• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Is this a cracked head?

mrmolding

FBBO Gold Member
FBBO Gold Member
Local time
2:32 PM
Joined
Oct 3, 2012
Messages
719
Reaction score
532
Location
CA
So I recently got a 70 road runner with a 383 that was rebuilt about 10 years ago. The heads are 440 source attached to a performer rpm. I bought the car with a noticeable tick but I thought it was the air cleaner hitting under the hood since it went away when just idling. I recently got a DP4B intake to get back hood clearance issues and decided I’d play with my sons scope camera after I took off the intake. This might have been a bad idea! I scoped each of the intake ports in the head an noticed that on the right front two ports as you are standing in front of the car, the intake valves have oily goo. Not carbon but fresh looking goo. The rest of the valves look fine. After staring at pics I wonder if this black line is a crack seeping oil. I’ve read about the bad batches of 440 source heads years ago. I also wanted to add that the intake was almost loose. It took no effort to loosen the bolts and all bolts were wet with oil. I included pics of a few valves that look ok. Thoughts?

A10AD2E7-BCD0-42B8-8BEB-2B6B5FDBE989.jpeg 1DF7D90B-681A-49E1-A0D0-549ED2380C4E.jpeg 908C9E7D-9FD4-40E9-A5D0-72E10993AEAC.jpeg AC751732-C230-4EAA-B9F0-474314267699.jpeg 3106C5F9-8017-4DE9-A062-6FC2CEBCCA4D.jpeg
 
Bad valve guides? If they have to come off, the machine shop can tell you.
 
" I also wanted to add that the intake was almost loose. It took no effort to loosen the bolts and all bolts were wet with oil"

Intake gasket not sealing allows oil to get sucked in.. Very common... You tick could be allot of things but the oil most likely is just from the intake..
 
" I also wanted to add that the intake was almost loose. It took no effort to loosen the bolts and all bolts were wet with oil"

Intake gasket not sealing allows oil to get sucked in.. Very common... You tick could be allot of things but the oil most likely is just from the intake..

That might be good news! There was oil pooling around kick down area bolts on intake. Maybe I’ll bolt up the new intake and see how it does. Thanks!
 
Thanks so much for the help everyone! If anyone is wondering the difference in height between a performer rpm and a dp4b (closer to stock), take a look at pic.

D0C9B70F-2123-44F6-AA5D-CEBE9A10975A.jpeg
 
The oil on the valves is either the loose intake which will leak oil and collect on the valve or bad valve guides. The DP4B is a real good manifold for mild to moderate build motor and using 5500 RPM or so. Very flexible.
 
The tick is probably either a lifter or exhaust leak.
It could possibly be a fuel pump pushrod as well.
 
If the tick is louder under load (brake torque) it is most likely an exhaust leak. A stethoscope or piece of rubber hose will find it easily. If using the stethoscope pull the end out and just use the hose and ear set. Probe around next to the exhaust ports. If its leaking you will hear it with pin point accuracy. Use white Teflon thread sealer on the intake bolts. You will have no more puddles. Do not pull the heads . I doubt at this time there is a proven problem with them. Once it's running again allowing the carb to suck some water out of a pop bottle using a 1/4" hose will clean up that chamber and valves.
Doug
 
The oil on the valves is either the loose intake which will leak oil and collect on the valve or bad valve guides. The DP4B is a real good manifold for mild to moderate build motor and using 5500 RPM or so. Very flexible.
Thanks!
 
If the tick is louder under load (brake torque) it is most likely an exhaust leak. A stethoscope or piece of rubber hose will find it easily. If using the stethoscope pull the end out and just use the hose and ear set. Probe around next to the exhaust ports. If its leaking you will hear it with pin point accuracy. Use white Teflon thread sealer on the intake bolts. You will have no more puddles. Do not pull the heads . I doubt at this time there is a proven problem with them. Once it's running again allowing the carb to suck some water out of a pop bottle using a 1/4" hose will clean up that chamber and valves.
Doug

It is louder under load. Thanks!
 
I can often find an exhaust leak by starting COLD and waving my hand near and around all the connections.
Careful though... it doesn't take long before it's hot enough where you can burn your hand.
So it sometimes takes a few tries to check everywhere.
 
I can often find an exhaust leak by starting COLD and waving my hand near and around all the connections.
Careful though... it doesn't take long before it's hot enough where you can burn your hand.
So it sometimes takes a few tries to check everywhere.
You can also plug up the tailpipe momentarily and that could help you locate the leak.
 
It's funny, the tick became secondary after I realized the air cleaner was hitting hood and then I found oil on valve. The tick help is fantastic as well! I reminds me of a header tick so I'll get to that after I put on the DP4B.
 
Looks like a casting line to me.

Oil very likely coming from leaking manifold.

Reseal manifold and forge ahead.
 
Auto Transport Service
Back
Top