OK a Quick 1200 Q for you

I have a Brosel Solex H30/31 carb on my 1200 and a 60's VW (not Bosch) Dizzy but at partial throttle and under load I get hesitation and misfiring - when I floor it its fine. I've tried swapping the Dizzy for an early 60's Bosch one - no better - and I've cleaned out the carb (not actually driven it since doing the carb) - any idea what could be happening?

Could it be I have the wrong Dizzy (these are vac advance only) and its not advancing properly at partial throttle? If this is the case any idea of the best Dizzy for this carb (Model no etc).

Or is it another problem?

 

I would say first place to look is the pump jet on the carb....
Thats the little brass 'tap' that sits in the top of the carb...
When you operate the throttle, fuel should progressivley squirt from this tap....if they get blocked, it gives you massive flat spot and severe hesitation...
If its blocked up, the tap can be removed (simply pulls out with pliers once you have removed the top of the carb)....to clean, rod it with a either single strand of auto electric cable or fine steel wire (such as the type found on your wire brush!)
Then refit, make sure its all the way home and facing correctly down into the carb......then test again, if working correctly, your bug will now feel amazing!
GaV

 

I'll give that a go - I cleaned the carb and fuel suirts from it when I pull the throttle lever fast, but nothing when slow - I'll try again - hopefully that'll sort it! Cheers!

 

They can get 'part' blocked by dirt......also worth checking the accelerator pump diaphram.......

And, as its a 'replacement carb', the fuel taps are normally too small, I drill my ones out to .7mm, that sorts out the flat spots and gives the engine a bit more vavaavooom.....!

GaV

 

Wheres the fuel taps on the carb? Also is the accelerator pump diaphram the bit on the side?

Also the carb has only done 1800 miles

 

Thing is before it was serviced it was running perfectly - I had it serviced (not by me and by serviced I mean new plugs, points, condensor, valve clearances checked and adjusted, new fuel filter, new Dizzy cap and rotor arm) and it was running shite, since then its had another distributor fitted, then removed again as didn't make any difference, points re-checked, new coil, plug leads, new fuel lines, the carb cleaned (didn't clean the jet out as you described tho) timing checked and re-checked, oil changed. I've even had the carb set up using an emissions analyser.

Also in addition to the weird misfire its now having trouble hot starting - never did before Also this problem only occurs when the cars hot and off the choke, when its cold and on choke its fine?

The only thing the guy who serviced it did to the carb is he said there was a problem with the choke butterfly staying open which he adjusted.

 

Was he an aircooled expert ? a lot of people try and set it to lean to reduce emmisions but it works the other way with aircooled you need it richer to make it run correct sounds to lean to me. the other thought is the ignition timing needs advancing or setting for total advance.

 

Yes, pump diaphram is on side right hand side of carb.......
Fuel tap sit on top of carb (once you have removed the carb top) and looks like a small brass pipe, bent like a swan neck.....
Have you checked the timing.....?

 

I wish you lived closer to Bristol dude! I'd take my little 1200 to you for a 'spruce up '

 

My 1200 tip? Stick with it - they are good motors. Practice heel and toe so that you can utilise what power there is. And full throttle is the only throttle

 

Mines quick enough for me sits at 70 (as long as theres no hills) so i'm happy, for now

 

i got a 1200 engine, then i turned it 1496cc :lol:

the 1970 crank case takes bigger barrels and pistons but its at that point that you notice pistons/barrels/pushrods/deflector tins/headtins/heads/manifolds are all very different.

but happily I have fitted 1600 conrods/pistons/barrels/heads(SP) to a 1200 bottom end although i have yet to start it up!

what sort of limit RPM was is the crank good for?

im thinking of sticking in one of those 4500rpm governors in so i dont break the 1200 crank.

 

If you have fitted 1600 conrods, then the crank is not a 1200 crank.
13-1600 rods do not fit 1200 cranks...rods are too narrow.
BUT 1200 rods will fit a 13-1600 crank if you machine them, 1200 rods are too wide

1200 cranks are good to 5,000, mine often sees 5,500rpm.....they snap at anything over 6,000.......but flexing starts as low as 4,000rpm......
(if you flex them too much, metal fatique sets in and it may snap at tick over when you least expect it !!)
Bearing life on 1200 cranks often used above 4,500 is very short...expect less than 10,000 miles. The centre main wears on the sides but top to bottom remains untouched.......
If knew how to post pics, I have an excellent example.....

GaV

 

im positive its a 1200.

the heads were 1200, the pushrods were somewhere around 1/2-1" shorter! there is definatly several mm less throw. also the air deflector tins were several fins shorter than normal.

its a unit which was remanufactured at some point im wondering if its been ground different.the 1200 conrods were shorter and obviously has smaller gudeon pins.

im going to fit a governed rotor arm which limits it to 4500rpm so i dont break it, but looking at the specs in the haynes i have the power band is lower than a 1300/1600 anyway so i shouldnt need to rev it so hard.

 

One way of telling what crank is fitted, is by looking at what exhaust fits the motor...
If you have a 13-1600 crank (69mm) then only a 13-1600 type exhaust will fit (because the engine is at least 10mm wider)

The lil 1200 crank (64mm stroke) is narrower, which is why all 1200 engines have to use a unique 1200 only exhaust.

My guess is its a 1200 motor with a big bore kit (83mm 1385cc kit??)
This is the only big bore kit currently available for 1200's which have unique pistons machined to accept the smaller 20mm wrist pins.
(all 13-1600 motors use 22mm wrist pins)

GaV

 

it `was` a 1200 when I got it, D code block, smaller conrods with smaller gudgeon pins, 1200 heads etc and 77mm pistons

but 1600 rods(from a fastback) fitted to the crank and being a later D code case 1600 pots fitted into the case, so then i fitted 1600 SP heads etc

one thing i did do was with the heads off on build up i used my vernier caliper to measure to stroke, which came out at 64mm

so basically im ending up with a 64mm crank 85.5mm pistons and stock length barrels resulting in slightly lower compression.

this could be a unique combination engine i have built

 

I scratching my head, not sure how you managed to use 85.5 pistons and barrels with a 64mm crank ???

I did some sums......worked out that would give you a deck heigh of at least .250th
Thats a compression ratio of less than 5.25:1

Im surprised it 'starts'..........
Unless you had the barrels shortend / machined down ?

GaV

 

I havent tried starting it yet :lol:

hmm nice low compression, just right for a long lifespan :lol: or a turbo!
or even TVO fuel

im just doing it for the giggle really, its built for the total sum of a gasket set all the rest are bits i had kicking about.

soon as i get the inlet manifold sorted we`ll see what happens

 

Good Luck, let us know how it goes....
Ive got my vintage HOT 1200 to build this year.......
So far.......
1967 small bore 1200 case and entire bottom end
ERSON V300 cam (vintage early 70's cam!!)
1300 twin port heads
Twin Dellorto FRD 34's (baby dells)
but also have a twin Dellorto DRLA 36 kit (depends how brave I feel)
Not sure about pistons...
cant decide between 1192cc or 1385cc big bore kit.

GaV

 

Be brave Gav - the force is with you .............:lol:

 

1200 old skool cool

Me again...[1200 converted to 1385..power pulley..schradek oil pump...1;1;1; rockers] all sitting in a 65 6 v lowered front,empis,spax,empi shifter,etc etc......UPDATE on my carb set up...have now modified inlet manifold ends so that they slip into dual port holley bugspray manifold and cut and shut heat risers to fit.....now modifying throttle lever[extending distance from carb] and drilling new throttle hole in fan housing 4 inches to left of original near to coil[thats where arm is !!! soon be ready to fit onto my motor and will try post some pics if it all works........ps anyone lighten 6v flywheels? old speed/only way to go Ganzaigeorge

 

A Quick question for the 1200 experts out there - which is the best Carb and distributor setup for a standard 1200 Beetle engine to give it the best peformance and engine longevity?

 

HEAD SWAP

Can i fit 1300 twin port heads onto a 1200 case?Wont ther be a gap between top of barrel and side of head? If it can be done then please tell me how......thanks Ganzaigeorge

 

interesting this thread as my 1200 in my 59 runs sweet...was gonna upgrade my engine but much thought im keepin it as its rock solid and will sit at 60mph all day long...but...if i wanted to make it a bit quicker at little cost what will i have to do and what parts are needed?

 

Some anwers to your questions...
I find any Solex carb works well on the original 1200 manifold
28, 30 or 31......they all work well...however to get the very best out the lil engine, you need to up jet to around 130, if you fit a 'stack' on the carb (means running without original air filter) then you can run even larger gets, Im currently running a 140 main jet with a vintage Speedwell stack, the motor pulls strong to 80mph.

For the very best 1200 performance you need twin port heads, 1300 twin port heads have the correct bore register and will work with 1200 barrels....
My last HOT 1200 engine run twin port heads, late 1200 pistion (high compression type with dome) engle 100 cam etc....
I was quiker to 60 than a stock 1600 beetle, was still running the tiny solex 28 carb but managed a 20sec 1/4 mile drag race, thats a whole 4 seconds shaved off the 0-60mph time !!! and I didnt even fit the twin carbs!!
GaV

 

Quoting the mighty HOT 1200:

Some anwers to your questions...
I find any Solex carb works well on the original 1200 manifold
28, 30 or 31......they all work well...however to get the very best out the lil engine, you need to up jet to around 130, if you fit a 'stack' on the carb (means running without original air filter) then you can run even larger gets, Im currently running a 140 main jet with a vintage Speedwell stack, the motor pulls strong to 80mph.

This may help with your jetting predicament!

 

i have a 72 1200 bug and i love the engine to death its just so damned nice!!!! id love some extra poke out of it i have heard of the big bore kit but had no idea where its from also can you tell me if the 1300 heads bolt staright on??? also will the inlet manifold need modifying as im guessing you have to use twin port manifold ends!!!!

 

Yes the 1300 twin port heads bolt up, no problem
(you will need to trim down the top centre head studs and find some t/p cylinder tinware)
Use a 1300 t/p port set up and your existing 1200 carb (if you use a 1600 t/p set up, you will need to find a solex 34)
But, best to take advantage of the twin port heads and run some small twin carbs (such as Dellorto FRD)

A 1192cc (1200) engine can make over 60bhp with the right bits and be totaly drivable with no over heating issues which bother bigger engines...use a nice 4 into 1 1200 header (still available) a very mild cam, some twin port heads, twin carb set up and a power pully, and you will be amazed.......:lol:

 

Out of curiousity how much would it cost to get a 1200 built up to that spec?

 

Allow £300 for parts, if you want 1385cc pistons
(does not include exhaust and carbs)

With the twin carbs, tuned exhaust,1385cc pistons, Engle 100 cam, twin port heads, power pully , you should see 60+bhp (Ive had 58bhp from 1192cc)
Not amazing but you will have a Bispoke fully balanced vintage style 1200 motor

 

I charge £350 plus parts........
(add £150 for total balance and matched weighted pistons if required)

Allow £300 for parts, if you want 1385cc pistons
(does not include exhaust and carbs)

With the twin carbs, tuned exhaust,1385cc pistons, Engle 100 cam, twin port heads, power pully , I will gaurantee you 60+bhp (Ive had 58bhp from 1192cc) and will even rolling road it for you with print outs to prove it:lol:

You wont get much change from £800, but then isnt that the price of a cobled together Recon engine from big glossy adverts?
But you will have a Bispoke fully balanced HOT 1200.....One of my customers has had his HOT 1200 for three years now, no problems and gives it 'stick' at every opertunity

where in Norfolk are you, highly interested in warming up my original 59 split 1200 at some point in the future.

 

For those thinking of fitting a HOT cam to their 1200 motor....
Keep it mild......very mild.......!

High duration/high lift cams increase Valve Overlap (inlet and exhaut) open at the same time. This 'bleeds' off cylinder compression at low r.p.m (hence the reason perforance cams can have a 'lumpy' tick over.
Now this is fine on a larger cc'd engine say 1600 and bigger, but if you have the tiny 1192cc, then choose your cam wisely !!!!
I built my HoT 1200 motor with the Engle 100 and found it to be a perfect match for the lil old 1200, its got plenty of lift but limited duration.
Look at the cam data, keep overal duration less than 280, this will help keep the power band where you want it (below 5,000 rpm)

GaV

 

. . .I have found the Engle 100 to be a perfect match for the lil old 1200, its got plenty of lift but limited duration.

GaV

GaV - Have you run the Engle 100 on a 1385?

How did you like it if so?

I recently broke in my 1385 with E-100, 1.1:1 rockers, 28 PICT1 I plan to upjet if need be, '65 square boss heads, 34mm intake manifold. Happy so far but the car is in paint and I will not drive it for another 4+ months.

Not looking for a huge increase, just a little extra. Trying to keep the car as original 'looking' as possible.

Couldn't pass on the black Santana pulley though