Julian Thompson Posted July 5, 2007 Share Posted July 5, 2007 I'm just in the process of ordering a carbon prop for my blackbird 7 from RiF and I have a sheet of different props that RiF's suppliers have made before. Length is not so much of an issue ( 😳) but it is the attachment to the English Axle and the front Engine output that is critical to get right. I have been threatening to go out to the car and actually try and take some measurements but to be honest it is not easy to be accurate under there unless I stripped it all down... ..anyone know the size/pcd etc on the English Axle and Blackbird prop output flange (itself a custom item of some sort?) Bear in mind the plan here is to ditch the reverse box... Can anyone offer me any advice as to the best way to proceed as RiF is waiting for me to give him a nudge once I can commit to a size/style of prop..... Link to comment Share on other sites More sharing options...
Mike Molloy Posted July 6, 2007 Share Posted July 6, 2007 Do you have the Nova rubber donut coupling? If so there is a little diagram here. I'm sure Graham Dyson at Nova would give you the necessary dimensions. My props were stickered Bailey Morris, so I guess they would have a record of the design. They were also the ones who sent me the info on the "resilient torque tube" props with Transit centre support bearing that BEC folks use if they don't have a rev box. Worth having a chat with them. Also read up about UJ angles and propshaft vibrations. There are some caveats to be wary of. Strange that you have a live axle. I thought all the Blackbirds were De-Dion with the Ford diff. Link to comment Share on other sites More sharing options...
Julian Thompson Posted July 6, 2007 Author Share Posted July 6, 2007 Thanks Mike - that's super helpful! I do have the rubber donut thing, yes! Mine is a LA because it is not a factory blackbird, it's a creation! 😳 Link to comment Share on other sites More sharing options...
Mike Molloy Posted July 6, 2007 Share Posted July 6, 2007 "Creation"... Ah-ha.  Barry Hunt built his hill-climb special 'Bird using a LA setup. I think it saves a fair bit of weight over the De-Dion (the Ford diff alone weighs over 20kg...) Barry really went to town with the weight saving (corner-weight scales in your garage can be a monkey on your back...) and eventually managed to get below 400kg. That was for a fully stripped out car on slicks. I note Meaden's Fireblade was reported as 369kg in road legal trim, so quite a bit less. My De-Dion 'Bird weighs 450 - 460kg with foam seats, aero, MB mags, RS cage etc., so actually not much less than a R500. Paul Harvey once told me he prefered the feel of the live axle, especially for track use. Hence the evolution of the Fireblade design from the Blackbird.  Please keep up the good work posting photos of all your mods and tweeks.  This is an interesting account of a Striker build using Bailey Morris props. Edited by - Mike Molloy on 6 Jul 2007 13:09:09 Link to comment Share on other sites More sharing options...
Julian Thompson Posted July 6, 2007 Author Share Posted July 6, 2007 Mike - those are interesting figures. Nick reckoned that my 'bird was 390kg as it stood when I got it but I've shaved about 10kg more so far... I think the carbon prop, junked reverse box etc... will be worth a bit more weight saving. Apparantly the R500 was a little optimistically weighed at 460kg? (I'm sure I read that somewhere!) I can definately feel the lack of compliance and more skittish nature of the live axle on bumpy roads compared to my SLR - that felt much more planted at the back. On smooth roads I don't detect much difference. There is a company now making a rather nice differential unit that has a reverse built in to it.....it's about £2500 but looks amazing. I can't use it because of my Tractor Axle but you could....be worth 10 -15kg I bet 😬 Link to comment Share on other sites More sharing options...
RiF Posted July 6, 2007 Share Posted July 6, 2007 I know how you can shave even more weight off 😬 😬 Carb 😬n instead of ally  RiF Driving one of the first Duratec 7, and building CA07BON for Henrietta 😬 😬 😬.for pictures of 7 and carbon andCA07BON Link to comment Share on other sites More sharing options...
Area Representative Nick Chan Posted July 6, 2007 Area Representative Share Posted July 6, 2007 Julian, I think the 'Bird was around 410 kgs so you have got it down to 400 kgs which is pretty 😳 😳 It was weighed by Richard Price shortly after he had weighed your old SLR and that came in within a kilo or two or the expected weight so I reckon the BB weight was close enough. Pics of the car on the other thread looks like you are having lots of fun. I hope Andrea doesn't blame me too much for you becoming a Blatchat addict again 😬 Cheers Nick PS I have just read the posting by NeilG about going in the Blackbird sold this week and what an experience - almost makes we want to have another one again! The BEC has gone - now onto an R400!! Link to comment Share on other sites More sharing options...
blade_runner Posted July 6, 2007 Share Posted July 6, 2007 My blade is 417 kg with just under a full tank of juice, the only carbon is the dash. 'Pinky Pics' here Link to comment Share on other sites More sharing options...
Julian Thompson Posted July 6, 2007 Author Share Posted July 6, 2007 Nick Ah - yes - 410 - not 390 - my memory failed me there! Still - pretty light but not as light as my wallet if RiF has his way with lashings of carbon 😬 Yep, having lots of fun (except for this rain!) and Andrea's not too bad about it. Work has suffered somewhat, however 😬, with my workshop being turned into a "Caterham development centre" for a week or two 😬 😬 Next phase is the electric clutch and cooling system revisions... Link to comment Share on other sites More sharing options...
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