Terry Field Posted June 21, 2005 Share Posted June 21, 2005 Peter, Someone at the Wotton Hatch last week suggested I speak to you for some XFlow advice, but I didn't get chance at the time. I would appreciate some advice on the following if you can please. I have a 1700XFlow built by Vulcan with 2k on the clock and running a Lucas dizzy. The compression ration is 11.7:1. Running on 40's. I recently put it on the rolling road at Race N Road, but it was pre detonating so Steve Greenald could do nothing with it. He said that there was too much mechanical advance in the dizzy. After discussing it with Steve, I have sent the dizzy to Aldon and asked them to calibrate it with 7deg mechanical advance, and (to use Steve's words) 'to fit some fairly strong springs'. I have also asked Aldon to supply a range of springs so that we can try different combinations on the rolling road. I am waiting for Aldon to give me a call to discuss the way forward. Steve has also advised fittting a Lambda sensor next time it goes on the rolling road. The alternative ( which I can't really afford at the moment) is to fit a lumenition system, which Burtons supply for about £225. I have no knowledge of whether a lumenition system would be appropriate or what would be involved in fitting it. Do you have any thoughts about the use and settings of the dizzy, and whether this is likely to provide a reasonable basis for this engine? If I did go down the Lumenition route (now or later), how good are they and how easy are they to fit? Sorry to take the liberty of dropping this on you, but you came highly recommended 😬 I will buy you a pint at next months meet thanks Terry 1700XF - Team Lotus with flares. Link to comment Share on other sites More sharing options...
Peter T Posted June 21, 2005 Share Posted June 21, 2005 Ok, so i can calculate roughly, i need some more information on exactly waht spec you are using in your engine please. Cam profile and duration. Piston spec ( ie cast or forged & what make) Distributor number. Verniers fitted? There are several other questions i would like to ask also, did you purchase the engine with the distributor? What power did Vulcan quote for that spec, and have the Webers been rejetted to suit this? Sorry for the amount of info, but i need to assertain if your problems of detonation are directly related to just one factor. I have rarely seen this on x-flows, and they really are not to fussy when it comes to ignition requirements that are that fine, only when you start running very high CR's do they present a problem. Do you know how much advance steve dialled in ? I have a reference book that i can advise you of, but i am in my office now and not with me, so i will guide you with more info later. Carbon Components from K9 Composites Link to comment Share on other sites More sharing options...
Peter T Posted June 21, 2005 Share Posted June 21, 2005 PS, is this with an unleaded head, and what fuel are you using? With or without an additive? Cheers. Carbon Components from K9 Composites Link to comment Share on other sites More sharing options...
Terry Field Posted June 21, 2005 Author Share Posted June 21, 2005 Peter, Thanks for the quick response. To answer your questions as best I can; I am running a Kent 244 cam. I don't have any further details, although I could look it up when I get home. I believe it is a standard 244. Accralite pistons. No verniers The dizzy came off the original 1600 engine which preceded this one. It already has an 'Aldon' label on the side, but that is all I can tell you at the moment as the dizzy is with Aldon. Vulcan quote 145 bhp, and the carbs were rejetted by them. The head is unleaded, no additives, running on Optimax. I don't know how much advance Steve dialled in, save to say that he was looking for about 14deg btdc at the crank and 7deg mechanical on the dizzy. The only other info I have is that the engine C/R is reckoned to be 11.7:1 (Vulcan figure) and Steve measured each cylinder at 150+psi on the compression test. Let me know if you need anything more Thanks again, Terry 1700XF - Team Lotus with flares. Link to comment Share on other sites More sharing options...
Peter T Posted June 21, 2005 Share Posted June 21, 2005 Thanks that gives me something to work with. I'll get back to you later. Carbon Components from K9 Composites Link to comment Share on other sites More sharing options...
Terry Field Posted June 27, 2005 Author Share Posted June 27, 2005 Hi Peter, Did you get chance to give it any thought 🤔 i'm hoping that the guy at Aldon is back from holiday this week and will be able to have a look at the recalibration. Terry 1700XF - Team Lotus with flares. Link to comment Share on other sites More sharing options...
Peter T Posted June 27, 2005 Share Posted June 27, 2005 Yes i did give it some thought, sorry that i did not get back to you. Based on the figures that you supplied me, i think your problem lies elswhere regarding the detonation. Everyone imediatley thinks that just ignition causes the problem you have, but there is more contributing factors that are relavent, one being the fuel that you use. The ignition that Steve suggests is spot on, so hopefully this should sort your problem, but if it does not then i would recheck the exact amount of combustion pressure on each cylinder, this could assertain the amount of CR that you have, also would show any bad seating valves that also can promote detonation, but if it was me i would whip the head off and see exactly what has been happening, because it might only be one cylinder that is causing it. Carbon Components from K9 Composites Link to comment Share on other sites More sharing options...
Peter T Posted June 27, 2005 Share Posted June 27, 2005 Ps, i just remembered something, have you checked that your pulley markings are at TDC, i came across this once and found it was nowhere near it and when we timed it using a strobe we found it was more than 6 degrees out, not the end but something worth checking. Carbon Components from K9 Composites Link to comment Share on other sites More sharing options...
Terry Field Posted June 27, 2005 Author Share Posted June 27, 2005 Peter, Many thanks for the response. When you say 'based on the figures......your problem lies elsewhere' what did you mean? Are you saying that you don't think the dizzy issue is the cause of the problem? And I am using Optimax. Steve did check the TDC for that very reason, and checked it with a strobe. Im reluctant to take the head off yet, after all this is a new engine, but if the recalibrated dizzy doesn't do the job, then more drastic investigation will be called for. Terry 1700XF - Team Lotus with flares. Link to comment Share on other sites More sharing options...
JampJ Posted June 27, 2005 Share Posted June 27, 2005 I seem to remember Graham Sewell, contacting Aldon, and Combining figures from Dave Andrews to get suitable settings. graham.sewell@oracle.com. Cheers J&J JFDI (Just F*****g Do It) Link to comment Share on other sites More sharing options...
Barrie Posted June 28, 2005 Share Posted June 28, 2005 Does anyone have an address for Race N Road. Thanks Link to comment Share on other sites More sharing options...
Terry Field Posted June 28, 2005 Author Share Posted June 28, 2005 Spoke to Aldon yesterday and they confirmed that Steve Greenalds figures (7deg mechanical advance) were spot on for the engine. Top marks for Aldon - they rang me twice to discuss numbers and other bits of refurbishment to the dizzy, and will have it back in the post within 24 hours. Barrie, I think they are called Road N Track 07774 773824. Steve Greenald is your Man. Terry 1700XF - Team Lotus with flares. Link to comment Share on other sites More sharing options...
pete east Posted June 28, 2005 Share Posted June 28, 2005 Terryfield - I have had a Lumenition set up on my crossflows for 15 years and it is an outstanding piece of kit, I dont believe that I have had a single misfire in all that time. The sensor unit was damaged recently when the screw which secures it to the baseplate came adrift, but even this did not stop the engine which continued to run until the sensor got in the way of the beam splitter rotor, and knocked the blades off it, But it was an easy fix. It seems to be one of those things which does all it can to keep the car running and once installed needs no fiddling with (other than checking that the sensor securing screw is locked) I cant recommend the lumenition system enough. Link to comment Share on other sites More sharing options...
Terry Field Posted June 28, 2005 Author Share Posted June 28, 2005 Pete, That's great feedback. I must admit I am tempted, but just for financial reasons I am going to give the dizzy another go. If it doesn't work well enough, I may give you a call for some more info. Terry 1700XF - Team Lotus with flares. Link to comment Share on other sites More sharing options...
graham bass Posted June 28, 2005 Share Posted June 28, 2005 Terryfield, I have a bosch unit taken off my 1700 x-flow 244 cam etc. when I converted to emerald last winter. This has the electronic trigger and is as per bosch unit in Burton Catalogue (though the electronic box unit is not fitted to the dizzy body but on a remote lead) If you're going down the route of purchasing another distributor I can supply parts numbers etc if it provides an alternative option. Mail me if you want details. Regards Graham Link to comment Share on other sites More sharing options...
BrianHorn Posted June 28, 2005 Share Posted June 28, 2005 Just my tuppence worth....I fitted a Lucas Constant Energy ignition system as recommended by and purchased from Roger King. Have'nt had any trouble so far. About £245 IIRC. Link to comment Share on other sites More sharing options...
Terry Field Posted June 28, 2005 Author Share Posted June 28, 2005 Graham, thanks, wish I had known about that two weeks ago ☹️. Anyway, let's see how the new Aldon unit works. If not there seem to be plenty of alternatives on offer Terry 1700XF - Team Lotus with flares. Link to comment Share on other sites More sharing options...
pete east Posted June 28, 2005 Share Posted June 28, 2005 Terry - If you wish ,it would be worth visiting the Lumenition web site, as they have a downloadable set of pages which fully describes the systems and the fitting procedure (which is about an hours work max) I believe the only point about the system that I am not quite happy with is that you cant buy the plastic Chopper (beam splitter) separately. One is obliged to buy the fitting kit which to be fair is not that expensive (although the sensor and control module is a bit more pricey) and this contains two rotors one for a 4 cylinder and one for a 6 cylinder engine. I asked if I could have a kit which just had two 4 cylinder rotors in it so I could keep one as a spare and they said no, If I wanted another 4 cyl rotor i would have to buy yet another fitting kit at about £12. Apart from that the system is well worth having and even tolerates a bit of wear in the distributor. Link to comment Share on other sites More sharing options...
Terry Field Posted June 28, 2005 Author Share Posted June 28, 2005 Pete, many thanks, I will have a look. In fact, Aldon have rebushed the dizzy for me so it should be OK in that area. Terry 1700XF - Team Lotus with flares. Link to comment Share on other sites More sharing options...
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