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Massive Oil Consumption

nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
Joined
Jul 31, 2001
Messages
8,615
Many factors determine gap as was stated earlier- ..broncobowsher correctly stared one of them-bore size. We are assuming just regular old Bronco use...?

Piston composition- most manufacturers will state the clearances needed for cast, hypereutectic, forged as they are all different specs...whether the engine is designed for nitrous, red line rpm use or street, block material...lots of variables.

Call the piston manufacture to verify their specs for your use.
 
OP
OP
77RHINO

77RHINO

Full Member
Joined
Feb 22, 2011
Messages
308
I just dropped the block and heads off at the machine shop, and left most of the pistons in there so they could see what I was talking about. They are going to check everything out and get back to me in a couple days with some answers. Thanks again for all the help, I will keep this updated once I get more info!

Ryan
 

englewoodcowboy

Lick Creek Restorations
Joined
Jul 25, 2010
Messages
4,200
Hopefully they will turn it around quickly for you. We had an over heat issue on the red ranger we dod for a customer and our machine shop turned it around in a week for us so we could get them back on the road. Hang in there, you will find the cure, we always do.
 

offrdude

New Member
Joined
Feb 26, 2018
Messages
9
rings are a possibility but not likely. for the kind of consumption you are talking about. all external oil leaks must be repaired first to get an accurate oil consumption. i agree with the most that oil is probably sucked through the intake or valves i would make sure it is correct there. for the rings to be doing that they would have to be the wrong rings and yes i have seen that before.
 

73azbronco

Contributor
Bronco Guru
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Nov 11, 2007
Messages
7,796
The pistons are marked .030, my rings are .017 right at the top of the cylinder, but open up to .020 once its down in there an inch. With the #6 piston at TDC (just picked one), I have roughly a .021 gap, measured with a feeler gauge. This was my first engine to build, so I have been learning as I go with it, and assumed the parts I received were accurate.
Uhhh, yeah, thats not right.

I push the ring in with a piston with no rings, ensures a squared up ring.

Should not have that much taper/change on a bored out motor. I would say if it was 20 at the bottom, maybe, but not an inch. I bet your check just was not square.

Any word from machinist?

I'm still betting bad PCV setup, not enough baffle, based on your compression numbers on OP. You don't have those numbers with a bad cylinder, usually.

What was the idle vacuum pressure?
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,835
rings are a possibility but not likely. for the kind of consumption you are talking about. all external oil leaks must be repaired first to get an accurate oil consumption. i agree with the most that oil is probably sucked through the intake or valves i would make sure it is correct there. for the rings to be doing that they would have to be the wrong rings and yes i have seen that before.

Must have missed the first 4 pages of this post. We are already finding that the bores have some funkiness going on. Everything else has been looked at. It is already apart and at the machine shop. We are all just waiting to hear back on what they find.
 
OP
OP
77RHINO

77RHINO

Full Member
Joined
Feb 22, 2011
Messages
308
I took it to Precision Auto Machine here in Bham, they were recommended by a local customs shop that I've used a few times. I haven't heard anything back yet, but don't expect to until maybe tomorrow or Monday. By the looks of his shop, he must be the go-to guy for engine work.

IIRC idle was around 14-15 around 650 RPM. At one point during my PCV tests it was 18-19, but I want to say the PCV plumbing and carb settings were different. I have done different valve covers (for baffles), breathers, filtered caps, deleted PCV, changed carb metering rods and springs, etc., all making different numbers while chasing this issue. Once I can get it back and assembled I will post that information up.
 

Mikesimp70

Full Member
Joined
Jun 20, 2017
Messages
341
I took it to Precision Auto Machine here in Bham, they were recommended by a local customs shop that I've used a few times. I haven't heard anything back yet, but don't expect to until maybe tomorrow or Monday. By the looks of his shop, he must be the go-to guy for engine work.

IIRC idle was around 14-15 around 650 RPM. At one point during my PCV tests it was 18-19, but I want to say the PCV plumbing and carb settings were different. I have done different valve covers (for baffles), breathers, filtered caps, deleted PCV, changed carb metering rods and springs, etc., all making different numbers while chasing this issue. Once I can get it back and assembled I will post that information up.

Any word?
 
OP
OP
77RHINO

77RHINO

Full Member
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Feb 22, 2011
Messages
308
No updates to report, the heads were being checked out this past week and they were switching some tooling around to do to V8 blocks this week. I'm not gonna rush them on something like this though, too important for them to half-ass it to get it out.

Also, we just had our little girl so I've been tied up with her anyway!

Thanks,

Ryan
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,355
Wow! Congrats dad!
Now instead of you messing with your trucks head, she's gonna' be messing with your head for the next fifty years or so!

But have fun anyway. Won't be long before she wrestles your Bronco from you anyway.

Paul
 

Mikesimp70

Full Member
Joined
Jun 20, 2017
Messages
341
Also, we just had our little girl so I've been tied up with her anyway!

Congrats! Enjoy that little one, it really does go by fast!

My girls are both teens now and thats a whole different kind of fun! (And expense).
 

73azbronco

Contributor
Bronco Guru
Joined
Nov 11, 2007
Messages
7,796
So they are "fixing" it, but did they identify why the consumption?
 
OP
OP
77RHINO

77RHINO

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Joined
Feb 22, 2011
Messages
308
Thanks guys! She's been really good, were trying to teach my toddler son that she's not a playtoy and he can't be too rough!

I've got all the parts back, and found an expensive lesson in all this. When ordering rings, make sure you get a complete set and know what to look for! I had the top two, and the oil waffle rings, but not the oil tension rings that go with them. Bags were labeled 1,2,3, and should have had a 4th bag with the additional rings. I've never been that deep in an engine before, and didn't know I had an incomplete set. Everything has since been cleaned up, new cam bearings have been installed, and I'll be starting reassembly this weekend!

On a good note everything was wearing well, he gave it a light hone and the heads checked out good, so now I should be set.

Thanks for all the advice!

Ryan
 

Mikesimp70

Full Member
Joined
Jun 20, 2017
Messages
341
Thanks guys! She's been really good, were trying to teach my toddler son that she's not a playtoy and he can't be too rough!

I've got all the parts back, and found an expensive lesson in all this. When ordering rings, make sure you get a complete set and know what to look for! I had the top two, and the oil waffle rings, but not the oil tension rings that go with them. Bags were labeled 1,2,3, and should have had a 4th bag with the additional rings. I've never been that deep in an engine before, and didn't know I had an incomplete set. Everything has since been cleaned up, new cam bearings have been installed, and I'll be starting reassembly this weekend!

On a good note everything was wearing well, he gave it a light hone and the heads checked out good, so now I should be set.

Thanks for all the advice!

Ryan

Glad to hear its going well with the new kiddo and your oil consumption woes will be behind you soon!
 

nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
Joined
Jul 31, 2001
Messages
8,615
Good to hear you are good to go!
 
OP
OP
77RHINO

77RHINO

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Joined
Feb 22, 2011
Messages
308
Good news! I've rebuilt and installed the engine and driven it 4 times so far and have not found any signs of consumption! I'm still breaking it in so it'll be easy driving for the first 500 miles before really working it. I haven't seen any smoking at all, through various loads/speeds/RPMs, and the dipstick is still showing full so I hope this is the end of this issue! Once its broken in I will get it dialed in better, during some inspection I found a kink and a split in my fuel line behind the frame going into the tank, so now with new rubber and better/consistent fuel pressure I have more carb tuning to work on!

I appreciate everyone's help on this!

Thanks,

Ryan
 
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