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Please help Problem with 74 Roadrunner 318

Daniel M

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Mar 20, 2022
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Location
Hartselle AL
HI i'm new to this forum and I came here for some help. I'll give you some background. So I have always been a Mopar guy and last year I bought a 74 roadrunner 318 auto red with white stripes. When I was a teenager me and my dad restored a 70 Charger R/T and stupidly I sold it. So with dad getting older I wanted to do a project with him again. The body of the Roadrunner is excellent but the motor was acting up so bought it home and decided to rebuild the engine and replace the 2bbl. with a 4bbl. So broke down the engine had it bored 0.30 over, KB167 pistons, compXE cam, new lifters, heads reworked, Melling high volume oil pump and Edelbrock aluminum intake with 600 holley. So now the problem. When first fired it runs good sounds good and after a few minutes is becomes a smoke machine and uses oil. I pulled the intake off and there is oil puddled on top of every valve so I replaced the gaskets thinking they were leaking. I restarted the car same thing. So I then got a cast iron 70 intake from a 340 and tried that same thing again. So as a last resort I put the 2bbl. back on same thing so now I'm at a dead end I have never seen an issue like this. The heads have new seals so I don't think that's the issue but now I'm questioning everything. Any help would be appreciated.
 
Hmmm....so you actually see puddles of oil on top of the intake valves when you pull the intake off and look down the intake ports?
1. Did you have the block's deck and/or the heads' block surface milled? If so, how much?
2. Did you remember to install the valve stem seals? (just look to double check)

It sure sounds like your intake manifold(s) aren't sealing right and your sucking oil into the intake ports.
 
So nothing was milled or decked and I have checked all valve seals are there. I noticed on the for C bodies only forum a guy was having the exact same issue as me but the thread ended without what was done to fix the issue
 
As far as I am aware. Why do you ask? Could that be the issue? This is my first Mopar small block, I have always messed with big blocks so maybe there is something I'm missing.
 
Oil plug installed (directs oil from pump to filter)????
 
Valve guides ok? You should check the intake fit without a gasket, use plastigauge or white grease to check the sealing pattern.
 
yes valve guides were replaced and the intake seal is good on all the intakes I have tried. I just do not understand how it could get this much oil up top.
 
PCV valve could be sucking oil, check the intakes themselves for oil. If you have eliminated the intake seal, and the valve guides/seals, there are not very many ways for oil to get to the intake valves.

Mark
 
I'm starting to wonder if I should pull the heads back off and take them to another shop and let them look at them. I did look and they have new seals, guides and springs. Also the motor did not smoke like this before it was torn down.
 
Are you sure it's oil and not brake fluid? As I said there are not many ways to get oil in the intake, and once you've eliminated each possibility there's not much left.
Might want to try a leak down test just to confirm your seals.

Mark
 
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I'm pretty sure its oil but when I get off work I'll go check I did not think about that. Who knows maybe its that simple. Seems like the simplest stuff is the hardest to find sometimes
 
This is a long shot & most likely wrong, but. Way back when, I had a slant six that sucked a screw down into the valve train. I didn't have time to take it apart so my wife suggested having a local shop do it. Well, they were a GM lover garage and they did get the screw out but...... after I got it back, it smoked like hell, & had fluctuating oil pressure. They took it back & put new oil seals on it and still the same. I asked where they got the head gasket and called them. It turns out that they only sold one type of slant six head gasket. In this case, the the engine was a 1983 hydraulic engine. I found out there are 3 different gaskets & they had put the wrong head gasket on it where the drain back holes were different so the oil pooled up & ran into the cylinders. It was like a mosquito fogger and and drank a quart of oil in less than 100 miles. That was the last time I let anyone do engine work for me. I went out & bought a some metric tools, as I did not yet own any. Then I went to a bone yard and pulled another slant from a wreck for $50 bucks & installed it myself. Problem solved! The point is I am wondering if the wrong head gasket was used???
By the way ............ Welcome aboard!
 
Welcome. Were the guides checked for not being to long with the bigger lift cam.
 
Did you install the rocker arm shafts correctly ?

Welcome to the site. Double checking this is pretty simple. If the holes are pointed up, and considering your high volume oil pump, you could be flooding the valve covers with oil.
 
Welcome to the site. Double checking this is pretty simple. If the holes are pointed up, and considering your high volume oil pump, you could be flooding the valve covers with oil.
So I checked the rocker shafts and took the booster hose loose still smoking.
 
I took the pcv out and plugged the hole then took off the breather and stuck my hand over the opening while at about 2000 rpm and noticed no suction and no build up of pressure.
 
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