How to: Engine jetting and timing

[pkrboo]

I know you like a dizzy but using a megajolt ECU replacement dizzy running off the MAP maybe the way forward?

[Zed]

Apr 9, 2018 15:20:38 GMT pkrboo said:

I know you like a dizzy but using a megajolt ECU replacement dizzy running off the MAP maybe the way forward?

I don't like them, but I like that there aren't endless ways to set them up. One less thing to learn. If I accidentally did learn, I'd have to go mapped, but I don't fancy it the other way round. Ignorance is bliss.

[Eoin]

Apr 9, 2018 15:51:51 GMT Zed said:

Apr 9, 2018 15:20:38 GMT pkrboo said:

I know you like a dizzy but using a megajolt ECU replacement dizzy running off the MAP maybe the way forward?

I don't like them, but I like that there aren't endless ways to set them up. One less thing to learn. If I accidentally did learn, I'd have to go mapped, but I don't fancy it the other way round. Ignorance is bliss.

But you're not ignorant any more. It's a slippery slope.

[Zed]

Apr 9, 2018 16:40:26 GMT Eoin said:

Apr 9, 2018 15:51:51 GMT Zed said:

I don't like them, but I like that there aren't endless ways to set them up. One less thing to learn. If I accidentally did learn, I'd have to go mapped, but I don't fancy it the other way round. Ignorance is bliss.

But you're not ignorant any more. It's a slippery slope.

Quite often I think I understand something, then later I realise I didn't.
Spent a fair bit of today failing to hear the hiss of a leak but with the servo end of the pipe plugged I still have a tuning anomaly that goes away with the manifold ports blocked, so... I going to replace all the pipe, totally remove the steel bit in the engine hole and add another one way valve at the engine end. Normally there would be one hear bit as Brazzy servo vac inlet doubles as one I didn't fit one. I don't suppose it'll help but will allow me to remove the engine more easily so might as well.

[pkrboo]

Apr 9, 2018 15:51:51 GMT Zed said:

Apr 9, 2018 15:20:38 GMT pkrboo said:

I know you like a dizzy but using a megajolt ECU replacement dizzy running off the MAP maybe the way forward?

I don't like them, but I like that there aren't endless ways to set them up. One less thing to learn. If I accidentally did learn, I'd have to go mapped, but I don't fancy it the other way round. Ignorance is bliss.

Bad phrasing by me.

[Zed]

Apr 10, 2018 9:26:25 GMT pkrboo said:

Apr 9, 2018 15:51:51 GMT Zed said:

I don't like them, but I like that there aren't endless ways to set them up. One less thing to learn. If I accidentally did learn, I'd have to go mapped, but I don't fancy it the other way round. Ignorance is bliss.

Bad phrasing by me.

I knew what you meant and you were right, I just can't face it! Hopefully I'll get running well enough to be satisfied with my 1970's technology at which point further fine tuning won't be possible so I can go back to ignorantly driving it.

Just realised why my diddy jets haven't turned up - they sent them to demented dad's address. More now sent at no cost.

I've been shopping at The Green Spark Plug Co. Cheaper than Eurocarb, free post, nice people. 👍

[Zed]

Update.

Servo hose replaced with stiffer wire reinforced stuff to one manifold. Non return valve fitted near engine. Balancer looks much better but still not the same as when both manifolds are blocked. It'll have to do.

48 idle jets arrived and fitted. Now with main stacks out and accelerator pumps backed right off I'm between 14.5 and 17 AFR. Engine is still happy, no bucking and farting. 14.7 and thereabouts is the hottest, the "death zone". Leaner still will be ok if the egine doesn't fart so I'm going to get some 45s. They don't come any smaller.

I was hoping this process would gelt me to a bucking and popping idle jet so I could go back one bigger and know I'd done my best for lean cruise. Maybe the 45s will do that.

Meanwhile, like a naughty boy eating cake without finishing his sprouts...

Down from 145 to 140 mains. Too lean and pinking under lowish revs WOT. 145s are also on the lean AFR side, but despite them being technically already too big for 32 vents, I'll order some 150s.

[Zed]

WOT from 1500 to 4500rpm in 4th starts at 14-15 AFR and gets progressively richer to 10.8. Something to be fixed there. I'm thinking different airs, I've asked on the Samba but they'll all be fast asleep I expect.

[chad]

So what are you going to do when you've got this tuned?

Tune your canal boat engine with a big turbo and intercooler?

[Zed]

Apr 14, 2018 12:11:52 GMT chad said:

So what are you going to do when you've got this tuned?

Tune your canal boat engine with a big turbo and intercooler?

Paint the boat, starting with the roof.

[chad]

Is painting canal boats a sort of Forth Bridge job or can you do it and then leave it for a few years?

(assuming it's not a concrete one)

[Zed]

It depends how well it's done. I hope for 8-10 years.

[VW Toast]

You only doing all this tuning so you can hang with the BWA crowd and talk bollox while looking at tottie

[Zed]

Apr 19, 2018 7:52:21 GMT VW Toast said:

You only doing all this tuning so you can hang with the BWA crowd and talk bollox while looking at tottie

I'd have to add a turbo to do that. It's not a fast bus, I just wanted it tuned properly.

So far I've managed to confuse myself. I put the original guessed jets back in to go camping as it hasn't gone bang with those! I'll start again when I get home.

[boris]

Apr 6, 2018 16:46:01 GMT chad said:

So that's why you now have a top speed of 35mph:

" When I say fine I mean it doesn't object, cough or splutter, but it doesn't go very fast, 35mph tops."

You would be surprised. Sometimes I look down at the gauge and on the flat or downhill around 65mph I see 15:1 to 16:1 and its running on the primary barrel judging by how far off the floor the accelerator pedal is.
Up hill it hits 12:1 and lower if I can hit the bottom of the hill rolling above 60 mph as the power valve cuts in.. coming off the top of the hill it will still be doing 60mph.
Same hill struggle to reach 50 mph if hit it below 55...