TOPIC: 1979 Bedford RV 2.3 with Weber 34ICT and Groove positioning

Hi Folks,

I finally got access to this forum, been reading your posts and finding all very interesting what this little groove can do. A friend of mine got the personal licence and offered me to use these bits to groove the carburettor of our 1979 Hymermobil camper based on a bedford CF chassis.
The camper has a 4 cylinder, 2300cc engine with a Weber 34 ICT carb fitted. The engine has 80hp which is used to pull this 2500kg camper. I'm from the Netherlands, Europe so please forgive my metric numbers.

Anyways, I have two similar carburettors of which on is spare. We did the groove on that spare one with the medium bit which turned out quite nice. The groove is right after the closed throttle valve. We tried to get a 15 degree angle on the bit. There were some slight differences in jetting so I'm not sure if it was originally used on this vehicle. Put the jets in from the other carb and mounted it.

YES there is a difference, the engine idles smoother and will idle real low rpm. It seems to pull better with a little throttle but it's kinda hard to tell with this engine pulling a heavy load. I have also done the groove on our 1999 peugot 306 1.6i which is REALLY responsive to gthe groove but I'll save that for another topic I'll start.

So at cruising speed, which is around 90kmh of 55mph, I still need to give about 30-50% throttle to keep here there. This means the throttle plate is way past the groove which may decrease of effectiveness of the groove. We went away for a couple of days and found that we actually consumed 10% more fuel than normally. She does around 16 MPG but was now doing 14.5MPG. So not what I expected. I reasoned that it could have been various reasons but one being the groove not being optimally with regard to the throttle plate at cruising speed. Being really eager to get results I decided to groove the other carb as well. This time I adjusted the plate at about 70 degrees whereas 85 degrees is completely closed. This left just enough room for the groove to be made and so I did. The result is that the groove has more curve following the throttle plate. I kept the bit inline with the plate so I guess the angle is around 20 degrees.

I see most people cutting the groove right after a closed throttle plate. So one question I have is if my second groove with an partially opened groove that follows the plate is a good way to groove with engines that work hard (and thus more throttle). I haven't seen much discussion on that so I'd like to see what others think about this.

After fitting back the newly grooved original carb I found that the emulsion tube of the first grooved carb was totally different from the original one which is probably the main reason for the high fuel consumption. I have not done much driving with the latest setup other than around the block to feel things and make final adjustments to the ignition timing.
It does feel a bit more responsive but I guess we need to go the distance to see how she really does.

I have the sparkplugs gapped to 1.2mm and the timing is 9 degrees advanced from stock. The engine is nice and basic and does not have a PCV going to the inlet manifold, only brake assist and ignition advance.

Hope to get the discussion going about the groove positioning. I will shortly right up my experiences with the groove in our Peugot hatchback 1.6.

If you have any questions or suggestions, please let me know.

Floris

Her are two pictures of the first groove we did. Unfortunately I have not made pictures of the second groove but perhaps in the future I can.

Hope you find them informative.

Welcome to Gadgetmanland Floris!

Thanks for your post and pics!

Generally I think putting the Groove deeper down the throttle bore will reduce it's effectiveness since the throttle blade opens away from the bore wall. But with a few carb's to play with you can try, and can play w/ jetting too. Did the exhaust clean up? A big indicator.

Is that carb TB aluminum or iron can't tell from pics.

electronic ignition or points?

Sounds like simple engine, would love to see more pics of motor, what is engine make?

w/age I'd sure check all over for possible vac. leaks. Intake gaskets, vac. hoses, brake booster and dist. vac. advance also carb. gaskets.

Older carb. engines, usually lots of room for improvements w/ Ignition...

If crankcase looks dirty might try Ron's Castrol regular non-synthetic trans. fluid trick--1 Qt in engine oil, esp. if exhaust pulses at tailpipe.

Lots more to try, depends on your $$ and time...

Tracy G

Hi Tracy,

You might be right about the plate moving away from the body however, most air is directed towards the groove so in time, eventually, we will know more. Was just curious if people have tried this route...

The body of the carb is aluminium.
About the engine: a Bedford 2.3 liter slant 4 with points originally but I have that changed to electronic pickup. This fall I will install Aaron's plasma setup on this camper. Have most of the stuff ready.
I have 10 years experience with Hydroxy gas on engines but look forward to try some other stuff out there such as the plasma with water vapor/super steam and of course with the groove. Yes there is much we can do with this engine, very straight forward, no BS.

I don't have a vacuum tester yet but checked for leaky gaskets with some brake cleaner and found nothing suspicious. It idles at about 40hg inch of vacuum. The engine has about 150k km on it and does go through considerable amounts of oil. Yes it's leaking, hey, it's old british so it leaks. It also smokes a little on high vacuum so the valveseals aren't the best probably. And then you said that thing about pulsing in the tailpipe. Yeah it's doing that actually when idling with the tight advance now. With Stock advance it didn't cough but now some. Are you saying a good smack of transmission oil to the engine oil help cleanup the engine or improve anything??

OK so enough for today, it's too hot here. Happy to be here. Thanks for your time.

Tracy,

Would you care to explain what you mean when you said:

If crankcase looks dirty might try Ron's Castrol regular non-synthetic trans. fluid trick--1 Qt in engine oil, esp. if exhaust pulses at tailpipe.

Did Ron write something about this somewhere???

Thanks,
Floris

Hi Floris, I don't remember just when Ron started recommending the Castrol ATF trick, might try looking around here in the Index section. I've heard of this ATF trick before though, known of it for years, just never done it myself. I've been using XADO treatment from Ukraine in my engines had good results sellers on ebay have it.

Aaron's Plasma Ignition is great you will dig it, I've posted here about how I did mine.

I learned to think in terms of 2 things: Anything to increase efficiency, Anything to reduce losses.

Increase: fuel vaporization: (the Groove, kill vacuum leaks) carb. float level, jetting, idle mix
screw adjust., pressure regulator in fuel line
spark power
exhaust efficiency: free-flow mufflers, pipe diameters, exhaust wrap on pipes where
temps drop down to keep velocity up--NOT too close to engine!
engine compression efficiency: (XADO)
engine breathing: (K&N air filt. or similar, and exhaust system)

Decrease: Internal engine friction losses: Castrol ATF in oil to free lifters/valves, XADO to
cut friction/wear

rolling losses: 44PSI tires instead of 35PSI ones can run tires a bit higher w/ due
caution & diligence, alignment specs & front end part condition

wind resistence: can use Airtab stick-on airfoils on boxy-shaped vehicles search for
Airtab on internet, roll up the windows

toxic junk in gas: new hologram chip from holidium labs available at theholotree
dawt kom (get it?) cancels harmful junk in gas increasing
combustion efficiency (it does work)

Anyhow there's a few thoughts for ya, Floris...

Tracy G