460 Ford Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
I have a 1978 460 (C6 trans) with the D3VE heads. Freshly built engine with Comp Cams performance cam, springs and lifters coupled with Scorpion roller rockers. I have discovered an oil leak from the bell housing and have read the horror stories of a rear seal not being installed correctly. I read about the bolt on the upper left side bell housing and it had no sealer on it. I sealed it but the leak is still present. I cannot see the bearing seal on the rear of the crank because of the bellhousing plate prevents a visual without removing the trans. Before I pull the C6 to view the rear seal, I thought I'd eliminate any other areas where the oil may be coming from before I undertake that task.

When heads came back from the machine shop, the right head was missing a plate (or bracket) from the rear of the head. Below picture shows the plate installed before the shop work was performed. This plate was not connected to any other accessories or parts on the engine when I pulled the engine apart. Since the two 9/16" bolts run into the top of the head, I was thinking that those bolts may be where the leak is coming from but I can't get a good view of these bolts as the firewall (and HVAC plenum) is in the way. I cannot see the bolt holes when looking from the top of the head (with valve cover removed) but those bolts might be running through the oil return for the right head.

Can anyone advise what purpose these two bolts and plate serves?
Is is possible these two missing bolts (and plate) are the cause for my oil leak
Bag Woolen Cap Personal protective equipment Luggage and bags
 

·
Premium Member
Joined
·
9,536 Posts
If the thermactor air injection passage is drilled above the exhaust ports simply install a napa 2188 steel cup. One in each end of the casting is needed.








Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
See our products in the Vendor for sale section
Customized crate engines
ParklandAutoMachine.com
R-H-P.biz
"Parkland Performance Auto Machine" Formerly RHP
(253)-988-6648
Log In or Sign Up to View
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #3 · (Edited)
Scotty,

Thanks for your reply!
If the thermactor air injection passage is drilled above the exhaust ports...
Are you suggesting that these two bolts and plate were originally intentioned to support thermactor air injection system? They are definitely above the exhaust ports. See below side view pic.
Gas Circle Audio equipment Cameras & optics Wire

One in each end of the casting is needed
I assume you are talking about the head casting. So, "end of casting" is on the front of the head and back of head. Correct?
Would there be these same holes on the left head as well?
 

·
Administrator
Joined
·
5,050 Posts
Those two bolts & plate were put there because the original OEM tube that took all of the exhaust gasses was taken off and is now gone. Somebody just tried to plug the hole the wrong way. What Scotty was saying was how to plug the hold the correct way. With that said I don't think your oil leak will be there. I'm pretty sure those bolt holes are blind and can't leak because they don't have anything to leak.

You may want to check your rear lifter galley plugs that are above the rear main seal. They need to be put in the correct place with a little thread sealer or they can also leak. You would never notice the front ones leaking because they are inside of the timing cover.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #5 ·
Thanks. I guess I'll be pulling the transmission to check where the leak is coming from unless I can find a way to get an Endoscope Borescope Inspection Camera up behind the motor plate.
 

·
Registered
Joined
·
107 Posts
Besides the top left Trans bolt and valve cover Gaskets, other areas to check, which you may have already...
Rear intake manifold "China wall"
Oil pressure sending unit
Oil pan seal (esp. the one piece type and/or aftermarket oil pan)
Oil gallery plugs (as Chris noted above)
Rear cam cup plug
Rear main oil seal
And... damaged head gasket (at oil drain back hole).
 
1 - 7 of 7 Posts
Top