Guys,
I finally got my engine back a few months ago and after putting it back in the car and getting it fired up I heard a small knocking in the car. Obvioulsy it was not normal sounding so after about 20-30 minutes of getting the car fired up and thinking maybe it was some timing problem it never went away. So I took the car back to the engine builder and let him take a look. He just called me back today and let me know that it was just the dipstick had pushed into the windage tray and was causing a rod bolt to get into it slightly.

However, he did tell me that the oil was quite a bit blacker than it should have been for no more than the car was ran. to the point it had made the bearings shiney and he went ahead and put a new set of bearings in. he said he noticed a bit of fuel in the oil and said that it was most likely due to excessive fuel bleed off from the carb. He isnt a quadrajet guy and suggested that i get it tuned to the car, or call Quick Fuel and get them to suggest a carb. My cam is a larger roller cam and requires a little bit richer of a mixture, and i could definately tell it was rich when i was trying to first get it fired up, almost to the point it was burning my eyes.

The quadrajet in the car currently was set up by Mark from M&J PROFORMANCE. I honestly dont know how to confirm if it was indeed tuned or not, but i dont have any reason to think he would have lied to me. It was supposed to have been set up based on all the car specs that i have to him. He also ported the heads.

The car is set up with the following.
Cutlass 442 W30 body
Eagle Stroker kit w/block bored .030 for a 488ci engine.
3:42 rear end gears
4 speed transmission
RobbMC mechanical fuel pump.
Edelbrock Performer RPM intake
Erson custom roller cam (from CutlassEFI)
1.6 ratio
Net valve lift intake .558/exhaust .534
Dur. @ .050 intake 230/exhaust 242
Lobe separation 108
Car is mostly only driven on the street. Much more of a show car that I want to be nasty between stoplights around town. May see the track 2 or 3 times a year at most.

My questions:
1. Is the quadrajet the right carb for my setup or is it a bit small?
2. is the fuel in the oil from the carb being too rich? If so how might i lean it out? And how will i know that i have it correct?
3. I called quick fuel and their tech suggested a Q-850 carb for my setup. Does this seem too large for what i am trying to do. Only reason I ask is that the engine builder mentioned something about 650-750cfm with the smaller cfm giving better low end torque but sacrificing the all out HP, and vise versa on the larger cfm. I was just kind of thinking the 850 may be big, but I assume no one knows their carburetors like the tech's from the carb company, right?
4. Is quick fuel a brand any of you have tried and would recommend?

I am not opposed to changing the carb if need be. The most important thing about my car is that i dont ruin the engine by breaking down my oil with gasoline. But at the same time i dont want to spend $700 on a different carb if i dont need to.

Any help you guys can offer is appreciated.

 

What kind of fuel pump are you using ?

 

Rochester carbs have been used on stock and performance engines for the last 1/2 century. What you need to figure out if 1, the carb is in fact loading your oil with fuel and 2, is it set up right for your application.

What is your fuel pressure? Is it the pump that's leaking? Is the float too high? Is the carb running rich as per an A/F tester? The smell test @ idle is not a good gauge of a rich condition. Is the timing correct? JMO

 

Electric fuel pump or mechanical? If it is mechanical, then it may be a ruptured diaphragm. If electric be sure to have a fuel pressure regulator and set it to around 5 psi.

 

The fuel pump is the RobbMc mechanical fuel pump. I'm not sure if it is faulty but it was brand new when put on the engine and has only been run 30 minutes or thereabouts. Any quick way I'd be able to tell if the diaphragm is ruptured?

I do not have a pressure guage on the fuel line, but would you expect the pump I have chosen to vary greatly from stock? What pressure do I need to set it at? Timing is around 34 degrees but drops off to around 13 at idle.

 

The Robbmc pump is supposed run at 7 #'s max pressure. But if for some reason it goes higher the Rochester carb may flood. With the car idling and looking down into the carb, do you see any dribbling of fuel? Also repeat this exercise after about 5 mins of turning your engine off when it's hot. Are you still running points?

 

I would check your mechanical fuel pump As GAoldsman stated. It might have a bad / ruptured diaphragm. Just because it's new doesn't mean its not defective.

 

I am running the pertronix electronic points replacement. I kept the same distributor but swapped the points and coil out withthe pertronix kit. I am going to pick the car up today from the engine builder and i will take a look at the carb when it is idling to make sure there is no dribbling of fuel. Probably the best bet for me is just to go ahead and take it to someone who knows how to work on Q_Jets. I would like to keep it as stock looking as possible and keep money in my pocket instead of having to shell out for a new carb.

It sounds like you guys think the issue may be able to be fixed without having to replace the rochester which is OK with me.

I will check the fuel pump before i take it to anyone just to make sure its not something easy to spot before having a professional look at it. Will it be obvious to see the diaphram is ruptured if it is?

 

Oh great, another guy who thinks "it has a Q-Jet, thats the culprit to EVERY problem"! I would think if there was that much fuel in the oil after only a half hour run time, and was coming from the carb it would have to be bad enough that it wouldn't run. A much more likely cause would be the fuel pump. I would defiantly look into that.

 

[QUOTE=matt69olds;603232]Oh great, another guy who thinks "it has a Q-Jet, thats the culprit to EVERY problem"!QUOTE]

Actually I am not another guy that thinks a quadrajet is the only problem. I just know I have a fuel issue and guess what is one of the major components to a fuel system... that's right, you guessed it, a carburetor!!! I will do my due dilligence to go over all the components, but in fairness there is a wealth of information from people on this site that have already gone through trials and tribulations with their cars that may be able to shed some helpful light on my situation.

No one is blaming the Q-Jet. I just know that for higher performance they do need to be tinkered with, which mine supposedly has been. From the descriptions about my car and situation I just need to know if it is right for my application or where other potential problems may come from.

I dont necessarily like being grouped into a category that makes me seem like I am blaming some issue on brand, bias, popular opinion, abuddy of my cousin had one and it didnt work, etc. I am simply looking for help to let me know if there are tricks I dont know that can keep money in my pocket.