1776 Jetting tips needed guys :)

[Lee.C]

Hey guys as the title says I need a few jetting tips for my frind (G77) 1776cc type 1 motor, Here are the Spec's:

- AS41 case, full flowed etc
- 69mm Counterweighted VW crank
- 90.5 cima b+p
- FK8 Cam
- 1:1.4 Ratio Rockers
- Straight cut timing gears
- Berg Cro-moly pushrods
- Scat mini D port heads 40x37.5
- Scat H beam rods
- 40 DRLA's on short match ported manifolds
- 9:1 Comp ratio
- Berg Deep sump
- Berg 30mm HD oil pump
- Berg equalizer pulley (stock size)
- 1-5/8 Stainless header & Turbo muffler
- Bosch 009 dizzy with petronix2 electronic ignition (10degs BTDC @ idle - 32degs BTDC @ 300rpm)
- 8mm HT leads
- Stock fuel pump/ 8mm fuel line

So what would you put in as a base setting/starting point  Let here your views- idles, mains, emulsion tubes, venturi's etc etc 

Thanks for the help guys 

[Jim Ratto]

which venturies are in the carburetors now?

[Lee.C]

I was hoping you would drop in dude 

It has 32's in there at the moment BUT I was thinking that may be alittle big

Here is one set up I know has been tried but it seems to get very "chocked up" apparently 
32venturi's, 60idles, 140mains, 180emulsion tubes

[Jim Ratto]

with that K8 cam I think they're a little SMALL
I'd go for at least 34mm, but would really want 36mm

145 main (maybe 150 depending on how well that motor picks up into the main circuit)
175-180 air

Idle jet? I'm guessing a 55

I set up an almost exact motor of what your friend has, except it had 48IDAs and we used 36mm vents and 145 main, F11, 180 air, and 60 idle (they were 48IDAs after all)

That engine should kick some serious ass.

[nicolas]

i think 32's can work... but i am not an expert.

50 (as it is clogging up like you say) or 55 idle should do the trick

135- 140 fuel

180 (always on DRLA's small vents)

the emulsion tube is hopefully the correct one. i can't seem to remember which one to use at the moment, but i had the 'wrong one' installed in my engine and it did not perform well at low rpm's, but would haul a$$ above 4000 rpms.

this could work on a good torquey setup, but i am not sure what the fk8 does rpm wise in a 1776.

[Lee.C]

with that K8 cam I think they're a little SMALL
I'd go for at least 34mm, but would really want 36mm

145 main (maybe 150 depending on how well that motor picks up into the main circuit)
175-180 air

Idle jet? I'm guessing a 55

I set up an almost exact motor of what your friend has, except it had 48IDAs and we used 36mm vents and 145 main, F11, 180 air, and 60 idle (they were 48IDAs after all)

That engine should kick some serious ass.

i think 32's can work... but i am not an expert.

50 (as it is clogging up like you say) or 55 idle should do the trick

135- 140 fuel

180 (always on DRLA's small vents)

the emulsion tube is hopefully the correct one. i can't seem to remember which one to use at the moment, but i had the 'wrong one' installed in my engine and it did not perform well at low rpm's, but would haul a$$ above 4000 rpms.

this could work on a good torquey setup, but i am not sure what the fk8 does rpm wise in a 1776.

Thanks for all the help guys - I was thinking the idles were alittle big - more road tests I guess 

Also nicolas - we seem to have the opposite problem to the one you describe with the emulsion tube - every thing seems ok till about 4500/5000 then eventually it starts coughing and banging no matter what the setup 

One last thing - what fuel pressure would be good for a set up like this 

Cheers guys

[Lids]

3.5 psi, but what fuel pump are you using?  the cb rotary one doesn't need a regulator.

[Lee.C]

as it says in the spec's dude - stock pump with 8mm fuel line 

[Jim Ratto]

if you're having ONLY high rpm misfiring issues, it very well may NOT be the carburetors. I'd look @ ignition.

There's a difference from jetting for ultimate power/response, and trouble-shooting because of poor running. I'd avoid screwing around with carbs until your friend makes sure everything else is in working order...

head torqued?
valves adjusted?
Cam not flat?
New plugs that are gapped and firing?
ignition set up is tuned and working right?
Vacuum leaks?
float levels dead on?
Linkage working together?

BTW stock fuel pumps can create WAY too much pressure if they are not shimmed right. But your friend would probably experience rough running at part throttle and idle if it were receiving too much pressure.

I don't know Dells like I know Webers, but i think you're looking at jets and should be trying to trouble shoot an issue. 

[fish]

What Ratto said + with 1776, K8, 1.4, 9:1 you really want bigger carbs, 45 drla/ 48 idf, 36 vents, 55-60 idle, 155 main, 180 air, F11 or equivalent, make sure your 009 isn't floating.
Let us know how you go.

[Lee.C]

if you're having ONLY high rpm misfiring issues, it very well may NOT be the carburetors. I'd look @ ignition.

There's a difference from jetting for ultimate power/response, and trouble-shooting because of poor running. I'd avoid screwing around with carbs until your friend makes sure everything else is in working order...

head torqued?
valves adjusted?
Cam not flat?
New plugs that are gapped and firing?
ignition set up is tuned and working right?
Vacuum leaks?
float levels dead on?
Linkage working together?

BTW stock fuel pumps can create WAY too much pressure if they are not shimmed right. But your friend would probably experience rough running at part throttle and idle if it were receiving too much pressure.

I don't know Dells like I know Webers, but i think you're looking at jets and should be trying to trouble shoot an issue. 

Thanks for all the tips dude but it is almost certainly jetting - the "faults" for want of a better trem only show up after a while of driving and trust me the plugs are BLACK when checked - we do have some IDA manifolds for these heads though

[Jim Ratto]

how are you checking plugs? With clean cut after high load in top gear? If not the plugs being black doesn't mean anything.
And if you are and the plugs are black, it could be because of excessive pressure, a bad float, float setting off, a leaky needle valve.

BUT..... 

again, I come back to this! If it only runs poorly at higher rpm, it most likely is not because it is jetted too rich

In my experience, a too rich curve (even way too rich) won't run "bad" at high revs. It won't run as good as the correct mixture, but it won't raise your eyebrow and get you to start unscrewing shit out of the carbs. For instance, I had a piece of crap liquid filled fuel pressure gauge that had me pulling my hair out about 15 yr ago. Car would warm up and it ran fine, but the gauge showed 0psi, so I cranked up the Holley reg until it "showed" 3psi. BUT, then the car ran like pure crap, UNTIL it came up on cam and ran up in  the revs, then it cleared out, and ran hard (again not as hard once it was correct). At lower rpm, under any load, it was burbling, coughing, black acrid smoke from muffler, horrible throttle response, but i would keep my foot in it and hold the gear, and it would come up in rpm and cleanup and go! If kafercup reads this he will most definitely remember this.... he was driving behind me and his eyes were red and he was getting asphyxiated! Turns out the gauge was wrong and fuel pressure was probably up @ 6psi! A new non liquid filled unit fixed it all.
Too rich will kill throttle response, give you a soft idle, run rough as it comes up on mains, but then it should run acceptably. This is typical. I'm sure a way over-rich situation could really kill top end running, but more than likely it is something other than jets, dude. I'd rule out any ignition trouble before anything else.

Valve adjustment, heaad torque, bad spark (for a number of reasons!) all will cause "black plugs"... even point gap!

[Lee.C]

how are you checking plugs? With clean cut after high load in top gear? If not the plugs being black doesn't mean anything.
And if you are and the plugs are black, it could be because of excessive pressure, a bad float, float setting off, a leaky needle valve.

BUT..... 

again, I come back to this! If it only runs poorly at higher rpm, it most likely is not because it is jetted too rich

In my experience, a too rich curve (even way too rich) won't run "bad" at high revs. It won't run as good as the correct mixture, but it won't raise your eyebrow and get you to start unscrewing shit out of the carbs. For instance, I had a piece of crap liquid filled fuel pressure gauge that had me pulling my hair out about 15 yr ago. Car would warm up and it ran fine, but the gauge showed 0psi, so I cranked up the Holley reg until it "showed" 3psi. BUT, then the car ran like pure crap, UNTIL it came up on cam and ran up in  the revs, then it cleared out, and ran hard (again not as hard once it was correct). At lower rpm, under any load, it was burbling, coughing, black acrid smoke from muffler, horrible throttle response, but i would keep my foot in it and hold the gear, and it would come up in rpm and cleanup and go! If kafercup reads this he will most definitely remember this.... he was driving behind me and his eyes were red and he was getting asphyxiated! Turns out the gauge was wrong and fuel pressure was probably up @ 6psi! A new non liquid filled unit fixed it all.
Too rich will kill throttle response, give you a soft idle, run rough as it comes up on mains, but then it should run acceptably. This is typical. I'm sure a way over-rich situation could really kill top end running, but more than likely it is something other than jets, dude. I'd rule out any ignition trouble before anything else.

Valve adjustment, heaad torque, bad spark (for a number of reasons!) all will cause "black plugs"... even point gap!

Again thanks for the indepth info dude - as I said this has all been passed on to me and I have had no hands on experience with this engine YET so lets hope Gav (G77) reads this and takes some notes 

P.S as far as I know the 009 dizzy is perfect and has a brand new petronix kit in it 

[Lids]

as it says in the spec's dude - stock pump with 8mm fuel line 

My advice would be to ditch it, fit the CB, then no need for a regulator, just a tee piece.  Its a rotary pump, mounts under fuel tank really really quiet.  it comes with push fittings so it cna be hooked up in a matter of mins.

New 009's are shite.

[Bruce]

50 (as it is clogging up like you say) or 55 idle should do the trick

I've never been able to make a 50 idle jet work below 10,000' elevation.
The jets he has should be close.  If the engine is running like crap, it isn't the jets.

[Neil Davies]

Lee, what plugs are in the motor? I had a bad batch of Champion plugs several years ago in my brother's bug which would misfire as the engine warmed up, more at higher revs. Worth getting a different brand of plugs from a different shop and swapping the lot. Even try stuff in the Manx and swap piece by piece so that you know what works.

I've also had a cracked rotor arm on my Ghia which caused similar misfires...