Westerbeke 100 Head bolt

The long head bolts for the Westerbeke W100 are no longer available. This is Westerbeke part #024372. It's Mazda ZB part #10137.

I took this to a local Bolt store and it fit a 14mm - 1.50 nut. I ordered a thread cleaner from McMaster-Carr and it did not fit.

Anyone have any specs on the threads on this head bolt?

I tried Westerbeke and they couldn't help me. I'm putting the head back on next week and would like to be able to have some back-up info in case I have to make a new bolt.

Get a 14x 1.50 bolt and see if it threads easily into the block holes. Thread chasers can be a little fat for head bolt holes, not surprised it did not want to go. If a new bolt threads in well, get a class 12.9 and it should work.

They look to be available, just not home depot cheap:

-- https://discountmarinesource.com/st...roduct_id=2939&search=024372&description=true

Thanks Sky,

Here is a photo of my head bolt fitting into the 14mmx1.50 hole.

I'll try a new bolt to see if it fits in the block.

I bought a new tap to clean out the holes in the block. (as I mentioned, Tap would not go down hole in block - did not try forcing it.)

I shot a light down the holes and they are full of crud.

Absent my ability to use a tap, is there a way to get the crap out of the bolt holes in the block? (Tried compressed air - still gunky)

Gkesden- I did try Discount Marine just now. They are out of my Westerbeke service area, but the order was not rejected. Let's see.

bsent my ability to use a tap, is there a way to get the crap out of the bolt holes in the block? (Tried compressed air - still gunky)

Click to expand...

How about a gun bore brush? Something like 38 special/9mm? Then vacuum after or during if you can to suck the loosened crud.

To clean bolt holes I run a bottle or rifle brush in the hole soaked with diesel or some other solvent. Then suck out with a tube on a shop vac (I have a nasty vac just for this). Or blow out with comp air (but then crap goes all over). Repeat as necessary. Next, wire wheel the bolts lightly, then run each down in a hole with diesel or solvent present. Hand spin bolt up and down til it feels smooth. Make sure bolt head goes down smoothly below it would be when holding the cyl head down.

I generally do not use a tap or a thread chaser as there are many many variations in size for a given dia and pitch and we don't know what the factory used.

I have good luck cleaning threads with dental pics.

A tap or die will try to re-cut the threads and weaken the ability of the fastener to hold. A thread chaser would be better to use. They don't cut. They push the debris into little channels and either push it out the top of the hole as the chaser goes down or collect and hold it.


https://www.amazon.com/metric-threa...07a7ad163b0c2ef454feaea017bdb2&language=en_US

gkesden said:

They look to be available, just not home depot cheap:

-- https://discountmarinesource.com/st...roduct_id=2939&search=024372&description=true

Click to expand...

Gdesken, on the replacement bolt from Westerbeke, Discount Marine says “no longer available”

Ski in NC said:

Get a 14x 1.50 bolt and see if it threads easily into the block holes. Thread chasers can be a little fat for head bolt holes, not surprised it did not want to go. If a new bolt threads in well, get a class 12.9 and it should work.

Click to expand...

Ski,

I have better luck/choices with class 10.9. Is that the same as grade 8? (For some reason I think grade 8 is good for head bolts).

Thanks for previous replies.

10.9 is similar to SAE grade 8 in material strength. But we don't know what the original head bolt strength is. 12.9 is higher strength than 10.9.

Any markings on the original head bolts?

Why are you replacing them? Stretched? Corroded?

No markings on bolts

Some of the short ones are a little corroded

The long ones (no longer available) look pretty good.

Just trying to get a source as I don't want to have to replace an engine because I snapped a head bolt.

Got the gun cleaner kit. Also went to friend Bobby and sized the bolt in his $10 plastic bolt sizing thingy.

1/2NF 20, 5-27/32". Go figure. SAE in a Mazda truck block. Forget your lying eyes and post #4. No wonder I couldn't use the 14mm tap.

Just have to figure the right grade and I can locate some in case I have to and cut them down to size.

Making a rig to vac out bottom of hole.

Even the short ones cost 26 bucks. And they are back ordered.

An "aerosol" type can of compressed air used in cleaning computer keyboards might help if you don`t have an air compressor handy. They come with a tiny extension tube, like on WD40 cans.

Ouch. Looks like they found a ghost listing. They showed available when I looked, then y'all saw them unavailable, now I look -- and the whole catalog page is gone.

I'll look around some more on Monday. A bolt,shouldnt be disco'd!

gkesden said:

I'll look around some more on Monday. A bolt,shouldnt be disco'd!

Click to expand...

If they changed the part number it would appear discontinued.
I've run into this in the past.

This bolt is discontinued. It shows up in the online catalogs, but when you order it, you are notified several days later that it is “no longer available.” Someone might have some old stock around. No way to tell without an order or phone call though. Remember, that although the head gasket sets, and rebuild kits, are still available for this engine, the head bold is a seldom fail item. So why carry it 30+ years the engine stopped being manufactured.

I have no problem with the Aftermarket folks on this, just needed to figure out the work around. (I was in a machine shop last year and saw an old Simplex being rebuilt. Getting parts for the Westerbeke seems easy compared to the Simplex parts.)

The funny thing on this engine was the studs holding the intake manifold and water tube.

They are 5/16NF at both ends. Try finding those. I ended up buying some grade 8 bolts and cutting off the heads.

So a couple of things. Between the gun brush, the tap, some Tapmatic #1 Gold Cutting Fluid, the modified vac head, and lots of shop towels I was able to turn in by hand a bolt into all the holes in the block.

As we discussed the long bolts are no longer available. I was told that the short bolts were not available until the end of March.

Time to find an alternative. I took a picture of the bolt head. No markings.
Looking at the long bolt, it seems I can buy a 1/2x20 6" Grade 8 at McMaster-Carr and just cut off 1/8".

Anyone foresee a problem with that strategy?

John

The unthreaded part (shank) may not allow the bolt to go all the way into the hole. If it's forced in, it could strip the bolt hole threads.

You might try calling ARP and see if they have some head studs that would work. I think they can put together a custom kit for you if they have something in their inventory that will physically fit, assuming you can use a stud in place of the bolt. With overall length, thread spec, and threaded length you should be able to ask them what they can do.

https://arp-bolts.com/

ARP is a good call. I've used their head bolts on several motors. Even in stainless, their psi is something close to 180k lb/sqin. IMMSC.

PMF1984 said:

... Grade 8 at McMaster-Carr and just cut off 1/8".

Anyone foresee a problem with that strategy?

John

Click to expand...

Grade 8 may take a grinder to cut, but the heat might affect the existing heat treatment. Just not sure about this. If kept cool, prolly OK. Sounds like unproductive work. How about a GR8 heavy flat washer under the head? Typically avail. in small OD too.

ARP has just what I need, thanks.

Hi, use compressed air with a long tip to blow the crud out. Wrap the tube with a rag to catch the crud, especially if you used some type of crud cutter/solvent. Don't want that to go into your eyes, etc.

I cut the Grade 8 bolts with a hacksaw, rounded the ends a little on a wheel, and then ran the new stud through a die. Worked great.

I made a rig to vac out the bolt holes after: 1. Brushing them out to get the loose stuff, 2. Running a vac attachment down the hole, 3. lightly turning a tap down them with some cutting oil, 4. Twisting a shop towel down the hole to soak up the cutting oil, the the final vac out. Bolts went in by hand to bottom on a test run.

Head went on ok, it’s a two man job. labeling the bags of nuts really helped with all the other little things.

Had to make some exhaust gaskets tonight, tomorrow final assembly.

Thanks for all the pointers.

John

Just for point of interest, the W70 and W100 engines are Perkins designs, hence the inch hardware. They were made exclusively by Mazda's engine division. Far as I could find the 6 cyl was only sold to Westerbeke, while the 4 cyl was also used in many Hyster and Yale forklifts, and other applications. (unfortunately, the 70 and 100 head bolts are different.)

How does the flow controller and exhaust manifold look? You might want to get these while you still can. About $280 and 1200, 4 weeks.

Thanks Nate,

Yeah, so you are correct. The Mazda ZB block was based on an earlier Perkins design. Good news is that the Titan truck with the T4100 and E4100 engine was sold throughout the Far East. So engine parts for rebuilds are available.

My manifold and flow controller were replaced by the PO. There are a few marinized parts that I could use that are no longer available, but they are not at the critical stage, and there are work arounds.

I had a start up at the dock yesterday. Seems to run smoother than before. Still have to change oil and engine zincs before I take it out.

Also need to apply some paint.