02GF74
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| posted on 18/2/06 at 11:37 AM |
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quick question 3; vacuum advance and timing
first part of q is relatively easy; not so sure a bout the second.
I have 1300 cc crossflow; no idea if standard cam but block has been skimmed so slightly higher CR. It was twin dellorto 40.
Now I am looking for a side entry cap, see other Q; found geezer selling bosch for fast road/rally applications with no vacuum advance. So first
question:
1. how will having no vacuum advance make a difference? (I understood it was there to help economy at low rpm). I am not interested in economy just
max power!!
2. secondly they can build it to any advance curve; what advance should I go for bearing in mind I have no idea of engine build?
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rusty nuts
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| posted on 18/2/06 at 01:10 PM |
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Using Dellorto's will not give a steady vacuum so you won't need vacuum advance . The only accurate way to check for advance curve would
be a rolling road? checking the best amount of advance at something like every 500 rpm . Use a Valencia distributor and Peugeot 205 GTI side entry cap
. May be worth thinking about Megasquirt systems which can be programmed easily ?
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paulf
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| posted on 18/2/06 at 01:12 PM |
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If you fit Megajolt you can throw the dizzy away , and set the advance to exactly what you require by adjusting on the road or rolling road.You will
also get a built in rev limiter and shift light outputs.
Paul.
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Deckman001
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| posted on 18/2/06 at 01:22 PM |
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quote:
Originally posted by paulf
If you fit Megajolt you can throw the dizzy away , and set the advance to exactly what you require by adjusting on the road or rolling road.You will
also get a built in rev limiter and shift light outputs.
Paul.
T'is the way to go !! 
Jason
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phaeton
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| posted on 18/2/06 at 04:09 PM |
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Megajolt is the way to go. It works great on my crossflow
[Edited on 18/2/06 by phaeton]
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phaeton
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| posted on 19/2/06 at 10:32 PM |
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The megajolt setup cost me about 160 euro (= +/- 110 pound?). And i have got a lot of spare parts. I've orderd the components with RS so
everything in multiples of 5.
I havn't got a rr plot after installing the MJ but idle is a lot smoother and it starts very good. After installing the engine hasn't run
for about 3 months and started the firsttime. Normally i had to fiddle a lot to get the engine running after such a period.
ps. I'm using a TPS when using a map sensor it will be more expensive
[Edited on 19/2/06 by phaeton]
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paulf
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| posted on 19/2/06 at 10:40 PM |
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hi Dave .
£75 for a TPS megajolt and £85 for a map sensor version, plus the cost of the ford edis and coil pack plus about £20 for a trigger wheel for a
crossflow.
My car runs much smoother with it but dont have any rolling road data..
Paul.
quote:
Originally posted by Dave Ashurst
quote:
Originally posted by phaeton
Megajolt is the way to go. It works great on my crossflow
[Edited on 18/2/06 by phaeton]
Does a complete megajolt installation work out about the same cost as a new rally distributor?
Around £150 ?
And as anyone got rolling road plots comparing megajolt with distributor ignition?
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02GF74
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| posted on 20/2/06 at 09:51 AM |
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quote:
Originally posted by Dave Ashurst
quote:
Originally posted by phaeton
Megajolt is the way to go. It works great on my crossflow
[Edited on 18/2/06 by phaeton]
Does a complete megajolt installation work out about the same cost as a new rally distributor?
Around £150 ?
And as anyone got rolling road plots comparing megajolt with distributor ignition?
there's a geezer on ebay6 selling the non-vac dizzy for £90.
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02GF74
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| posted on 20/2/06 at 09:52 AM |
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quote:
Originally posted by rusty nuts
Using Dellorto's will not give a steady vacuum so you won't need vacuum advance .
yay, saw similar repsonse for simil,ar question.
The engine seems to idel quite smoothly with the advance, pipe connected to front carb. I guess I can disconnect and plug the carb to see what
difference it makes.
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