What am I overlooking on 302 SBF

[1320 BOWTIE]

Thanks for your response. The noise is definately coming from lower. I did check to see if there was any marking on the covers or rocker arms, but I'll check it again.

[PackardV8]

While you're in there, try replacing the high volume pump with a regular pump. I had one on a SBF engine with tight clearances and the pump was fighting the bypass and the cam gear for a long time until the oil was full warm.

[Joe-71]

You didn't say what year 302 you are working on, but you might have a fuel pump eccentric that is wrong, or the fuel pump is starting to have a diaphram problem after sitting while the engine was being built. Fuel pump noise is sometime hard to isolate. Joe-71

[1320 BOWTIE]

Joe-71,
We are using an electric fuel pump on the dyno. Thanks for the response. Hoping to disassemble it this weekend.

[Steve.k]

I just barely noticed shine mark on cover. Very tough to see. Also check the slot in rocker, you maybe also getting close to end of lift slot. A lot of those rockers have limited room for movement.

[1320 BOWTIE]

While you're in there, try replacing the high volume pump with a regular pump. I had one on a SBF engine with tight clearances and the pump was fighting the bypass and the cam gear for a long time until the oil was full warm.

Jack, What sort of noise were you getting? Our's sounds like metal to metal contact and goes away when the oil warms up. We've had this apart 4 times with nothing found. Thanks for your input.
Gene

[pdq67]

An old pdq67 story.

My ol South Bend, IN APGreen Boss sold his, "Discoveror", motorhome to a guy. He started it up and said he could hear a carb leak and I listened and couldn't hear it.

Anyway, long story short, he replaced the stock 390 cfm, 1850 type carb on the 413 MOPAR engine and still thought he heard the noise.

Earlier, he had given me his old carb, plus a 2nd one off it so I had two of them matched. (My Boss had chased this so-called, "noise", before and never found it...).

He was a real prick, but I offered to give him his carb back. He reinstalled it and he said the noise went away and he said, "You mean that you would give me my carb back and I said yes, you gave it to me!". He looked at me kinda funny and said thanks.

AND I NEVER did hear that so-called vacuum leak, "Noise", so go figure.

He gave me the new carb so I still had two of them matched until Doc's f** Stepsons stole both of them!! I always thought that (2), 390 carbs on a SBC 2x4 intake would be nice is all.

I guess what I am trying to say is that it is funny how we chase, "noises", around. Good luck finding it.

pdq67

[Steve.k]

Any luck?

[blackford]

I'll just throw this out there because it can cause the engine to be noisy...Are the pistons in backwards (180 out with thrust face facing the wrong way)?

[JeffD]

Couple things came to my mind, mostly stuff you probably checked:
1. you said you replaced the crank - don't know if early vs. late balance on a 302 crank would cause this issue, would most likely be a bad vibration rather than a knock.
2. cam bearings. did you replace them? wondering if one is loose/wrong in the set the cam could be loose/knocking on one journal?
3. I second the standard volume pump - just from an overall stock engine/stock pan/no need for it/overload the dist. & pump drive
4. does it have a windage tray? oil pan with a welded baffle?
5. loose flexplate should not be tied to oil temperature so doubt it could be that.

just some thoughts.

Jeff.

[1320 BOWTIE]

Any luck?

No luck yet, Steve. We found nothing wrong Saturday. Under close inspection everything looks great. Pistons & rods are facing the correct way. No marks anywhere. We are planning to disassemble the engine Wednesday afternoon.

[Steve.k]

Yes to bad. I hate this type of stuff can be a real bugger to find. Good luck on tear down.

[barnym17]

Have you ever tried lighter wt oil? The noise disappearing when hot could be due to the oil thinning out when hot if it's related to the pump or bypass. worth a shot before disassembly.

[cjperformance]

How sturdy is the bottom of your oil pan? I had a 302W come in about 5 years back with a home made hi vol oil pan, the bottom was almost flat and thin. Anyhow this came in to diagnose a noise, at cold idle or just above it had an odd metallic thump but not in time with engine rpm. After a lot of frigging about , i found it was the bottom of the pan pulling up against the (3/16" clearance!) oil pickup. With hot oil it did not make the noise. Reinforced the pan, gave the pickup about 3/8" plus the gasket clearance and end of problem.

[n2xlr8n]

What about the cam/thrust plate area of the engine. Maybe somebody made some changes that could possibly cause trouble. Does it have the correct thrust plate that's thicker than the one used on the 351C, 400, 460 etc? I was just wondering if the cam couldn't be moving back and forth and making a racket when the pump is working hard and pulling it back too far. Then once the oil warms up the sound goes away.

Another vote for this or the HV oil pump.