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-   -   Need your thoughts.. Engine trouble (http://www.hotrodders.com/forum/need-your-thoughts-engine-trouble-141527.html)

camaro freak 07-06-2008 02:32 PM

Need your thoughts.. Engine trouble
 
We built a 383 SBC that is all fresh using an Eagle kit and used 350 block that was given to us. We had a NAPA shop clean it, do the .030 over bore, inspect the block and freeze plugs and cam bearings. We installed everything following every step in the rebuild book to the point. We installed a roller cam, lifters, and rockers setup. Vortec heads that we bought new and only put about 1,000 miles on them with the previous engine we had. Double roller timing chain set. A nice single plane intake. A new HEI distributor. A new 750 Speed Demon carb. All new wires, plugs, electric fuel pump with reg set at 5 psi. A new dual electric fan setup on radiator. We set timing at about 10 deg then hooked up advance. I noticed there was not much adjusting we can do on the timing before we have problems idling or run on issues so we left it at 10 because it seemed to be happy there. We adjusted the carb per instructions and got the engine to idle pretty good and even accelerated pretty good while setting in park and had no temp problems. We went for a test spin and noticed that when we stepped on the gas we had a hard stumble followed by a fluttering spitting and sputtering that choked the engine to almost dying but then a slight recovery with the engine having just enough power to keep rolling the car but sounding fluttery and sputtering. We traveled about 1/4 mile with it only recovering a little when we noticed the engine temp gauge was buried in the red. We pulled over and shut the car off. We could hear boiling so we just turned on the fans and waited until it cooled down. We started the car and it started good and idled decent. So we decided to just drive it slowly home. We went maybe 1/8 mile and it was pegging the red again on temp. We got it home let it cool. Radiator was half empty. Filled radiator. I started it. Idle was good. I noticed some steam coming from the valve cover breather hole. It didn't seem like that much really just a slight whisper of vapor. The car has Aluminum tall valve covers and I was told that some condensation will form in there. I decided to do a compression test. The lowest was 195 and the highest was 205. I came out the next day and noticed the radiator was half full looked under the car, didn't notice any leaks so I filled it and moved the car off the driveway and to storage for the week. Today I wanted to mess with it some more so I pulled it on to the driveway and after it cooled checked the radiator. Again it was half full. I am not sure where it is going because I don't see any leaks. I added UV leak detector and will fill it again later. I am gonna replace the t-stat this afternoon but I am wondering what is going on?

Jmark 07-06-2008 03:04 PM

If there is no water on the floor but the radiator is always half down, i'd ck the oil pan. Pull the plug and see if water comes out. Doesn't sound too good at this point.

camaro freak 07-06-2008 05:19 PM

plug...
 
Will do that. Thanks

burnt olds 07-06-2008 06:52 PM

Need your thoughts.. Engine trouble
 
when you say moved it , are you running it , or pushing it ?
smell the exhaust ?
sweet smell ?
drill a small hole in thermostat to vent air out so you don't second guess the full mark .
or you can buy the one with small steel ball that vents the air .
is your heater core hooked up , check for fluid under carpet

camaro freak 07-06-2008 07:25 PM

response...
 
Yea I can drive it to move it short distances. It will idle in gear and it doesn't appear to overheat when idling in park. When I hit the gas in park theres an off idle stumble or flutter then it revs up. The engine just don't sound right. The exhaust sounds very muffled for having duel exhaust with an X pipe and super 40s at end. Response is sluggish and it revs slowly. Also, the car had a 350 prior to the 383. The 350 developed an off idle stumble that was very similar to this current problem about 3 months before we built the 383, however it wasn't overheating and we have replaced everything with new parts except the heads, exhaust system, transmission, power booster, fuel lines, power steering pump, electrical wiring, hoses, air cleaner, radiator, all the vacuum accessories, starter, and sending units. These are the only things we reused.

speedydeedy 07-06-2008 07:34 PM

Did you check for water in the oil as mentioned?

camaro freak 07-06-2008 07:50 PM

more...
 
I plan to check for water in oil in the mourn. I just started it and checked both exhaust pipes, it smells rich or lean a little not sure what a sweet smell would be. Pressure from both pipes is good. I put my hand over the carb with it running, covering as much as I could to see if it would stumble or if it would speed up to see if it was rich or lean but I got no change.

camaro freak 07-06-2008 08:19 PM

more...
 
Ok! I pulled dipstick. The oil in the car has about 50 to 70 miles on it. The level was over the full mark by about 2 inches and it seemed very thin. It was almost like sewing machine oil, mostly clear with a slight tan color to it. I poured UV leak detector in the radiator and filled it up. I ran the car until the T-stat opened and the temp went back down and the fans kicked on, about 20 mins. I turned it off and waited about an hour. I pulled the dipstick, slipped the special glasses on and turned the black light on. The oil on the dipstick definitely had a slight green glow to it. Under the black light and looking through the glasses, the oil looked like anitfreeze does to the naked eye. So, am I mistaken in thinking that antifreeze must be getting into the oil? Also, where do I go next with this? Could the steam vapor I seen from the valve cover hole be related to this? Also how can I determine if it's a head problem or block problem?

64chevkev 07-07-2008 01:27 AM

Quote:

Originally Posted by camaro freak
Ok! I pulled dipstick. The oil in the car has about 50 to 70 miles on it. The level was over the full mark by about 2 inches and it seemed very thin. It was almost like sewing machine oil, mostly clear with a slight tan color to it. I poured UV leak detector in the radiator and filled it up. I ran the car until the T-stat opened and the temp went back down and the fans kicked on, about 20 mins. I turned it off and waited about an hour. I pulled the dipstick, slipped the special glasses on and turned the black light on. The oil on the dipstick definitely had a slight green glow to it. Under the black light and looking through the glasses, the oil looked like anitfreeze does to the naked eye. So, am I mistaken in thinking that antifreeze must be getting into the oil? Also, where do I go next with this? Could the steam vapor I seen from the valve cover hole be related to this? Also how can I determine if it's a head problem or block problem?

Just wondering if when you were installing your heads did you put thread sealer on the bolts?? I know the guy who built my 383 used a manual as well (he had never built a SBC only Mopar)must have forgott to and it basically is sounding like the exact same problem only I never got mine to run before I found this out. Definitely drain the oil and if there is antifreeze in it it will be at the bottom. You will notice right away. You can try removing the valve cover and try pressuring up the system with a coolant pressure tester to see if it leaks around the bolts. If it does you will have to drain your system completely (oil and coolant) including draining the block on both sides through the 3/8" pipe plugs. Then you have to remove the head bolts (I did mine in reverse order from the torque sequence)one at a time blow the hole out as best you can and put the liquid thread sealer on the threads and retorque. Once you have all the bolts resealed I would pressure test it again to make sure. I tested my system to 18psi.

This has seemed to work so far for mine so far (only about 500 miles though)and this process was given to me by a very well respected chevy mechanic in town. I'm not guaranteeing this is the problem but it sure sounds like it. Make sure you change the oil at least 2 or 3 more times as well to make sure you get all the antifreeze out.Let me know how you make out.

camaro freak 07-07-2008 07:54 AM

more...
 
The book said to use non hardening permatex sealer on the threads. I used the brown stuff on the bolt threads on this engine but on all the other engines I have built I used the silicone sealer I think the black sealer and I have yet to have one of them have this problem. Maybe thats it. I am headed out now to drain the oil and I ordered a radiator pressure tester last night.

camaro freak 07-07-2008 09:00 AM

latest...
 
Ok. Drained oil. I caught the first pint of oil in a clear plastic bottle. I caught the next 2 quarts in a clean bucket and the rest in another clean bucket. From start to finish the oil looked like any other oil that I have changed in any car. Black and nothing that jumped out at me. I put the oil under the black light and put on the UV glasses. Yea there is a slight greenish glow. For sh..s and giggles I thought what does new oil from a sealed container look like under the black light. Yea the new oil has even more of a green glow under the black light than the oil I drained out! So now I'm not sure if I do have water in there. I am letting the oil samples sit and I will check on them late tonight. If there is water in the oil will it be highly noticeable or is there something I should know?

BBCMudbogger 07-07-2008 09:54 AM

One of your previous post mentioned level on the dipstick 2" above full....how much oil came out of it?

dawg 07-07-2008 10:23 AM

as far as the stumble off the line and seeing its a demon carb remove the bowls and clean out the metal chips (BG carbs are notorius for garbage in the bowl area straight from the factory)
then adjust your pump shot primaries and secondaries
for your fix probly a bigger cam.
as far as the coolant you probly gotta burp the system a bit to really fill the block and radiator.
water in the oil will show up in the pan as a milky mess.

64chevkev 07-07-2008 11:46 AM

Quote:

Originally Posted by camaro freak
Ok. Drained oil. I caught the first pint of oil in a clear plastic bottle. I caught the next 2 quarts in a clean bucket and the rest in another clean bucket. From start to finish the oil looked like any other oil that I have changed in any car. Black and nothing that jumped out at me. I put the oil under the black light and put on the UV glasses. Yea there is a slight greenish glow. For sh..s and giggles I thought what does new oil from a sealed container look like under the black light. Yea the new oil has even more of a green glow under the black light than the oil I drained out! So now I'm not sure if I do have water in there. I am letting the oil samples sit and I will check on them late tonight. If there is water in the oil will it be highly noticeable or is there something I should know?

When you drained your oil it would have looked like straight antifreeze at first if there was any in the oil. How big of a rad do you have?? I know mine takes 15 litres at least by the time you fill the block and everything. I would fill it with the engine running and the rad cap off and bring it up to temp and just keep topping it up if you dont see any leaks. Sometimes squeezing the top rad hose repeatedly helps to work the air out as well

alittle1 07-07-2008 12:22 PM

When you were doing the bottom end, putting in crank and attaching rods, did the rod bolts hit the oil pan rail. And, if it did, who clearanced the bolts by grinding on the block? There is a possibility that whoever that clearanced the block ground too deep and hit the water jacket that runs along the bottom, or came damn close and the block is weeping under pressure.

If you filled the rad up a couple of times and it is still down, you either haven't filled it up full in the first place or the the coolant is ending up in the oil pan and you can't account for the EXTRA oil. Something is right here!


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