73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: 1979C20 on May 24, 2011, 01:49:27 pm
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So, I was driving down the highway to go out fishing with my buddy, and I was cruising 60 or 65 at 2600krpm or so. And when I came to a stop sign after a few miles of driving, my truck was idling like crap. It sounded like timing, and like a misfire or two. So I kept driving. When I left the stop sign my truck had zero power. When I got to Saguaro I moved my distributor a bit to see if the problem would change and no difference. When I got home, first thing I did was grab a squirt bottle and spray my header tubes with water to see which cylinders were firing and 3 and 5 were dead. I checked for spark and had it. So I figured maybe I was low on oil, starved the cam of oil and flattened 2 lobes. I pulled my valve cover off and all of my valves were moving equally when I started it. I'm uploading a video of the rocker arms on youtube and will post a link when its done. But, After I checked the valves I thought maybe my vacuum advance was sticking. I pulled my distributor, checked my cap and rotor, and then swapped my distributor with a different one. Still no fire. So I'm not sure what the problem is. I tried a carbon drop, where you rev up the engine and slowly poor water into the carb to try and clear any carbon off of the valves, thats not the problem. I checked for vacuum leaks around those two intake ports, and one of the intake bolts was loose and it sucked in a very tiny tiny amount of the carb cleaner and raised the RPMS but I snugged down the bolt and It doesnt do it anymore. So I'm wondering if there is a hole/crack in my pistons, crack in my block between the two pistons, blown head gasket(not leaking any fluid into one another), cracked or warped head, or even piston rings. My engine has always run very rich. Maybe during this drive and over time it has been fuel washing the cylinders and took out the rings? I need to do a compression leak down test to find where exactly I am losing compression, as I'm sure I am. But I cant find a leak down tester for rent. So, other than what I have listed, What would any of you recommend? The noises I can hear are: A constant ticking sound, and a metallic slap sound in the exhaust when I hold the rpms up a bit. I was thinking, the compression leak wherever it may be is the ticking and the slap sound is piston slap or something? It also sounds like its backfiring through the exhaust at higher the idle RPMS. sorry for rambling. But I really need some help!
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http://www.youtube.com/watch?v=oNI-zHFzDVk&feature=youtube_gdata_player (http://www.youtube.com/watch?v=oNI-zHFzDVk&feature=youtube_gdata_player) here is a link to the video. It was hard to start it because of the 2 dead cylinders. And dont mind the techno, my stereo was on random.
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Compression test should tell you what is going on. Backfire from the carb sounds like the exhaust valves in your 2 suspected cylinders.
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Did you remove and inspect the plugs?
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I forgot to mention that, I replaced the 2 plugs. And its backfiring/thudding in the exhaust, not the carb.
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Harbor Freight has a pretty cheap leakdown tester. Maybe bite the bullet and just buy it ($40 item 94190). Does your motor blow smoke? If so what color? When you had your valve covers off for the video, did you see good oil flow after a few seconds?
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Id start with a compression check and report back the findings for all 8 cylinders.
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My truck always burned oil, it had 60k original miles on the engine when I rebuilt it, but I didnt bore the block and I used stock pistons. So I'm sure it needs to be bored. It goes through 2 quarts of oil in 2-3 weeks. Since those cylinders are dead there is black smoke from all of the unburnt gas. The engine is running very rich now. There was great oil flow. That was the first thing I checked. Its all over my block. Haha. I need to go rent a compression tester and I guess Ill have to buy a leak down tester. I can build one for like 30, but I guess 40 isnt bad.
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I am wondering why oil wasn't squirting out all over without the valve covers on? I didn't see any clips on the rockers that prevent the oil squirting out.....
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The oil was splashing and kind of squirting, but it wasnt SPRAYING. Its all over my headers and the side of my block. Its a high volume oil pump, 30wt oil and the pressure is always between 40-70 depending on temp and how long i was driving.
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Ah...Couldn't tell in the video...
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So did what have you found out? Inquiring minds want to know.
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Im still waiting on a leak down tester. I need to be saving money for the blazer im getting next week so i can have a daily driver and then im digging into whats wrong with my truck. But ill post back as soon as i figure anything out. But i gotta put like 150 bucks into the blazer once i get it for a torque converter, windshield, and registration/insurance.
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So, i went down to harbor frieght today and bought that 40$ leak down tester. Brought my number 3 piston to tdc and hooked it up. As soon as i started putting air in it i could hear it leaking. Set the regulator to about 50 and then checked for the leak and it was coming out of number 5 spark plug hole. And vise versa. So im assuming that means a blown head gasket. Its not burning any oil or water. Theres no water in my oil. so, i jumped the gun and bought a head gasket and intake gasket set. Gonna jump into it tomorrow. Hopefully the gasket will be obviously blown. If it iant ill take the head down and have it magnafluxed.
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Hopefully it's a simple head gasket fix. But check real good to see if it torched the block between the cylinders too. if you ran it very long with the blown gasket, it might have damaged the block surface.
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Okay started digging in today. All i have left is pull the valve cover, loosen the rockers, pull pushrods, pull head bolts, pull temp sensor, then pull the head. It took me about 30 or 40 minutes to get this done but i had to stop to pick my girlfriend up from work. So, ill finish taking it apart tonight or tomorrow.
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Aaaaaaaarighty then. I jumped on into my engine bay tonight. Pulled my powersteering pump off, valve cover, and all the head bolts. popped the head off and flipped it over. The gasket was in fact blown.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-03195101.jpg)
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-03195231.jpg)
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-03195047.jpg)
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-03195302.jpg)
So I grabbed a peanut grinder with an abrasive pad and started cleaning up the head to put the new gasket on. And where the gasket was blown, I found this.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-03200604.jpg)
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-03200617.jpg)
The block doesnt look too bad. The number 5 piston is SHINY!!! I guess it was burning a very small amount of water. Theres a small amount of surface rust where the gasket was missing.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-03195356.jpg)
Better look at the piston, kinda.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-03195415.jpg)
So now I think I'm going to pursue the path of Vortech Heads and Intake.
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not bad man...looking good. keep up the progress
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That one blew real good! Keep the pics a comin man!
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I think you found the problem. What casting are those heads?
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Ill check the casting as soon as i get home for ya, grim. Theyre the stock 79 350 heads.
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Snapped a pic of the numbers real quick.
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Okay, my dad picked up a set of stock 350 heads from a friend of ours for free basically. I just have to buy him a 45 dollar soft top for his CJ-7. Now, these heads are ugly. The spark plugs are kinda rusted in from sitting, covered in paint, and just gross. Im going to take them to the machine shop and have then crack checked and gone through, but should i take them my heads and use the parts from my heads on the new ones? Springs, valves etc? My heads were just gone through a year ago so i know the parts are good. Should i have them use the best parts from both sets? What do you guys think?
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Popped the other head off. I talked to my dad and he said it would make sense to take both pairs of heads to the machine shop and have them use the best parts to make two heads.
Pulled the other valve cover, nothing out of the ordinary.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-07174528.jpg)
Rocker arms and pushrods off.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-07184652.jpg)
All of the head bolts and the head off. I took a dead blow hammer and smacked it under the intake ports at the front and back of the engine to break her lose then wiggled her off.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-07185909.jpg)
Nothing wrong with the Head gasket and nothing wrong with the head(as far as I can tell).
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-07190112.jpg)
On the number 7 and 8 pistons, the head bolt in the middle end corners were soaked in oil. So I'm assuming that since I didnt use any thread locker on the head bolts when I assembled it, oil leaked past the threads into the cylinders.
Casting number of the new(to me) heads.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-07190651.jpg)
The new to me heads. Poor spark plugs. And the heads were sitting in the rain for a few years(I live in Arizona, so they didnt see MUCH rain).
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-07190715.jpg)
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-07193356.jpg)
Most of my parts under my bumper.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-07190951.jpg)
My mess of an engine bay.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-07191009.jpg)
And the passenger side mating surface. Doesnt look too bad.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-07191025.jpg)
Now, what can I have the machine show do to these heads to make them better flowing and increase my performance but not break the bank? Just something simple.
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I looked up the casting numbers of the heads.
My old heads:
Casting # 462624
Year 76-87
Engine application 350
Valves 1.94/1.50 or 2.02/1.60
Horse power range Not listed(horse power of engine rated at 350hp stock)
Chambers 76cc
Notes PRONE TO CRACK
New to me heads:
Casting # 333882
Year 70-80
Engine application 350 or 400
Valves 1.94/1.50
Horse power range 150-180
Chambers 76cc
Notes Intake flow 137.2 CFM Exhaust flow 95.4 CFM
Will these heads be safe on my engine considering the fact they are rated at 150-180hp and my engine casting number said 350hp 4 bolt main in a truck?
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From what I have heard, the notes on the 882 heads should read 'prone to cracking'. I have a set of them on my 406 currently being reworked for a bad valve guide, but they have been worked before and I was told they have 2.02 valves in them. That motor makes 400+ hp and they worked fine until oil started pouring into one of the cylinders through the intake valve. When I get that motor in the next project I will be waiting for them to crack...
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Grim, the 882's are prone to cracking as well??
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Everything that I have read or heard about them leads me to believe that they have terrible flow characteristics and yes, they are prone to cracking.
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Well, for some hand-me-downs, and a vehicle for a little while longer they will have to do. Theyre working for you alright though?
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They did for about 2k miles until the valve guide started leaking but that's not really related. I pulled that motor and put in my 355 with 993 heads, which may not be any better, I haven't researched them. They're probably all about the same. Eventually I would like to put some vortec's on both of those motors but you have to work with you have and what you can find cheap sometimes. As far as HP though you should be fine running those heads. They just don't like a lot of heat.
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Well, Its odd because my truck has never gotten hotter that 220, for like 5 miles before I realized my heater core was leaking and the radiator was 1/4 full. My truck normally sits between 175-195 with a 180 t-stat. So I honestly dont know why it cracked, or if that heat was the problem. And if that heat was the problem, why didnt I have a problem sooner?
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Could be this, or maybe it had just finally seen enough heat cycles:
http://forum.73-87chevytrucks.com/smforum/index.php?topic=18711.0
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I would assume heat cycles.
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Took them to the machine shop. He said that the 883's are an older cast so it may or may not have hardened seats. And they 883's arent quite as notorious to crack. They are thicker, the 624's have material removed around the water ports to lighten the head, which makes them weaker and makes them run hotter. So, hes going to pull apart the 883's and check them out. Going to.use whichever parts he may need from my 624's. Going to be about a week or 2 since theyre busy. Ill post back findings.
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Okaaaay! Just called up the machine shop to check progress. Bill, at B&B Machine in Mesa is a customer oriented business man. I went there for my machining when I rebuilt my engine, crack check, heads gone through, block crack check, vats, replace worn valve seats, walked away at 320$. I had problems with getting oil pressure when I brought the engine home and eliminated the oil cooler and know there was oil flowing, but no pressure. I pulled the engine twice thinking I had it fixed and being wrong. I called the machine shop and BIll and Mike came TO MY house and found they accidentally put a metric sized plug in the oil passage way and they fixed it on the spot. Well, When I called and talked to Bill, he said my heads need valve guides and hardened seats installed because they are 70's heads, gonna run me 435$. Then, he said "but since I dont know what happened to the other set of heads, I dont know if its something you did wrong or if its a crack we missed, so I'm going to cut that price in half for you". About 220 And he said he should have them done this afternoon. If you guys ever need machining around Mesa, Go to B&B! And you can even tell them Kyle Taulton recommended you and he might give you a bit of a deal, but dont quote me on that.
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That's a steal! Hope they work well for you.
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great to hear theres still some stand up people out there.
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Okay! Picked up my heads yesterday at 430. Brought em home, got them all torqued down and got the valves adjusted. I used a remote button on the starter to turn the engine to compression for each piston, and cranking the engine caused my fuel pump to fill up the lines and when i was finishing up the last 2 pistons, fuel started puking out of my carv all over.my.wngine bay. My carb is sitting on my passenger wheel well with the fuel line still hooked up. so, i didnt feel confortable pressing the button anymore because i didnt want to explode. I unhooked it from tbe battery and called it a night.
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Looks good, but you didnt paint them?
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I called the machine shop and BIll and Mike came TO MY house and found they accidentally put a metric sized plug in the oil passage way and they fixed it on the spot. Well, When I called and talked to Bill, he said my heads need valve guides and hardened seats installed because they are 70's heads, gonna run me 435$. Then, he said "but since I dont know what happened to the other set of heads, I dont know if its something you did wrong or if its a crack we missed, so I'm going to cut that price in half for you". About 220 And he said he should have them done this afternoon. If you guys ever need machining around Mesa, Go to B&B! And you can even tell them Kyle Taulton recommended you and he might give you a bit of a deal, but dont quote me on that.
I don't mean to be a jerk, but it sounds like this guy rebuilt your new heads wrong and lost your old heads. I'll give him points for honesty, but I'm not really seeing a good reason to give him any business. I hope you don't find out other stuff he did wrong the hard way.
I hope you get it all sorted out but you might consider avoiding this guy in the future.
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I called the machine shop and BIll and Mike came TO MY house and found they accidentally put a metric sized plug in the oil passage way and they fixed it on the spot. Well, When I called and talked to Bill, he said my heads need valve guides and hardened seats installed because they are 70's heads, gonna run me 435$. Then, he said "but since I dont know what happened to the other set of heads, I dont know if its something you did wrong or if its a crack we missed, so I'm going to cut that price in half for you". About 220 And he said he should have them done this afternoon. If you guys ever need machining around Mesa, Go to B&B! And you can even tell them Kyle Taulton recommended you and he might give you a bit of a deal, but dont quote me on that.
I don't mean to be a jerk, but it sounds like this guy rebuilt your new heads wrong and lost your old heads. I'll give him points for honesty, but I'm not really seeing a good reason to give him any business. I hope you don't find out other stuff he did wrong the hard way.
I hope you get it all sorted out but you might consider avoiding this guy in the future.
No, he actually had both sets of heads. He asked me if i wanted the old ones back, even. I yold him to keep them for the parts because i dont want to store them. He is an honest hard working customer oriented business man. If he wasnt he wouldnt have been in business for 15+ years.
Beastie, no i didnt paint them, because i dont know how long it will be before i have to start over from scratch on the motor. I should have bored the engine when i first built it, but i was an impatient teenager and wanted a truck. So the cylinders were pretty scratched from the pistons slopping around. And i need my truck back, my parents are getting impatient that i keep having to borrow vehicles. So i figured skip the hassle of painting them and throw em in there naked. The match my water pump now, as it was replaced a few weeks ago due to a hole in the back plate.
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Alright! Finished up puttin her together today! One thing that i am extremely upset about, and about to go to checker and raise heck, when i first started it up to time it and get water in the block, the temp gauge raised to about 160 so i figured the tstat opened. I filled the rad to the top and started her back up to adjust the idle and look for vacuum leaks if any. Took me avout 10 mins. I went back and looked at the temp gauge. 260. Oh S***. The machine shop installed little warranty tags on the heads, and the center of the tag will melt out of it if the temperature goes above 260° well, sure enough, they started melting, which may void my warranty. So i popped the water neck off and pushed the center of the tstat down with a screw driver and it started steaming and most of the water drained out of the radiator. I just replaced the tstat like 2 months ago, and it seized and could very possibly have damaged/warped/cracked my brand new(technically) heads. So i pulled it out and my truck is running at 180 steady. Im very unhappy. Checker will be buying me a new engine if anything is wrong with my heads. I will make sure of it. on a second note, i finished putting my truck back together, and drove it about 8 miles tonight. Im amazed with the power it has with the taller tires on the rear. It doesnt have as much off the line acceleration, but i spun the tires all through first gear and halfway through second, at about 3n4 throttle and easy acceleration off the line. I will post pictures tomorrow when i get to a computer for photobucket.
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I'm going to repost a few pics just so its easier to follow, and because I uploaded the others and I'd rather post the IMG code.
Got the sexy heads back from the machine shop.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-17170705.jpg)
Slapped em on and torqued them down. there is a specific torquing order for the bolts, from the center out in a clockwise spiral. and I
torqued them in a certain pattern, 30, 50, and then 65, in the special order.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-17202420.jpg)
Got the pushrods and rocker arms in and adjusted. Bring the cylinder to TDC compression and then tighten the rocker nut while turning
the pushrod. When the pushrod stops turning, turn the nut another 1/4 turn.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-17210623.jpg)
Set the intake gaskets on with a thick bead of RTV around the water port corners, both sides of the gasket.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-18182913.jpg)
Got the intake torqued down to 30lbs. and the carb bolted on and vacuum lines ran.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-18185257.jpg)
Valve covers on.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-20160407.jpg)
The fitting for the temp sensor to the block was out of round some how. /:
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-20160328.jpg)
Quick fix with a bench vice. (:
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-20160706.jpg)
And here is that warranty tag, you can see the hole in the middle where the metal melted out, I'm guessing its something soft like lead
or some sort of solder. It dripped on the head and the motor mount clam shell.
(http://i1230.photobucket.com/albums/ee497/1979c20/2011-06-20185657.jpg)
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I've put several top ends together and I admit its been a while, but I don't think I've ever seen the rtv around the end water ports. The only rtv I thought was required was on the front and back if you do that instead of using the small gasket pieces ??? I'll have to look it up soon myself, but on the rocker nuts I thought it was zero pushrod play and then 1/2 turn?
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I looked around all over the web and i read that with hydraulic lifters to take it to zero play and another 1/4 turn. The rockers arent rattling, so it should be fine.
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I've put several top ends together and I admit its been a while, but I don't think I've ever seen the rtv around the end water ports. The only rtv I thought was required was on the front and back if you do that instead of using the small gasket pieces ??? I'll have to look it up soon myself, but on the rocker nuts I thought it was zero pushrod play and then 1/2 turn?
+1, zero lash and 1/2 turn.
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I've put several top ends together and I admit its been a while, but I don't think I've ever seen the rtv around the end water ports. The only rtv I thought was required was on the front and back if you do that instead of using the small gasket pieces ??? I'll have to look it up soon myself, but on the rocker nuts I thought it was zero pushrod play and then 1/2 turn?
+1, zero lash and 1/2 turn.
well, im mot pullin the covers off now. When i first built the engine my dad told me zero lash, then back it off 3/4 turns. Maybe thats why i have a bit more power now.
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I've put several top ends together and I admit its been a while, but I don't think I've ever seen the rtv around the end water ports. The only rtv I thought was required was on the front and back if you do that instead of using the small gasket pieces ??? I'll have to look it up soon myself, but on the rocker nuts I thought it was zero pushrod play and then 1/2 turn?
+1, zero lash and 1/2 turn.
well, im mot pullin the covers off now. When i first built the engine my dad told me zero lash, then back it off 3/4 turns. Maybe thats why i have a bit more power now.
So you are saying you set zero lash, then BACKED off 3/4 of turn??? With hydraulic lifters....
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When i first built the engine, yes. I guess my dad didnt realize they were hydrolic.
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What about the rtv on the intake gasket? Anyone else seen that or advise doing that?
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I use the side gaskets as-is and use The Right Stuff gasket maker in the front and back instead of the rubber S-gaskets. RTV works too but I don't apply any to the faces of the side gaskets. Make sure to put some on the bolt threads or oil will leak up around them.
zero lash and a half turn
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Okay guys, just a quick update. In the WEEK I got to drive my truck before I lost my license for 3 months, my truck ran great! Ran at 200 pretty much all the time in the heat and 180 at night. I need to put water in the radiator as its about 1/5th low. I need to remove my oil cooler and get a standard oil filter adapter because my stock oil cooler lines are leaking pretty bad and I dont like it much. I lost 2 quarts in the week or so I drove it and i know it leaks. It has disgusting power now. I turned a corner and 1/4 pedal accelerated to 10 mph then nailed the throttle and squealed the tires through 1st gear, broke them loose again and burned 'em halfway through second. So im starting to thonk my truck always had conpression issues in those 2 cylinders. And, the 883's are consodered "the best of the worst" when it cones to flow.