1.8s timing adjustment

[Simon Dobbo]

Hi all

sorry if this has been covered before but can’t find much info.

for a novice

i found the notch on the pulley and the pointer - already painted white.

when using my mates strobe do I want them aligned with no adjustment on the strobe.

or do I dial in 10 degrees before tdc and set it there?

im unsure and the Haynes manual is confusing me - plus do I set differently for using unleaded fuel?

I am running it on premium E5

[Sutty2006]

I can’t help with timing lights. I’m pretty crap with them myself and need to do my 2.0 CIH. 
 

these engines run on unleaded fuel not leaded, so bear that in mind. 👍

[Opeloutbacks]

When I collected my Manta it was effectively running on three cylinders, caused by timing being out a tooth on the pulley! 

I decided I best get the carb setup and timing at the same time. So mixture etc was aligned. I did time it with a stobe, to what I thought was right, but after gas analysis, it needed retiming. I thing 6 degrees, but don't have the printout to hand.

I had an old school krypton tune, by a mobile guy, but he won't leave Derby!

Edited September 15 by Opeloutbacks

[Opeloutbacks]

I aligned all the white markers, then timing was done

[Jessopia74]

Depending on the pulley! If original, then the needle and notch in pulley are the +10degrees advance set(so zero on your timing gun). 

[Simon Dobbo]

So I set the gun at 7 degrees in the end

 

does that mean I now have 17 degrees BTDC - 

 

guessing that too much but seems to run well and pull away with stalling more easily etc

possible small amount of pinking so will need to do again.

Without stalling I mean

[Jessopia74]

21 minutes ago, Simon Dobbo said:

So I set the gun at 7 degrees in the end

 

does that mean I now have 17 degrees BTDC - 

 

guessing that too much but seems to run well and pull away with stalling more easily etc

possible small amount of pinking so will need to do again.

Without stalling I mean

Yes, you’re at 7+10deg. That is too much. At 15degrees I did see a tiny about of det(knock) starting at around 3500 in 4th with full load, so backed it if 1degree and it was gone. If I could re-jet the Varajet carb it would help no doubt, but could not be bothered as I do have a plan to fit a 1800E head/plenum with Megasquirt that I have , if I ever get around to it 🫣

Edited September 15 by Jessopia74

[Simon Dobbo]

10 hours ago, Jessopia74 said:

Yes, you’re at 7+10deg. That is too much. At 15degrees I did see a tiny about of det(knock) starting at around 3500 in 4th with full load, so backed it if 1degree and it was gone. If I could re-jet the Varajet carb it would help no doubt, but could not be bothered as I do have a plan to fit a 1800E head/plenum with Megasquirt that I have , if I ever get around to it 🫣

Thanks again

 

Mine has had the varijet replaced with a Webber.

Eventually i might look at an old fashioned Crypton tune or a day on rolling road to ensure all set to full pottential.

Im guessing to more advance the better to a point

[Jessopia74]

8 minutes ago, Simon Dobbo said:

Thanks again

 

Mine has had the varijet replaced with a Webber.

Eventually i might look at an old fashioned Crypton tune or a day on rolling road to ensure all set to full pottential.

Im guessing to more advance the better to a point

Yes, (mostly) run as much as you can without hitting detonation. When tuning ECU's we run at just on the limit mostly, but within 2-3degrees in the upper rev range does not make as much difference to engine pickup in 

[Simon Dobbo]

A few years ago I had my Spitfire set up at Denis Vesey following exhaust and cam changes etc.

Made such a difference - I might give them a call and just go for it to ensure im getting the most out of the Webber etc.

[Jessopia74]

2 hours ago, Simon Dobbo said:

A few years ago I had my Spitfire set up at Denis Vesey following exhaust and cam changes etc.

Made such a difference - I might give them a call and just go for it to ensure im getting the most out of the Webber etc.

Definitely a good idea with the Webber 👍

[Simon Dobbo]

Booked it

 

Dennis Vessey rolling road tune and carb re jet if needed - Tuesday 8th October

 

Was set up by home mechanic so Im sure it cant hurt and will make a difference

Ad ill have new oil seals and clutch in by then

[Jessopia74]

1 hour ago, Simon Dobbo said:

Booked it

 

Dennis Vessey rolling road tune and carb re jet if needed - Tuesday 8th October

 

Was set up by home mechanic so Im sure it cant hurt and will make a difference

Ad ill have new oil seals and clutch in by then

Excellent, be interesting to see what they come out with jets. Is it a 36/38 carb? 

[berni]

There isnt any need to advance the 18s unless you want to create feuling issues and burn ya valves out quicker. May be nice off the lights now . Problems later 😏

[Simon Dobbo]

55 minutes ago, Jessopia74 said:

Excellent, be interesting to see what they come out with jets. Is it a 36/38 carb? 

No it is a 32/34 DMTL according to the paperwork that’s in the glovebox.

a kit from Eurocarb - says it’s correctly jetted etc for the Manta 1.8s

but guess it’s been set up by ear - a proper tune can’t hurt

43 minutes ago, berni said:

There isnt any need to advance the 18s unless you want to create feuling issues and burn ya valves out quicker. May be nice off the lights now . Problems later 😏

Possibly - not my area - I’m a gas engineer 😂

I’m sure Dennis Vessey will advise etc

they were good before

 

im interested to see what the output on rolling road is before and after.

 

wondering whether to do anything with exhaust before hand

rear 2 boxes have been replaced with stainless so know idea if they are standard shape etc or not.

i will take a better look at the weekend.

is it a CAT at the front?

want to keep it standard as possible as it’s so original - but it has had carb change

would love exhaust to have bit more sound to it - it’s very quiet and tailpipe is tiny

It’s always been a bit boggy and spluttering occasionally

 

[Jessopia74]

No CAT, it’s a resonator box. Is SS, then likely to be modern packed silencer design, so should be slightly less restrictive. Main restriction to most engines we use is what’s bolted to the engine. I.e inlet and exhaust manifolds, but they are still pretty good in comparison to older engine designs. 
 

I would have liked to see a bigger crb tbh, but it’s still more reliable than an old Varajet 

 

[Simon Dobbo]

3 minutes ago, Jessopia74 said:

No CAT, it’s a resonator box. Is SS, then likely to be modern packed silencer design, so should be slightly less restrictive. Main restriction to most engines we use is what’s bolted to the engine. I.e inlet and exhaust manifolds, but they are still pretty good in comparison to older engine designs. 
 

I would have liked to see a bigger crb tbh, but it’s still more reliable than an old Varajet 

 

Yes

as I say it was done before me and that’s what Eurocarb/Dellorto recommend

i certainly don’t want to spend out to replace if I don’t have to.

receipt with it shows was £500 ish as a kit and was only early this year

Haynes manual seems to say 10 DBTDC but go for 7 DBTDC for unleaded

so that is an advance isn’t it

We will see what we can get with the expert and the equipment

[Jessopia74]

Advance is more before TDC, so the pressure in cylinder is higher at point the piston reaches TDC. Ignore the manual, it was based on unleaded been lower RON then leaded, and the fact unleaded back then did not have any corn juice in it. 
 

With what fuel your going to be running, I would definitely expect your tuner to set initial more advance than 10degrees, possibly around 14.

[Simon Dobbo]

54 minutes ago, Jessopia74 said:

No CAT, it’s a resonator box. Is SS, then likely to be modern packed silencer design, so should be slightly less restrictive. Main restriction to most engines we use is what’s bolted to the engine. I.e inlet and exhaust manifolds, but they are still pretty good in comparison to older engine designs. 
 

I would have liked to see a bigger crb tbh, but it’s still more reliable than an old Varajet 

 

So the front pipe and box look original and a little like a cat but no sensors so thought not

rear 2 boxes replaced with stainless but look to be pretty standard not custom fitted

[Jessopia74]

17 minutes ago, Simon Dobbo said:

So the front pipe and box look original and a little like a cat but no sensors so thought not

rear 2 boxes replaced with stainless but look to be pretty standard not custom fitted

See what your man thinks when you get there I guess.

[Simon Dobbo]

On 16/09/2024 at 20:59, Jessopia74 said:

See what your man thinks when you get there I guess.

Hi

 

I stareted a new topic on carb adjustment and hot start.

Maybe you can help with some advice?

[Kr1s]

On 16/09/2024 at 19:30, Simon Dobbo said:

it is a 32/34 DMTL

This was certainly the standard, bolt on replacement offered for the 1.8 - I bought one for my first Manta.

It was smoother, had better throttle response and started better than with the Varajet, but it wasn't actually as quick, I imagine at least in part because ultimately the Varajet is bigger at 35/46.

[Simon Dobbo]

Had it run up on a rolling road

was running very lean.

new main and idle jet and it’s much smoother and has more power.

 

just have the hot running issue to look at now.

been flat out for 2 weeks so not had chance.

was getting it on mates ramp today to check breathers and fuel pipe but he’s ill so lost the chance

getting worried now as taking it to NEC in less than 2 weeks.

[BarryD89]

On 16/09/2024 at 19:30, Simon Dobbo said:

would love exhaust to have bit more sound to it - it’s very quiet and tailpipe is tiny

 

Can recommend the Sportex exhaust, nice sound at idle and positively encourages a throttle blip when changing down.  

[BarryD89]

On my old 1.8 Hatch.