New 347 smokes.....Bad
#1
New 347 smokes.....Bad
The problem: Fresh engine smokes bad and uses oil. Oil on my valves and in my intake right below the carburetor. Smokes a little on start up but really smokes once it warms up. Slowly bringing the rpm’s up will increase the smoke a little. Revving it up and down create a James Bond level smoke screen.
The engine: 302 roller block with a scat 347 stroker kit.
Heads: Flo-Tek aluminum heads. Bought new last summer had them on my 289 for a few hundred miles. No smoke. I had to change the valve springs for the cam in the 347. I went ahead and pulled the valves to clean them since there was some carbon because the 289 ran rich. I just soaked them in simple green and wiped them clean. I did not use a wire wheel on them.
What I have tried so far.
After I put a couple hundred miles on it I ran a compression check(cold) and all of my cylinders were within 10% of each other. I checked my spark plugs and the #5 was the only one that looked a little oily.
I pulled the intake and saw oil on my valves. The heads have pc valve seals, shooting for a quick fix I added some umbrella seals I had available to the valves on top of the existing pc seals. Then put the intake back on. Still smoked.
I have read the HV oil pumps can flood the top of the engine and cause problems so I pulled the pan and replaced it with a stock volume oil pump. Still smoked.
I ran an inspection camera down my intake, still have oil on the valves. At this point I also noticed the oil in the intake right below the carburetor.
I have tried running it without the pcv valve and it makes no difference. I have checked the pcv valve hose does not have oil in it. My valve covers are baffled.
I am pretty much out of ideas at this point, I don’t see any way to get oil in the top part of the intake except the pcv valve. Thanks in advance for any help you can offer.
The engine: 302 roller block with a scat 347 stroker kit.
Heads: Flo-Tek aluminum heads. Bought new last summer had them on my 289 for a few hundred miles. No smoke. I had to change the valve springs for the cam in the 347. I went ahead and pulled the valves to clean them since there was some carbon because the 289 ran rich. I just soaked them in simple green and wiped them clean. I did not use a wire wheel on them.
What I have tried so far.
After I put a couple hundred miles on it I ran a compression check(cold) and all of my cylinders were within 10% of each other. I checked my spark plugs and the #5 was the only one that looked a little oily.
I pulled the intake and saw oil on my valves. The heads have pc valve seals, shooting for a quick fix I added some umbrella seals I had available to the valves on top of the existing pc seals. Then put the intake back on. Still smoked.
I have read the HV oil pumps can flood the top of the engine and cause problems so I pulled the pan and replaced it with a stock volume oil pump. Still smoked.
I ran an inspection camera down my intake, still have oil on the valves. At this point I also noticed the oil in the intake right below the carburetor.
I have tried running it without the pcv valve and it makes no difference. I have checked the pcv valve hose does not have oil in it. My valve covers are baffled.
I am pretty much out of ideas at this point, I don’t see any way to get oil in the top part of the intake except the pcv valve. Thanks in advance for any help you can offer.
#2
did you put the valves back in their original places? or pull them all and then put them back in without marking them for location? I'd think doing a quick lapping of the valves might fix it.
Or the oil control rings on the new short block are not correct and you're getting blow by causing it to smoke. You said you did a compression test cold, they were all within 10% but what was the number- if they all leak the same amount the % diff could be small but doesn't mean they aren't leaking too much. did you try a compression test with it warm since that's when it smokes more?
Or the oil control rings on the new short block are not correct and you're getting blow by causing it to smoke. You said you did a compression test cold, they were all within 10% but what was the number- if they all leak the same amount the % diff could be small but doesn't mean they aren't leaking too much. did you try a compression test with it warm since that's when it smokes more?
#3
Thanks
racer_dave - no, I did not mark the valves and put them back in the same spot. I didn't even think of it. I don't see lapping the valves could help with a smoking issue though, there shouldn't even be oil in that area. I would think if the valves were not sealing that would just cause a compression issue.
The oil rings is a possibility but I wouldn't think that would explain oil on top of my valves and in my intake.
Cold compression test was 145-155. I have not done a warm compression test, trying to get my spark plugs out around my headers with the engine hot will not be a good time, but when I get a chance I will try it.
Thanks
The oil rings is a possibility but I wouldn't think that would explain oil on top of my valves and in my intake.
Cold compression test was 145-155. I have not done a warm compression test, trying to get my spark plugs out around my headers with the engine hot will not be a good time, but when I get a chance I will try it.
Thanks
#5
also check the valve covers. What kind of valve covers do you have. I had a similar issue when i did a rebuild. I put a new set of valve covers and they did not have a splash guard below the hole for the pcv valve and oil was getting sucked into the intake from the pcv valve
Thread
Thread Starter
Forum
Replies
Last Post
whosniffedme
Archive - Parts For Sale
3
05-08-2016 10:35 AM