engine question that will probably make you angry
Thread Starter
|
Elder User
Joined: Jan 2014
Posts: 531
Likes: 8
From: Bakersfield, CA
engine question that will probably make you angry
Just got a 56 f100 with 292 y block. know nothing about the Y. compression ranges from 110 to 125,( with oil squirted in the cylinders) except for #6 which is 55. Want to keep the engine running for a while until I can get an updated replacement. The impossible question is what could be the cause of the lowest cylinder from easiest/cheapest to the hardest/most expensive. What is the least invasive way to diagnose the problem. I don't want to throw good money after bad.Thanks for your understanding.
Believe Nothing
Joined: Jun 2004
Posts: 7,514
Likes: 398
From: W. Central FL.
First thing I would do is check valve adjustment. Easiest fix would be if the valves are out of adjustment, a bit of time and set of valve cover gaskets. Worst case would be a broken compression ring that has scored the block, rebore, the works $$$.
Is the engine running?
What is dry compression.
I've found a compression test on an engine that has not run in years can be meaningless.
Edit: And BTW, unless the engine has been replaced, it is probably a 272.
Another edit: And welcome to the forum, since you have such a low post count.
Is the engine running?
What is dry compression.
I've found a compression test on an engine that has not run in years can be meaningless.
Edit: And BTW, unless the engine has been replaced, it is probably a 272.
Another edit: And welcome to the forum, since you have such a low post count.
Senior User
Joined: Jun 2011
Posts: 195
Likes: 0
From: Fresno, California
If the truck has been sitting for along time, you may be dealing with stuck rings. In which case, you MAY be able to free it up with Marvel Mystery Oil. That's the best case/cheapest scenario I can think of.
Other, more expensive possible scenarios are:
Scarred/gouged/rust corroded cylinder.
Broken rings.
Collapsed lifter.
Burned valve.
Stuck valve.
Burned Piston.
Dead Mouse stuck in exhaust valve. Okay, this one isn't very likely, but I have seen it happen twice. But that's one that would possibly clear itself up. Probably. Other things in this category are mud dauber wasps and other bugs that like dark secluded places to make their nests with mud. Again very unlikely, if the air cleaner and spark plugs were left in place when the vehicle was parked. But don't forget, they can still get in the engine through the exhaust system via an open exhaust valve.
Other, more expensive possible scenarios are:
Scarred/gouged/rust corroded cylinder.
Broken rings.
Collapsed lifter.
Burned valve.
Stuck valve.
Burned Piston.
Dead Mouse stuck in exhaust valve. Okay, this one isn't very likely, but I have seen it happen twice. But that's one that would possibly clear itself up. Probably. Other things in this category are mud dauber wasps and other bugs that like dark secluded places to make their nests with mud. Again very unlikely, if the air cleaner and spark plugs were left in place when the vehicle was parked. But don't forget, they can still get in the engine through the exhaust system via an open exhaust valve.
More Turbo
Joined: Jun 2003
Posts: 687
Likes: 80
Check the valve adjustment too.
I use the EO IC method, it's simple:
Pull valve covers and spark plugs, find a 0.19" feeler gauge.
With a socket on the crank bolt:
Rotate the engine until the #1 cyl exhaust valve just starts to open. Adjust.
On the same cylinder, rotate the engine until the intake valve is just starting to close. Adjust.
Move to the next cylinder.
Then re check your compression.
The y block is an easy engine to work on and parts are still available including aluminum heads and other high performance parts. Try John Mummerts web site.
I use the EO IC method, it's simple:
Pull valve covers and spark plugs, find a 0.19" feeler gauge.
With a socket on the crank bolt:
Rotate the engine until the #1 cyl exhaust valve just starts to open. Adjust.
On the same cylinder, rotate the engine until the intake valve is just starting to close. Adjust.
Move to the next cylinder.
Then re check your compression.
The y block is an easy engine to work on and parts are still available including aluminum heads and other high performance parts. Try John Mummerts web site.
Fleet Owner
Joined: Jul 2004
Posts: 27,290
Likes: 1,055
From: NM
Check the valve adjustment too.
I use the EO IC method, it's simple:
Pull valve covers and spark plugs, find a 0.19" feeler gauge.
With a socket on the crank bolt:
Rotate the engine until the #1 cyl exhaust valve just starts to open. Adjust intake valve on that cylinder.
On the same cylinder, rotate the engine until the intake valve is just starting to close. Adjust exhaust valve on that cylinder.
Move to the next cylinder.
Then re check your compression.
...
I use the EO IC method, it's simple:
Pull valve covers and spark plugs, find a 0.19" feeler gauge.
With a socket on the crank bolt:
Rotate the engine until the #1 cyl exhaust valve just starts to open. Adjust intake valve on that cylinder.
On the same cylinder, rotate the engine until the intake valve is just starting to close. Adjust exhaust valve on that cylinder.
Move to the next cylinder.
Then re check your compression.
...
For the purposes of this test (cranking speed compression), unless one of the valves on #6 has less than zero clearance, it's either a burned valve or a bad ring situation. Not really any point to checking all the valves yet.
More Turbo
Joined: Jun 2003
Posts: 687
Likes: 80
Yup. Your edits are correct.
You have a point regarding the #6 cyl, but I would check 'em all anyway.
H'ed get a feel about how the entire valve train was working.
You have a point regarding the #6 cyl, but I would check 'em all anyway.
H'ed get a feel about how the entire valve train was working.
Trending Topics
Thread Starter
|
Elder User
Joined: Jan 2014
Posts: 531
Likes: 8
From: Bakersfield, CA
First thing I would do is check valve adjustment. Easiest fix would be if the valves are out of adjustment, a bit of time and set of valve cover gaskets. Worst case would be a broken compression ring that has scored the block, rebore, the works $$$.
Is the engine running?
What is dry compression.
I've found a compression test on an engine that has not run in years can be meaningless.
Edit: And BTW, unless the engine has been replaced, it is probably a 272.
Another edit: And welcome to the forum, since you have such a low post count.
Is the engine running?
What is dry compression.
I've found a compression test on an engine that has not run in years can be meaningless.
Edit: And BTW, unless the engine has been replaced, it is probably a 272.
Another edit: And welcome to the forum, since you have such a low post count.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Thread Starter
|
Elder User
Joined: Jan 2014
Posts: 531
Likes: 8
From: Bakersfield, CA
It's kinda a funny story, I guess. Saw this truck on Ebay in my home town. Talked to the owner and decided not to go look at the truck because I knew I would want it no matter what shape it was in. A friend who knows cars/trucks told me to stay away from it. He doesn't follow the crazy prices of the '56. I watched the last minutes of the auction only to see the final price so I could tell my friend how it ended. Did I mention I was drinking bourbon? In the last eight minutes I made a one time $100.00 BUMP just to watch the bidding take off. IT DIDN'T. I spent the next eight minutes yelling NO, NO, NO, NO! You know the ending. Believe it or not my wife is thrilled because now she doesn't have to look for a '56 everywhere we go.
Senior User
Joined: Jun 2011
Posts: 195
Likes: 0
From: Fresno, California
It's kinda a funny story, I guess. Saw this truck on Ebay in my home town. Talked to the owner and decided not to go look at the truck because I knew I would want it no matter what shape it was in. A friend who knows cars/trucks told me to stay away from it. He doesn't follow the crazy prices of the '56. I watched the last minutes of the auction only to see the final price so I could tell my friend how it ended. Did I mention I was drinking bourbon? In the last eight minutes I made a one time $100.00 BUMP just to watch the bidding take off. IT DIDN'T. I spent the next eight minutes yelling NO, NO, NO, NO! You know the ending. Believe it or not my wife is thrilled because now she doesn't have to look for a '56 everywhere we go.
More Turbo
Joined: Jun 2003
Posts: 687
Likes: 80
The engine may be nursed to run just fine. I'd definitely adjust all the valves, to give it all the advantage you can.
Is there oil on the valve train and maybe some oil .pooled in the head? That would be good because the Y block family flaw is that they get dry up there.
You say it backfires at high rpm. Checking the ignition timing won't cost anything, so I'd be setting that to about 5 or 10 degrees. Is this an original points distributor? If so set the points first or just replace them.
Check the carb float too if it's easy. Change the fuel filter if it's not pretty new looking.
You can do all that for less than $30 including valve cover gaskets.
Is there oil on the valve train and maybe some oil .pooled in the head? That would be good because the Y block family flaw is that they get dry up there.
You say it backfires at high rpm. Checking the ignition timing won't cost anything, so I'd be setting that to about 5 or 10 degrees. Is this an original points distributor? If so set the points first or just replace them.
Check the carb float too if it's easy. Change the fuel filter if it's not pretty new looking.
You can do all that for less than $30 including valve cover gaskets.
Posting Guru
Joined: Sep 2012
Posts: 1,314
Likes: 0
Turn it so that #6 has both valves closed. Connect an air line and feed a small regulated air flow to it. Listen to see where the air is escaping.
Double-check to make sure that there isn't so much air flow that the engine turns until a valve opens.
This will let you know if you have a valve/head issue or a ring issue.
Before going this far, how'd the spark plug for #6 look?
Double-check to make sure that there isn't so much air flow that the engine turns until a valve opens.
This will let you know if you have a valve/head issue or a ring issue.
Before going this far, how'd the spark plug for #6 look?
Lead Driver
Joined: Dec 2012
Posts: 9,707
Likes: 823
From: Wentzville, MO
Welcome filty56. I agree with the pull the valve cove recommendations. Too many things that could be your problem, seeing the valve train operate eliminates many of them. Valve cover gaskets are cheap and pretty easy to get and change. Valve, points and timing adjustments are all free except for your time. While some claim Seafoam or Marvin's Magic Mystery oil are nothing more than Snake Oil many on this forum swear by it and it's under $20. I've never heard of anyone claiming it ruined their engine, so it's a crap shoot if it will fix anything, but it won't hurt anything on the flip side. Good recommendation about shooting air in the cylinder and listening. OBTW you can run the engine with out valve covers, it just gets a little messy if you have a good oiling motor and then you can see if your engine is oiling well. Keep us posted and post some pictures
Thread
Thread Starter
Forum
Replies
Last Post
caleb1563
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
10
Jul 6, 2011 05:46 PM
Greenmillwork
335 Series- 5.8/351M, 6.6/400, 351 Cleveland
4
Feb 23, 2009 11:17 AM
walterperu
1967 - 1972 F-100 & Larger F-Series Trucks
12
Mar 17, 2006 12:36 AM