Willie
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posted on 17/5/03 at 03:19 PM |
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Lotus Twin Cam Conversion
Howdy Y'all,
Just in from a day and a bit of the Se7ens tour of Ireland (Lynch the Leprechaun). Some serious bits of motor car there, along with Cossie engined Mr
Hicost.
As I'm old fashioned I have a thing about Lotus Twin Cams. Stuff K series and Duratecs. It took Tim about 20mins to reset idle speed with a
laptop...30secs on a Xflow with a screwdriver. Development?
Anyway, I'm sorely tempted to stick a Lotus Twin Cam head on my 1300. It would rev well (Shorter stroke than 1600), and would go well with a
set of well set up webers etc. Does anyone have any sites or anything with information? I reckon if I got stuck in a did it I'd be able to,
but I'd like to read up a bit first incase there are legendary problems I don't know about.
I'll get the car on the road first, then stick head on later.
Take it easy, and any help appreciated.
Willie
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steve m
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posted on 17/5/03 at 09:13 PM |
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There is a twin cam head on sale on ebay
i would have thought tho that on a 1300 it would be pointless
steve
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Jon Ison
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posted on 17/5/03 at 09:19 PM |
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3 letters..BDA they used to rule the 1300cc NASA class till the bike came along..............
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Willie
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posted on 17/5/03 at 09:58 PM |
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Steve,
Everything is pointless unless you have a reason. Mine is the fact I live in N.Ireland and am 18. I can't get insurance. Adrain Flux tell me
that I can do what I like to the engine and they don't care, just as long as it's 1300cc. So, when you consider I know where
there's a Lotus Head sitting, that I have been told is mine if I want it...it makes sense.
Plus...it makes a lovely noise.
My main problem is insurance, so keep it small cc but high power. Before you cry Bike...I've the Xflow in and I'm not pulling it out now
(Nearly finished car).
Willie
p.s.If insurance permitted, a 2ltr Duratec would be nice...on webers naturally
p.p.s. Should have said, I Adrain Flux will quote me when I'm 19...only a year to wait. But worth it. After being in a Caterham Xflow and
then a K yesterday...boyo boy it's all worth it.
[Edited on 17/5/03 by Willie]
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jollygreengiant
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posted on 18/5/03 at 06:07 AM |
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should not give any problems, but you might have to change the piston and you would need the front timing cover or a modified one to fit cos the 1300
block is an inch lower. There was a chappie who built a special 1300 using an 1100 crank and over bored piston with piper fuel injection etc and it
reved to 13000rpm?
[Edited on 18/5/03 by jollygreengiant]
Beware of the Goldfish in the tulip mines. The ONLY defence against them is smoking peanut butter sandwiches.
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Metal Hippy
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posted on 18/5/03 at 06:46 AM |
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Christ, any idea what kinda power that thing had?
Cock off or cock on. You choose.
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david walker
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posted on 18/5/03 at 08:18 AM |
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Well, you are going to have to pull it out! -The engine that is.
You can't just fit a TC head onto a X'Flow and go. As the JGG says, there are pistons (and rods), front cover and other things to
consider.
You'll need Lotus pistons, which at std size, require you to bore your block by 60 thou. They'll sit down the bore, which will mean
you'll need to use 1600 rods. Even then there is a little block decking to do. The compression ratio needs sorting, there will be quite a bit to
take off the head - probably ruining it for anything else. Front cover needs quite a chop & modification as JJG says. Youll need to sort the
timing chain but thats the easy bit.
Removing your X'flow from the car will take you about half an hour. The rest maybe a few weeks! Costs are very high these days with Lotus Twin
Cams. All parts have become expensive. Jon Ison suggests a BDA (BDH actually) head. You would probably carry out that conversion for the same money
and have something marginally better.
Maintenance wise they are more complicated. Getting to the distributor on a 1300 TC/BDA in a Se7en will be impossible, so budget for a distributorless
ignition system also.
When it's done, and I kid you not, a really good X'Flow will keep up with it.
Dave Walker, Race Engine Services - 07957 454659 or 01636 671277
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Stu16v
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posted on 18/5/03 at 10:55 AM |
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Aa David says, loads of hassle. It would be easier (and probably cheaper too) to stick a bike engine in. And the bike engine will certainly be much
more reliable.
Dont just build it.....make it!
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Willie
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posted on 18/5/03 at 12:50 PM |
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Guys,
Thanks for the help/advice. I've still got a real mind to do it though. I like being different than everyone else, and if people say something
is difficult...I tend to do it.
I knew I'd have to pull it out, but I was more wondering what parts you'd have to use etc. I think you use half a camshaft and put the
chain around it then on up to the top sprockets etc. But I was wondering things like what rods, pistons etc do you use. Obviously if the combustion
camber is in the piston in the xflow, and in the head in the Twink, you'd be better to use different pistons unless you really want no
compression at all.
With the stroke being longer in the 1600, why do you use it's rods? I thought it would be use the 1300s rods with different pistons, and
possibly deck the block. Use 1600 rods, and deck the block...is that not going to end up with the piston way out the top of the block?
I think I'd likely put a big valve head with webers on the Xflow before the twincam, but I just think a 1300 Twin Cam would be fun. Alot of
work, but I specialise in making simple jobs complicated.
Bike engine would be ok, but I don't fancy one as much as I fancy a beast of a car engine to be honest. I'm not fussed on the sequential
change. In my opinion these cars are all about fun, you just do whatever you want for fun. I fancied one, so built one. I fancied air horns on it,
so put them on it. I fancy a Lotus Twin Cam in it... But I may go off that notion before I get stuck in.
Willie
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jollygreengiant
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posted on 18/5/03 at 09:56 PM |
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That chappie with the 1300 special twinc, he did run his own engine reconditioners. I think his name was Dennis Gregory. 1980 ish I think.
Enjoy.
Beware of the Goldfish in the tulip mines. The ONLY defence against them is smoking peanut butter sandwiches.
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