Picked up an attempted project car, and doing reassembly. Kid lost all the hardware for intake manifold, water pump/housing, alternator, fuel rail etc. What are the size and pitch of bolts/nuts for said items?

 

I don't know the lengths for sure offhand, but I believe everything you mentioned is M8x1.25 (except possibly the alternator, but mine is in a box somewhere so I can't measure it for you):

Lower intake > Block: 4 bolts, 2 nuts

Upper intake > Lower: 1 weirdly long (~50/60mm IIRC) bolt, 4 nuts

Water pump / housing: 5 nuts, 2 bolts (IIRC)

Lower fuel rail: Two bolts, one longer than the other (and there's a plastic spacer that should go between the rail and the middle iron).

Upper fuel rail: Two bolts. I believe one of them has a longer un-threaded section than the other stock, but I doubt this matters in application. Look down the mount holes on the UIM and you'll see what I mean. Not sure why it was designed that way.

All of the stock hardware has 12mm flanged heads.

 

Most common size hardware are:

M6x1.0
M8x1.25
M10x1.25, M10x1.50


that should get you going.

 

i like to get cars that come in boxes too so, we're slowly working on a spread sheet that will let you look up the part in the Mazda catalog and then it decodes the part number to the size/shape/plating.

really quick, Mazda uses JIS standard bolts most of the time, and these get a part number that tells you style, size length and plating.

the JIS part is
6x1.0 with a 10mm head
8x1.25 with a 12mm head
10 is a 14mm head, the exhaust is 1.5 and the rest are usually 1.25

when you go to look at the Mazda part number its in 3 groups, 99796-0880, the first 5 are the style of bolt (plain, built in washer, etc) the next 2, 08 in this case is the bolt size in mm, 08 = 8mm, 06 = 6mm. the final two (80) are the length of the threaded part in mm, so the weird long intake bolt is 80mm
if there is a letter after it denotes the plating, the default is a gold zinc plate, but they can be black, or silver or Cadmium (dull gray), it depends on the application.

 

OP, this will actually work out for you in a couple of respects. I am just finishing a rebuild and replaced all the hardware. It greatly improved ground connections for the wiring harnesses and mating engine components. when you install a ground bolt, make sure to clean out the body threads and coat the new shiny bolt threads with a small amount of dielectric grease to prevent corrosion. I have noticed a significant reduction in electrical resistance at these connections. It also is nice to be installing non-crusty hardware. less wear and tear. Note that most of the holes on the manifolds are for stud hardware rather than bolts. This is so that a stud goes into the aluminum once and stays rather than a bolt going in and out and wearing out the cast hole. It sucks to strip out an aluminum thread. Use studs and nuts if you can.

As far as ordering goes, I ordered all my new nuts and bolts from Belmetric.com. They have a lot of the type of hardware originally used (except for the odd long intake bolt, etc... go to mazdatrix for that) but you can order hardware in bulk. Most of what I have ordered is yellow zinc. Exhaust nuts and bolts are a little different.

Plan on about:
200ct m6x1.0 thread 10mm bolts - these little devils go all over the car. Replacing them is a great idea
30ct m6x1.0 thread 15mm bolts - a little longer, you need them in a couple places
50ct m6 smooth flange nuts - 10mm wrench
50ct m6 serrated flange nuts - 10mm wrench
30ct m6 studs - I forget what length, but you'll need a few of them for the attachments for the intake

20ct 8x1.25 bolts of varying lengths, 1", 1 1/2", 2" I forgot what I ordered OP, sorry

Exhaust nuts are 10mmx1.5 threads
10mmx1.25 everywhere else, transmission, etc.

Best of luck, let us know if we can help out some more

 

Appreciate the help guys

 

I use Belmetric.com for all my hardware. They carry a lot of hex flanged screws that meet the JIS and IFI standard so they look very close to the original, but most of the standards these cars used are no longer available. Cost is also very low so it will be affordable to stock up.

Like these JIS screws

 

@professionalpyroman

This is amazing, been looking for this to replace as much of the hardware as possible!

Do you happen to know what sizes for the hardware used to attach the front plate to engine stand adapters? The bolt up top and two nuts for the bottom?

 

I forget which. I think those are the finer pitched 10mm threads with the coarse 10mm being for exhaust manifold stuff. I don't remember for sure, but I think that's it

 

To respond to my own question in case anyone else needs to know. Looks like the studs where the power steering bracket goes are M12-1.5, and the little bolt hole at the top of the side housing is M10-1.25.