460 Ford Forum banner

1 - 20 of 29 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter #1
Hello B B ford people. I built a 1971 429 engine using a used set of M-6049 A429 cobra jet heads that where all gone thru at a machine shop.
After running the engine up to temp 230 F starting leaking oil from the rear lower corner. don't know if it coming out between gasket and head or gasket and block
I used fel-pro gaskets and ARP head bolts. started engine a few more times total run time around 30 mints with no sings of a coolant leak inside or outside of engine.
Did i use the wrong gaskets or did the machine shop do a poor job on the heads. I had the block bored and checked out at a local machine shop.
Thanks
 

·
Registered
Joined
·
298 Posts
Make sure and check the valve cover first. The oil puddles up in the back lower corner and if that isn't sealing right, it'll leak.
 

·
Premium Member
Joined
·
257 Posts
Need more information, when you say leaking from the corner what do you mean? And where exactly do you see the leak? At the corner of the valve cover? Head? or down lower on the block? There are a few places the oil could be coming from. Check where the intake manifold meets the heads and china wall, real common to leak in the corners if not sealed correctly. Also, is the engine in the car with the transmission attached? If so check the two top transmission bolts, one of them, I believe the driver side, the hole for the bolt goes all the way through into the valley of the engine, if you don't put sealant on it that is another common leak. Check to be sure the oil pressure sending unit isn't leaking as well. And as mentioned above double check the valve cover gaskets. I recommend using the corklam valve cover gaskets.
 
  • Like
Reactions: dacofa

·
Registered
Joined
·
374 Posts
I always use a dab of silicon between the china wall and head to stop leaks there on the corner, plus I always use silicon on the china walls. That china wall set up on Fords is an enginening nightmare to keep from leaking.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #5
oil leak
Thank for all the great answers leading me in the right direction. I have checked and double checked all spots that it might be coming from.
I have a good video of the exact spot when it starts leaking please watch it
 

·
Registered
Joined
·
298 Posts
Unfortunately, it looks like head pulling time. Other side No Problem? But I'd look real close at the int/head mating corner that it might be coming from there and running down the back of the head to that corner. There is a gap in that back area it might be coming from. Or the head gasket that seals the oil return hole is torn, broken, etc and not sealing that hole properly.
 

·
Premium Member
Joined
·
257 Posts
I've watched that video a bunch of times, at the very beginning of the leak it clearly looks as though it is coming from up higher, watch closely at the very right side of the head block for where the first drop originates from. It looks to me as though the oil is following the gap between the head and block created by the gasket, it comes down the side of the gasket between the two then comes out onto that flat spot on the block. I would get a mirror back there and look real close at the intake head joint as mentioned above, you might only have to redo the intake manifold and china wall areas.
 
  • Like
Reactions: dacofa

·
Premium Member
Joined
·
9,311 Posts
There is a very small space between the head and the block right at the corner of the china wall. The head gasket does not come all the way to the manifold sealing surface.

Even if you silicone around all water and intake ports on BOTH sides you have to push silicone into the area at the corner where the gasket and head gasket meet but don't touch.

If when beading the china wall you don't get silicone into that small crevice it WILL LEAK !!!






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
Parkland Auto Machine
 

·
Registered
Joined
·
13 Posts
Discussion Starter #10
It sure looked like I had a good amount of ultra black in the corner . There was definitely oil under the head gasket on the back edge and bottom edge you can see it on the block it looks like the gasket is oil soaked
 

·
Registered
Joined
·
298 Posts
What does it look like at the drain back hole? I think that's where your problem is. That's to much oil to be coming from a small hole at the corner of the China wall. That would also be running down the backside of the block.
My money is on the drain back hole area being your problem source.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #13
It looks like the drain back hole in the block has a small ledge 1/8 inch down inside the hole.I don't think that would be the issue. If you look close at the block around the cylinder you can see there is oil there .
IMG_20210331_021742473.jpg
 

·
Registered
Joined
·
298 Posts
Just for fun (sarcism), use some brake cleaner or other stuff and clean the head/block surfaces, bolt the head on with the old gasket and pour a little oil down the drain hole in the head and see what happens. Also if you have a "machinist ruler, 6" or otherwise, try that against that gap on the block. That lip shouldn't make a difference only to slow flow some.
 

·
Registered
Joined
·
298 Posts
Are you referring to the hole in the block or the head
What does the head drain back hole look like? How well does the gasket mate up with head/block and the gasket doesn't overlap any where?
 

·
Registered
Joined
·
3,913 Posts
Hello B B ford people. I built a 1971 429 engine using a used set of M-6049 A429 cobra jet heads that where all gone thru at a machine shop.
After running the engine up to temp 230 F starting leaking oil from the rear lower corner. don't know if it coming out between gasket and head or gasket and block
I used fel-pro gaskets and ARP head bolts. started engine a few more times total run time around 30 mints with no sings of a coolant leak inside or outside of engine.
Did i use the wrong gaskets or did the machine shop do a poor job on the heads. I had the block bored and checked out at a local machine shop.
Thanks
230 is too hot
 

·
Registered
Joined
·
13 Posts
Discussion Starter #17
Gasket lines up with the drain hole in the head and in the block just like it's supposed too. Yes 230 f is hot . wanted to run it as long as possible trying to solve the oil leak imm having.
IMG_20210331_225941924_BURST001.jpg
 

·
Registered
Joined
·
298 Posts
I would bolt the head down and pour some oil down that drain, just to elimanate it from the problem source. Then just keep moving up the engine. Was any oil pooled up on the back of the block anywhere?
 

·
Registered
Joined
·
13 Posts
Discussion Starter #19
I did bolt the head back on poured oil down the hole many times waiting for a leak it did not leak. There was no oil on the back of the block the pictures I took of the back of the engine are right after I pulled the engine out did not clean anything thank you for all the advice.
 
1 - 20 of 29 Posts
Top