7 1/4" Dart Martin Evans or John Smith

t's me again and a question about a 7 1/4" Dart chassis and some castings I have just bought.

I and many others know that Martin Evans designed Dart in 1981/2. Then in 2012 John Smith revised and updated the design. Reeves do the castings for the Martin Evans version and Polly Engineering do the John Smith design.

I bought the chassis, mostly rivetted and bolted together with the rear outer frames in place, horn blocks rivetted in and buffer beams. The castings comprised of the wheels, all turned, unmachined cylinder set, original copies of the 1981/2 magazines, a folder containing copies of the 1981/2 articles and the 2012 articles and the Dart page from Polly Eng.

Looking at the castings there are some identification markings. The cylinder blocks say GOODWIN, DART and DT10, the slide valves DT12,, front covers DT14 and the rear covers DT15.

So two questions.

1. Are these Reeves or Polly castings?

2 are parts from Polly compatible with the Martin Evans design?

D Goodwin was Dave Goodwin from Rishton near Blackburn, an independent castings supplier. The codes are his casting list codes - DT for Dart castings.  He was active in the 80's and 90's, maybe also the 00's.

Edited By Bizibilder on 26/07/2022 19:43:53

Edited By Bizibilder on 26/07/2022 19:46:58

Blackgates list the Martin Evans design in their 2021 catalogue .

I've just found Dave Goodwins advert for Dart castings from November 1982 - probably his first for the design - the design series was just about ending about then.

Prices as follows: Main Horns £5.40, Axle boxes and keeps £4.20, D&C Wheels £16.00, Trailing wheels £6.00, Cylinder set £18.00, Motion plate £2.10.

I hate to think what todays prices are for the same components!!

Lets just say the prices have changed slightly.

I know of two suppliers for the castings. One (R) does the castings for the Martin Evans design and the other (P) does the castings for the John Smith design. Martin Evans design was semi scale and John Smiths close scale. P does not do the full range of castings so you need Rs castings in those cases.

Main Horns - R - £81.53 for the 4. Axle boxes and keeps - R - £50 and £25. D&C wheels - R - £549.09 set, P - £57.50 ea. Trailing wheels, 10 spoke is correct, R - £150.36 (12 spoke), P - £38.50 ea (10 spoke). Cylinder set R - £282.35 (cylinders 2, valve chest, front and rear covers, slide valves, and buckles, piston glands), P - Cylinder castings 2 req;d £67 ea, Front covers £8.60 ea, Rear covers £9.70 ea. Motion plate R - £54.36 (incl guides), P - Motion plate £65.00 Guides (correct scale in lost wax) £57.

Oh to have built this in 1982.

As a side note, by checking some of the dimensions I have worked out my chassis is Martin Evans design. The John Smith frames are slightly different profile to allow for things like the brake shaft and closer to scale outline and there are lots more holes for bolts and rivets. So soon I will be dismantling the frames and altering them to the John Smith profile by adding some metal in two areas, drilling the extra holes and filling unnecessary holes with rivets altering the bottoms of the hornblocks, then build up to the John Smith design. However as I have turned wheels, albeit 12 spoke trailing, I will be using those.

D Goodwin was Dave Goodwin from Rishton close to Blackburn, a free castings provider. The codes are his projecting rundown codes - DT for Dart castings. He was dynamic in the 80's and 90's, perhaps likewise the 00's.