bent valve rods!!! wtf happened????
- Thread starter samuraichamploo
- Start date
Michael Yount
Mustang Master
LONG way from N'awlins; TN is a fairly wide state, and Knoxville is all the way on the eastern end; the NC border is close by.
Any idea what caused the engine malfunction?
With gas, you'll need a bigger radiator. You can have one custom made; but starting with a diesel rad and having a shop put a 3-row 16-18 fin/inch core in will do the job. And it will bolt in. You won't have room for a mech. fan, so you'll need electrics - probably a dual set up as a single big enough to flow enough air won't probably won't fit either. And since you're carb, your Volvo fuel pump will have to go in favor of something for the carb. The Volvo clutch cable will work with a T-5; you'll need a custom cable for the carb. Let us know how it goes.
Any idea what caused the engine malfunction?
With gas, you'll need a bigger radiator. You can have one custom made; but starting with a diesel rad and having a shop put a 3-row 16-18 fin/inch core in will do the job. And it will bolt in. You won't have room for a mech. fan, so you'll need electrics - probably a dual set up as a single big enough to flow enough air won't probably won't fit either. And since you're carb, your Volvo fuel pump will have to go in favor of something for the carb. The Volvo clutch cable will work with a T-5; you'll need a custom cable for the carb. Let us know how it goes.
so do you think I have valve damage???
if the p/v clearance was a issue (we did check it with the old screwdriver in the chamber trick while cranking it slowly)
why would only one rod/lifter get ****ed?
if the p/v clearance was a issue (we did check it with the old screwdriver in the chamber trick while cranking it slowly)
why would only one rod/lifter get ****ed?
Michael Yount
Mustang Master
"(we did check it with the old screwdriver in the chamber trick while cranking it slowly)"
Have no idea what that 'trick' is, but it's not the appropriate way to measure p to v. I'd sure check it correctly before I put it back together. I think if you just replace the lifters and pushrods, you take a good chance at the same thing that happened before happening again. Don't forget to break in the new lifters at start up - 20 minutes at about 2500 rpm. Do you know what kind of valve springs are in the engine? If they are too strong, they can wipe the cam lobe out at start up. There are some flat tappet combinations that require weaker valve springs to be used during lifter/lobe break in, and then be replaced with the required stiffer valve springs once break in is complete.
Have no idea what that 'trick' is, but it's not the appropriate way to measure p to v. I'd sure check it correctly before I put it back together. I think if you just replace the lifters and pushrods, you take a good chance at the same thing that happened before happening again. Don't forget to break in the new lifters at start up - 20 minutes at about 2500 rpm. Do you know what kind of valve springs are in the engine? If they are too strong, they can wipe the cam lobe out at start up. There are some flat tappet combinations that require weaker valve springs to be used during lifter/lobe break in, and then be replaced with the required stiffer valve springs once break in is complete.
Well, thanks for all the help, anyway to tell if the valves are bent short of having to buy a new headgasket? (aka removing my head)
Michael Yount
Mustang Master
You could replace the pushrods and lifter, and then run cranking compression tests on all 8. If you had a bent valve, it should be losing cylinder pressure; might also tell you a bit about the 0verall condition of the engine. How are you gonna check piston to valve clearance? Heads on (drop valve method) or heads off (clay)? If you're planning on claying it, the heads have to come off anyhow - easy enough to pull the valve springs and check the valves. If you do that, don't forget to order your lifters so they go back on the same lobes.
and let me ask this completely off topic question.
Can i Or can I not reuse my stock EFI pump as long as I have a fuel pressure regulator when going to a carbed setup?
I keep hearing different things.
Can i Or can I not reuse my stock EFI pump as long as I have a fuel pressure regulator when going to a carbed setup?
I keep hearing different things.
Michael Yount
Mustang Master
The stock Volvo efi pump is more than capable of feeding even a modified 5.0L. So it will run along at 40, 50, 60 psi if you need it to. Consequently, you'll need the type of regulator that can make a 50 psi to 6 or 7 psi cut. So do your homework - I believe the type you'll need makes use of the return line in order to make the pressure cut. I believe if it were mine, I'd simply remove the Volvo pump, and plumb in a small electric (8 psi or so) of the proper capacity in the same location, and run a regular carb-type regulator and gauge at the carb.
For drop valve p to v measurement:
Positive stop – obtain an old spark plug for the Ford engine – most of us have at least one laying around. Put it in your vice, and with a tool of destruction you deem appropriate – cut off the ground tip and bust up the ceramic around the center electrode. Keep pounding to get the ceramic and center electrode removed so you’ve got a good ¾” or so of hollow space inside what used to be the ‘business’ end of the spark plug. If you happen to break the ceramic on the other end of the spark plug, don’t worry about it. Once you’ve got a nice hollow space in the tip of the plug, take a 5/16” tap, and cut threads inside that end of the plug. I found that diameter to go right in without any drilling required. Once you’ve cut threads, screw in a 5/16" bolt about 1.5” to 2” long. Then take your hack saw and cut the head off the bolt. Wouldn’t hurt to take your file/grinder and dress up the freshly cut surface so no sharp edges or shrapnel enter the combustion chamber. Also clean up the threads on the plug so that it easily screws into and out of the plug hole.
Determining TDC – remove the passenger side valve cover. Remove rockers from the intake and exhaust valves on the #1 cylinder. Rotate the engine (socket on crank bolt) until the #1 piston is down the cylinder on the intake stroke. Unscrew the spark plug in that cylinder, and replace it with the positive stop you just made. Only screw the positive stop in hand tight. Install your cam degree wheel and pointer (no easy task in some cases as harmonic balancer and other accessories will have to be removed). You may want to remove all spark plugs at this point because it will make it easier to smoothly turn the engine over in small increments. GENTLY rotate the engine clockwise until the piston comes to rest against the stop. Note the degree wheel reading. GENTLY rotate the engine in the opposite direction until the piston comes to rest against the stop. Note the degree wheel reading. TDC is exactly half way between these readings. Calculate where that position is on the degree wheel, remove the piston stop from the cylinder, and rotate the engine to TDC as you calculated it.
Drop valve measurement – now that the piston is at TDC (be sure you're at TDC during overlap - between exhaust and intake strokes) you can safely remove the valve springs on the intake and exhaust valves. I used an inexpensive KD tool for a small block Chevrolet (Blasphemy!). It bolts into the pedestal and has a crow’s foot that sits over the spring retainer. It’s nothing more than a pry bar. Be sure to screw the rocker bolt far enough into the pedestal to hold the tool. You (or your big friend Bubba) are going to apply significant force on the lever to compress the spring. A small magnet is invaluable for grabbing the keepers once the spring is compressed. Also, a couple of taps (lightly – careful here) with a hammer on the retainer can help free up the keepers. The valves may or may not drop down and touch the piston – be sure it’s at TDC to limit the valve movement. Set up your dial indicator over each valve. Rotate the engine to about 20 degrees BTDC. Now, in 5 degree increments, until you reach 20 degrees ATDC measure the distance between valve closed and valve touching the piston. You can move the valve up and down with your fingers, or if the seals are loose, up with your fingers, gravity will take care of down. You’ll have maps of closed valve to piston contact distances every 5 degrees from 20 BTDC to 20 ATDC for intake and exhaust. Rotate the engine back to 20 BTDC (back the way you just came – if you rotate the other way, the piston will drop all the way to the bottom and you’ve got valves dropping down into the cylinders – DON’T DO THAT!!) and set the dial indicator up over the intake and exhaust lifters (or pushrods if you don't have a dial indicator extension). Make the same measurements on both lobes – a map of lift on intake and exhaust lift at 5 degree increments from 20 BTDC to 20 ATDC. Multiply the lift times the rocker ratio. That is valve lift. At each 5 degree point, subtract valve lift from the valve closed to piston contact measurement. That is your piston to valve clearance. It should be more than .080” on intake and .100” on exhaust for engines revving less than 6500 rpm. As your rpm increases, your clearance should increase. If you’re revving to 8500 rpm, you probably want on the order of .125” to 150” on intake/exhaust to be safe.
For drop valve p to v measurement:
Positive stop – obtain an old spark plug for the Ford engine – most of us have at least one laying around. Put it in your vice, and with a tool of destruction you deem appropriate – cut off the ground tip and bust up the ceramic around the center electrode. Keep pounding to get the ceramic and center electrode removed so you’ve got a good ¾” or so of hollow space inside what used to be the ‘business’ end of the spark plug. If you happen to break the ceramic on the other end of the spark plug, don’t worry about it. Once you’ve got a nice hollow space in the tip of the plug, take a 5/16” tap, and cut threads inside that end of the plug. I found that diameter to go right in without any drilling required. Once you’ve cut threads, screw in a 5/16" bolt about 1.5” to 2” long. Then take your hack saw and cut the head off the bolt. Wouldn’t hurt to take your file/grinder and dress up the freshly cut surface so no sharp edges or shrapnel enter the combustion chamber. Also clean up the threads on the plug so that it easily screws into and out of the plug hole.
Determining TDC – remove the passenger side valve cover. Remove rockers from the intake and exhaust valves on the #1 cylinder. Rotate the engine (socket on crank bolt) until the #1 piston is down the cylinder on the intake stroke. Unscrew the spark plug in that cylinder, and replace it with the positive stop you just made. Only screw the positive stop in hand tight. Install your cam degree wheel and pointer (no easy task in some cases as harmonic balancer and other accessories will have to be removed). You may want to remove all spark plugs at this point because it will make it easier to smoothly turn the engine over in small increments. GENTLY rotate the engine clockwise until the piston comes to rest against the stop. Note the degree wheel reading. GENTLY rotate the engine in the opposite direction until the piston comes to rest against the stop. Note the degree wheel reading. TDC is exactly half way between these readings. Calculate where that position is on the degree wheel, remove the piston stop from the cylinder, and rotate the engine to TDC as you calculated it.
Drop valve measurement – now that the piston is at TDC (be sure you're at TDC during overlap - between exhaust and intake strokes) you can safely remove the valve springs on the intake and exhaust valves. I used an inexpensive KD tool for a small block Chevrolet (Blasphemy!). It bolts into the pedestal and has a crow’s foot that sits over the spring retainer. It’s nothing more than a pry bar. Be sure to screw the rocker bolt far enough into the pedestal to hold the tool. You (or your big friend Bubba) are going to apply significant force on the lever to compress the spring. A small magnet is invaluable for grabbing the keepers once the spring is compressed. Also, a couple of taps (lightly – careful here) with a hammer on the retainer can help free up the keepers. The valves may or may not drop down and touch the piston – be sure it’s at TDC to limit the valve movement. Set up your dial indicator over each valve. Rotate the engine to about 20 degrees BTDC. Now, in 5 degree increments, until you reach 20 degrees ATDC measure the distance between valve closed and valve touching the piston. You can move the valve up and down with your fingers, or if the seals are loose, up with your fingers, gravity will take care of down. You’ll have maps of closed valve to piston contact distances every 5 degrees from 20 BTDC to 20 ATDC for intake and exhaust. Rotate the engine back to 20 BTDC (back the way you just came – if you rotate the other way, the piston will drop all the way to the bottom and you’ve got valves dropping down into the cylinders – DON’T DO THAT!!) and set the dial indicator up over the intake and exhaust lifters (or pushrods if you don't have a dial indicator extension). Make the same measurements on both lobes – a map of lift on intake and exhaust lift at 5 degree increments from 20 BTDC to 20 ATDC. Multiply the lift times the rocker ratio. That is valve lift. At each 5 degree point, subtract valve lift from the valve closed to piston contact measurement. That is your piston to valve clearance. It should be more than .080” on intake and .100” on exhaust for engines revving less than 6500 rpm. As your rpm increases, your clearance should increase. If you’re revving to 8500 rpm, you probably want on the order of .125” to 150” on intake/exhaust to be safe.
QDRHRSE
New Member
....once a valve rod broke and came flying through the motor and ruined my muffler bearings. I think it was in my old Renault.... or was it my Peugot....one of those French pieces of crap.
Michael Yount
Mustang Master
SmockDoiley said:
I found out Sunday I have one pushrod with a mushed end it looks like the little ball is gone....the few times I heard it run it ran strong and made no noises.....I will take youir advice and hope all goes well, like I said there was no tell tale sign of any damage but the one rocker was loose with the one bad rod. I was happy to read your response that is what I wanted to hear I hope you are correct. I did not do the work so I have no Idea why it happened but hope install error is correct.....the missisg ball would wreak havoc if it fell inside the engine but I figure I would have heard that causing any damage.
Michael Yount
Mustang Master
"and hope all goes well" "I hope you are correct" "hope install error is correct"
Whole lotta hoping going on here. Sounds like you got an answer you liked better than mine.......good luck with it. Where is that little ball by the way?
Whole lotta hoping going on here. Sounds like you got an answer you liked better than mine.......good luck with it. Where is that little ball by the way?
QDRHRSE
New Member
Michael Yount said:
Mike,
Back in the 80's my brother had a volvo like yours (seriously)! Do those have push rods? We put a motor in it and I can't remember because I was but a teen. It was dark green.
Michael Yount
Mustang Master
Mine has pushrods now 
But the stock motor since 75 didn't - overhead cam 4 cyl.; 74 and earlier were pushrod motors.
But the stock motor since 75 didn't - overhead cam 4 cyl.; 74 and earlier were pushrod motors.
