X-Flow 1600 Distributor choices

[geoffd]

Hi all, I have a Kent engine in my 1970 Morgan that has been modified.
The engine is 1700cc, big valve Mexico head, BCF3 cam and is on a 32/36 weber, because there isn't room for 40's.
When I took it to the rolling road, they reset the timing so as not to give more than 35 degrees at 3500 rpm.
Because of a fuel delivery issue (sorted now with an electric pump) they couldn't complete the tune, although the car got to 108bhp, with a bit more to come.
The problem I have now is that, because the Accuspark dizzy is giving too much advance, the car is running retarded and hot at lower revs.
I need a dizzy that will give me 12 ish degrees at idle (950) around 23 degrees at 2000 and max out at 35 ish degrees at 3600 max.
I have been looking online, but none give advance curves.
The Aldon 103 FXY is listed as for tuned x-flows but again no figures.
I wonder if anyone has had a similar issue and did you solve it ?
Thanks in advance for any advice.
Geoff

[rallyrob]

Bestek ignition will add your own advance curve to one of their distributors, as will others too I would think, but I only know Bestek will do it for definite.

[Miniliteman]

The old figures for advance that are quoted are no longer applicable with modern fuels.
Total advance needed is much less than in the old days.
I've tested lots of XFlow/BDA/TC distributors over the years and the 103TC by Aldon looks like it could be what you want: 10 degrees advance at 2000 rpm, 24 total advance.
But Aldon could have changed their spec in the mean time so best speak to them or to Bestek as rallyrob suggested.

[Miniliteman]

Having said all the above ... I realise the 103TC from Aldon is a non-vacuum distributor and with a 32/36 Weber you should use a distributor with vac advance.

[HonkyWhiteTrash]

Having said all the above ... I realise the 103TC from Aldon is a non-vacuum distributor and with a 32/36 Weber you should use a distributor with vac advance.

Is that a typo? 103TC for a crossflow? Or do you mean 103FXY?

[Miniliteman]

No typo. The 103 series from Aldon can be used in any XFlow/BDA/TC just the advance curve is different and/or the vacuum advance is present or not.

[geoffd]

Thanks for the reply's. I'm not running vac anyway.
I have enquired with Aldon about the 103FXY and am awaiting a reply regarding the advance curve.
Have heard their their dizzys are a much better product than the Chinese offerings.
Wil have a look on the net for Bestek.
Thanks all, Geoff

[geoffd]

Hi again. had a reply from Aldon.
The 103 FXY gives crank advances of 0 @ 1000, +10 @ 2000, +24 at 5500.
Given 13 degrees at 1000 idle advance that would be 23 @ 2000 and 37 @5500.
Figures look good but I was always under the impression from tuners and tuning guides that max advance 35 - 37 should be achieved by 3500 - 3600
Am I missing something ?
Geoff

[Miniliteman]

Rpm at which max advance happens differs from engine to engine (spec).
I would use a distributor with vacuum advance that really helps not only with mpg but also for drivability.

[katana]

I would imagine if your current dizzy was fitted with a vac unit it would help with the retarded / hot running in the cruise area you speak of - higher vacuum in this area would advance the timing from its retarded state but leave the baseline advance for WOT application. Advance curve mapping is a tedious task but essential if you want a bespoke dizzy built - off the shelf maybe close but never exactly right!

[geoffd]

Thanks again.
After a long chat with Aldon and they had a conflab among the tuning staff as to whether an FXY or an FXR would be best, we decided to go with an FXR.
Will see when it arrives how it goes on the rolling road, and if it needs tweeking.
Fingers crossed.
Thanks all, Geoff

[Tony B.]

Geoff, I have a very similar spec but with a 234 cam and twin 40. I run an FXR with an igniter 1 and it works superbly, it was an FXY to start with and didn’t suit the engine perfectly but Matthew at Aldon recurved it to FXR spec and it’s perfect.

[geoffd]

Hi there. Very similar cams, in a way I wish I'd gone for a 234, but I built the engine nearly 20 years ago and the BCF3 was a tried and tested cam of the time (only done 400 miles since LOL )
I did attempt to put 40's on at one time but they won't fit - too close to the inner wing.
I think their discussion hinged around the carb type and the compression ratio. I can only guess at that as the head has shallow chambers.
I guess the "Y" is the safer bet, but they did say that once it goes on the rolling road, tweeks will be possible if necessary.
Hoping for the best, but at least the dizzy won't be out of a case from China and Aldon are on the end of the phone for assistance.
Have to wait 3-4 weeks for it but then straight to the rolling road and I will come back with results.
Best regards, Geoff

[Miniliteman]

So will Aldon supply a unit with or without vacuum advance?

[geoffd]

Hi there.
Non-vac unit which I'm happy with.
Have never run vac's on tuned engines since rallying Cortina GT's and Twin Cams in the 70's
Always found that they were too unpredictable.
Cheers for reply, Geoff