different angles at one point trying to get the rear motor mounts aligned. I also got the exhaust hooked up- that took longer than putting in the engine! Can anyone explain the point to the spacers and springs on the exhaust? Why not just bolt it up tight? I'm guessing it has something to do with thermal expansion of the bolts... But what a pain! The springs, spacers, washers... is this really necessary? What's the point?
I was thinking about adding an oil pressure gauge for the peace of mind. Do you have a brand or specific model you used? I'd be interested in knowing what you used.
You might want to add an oil pressure gauge line now while you have access to the back of the motor. I installed a tee so I would still have the light. It's no fun getting your hands down in there when it's all back together.
Looks really good, you did a nice job. Looking forward to hearing it in the engine running video.
So yeah, what did you use? An oil pressure gauge is a good idea...
I used auto meter. Supposedly they are an American company and so far the gauges are holding up. I installed the tri mini set. https://www.autometer.com/1-1-2-3-ga...water-elec.htm
They are 1 1/2", I didn't want them detracting from the dash board.
Yesterday I changed out the plastic tubing and put in the copper kit for the oil gauge and installed the hose adapter for the temp gauge sensor so I don't loose the hot and cold lights on the dash.
I'm going tp say it pulls down on the shaft, because the cam spins clockwise and the distributor is on the right side. I didn't think about, I just tried to follow the instructions. My understanding is there needs to be at least .010" end play to allow for thermal expansion, or the distributor might bind when it heats up.
I was thinking that all those shims you added, weren't needed. So, all the shims you added, do nothing ?
I used auto meter. Supposedly they are an American company and so far the gauges are holding up. I installed the tri mini set. https://www.autometer.com/1-1-2-3-ga...water-elec.htm
They are 1 1/2", I didn't want them detracting from the dash board.
Yesterday I changed out the plastic tubing and put in the copper kit for the oil gauge and installed the hose adapter for the temp gauge sensor so I don't loose the hot and cold lights on the dash.
Thanks. My car has a temperature gauge in the same spot, I thought about replacing it with a 2 gauge mount to include oil pressure, like yours. I'll have to look into it before I get too deep.
I was thinking that all those shims you added, weren't needed. So, all the shims you added, do nothing ?
Well, when you put it that way, yeah, you're probably right. But like I said, I was following the instructions, and the instructions said to make sure the air gap was between .010 and .062. And they came out good. I took the time to grind them down into nice little circles that fit perfectly under the distributor body. I filed the edges to make sure there won't be any sharp edges or filings that come off. And, I checked my distributor free play and now it's down to around .030, rather than more than .060 so I'm okay with that.
So Mista "which way does your camshaft spin"- you're right that it was a complete waste of time, I guess. But it wasn't your time, was it? Tomorrow, I might bleach my underwear. At my age, no one cares if my shorts are white. Even my wife doesn't want to see them, but if it makes me feel good to know my skivvies are white, well that's my time, isn't it? Maybe I'll even post pictures of nice white briefs here, so y'all can see how white my underwear is...
I'm just messin'... you're right I guess. But it's done, and I'm okay with that.
I was thinking that all those shims you added, weren't needed. So, all the shims you added, do nothing ?
Originally Posted by davek1661
Well, when you put it that way, yeah, you're probably right. But like I said, I was following the instructions, and the instructions said to make sure the air gap was between .010 and .062. And they came out good. I took the time to grind them down into nice little circles that fit perfectly under the distributor body. I filed the edges to make sure there won't be any sharp edges or filings that come off. And, I checked my distributor free play and now it's down to around .030, rather than more than .060 so I'm okay with that.
So Mista "which way does your camshaft spin"- you're right that it was a complete waste of time, I guess. But it wasn't your time, was it? Tomorrow, I might bleach my underwear. At my age, no one cares if my shorts are white. Even my wife doesn't want to see them, but if it makes me feel good to know my skivvies are white, well that's my time, isn't it? Maybe I'll even post pictures of nice white briefs here, so y'all can see how white my underwear is...
I'm just messin'... you're right I guess. But it's done, and I'm okay with that.
My point was for someone with a first generation OLDSMOBILE engine not needing the shimming. Keep in mind that someone with an OLDS engine may Google and find your posting. Knowing that they don't need to do the shimming according to the "instructions" and "why" is the important part.
April 11th, 2024, 10:49 AM
