Bolt question

[Tony Smith]

Originally Posted by 8threcce

Hi Phil

I found them at an auction

Could you please note down or do a simple sketch of the dimensions of the bolts?

[Grant Bowker]

At the recent OMVA Acton meeting/swapmeet, Gord Yeo presented the Hammond barn with two similar bolts. On first glance they look close but on measuring, there are issues. In the attached photo, the bolts from Gord are the upper ones. When held up against a variety of stovebolt engines (216, 235 and 261) they are too short to clamp the head. so they don't appear to be suitable for use on CMP engines (original or retrofitted). The next question is, what do they fit? I understood Gord to say some of the batch he got had green paint suggesting MV use. When compared to our rusting Ford V8, the Ford studs were 7/16 rather than 1/2 and the segment of the "special" bolt that would clamp the head is in-between the lengths of studs in the Ford block. Ideas about what they were meant to fit are welcome.

The lower bolts in the image came with my C15A project but were not in the 261 engine it came with so I don't guarantee they will fit. When held up against a variety of stovebolt engines (216, 235 and 261) they appear to be a suitable length for securing the cylinder head. But, the elongated hex between the threaded sections isn't long enough to hold the oil filter mounting plate above the cylinder heads I held it up to. The filter mounting plate I have has a profile on the surface that would mount to the head that requires it to sit above the head rather than curving to follow the shape of the side of the head. It was another loose piece so no guarantee it was an original CMP part either. I will try to find the filter plate to get an image so people can comment.

It looks like there were a variety of these two ended bolts made.

Based on overall length, my guess is that the lower bolt / stud (with red paint) is part number 5819675 used after serial no. 384--21499.

[Grant Bowker]

The attached image is of a trial done to see whether I thought 2 bolts could be welded head-to-head to make a replica of the specialized bolt. The actual parts were scrap spring u-bolts. For a finished product I would have used a belt grinder rather than an angle grinder for a flatter finish on the weld. The weld area was well grooved for penetration, the weld seems strong although not formally tested and the heat was not enough to even slightly loosen the rust bond of the nuts on the shaft so I doubt it did any harm to the properties of the metal.