WHEN TO USE WASHERS DURING AN ENGINE BUILD

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CFD244

CFD244

"I LOST MY ID IN A FLOOD"
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Hi Folks

So here I am working on a basket case 340, with 30 lbs of 50 year old Mopar engine related fasteners. I have been measuring hole depths etc to figure out the right bolts to use. Today, I was specifically measuring for timing chain/watepump/alt bracket bolts, and found that some of my fasteners have washers and some do not. This leads me to ask the question.............When do you use washers? And, the difference in application "flat vs lock". What say Ye? Thanks FABO.
 
CFD244 said:
Hi Folks

So here I am working on a basket case 340, with 30 lbs of 50 year old Mopar engine related fasteners. I have been measuring hole depths etc to figure out the right bolts to use. Today, I was specifically measuring for timing chain/watepump/alt bracket bolts, and found that some of my fasteners have washers and some do not. This leads me to ask the question.............When do you use washers? And, the difference in application "flat vs lock". What say Ye? Thanks FABO.
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I almost never use a lock washer. That’s what a torque wrench and lock tite is for.

Hardware store washers are ok at best. They are usually stamped. They are good enough for water pump bolts and such but not for head or main studs/bolts.

In general, if Chrysler used a washer then you should use a washer.
 
I tend to see it as spreading the load. I gives the underside of the bolt head a nice even surface to slide against. If the bolt head is gonna dig into whatever I am fastening, then I want to have a washer under there to promote a nice even tightening/torque. I rarely use lock washers as well. If you have another engine around maybe use that as a reference?
 
clementine said:
I tend to see it as spreading the load. I gives the underside of the bolt head a nice even surface to slide against. If the bolt head is gonna dig into whatever I am fastening, then I want to have a washer under there to promote a nice even tightening/torque. I rarely use lock washers as well. If you have another engine around maybe use that as a reference?
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Just a slant in my old truck. I'll see what that looks like.
 
About the only thing I use lock washers on are things directly attached to accessories or accessory brackets. Those bolts get vibration the whole time the engine is running. I use both though. A flat washer under a lock washer. But I agree though that a flat washer and some blue locktite are really all you need.
 
RustyRatRod said:
About the only thing I use lock washers on are things directly attached to accessories or accessory brackets. Those bolts get vibration the whole time the engine is running. I use both though. A flat washer under a lock washer. But I agree though that a flat washer and some blue locktite are really all you need.
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Would you say that flats would be fine under all of the timing chain/water pump bolts on a 340?
 
CFD244 said:
Would you say that flats would be fine under all of the timing chain/water pump bolts on a 340?
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I would. I would do it to spread the load and also because the timing cover is aluminum. Washers will help keep the bolt heads from chewing into the soft aluminum timing cover. Don't forget to coat the threads that go into the water jacket with RTV and also the four long bolt shafts with RTV. If you don't do those four, they will corrode to the holes in the timing cover and break off next time you try to take them out. Lastly, be REALLY careful with one of the bolts on the driver's side of the block. It is pretty shallow and backs up against #1 cylinder. If you use a bolt that's too long there, you will run the bolt right into #1 cylinder and crack the block. That will suck. So figure out which bolt hole that is and make sure not to use a bolt that's too long. I cannot remember which hole it is, but if you pay attention, it's pretty obvious. As a rule though, I put RTV on the threads on all those bolts whether they hit water or not, because it also acts as an anti seize and they come right back out next time.
 
RustyRatRod said:
I would. I would do it to spread the load and also because the timing cover is aluminum. Washers will help keep the bolt heads from chewing into the soft aluminum timing cover. Don't forget to coat the threads that go into the water jacket with RTV and also the four long bolt shafts with RTV. If you don't do those four, they will corrode to the holes in the timing cover and break off next time you try to take them out. Lastly, be REALLY careful with one of the bolts on the driver's side of the block. It is pretty shallow and backs up against #1 cylinder. If you use a bolt that's too long there, you will run the bolt right into #1 cylinder and crack the block. That will suck. So figure out which bolt hole that is and make sure not to use a bolt that's too long. I cannot remember which hole it is, but if you pay attention, it's pretty obvious. As a rule though, I put RTV on the threads on all those bolts whether they hit water or not, because it also acts as an anti seize and they come right back out next time.
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That hole is the one beside the frost plug on the D/S. My numbers matching engine is on a stand, and was "gone over" by the previous owner. I knew that there was a hole like that, and you are right, it's pretty obvious. When I spun that bolt out of the numbers engine, yup, it was too long. Luckily, it was just long enough to scratch the cylinder....I almost puked when I realized the bolt was wrong. That bolt cannot go any deeper than .875. Any more, up to 1.1 inches, it's in the water jacket. At 1.1 inches it's touching it. I'm glad buddy put a .125 washer on the 1.25 inch bolt that he used.
 
CFD244 said:
That hole is the one beside the frost plug on the D/S. My numbers matching engine is on a stand, and was "gone over" by the previous owner. I knew that there was a hole like that, and you are right, it's pretty obvious. When I spun that bolt out of the numbers engine, yup, it was too long. Luckily, it was just long enough to scratch the cylinder....I almost puked when I realized the bolt was wrong. That bolt cannot go any deeper than .875. Any more, up to 1.1 inches, it's in the water jacket. At 1.1 inches it's touching it. I'm glad buddy put a .125 washer on the 1.25 inch bolt that he used.
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Awesome! I'm glad you are familiar with that. It's been the demise of many a good build. It's repairable of course, but with a sleeve in #1.
 
Look at the classic ind / year one type sellers out there for bolt kits, they might have detailed enough photos the show what's what
 
RustyRatRod said:
So figure out which bolt hole that is and make sure not to use a bolt that's too long.
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A piece of coathanger wire or welding rod (or, the depth gauge that slides out of the end of a dial indicator) makes a handy quick gauge to check how much room you have from the underhead legnth to the cylinder wall.
 
I would never use a lock washer inside an engine, such as an oil pump bolt. It has an open end, which can cause it to break & occasionally they do. If the fastener is properly torqued, it should not loosen, negating the need for a lock washer.
Plain washers used with steel or c/iron I believe is mostly unnecessary. If the fastener has a lot clearance in the hole [ eg, 3/8" bolt in a 1/2" hole ] a washer would be a good idea to better spread the load.
On alum, use a washer.
 
I can't believe nobody has brought up Chrysler's conical lock washers. Chrysler has used them on both small and big block engines. Almost all of the front end accessories of both engines use them. The motor mount to K member bolts use them, the motor mount to motor mount bracket use them, solid fans use them, big block distributor hold down bracket uses one. Most of the bolts that have the washer on them are conical washers. Please use the correct washers at least on the front of the engine. Hardware store bolts and washers have no place on a Mopar engine!
Hardware store bolts come in 1/4 inch increments, a lot of Chrysler bolts come in 1/8 inch increments. So if you use hardware store bolts, you will probably have to use extra washers. Years ago, I helped a friend work on a 70 Road Runner, He had a 440 built with the Stage V Hemi head package. He had one of his Chevy buddy assemble the engine. He used hardware bolts and washers, mainly on the water pump and water pump housing, most of the bolts had a stack of at least 3 washers. It looked like HELL!!!! It still dynoed at 700 horsepower, even with the wrong bolts. :lol:
 
^^^^^^^^

Belleville washers, by themselves and on captive bolts and nuts. Keep em if ya got em, snag em when at the salvage yard and seek em out if available in the sizes you need.
 
Speaking of water pump bolts. FABO member @TrailBeast shared this and I saved it. It's for a Poly engine so I'm not sure if it's exactly the same as an LA. Maybe someone knows for sure.

poly318-water-pump-bolts.jpg
 
lemondana said:
I can't believe nobody has brought up Chrysler's conical lock washers. Chrysler has used them on both small and big block engines. Almost all of the front end accessories of both engines use them. The motor mount to K member bolts use them, the motor mount to motor mount bracket use them, solid fans use them, big block distributor hold down bracket uses one. Most of the bolts that have the washer on them are conical washers. Please use the correct washers at least on the front of the engine. Hardware store bolts and washers have no place on a Mopar engine!
Hardware store bolts come in 1/4 inch increments, a lot of Chrysler bolts come in 1/8 inch increments. So if you use hardware store bolts, you will probably have to use extra washers. Years ago, I helped a friend work on a 70 Road Runner, He had a 440 built with the Stage V Hemi head package. He had one of his Chevy buddy assemble the engine. He used hardware bolts and washers, mainly on the water pump and water pump housing, most of the bolts had a stack of at least 3 washers. It looked like HELL!!!! It still dynoed at 700 horsepower, even with the wrong bolts. :lol:
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My fastener stock is all OEM from years gone by. I am not using hardware store stuff. Just wanted to make sure I put washers where they need to be.
 
Oil pan bolts, valve cover bolts, intake bolts, pulley bolts, bellhousing to block bolts and starter bolts all had captured washers on them. Fuel pump bolts had shoulders on the heads, but no captured washers. Hope that helps a little. :)
 
I have often seen lock washers placed between bolt head and a flat washer which makes no sense what so ever. The point of a lock washer is to retard a bolt from backing off by biting into both the head of the bolt which is movable and a solid immovable surface such as a block or such.

Use the correct holding strength of Locktite or comparable product to secure bolts where vibration is present. For bolting down heads that have been shaved and or the top of a block shaved that reduces the depth of a blind hole, using a grade 8 washer that closely matches the diameter of the bolt would be OK as long as the correct lubrication is applied per torquing specs. One must not get too much oil or lube into a blind bolt hole, because as the bolt is sent home and contacts that puddle of lube, great hydraulic pressure is built up that may break something, or prevent correct torque and clamping pressure being applied.
 
I would only use a hardened washer under a head bolt or main cap bolt. A grade 8 washer wouldn't be the proper thing to use there. High torque fasteners like that should only have hardened washers under the heads if a washer is needed.
 
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