db's 66 Belvedere ***FOR SALE***

db · Post by db » Sat May 12, 12 6:31 pm

Great thanks mate

db · Post by db » Tue May 15, 12 10:07 pm

Two steps forward:
I made a longer and much improved clutch adjuster rod- i can now select gears with the engine running!

My gearstick was wrong so i made a plate to lengthen and angle it further back- this is all hidden inside the rubber boot.

...and three steps back

Step 1: Damn thing won't idle now and i've changed nothing

Step 2: One rear brake has seized on so i have to drop the axle AGAIN to get the wheel off

Step 3: I've had a quote for £500 to have exhausts made so i'll have to hack the old ones to bits and bodge it up myself

db · Post by db » Wed May 23, 12 9:57 pm

Time to 'fess-up

I've worked why I had one binding rear brake.
It baffled me for a while cos when i measured between the drum and backplate, the brake shoe was wider than the space ...

How could this be??? The only way this could happen is if the bearing was too far onto the shaft, not possible!
So, more investigating... i pulled both shafts out and bearing on the GOOD side wasn't on properly- Didn't make sense til i realised the retaining collars should be in front of the backplates- i'd fitted 'em behind. It was a case of two wrongs making a right

Anyhoo... all sortd now

db · Post by db » Fri May 25, 12 6:42 pm

Went for another little drive today

DAVE- It's a bugger to keep going when cold, but once warm I have it idling ok now at just under 1000, much less and the throttle acts like a kill-switch.
Even at 1000 I have to tease it- pumping the gas in to get it to rev. Once in gear, I have to constantly blip the throttle to get moving- there's basically nothing between idle and wheelspin

I've now checked the float levels at idle, mixture screws seem best at around 2 turns. Vac at 1000 is only about 5, suggesting the 2.5 power valve is about right?

Oh, when I was sorting out the axles, i'd wound the bias valve closed so I didn't lose too much fluid. VERY exciting moment reversing towards the fence when i remembered this was still closed- NO rear brakes

Dave-R · Post by **Dave-R** » Sat May 26, 12 8:47 pm

If there is no transfer slot showing then you might have problems from that. Because it will only idle around 1000rpm and dies at anything less I think there are still issues with the carb.

Is there any holes drilled in the throttle blades? If there is they may be too big.

db · Post by db » Sat May 26, 12 11:31 pm

Thanks Dave.
No, no holes in the blades.

Once it's warm i can get it to idle a bit lower, around 750-800. It doesn't like any throttle then though.
The vac is lower than i was expecting, does that indicate any problem or is it to be expected with my setup?

db · Post by db » Fri Jun 01, 12 8:42 pm

I've been loaned a couple of great books-
'Super Tuning And Modifying HOLLEY Carburetors' and 'HOLLEY Rebuilding & Modifying' A Workbench Book.

I've been studying these for the last few days and i reckon i've learned a fair bit

I started to suspect a possible vacuum leak so i looked to the one bit of the carb i'd neglected before... i stripped the throttle plate and gave it a proper clean and check. I think i found a blockage in one of the tiny idle bleed holes!
The Teflon strips that seal the secondary shaft had seen better days, luckily i'd kept the unused bits of my rebuild kit- now i know what those funny curled up bits of white plastic are for!
There was a slight misalignment of the blades (one closed a fraction before the other) which i've sorted.

I've returned the idle settings to the baseline given in the book so i'll start the tweaking process again from scratch...

Rich · Post by **Rich** » Sat Jun 02, 12 5:24 pm

I just know that you will get where you want to soon enough paul,,
you seem to have the right approach,just working your way through... keep it up boy n we will see you at the nats

db · Post by db » Sat Jun 02, 12 5:42 pm

Thanks Rich, I'd love to mainly for all those who've helped and encouraged me to get this far but i've pretty much resigned myself to aiming for next year

Cashflow isn't what i'd like at tho mo- wedding comin up an all that

db · Post by db » Tue Jun 12, 12 10:44 pm

Hi carb-tuning fans, welcome to the latest installment...

I've re-rebuilt the carb and reset the butterflies and mixture screws to the recommendations in the book.
I've fitted clear float sight windows thinking that would make setting them easier...hmm.
I fired her up and immediately floods of petrol came out and fouled the plugs- the rear float valve had stuck open. I pulled it out, checked it and mopped up the fuel.
I started it again and tried to get it to idle and basically I was back to square one.
Whatever I try, it'll only tickover when purely on the secondaries. If i crack the primary blades open even by a 1/4 turn on the throttle stop screw it tries to stall.
I've gone up to 4 turns out on the idle screws and it still won't idle on the primary. (there's no sec idle screws)
Manifold vac when idling is 12-15, when I try to open the primaries it drops to 3-5.

It clearly shouldn't be idling just on the secondaries and I can only rev past that huge hole by blipping the throttle to bring on the acc pump.

Any input greatly appreciated

Pete · Post by **Pete** » Tue Jun 12, 12 10:53 pm

Sounds to me that the carb is worn/blocked internally. Either that or there is a manifold leak, but given the readings you state that seems unlikely........

I think you have played enough - time to bin it out and put a double pumper on it - 4 speeds love them anyway.....

Mick · Post by **Mick** » Tue Jun 12, 12 11:02 pm

I dont understand it, that carb was on my car for at least two years and the only time i ever touched it was float setting and adjusting the vac can.
Have you checked the slot under the carb is set right. Maybe try drilling the throttle blades, start small though.
Mick

Pete · Post by **Pete** » Tue Jun 12, 12 11:11 pm

A process of elimination by blagging another Carb may be the next step if you can't tune it out..........

db · Post by db » Tue Jun 12, 12 11:13 pm

I had wear on the teflon spindle seals so i renewed them but that's made no difference.

Just saw your post Mick- damn i'd forgotten about drilling the plates, yes that's definitely worth a try.

Pete · Post by **Pete** » Tue Jun 12, 12 11:27 pm

There is another trick you can try...

Connect a strobe light to the king lead.
Start the motor and get it running.

Shine the strobe down the venturi and if there is a leak from any of the circuits you will be able to see the droplets cascading down past the throttle blades.

This is how I diagnosed the faults on the 2 x 4 carters on the hemi....it guarantees that no fuel is bypassing the bowl floats or any other area (other than maybe the transfer slots which are below the blades....).

Personally, if you have cracked open the secondaries I do not think you will gain much by drilling the primary blades but if you try the above test and still draw a blank then maybe it is worth a try.......

BTW - have you sorted out the timing properly yet? if not the nyou could be wasting your time...........

Mopar Muscle Association UK

db's 66 Belvedere FOR SALE