Help! > Specific Engine Help

Drawing boo-boos, faults and known problems and ways to over come them

<< < (2/3) > >>

Peewee:
very true

AlasdairM:
I may be mistaken, but I believe that whilst Bridport did originally supply Stuart with their castings, some 5 or so years ago this ceased - this may be (and this is my total conjecture here) why the quality dropped off?

I gathered the above info. from chatting to one of the "stall-holders" at MMEX last week, and also from a discussion with Andy himself on the Stuart stand.

Regards, A

Jo:
Double Tandem compound:

IMHO the author of the drawings for this engine never actually built it. You need to make the assumption that the single compound is ok, Stan Bray built one in ME and identified the problems with that, but all the bits that relate to the double should be approached  :Director: with caution.

The GA is not to scale :ShakeHead:. This is what you may wish to refer to as you notice many DTC specific parts have not been drawn up, but be careful. Many of the glands use 8BA studs but there is not enough space on them for the nuts. The same problem exists with the steam and exhaust ports which show 10 BA but there is only space for 12 BA nuts.

The DTC does not require bent connecting rods, they can be straight but the lengths must be reduced to take it into account (or you can reduce the valve rod length to compensate).

Jo

gbritnell:
Over the years I have built many models, engines and otherwise. I have built from castings, Stuart, Reeves etc. and also just from plans. I have gotten to the point where I always double check dimensions before cutting metal. I can excuse some mistakes as I have made them myself. What I can't excuse is a drawing for a part that has been around for years and has never been corrected. When an engine for example is designed, drawn up and built, it should have any errors corrected so it just makes you wonder if a particular engine was ever built from the drawings or if the author really cared enough to correct them after finding them.
In the not to distant past I built some engines from kits and the disclaimer on some of the drawings was "I'm not a draftsman so the drawings might not be totally correct".  :shrug: or the note 'fit at assembly' used too many times.
One glaring error can be found with the Holt drawings. The carburetor as drawn won't work, period. The fellows that have used it have made modifications to it just to get it to operate. Some builders have even switched to propane or model airplane type carbs out of frustration. Deplorable!!
gbritnell

Dave Sohlstrom:
On the Holt drawings I have. The cylinder spacing is 1.5" on the crank case, cam and crank shaft but the cylinder heads and cylinders are 1.625" in diameter so will not fit the crank case. I found this when a drew up the parts in 3D CAD and built an assembly.

Dave

Navigation

[0] Message Index

[#] Next page

[*] Previous page