David Jenkins
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| posted on 25/3/04 at 09:31 AM |
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Cheap rev limiter?
(don't know whether this should be 'engine' or 'electrics', but what the hell!)
Does anyone know of a basic rev limiter that can be used with a Ford X-flow engine? I'm not looking for any gadgets such as change lights - I
just want to stop it over-revving if I get carried away... 
'Cheap' is also an important factor in my purchasing decision... 
David
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timf
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| posted on 25/3/04 at 10:05 AM |
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http://www.autospeed.com/cgi-bin/browse.cgi?category=579&product=1003701223&skinny=&scope=shop&affiliate=&country=826&sc_recal
c.x=50&sc_recalc.y=12
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nick205
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| posted on 25/3/04 at 10:24 AM |
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David,
I'm sure I've seen 'mechanical' rev limiting rotor arms before. Have a look in the Burton Power catalogue or website.
HTH
Nick
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David Jenkins
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| posted on 25/3/04 at 11:09 AM |
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Tim,
The aussie rev limiter looked good - until I saw the postage! A$34 for the box, then A$27 for postage! Eek!
Mind you - still cheap...
David
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timf
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| posted on 25/3/04 at 11:11 AM |
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exchange rate at present works out at about £24 all in
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DNA Locost
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| posted on 25/3/04 at 11:17 AM |
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put a small sized house brick behind your gas pedal, this should limit your reving for just a few pence.
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Terrapin_racing
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| posted on 25/3/04 at 12:27 PM |
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Cheapest route is centrifugal rev limiting rotor arm (usually < £10)
Bosch do one - I've seen them fitted to CVH/OHC Pinto etc.
Not sure about x/flow.
Alternatively watch
www.racecar.com
sales site - I picked up a new OMEX rev limiter and launch control unit very cheaply.
[Edited on 25/3/04 by Terrapin_racing]
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Terrapin_racing
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| posted on 25/3/04 at 12:31 PM |
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PS: centrifugal rev limiting rotor arms cut the power like a b***ard - dead cut out
Not nice when your just on peak power.
I'd recommend a soft cut unit.
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David Jenkins
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| posted on 25/3/04 at 12:43 PM |
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Not desperately worried about a sharp cut-out - I'm just looking for engine protection when I cock up and miss a gear change, or get
over-excited!
I'm not going to be driving racing-style, up to the rev limit several times every lap.
Worth looking at, though... Burtons would be a good start, I guess.
Cheers,
David
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britishtrident
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| posted on 25/3/04 at 12:59 PM |
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The rotor arm cut off for Lucas distributer (as used on the original Lotus Twincam) aint cheap ---- was about 30 quid back in the 1980s as others
have said its brutal when it hits the rev limit.
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mranlet
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| posted on 25/3/04 at 06:10 PM |
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Most Go-karts use a simple bolt with a rubber bumper that hits the firewall at the target RPM.
If you're woried about weight, use a titanium bolt!
-MR
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blueshift
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| posted on 26/3/04 at 01:19 PM |
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Can anyone tell me how a soft-cut rev limiter works? I have been playing around with microcontrollers a bit recently and could possibly make a cheapo
homebrew rev limiter as well as the keypad immobiliser I'm thinking of. Maybe a combined unit.
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mranlet
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| posted on 26/3/04 at 05:05 PM |
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quote:
Originally posted by blueshift
Can anyone tell me how a soft-cut rev limiter works? I have been playing around with microcontrollers a bit recently and could possibly make a cheapo
homebrew rev limiter as well as the keypad immobiliser I'm thinking of. Maybe a combined unit.
...totally over my head...
Simplicity man!
-MR
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britishtrident
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| posted on 26/3/04 at 07:03 PM |
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quote:
Originally posted by blueshift
Can anyone tell me how a soft-cut rev limiter works? I have been playing around with microcontrollers a bit recently and could possibly make a cheapo
homebrew rev limiter as well as the keypad immobiliser I'm thinking of. Maybe a combined unit.
Many retard the ignition
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NS Dev
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| posted on 26/3/04 at 07:23 PM |
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don't know for 4 cylinder ford engines, but the 2.8i v6's (capri 2.8i, granada 2.8i or earlier Sierra xr4x4) had a rev-limiting rotor-arm
as standard, do they fit?
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David Jenkins
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| posted on 26/3/04 at 09:34 PM |
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quote:
Originally posted by blueshift
Can anyone tell me how a soft-cut rev limiter works?
I believe that they arrange things so that it only allows the engine to fire 'every other bang', or similar - divide by two - enough power
to keep the revs up, but not enough to rev faster.
David
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blueshift
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| posted on 27/3/04 at 01:01 AM |
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quote:
Originally posted by David Jenkins
quote:
Originally posted by blueshift
Can anyone tell me how a soft-cut rev limiter works?
I believe that they arrange things so that it only allows the engine to fire 'every other bang', or similar - divide by two - enough power
to keep the revs up, but not enough to rev faster.
David
Hmm. Could maybe do that, have to feed the ignition coil from something solid-state, wouldn't want to try switching a relay that fast.
Something to mull over when I'm not near the garage anyway.
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Northy
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| posted on 27/3/04 at 09:31 AM |
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Why not use MJLJ?
Graham
Website under construction. Help greatfully received as I don't really know what I'm doing! 
"If a man says something in the woods and there are no women there, is he still wrong?"
Built 2L 8 Valve Vx Powered Avon
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Stu16v
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| posted on 27/3/04 at 10:37 AM |
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David, unless you have done some serious tuning work to your engine, I wouldnt worry to much about the odd missed gearchange IMHO. A xflow in standard
form has made all its useful power at around 5000rpm, and there would be no point in revving it higher, unless, of course, you are in top gear! Then
the 'natural' rev limiter as supplied by Mother Nature herself comes into play-wind resistance.....
Missed gearchanges are a worry, but again, with an engine with lower states of tune, you usually realise you dont have drive before the enigne is
revved hard enough (and long enough) to worry about damage. Your mileage may vary of course, as wilder cams and lightened internals will let the
engine rev higher, and of course quicker.
If you are running points ignition, you have a natural rev limiter fitted anyway.
And of course, the best rev limiter in the world will not prevent damage if a wrong gear is selected on a rapid downchange. thats when things usually
get messy....
Dont just build it.....make it!
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David Jenkins
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| posted on 27/3/04 at 08:43 PM |
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Stu,
That's the way I'm starting to think - after seeing the cheapest rev limiter at over £60 I've lost interest!
My engine isn't tuned very much, so it'll peak out before I over-rev it, as you say.
I'll just watch the rev counter!
cheers,
david
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Jimbo
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| posted on 2/4/04 at 04:47 PM |
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Rotor arm rev limiter is Halfords part number HRA561 photo on this page
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