HELP Horrible cavitation 97 challenger single 787

[Lifted5.4Lariat]

Well fixed the issue. Finally got time to work on it and you guys were right, it was the carbon seal. I scooted it forward and re tightened the rear clamp. Runs and takes off instantly now. But now I'm having a problem with it sticking at 5k rpms. Raves were just cleaned and put on with all new gaskets. I switched out the plugs since I was running it really rich (broke in top end last tank, 25:1 fuel) and it cured it for about fifteen minutes. You have to drop the throttle to 4500 then punch it for it to get going. Sometimes you have to do that more than once. It sure pulls on the engine now since it gets on plane easy now once I figure out this one last thing I think it will be golden!

 

[Strizzo]

Are you running 25:1 on top of the oil injection? That may be why it doesn't want to clear out on the top end (I think it's supposed to be 100:1 plus the oil injection), but it's easy to check the raves to make sure they aren't sticking to be sure too.

 

[Lifted5.4Lariat]

No I was running 2.5 ounces per gallon in the fuel on top of the oil injection. Now I'm on my third tank and it's still got some oil In the fuel because it's still smoking quite a bit.. At times it won't go over 5k no matter what I try. Then I'll switch out the plugs even though they just have a light burnt look on the porcelain and it makes it to where I'm able to get it above 5k and to wot. Not really sure what's causing it to do this..

 

[Strizzo]

So did you check/clean the raves already? It sounds like it could be rave related but could also be that you're running nearly double oil mix with 50:1 in the fuel plus the injection since you said it was a bit better with fresh plugs? Do they come out oily?

 

[Lifted5.4Lariat]

The plugs don't come out oily after the first tank. The first tank plugs looked nearly fouled but the second tank plugs had just a light brown on the porcelain. I just got done doing a top end rebuild and had the raves machined down at that time and reassembled them with new base gaskets and o rings. If there was a minuscule hole in a bellow would that cause the symptoms I'm having?

Once you get it above 5k and get going 45-50 and say you let off and coast to 20 and then punch it it opens up strait to wot no problem. It's only a problem from a complete stop. It isn't cavitation since I know what that feels like. I would say it feels exactly like a bogged engine.

 

[Lifted5.4Lariat]

Well took it out today. Had about 400 pounds. When I would floor it it wouldn't rev above 5 k. If I brought it back down and hit it again it would maybe go to 5100 then of try it again and it would maybe go to 5200. At times I couldn't get it to go above 5k. But then every once in awhile if you floored it it would hit five then after about 10 seconds slowly pull to 7k and fly off. When it bogs it smokes tremendously but yet my plugs aren't oily, just a medium desirable brown. Really need to get this fixed.. I did take off one of my rave caps and noticed some oil around in there. Could a very slight rave leak cause this? It has the original bellow. Is the bellow the only thing that could cause the oil in the rave? What are the odds of that being my problem?

 

[Strizzo]

oil under the rave cap means there is a leak somewhere. this could be an issue if the leak is big enough that the raves aren't opening like they should. pull the raves and give the bellows a good inspection along with the o-rings and gasket to see if it looks like its leaking.

 

[Lifted5.4Lariat]

I already did.. Nothing looked out of the ordinary except for the excess oil. It also smokes like a freight train when it bogs. It is on its second tank of gas since oil was put in the fuel so it doesnt have much if any oil in the fuel. One thing I have heard of is aligning the oil injection. When I was priming the pump i pulled the lever open all the way when it was first started after the rebuild and the cable came off. I put the cable back on. Could I have messed with the alignment by doing that? The previous owner told me the shop he had it in rebuilt the carbs. I have not checked the high and low speed adjustments as of yet. Is it possible with the air box on? Should I have to rebuild the carbs? Really hoping this is a simple issue...

 

[Lifted5.4Lariat]

So i'm thinking replace the bellow? I cant see anything wrong with it visibly. There is a spring on the top and bottom and I have cleaned it twice since discovering the oil in there.

Sometimes when it trys to start going (after toying with the throttle of course) it will climb to maybe 5500-6k and then say if I hit a wave or something causes an extra pull on the engine it will bog back down instantly to the 5k range. Ussually toying with it after that will get it back up to WOT but sometimes it may take me 2 mins of playing with the throttle to get it up and going...

 

[Lifted5.4Lariat]

Also I'm on my third tank of fuel since the extra oil was in the fuel tank. When it bogs it does smoke a ton, almost more than when the extra oil was in the fuel. Could this be part of my problem as well??

 

[Strizzo]

you can check the alignment of the oil pump linkage pretty easily with a mirror and flashlight. there are tic marks on the arm and the pump that should line up when the throttle is at idle. if its putting in too much oil, it could be part of the issue. if it is out of alignment, you'll need to pull the airbox to get at the oil pump linkage at the carb to adjust the position. i have a feeling that might not be the issue, but its good to check so you know you're getting the proper oil mix. check your high speed adjuster, it should be all the way closed. if it doesn't stop before the little cap hits the end of its range, you might need to pull it off and close the high speed screw. other than that i'm about out of ideas. hopefully one of the more experienced guys can chime in.