Rallycross 1600 EG on 45's GS6 for my road car...........comments on parts requested.

the beast lives!
Jon

 

Excellent

 

cheers, need a rroad session now to run it in and find out if its got any power....
Jon

 

Back onto the std SA 1600 carb engine.
Well after a full std rebuild I have run it now in my CITI for > 6 months now std and it never fails to impress me.
You genuinely would be surprised how quick it feels.
Think the car must be very light, as its the poverty model with no std features at all.
It carburation is probably the cleanest of anything I have experienced (choke in winter for 1 mile), and it returns 40mpg round the doors.
Fires up in 1 to 2 secs after cranking.
Jon

 

I saw a citi at the weekend, I don't like the front end personally, looks like someone fitted a mk2 grill to a mk1 but otherwise, it looked good! if I had one I think I would look to fit a mk1 grille to it

did the race engine work in the end?

 

Holy thread revival.
To answer the race engine question, no, well not to my satisfaction anyway.
Rose tinted glasses makes me remember rallycrossing it in the early 90's and it had a tremendous power band.
Nothing, nothing, nothing then all hell broke loose between 5 and 8000rpm.
This motor isn't like that.
It makes about 150 on the rollers, but just doesn't sound right, to my deaf old ears.
It'll rev, so all 4 cylinders are working. I have tried another set of 45's, tried some different jet combos, played with ignition timing
the lambda on the gauge looks near right.
Can't play with the cam timing, as there is literally no spare clearance.
There isn't the urgency about the way the rev counter swings at the top end.
Or maybe I have been running 2 litre motors too long, and have got spoiled
I could rebuild the race 2L and whack that back in, but then I would have a race EG collecting dust..
So, what to do? Persever a bit more, I think..
So, radically, I am going to take out the GS6 cam and replace it with a 'normal' full race item. Whatever's on the shelf, I know there
is a GS3 there for sure.
Any fit another four branch as one of the tubes has a dint in it
Will let you know how I get on
Jon

 

Dyno results from last week, may get a bit of tech banter going (site is lacking tech imho)
Jon
25C ambient on the day so power is going to be down, probably 5 to 10hp, so matching my guestimate

 

Ok, a touch more tech for the ancient petrol heads that still use carberetters;
Lesson 1: A single size main jet change makes a significant difference to the AFR. Like, measurable for '5' change. So, get you mains sorted before your air correctors.
One size too small is a defo no-no.
Lesson 2: mega cams need huge idle jets on dcoe's for reasons I don't really understand. I mean LARGE, if my AFR gauge and the RR one are to be believed.
Lesson 3: Always doubt instrumentation......................
Jon

 

Hello Jon, with lairy cams you won't get and actual afr in the cyclinder due to the overlap from what I've read and experienced.

Best off tuning by ear at idle and as long as it idles fine call it a day.

Even my relatively mild Kent 1602r's exhibit this behaviour to a lesser extent.

Race cams don't have any compromise built in for low revs, same as motorcycles they all struggle to idle well, it's all in the tuning.

Nice pictures and tinkering in your shed, keep up the good work .

 

Anything less than mega sized idles and it was spitting back (indicating a too lean mixture) at idle.
Once past 3 turns out on the mix volume screws you cannot get more fuel into the idle circuit. So up a jet size.
Strangely the dash lambda still says lean.
It ticks over fine, for a 328 degree cam..........
Jon

 

Just euro ised the front of my CITI, think it looks ok
Jon