1965 Chevrolet Impala: carburettor

Showing posts with label carburettor. Show all posts

Wednesday, 29 January 2014

4-GC Idle Vent

Check it...
http://www.chevytalk.org/fusionbb/showtopic.php?tid/293265/

J

Wednesday, 2 May 2012

Quad'y

Picked up a Quadrajet off eBay for $20...

Old stock from Hume Performance at Warwick Farm. There is every chance
it has never been on a car and is coated in a light coating of surface
rust.

Has a Holley sticker on it which apparently means it is a Rochester
factory 2nd and was rebuilt/modified/rectified by Holley.

Serial Number: 7043266
Rochester ID: 70 (pre-1976)
Year Code: 43 (1973)
Emissions: 2 (49-State)
Division: 6 (Pontiac)
Transmission: 6 (Automatic)

Looks like it is off an auto trans 1973 Pontiac GTO with a 400 ci motor
http://www.thecarburetorshop.com/Kpontiac3.htm
http://www.carburetion.com/CarbNumber.asp?Number=7043266

Will need an electric choke conversion (now that I have removed the heat
riser) and we'll put a kit through it

Sunday, 19 February 2012

The one on the right!

With the carb rebuilt and back together, it was time to wack it back on and fire it up!

Time to pick a gasket (two came in the rebuild kit)...

The one on the right matched what was on the car to begin with, but I wanted to try the one on the left as it seemed to match the pattern under the 4GC.

Ahhh... no. With the carby sandwiching the gasket on the left, the old girl would fire, but quickly die and would only sputter along if I held plenty of revs... all the while hearing a MASSIVE vacuum leak.

Left it all for church, then after church dug into swapping the gasket for the one on the right.

With the right gasket in place... muuuuch better! Idled fine, revved fine; all good.

J

Saturday, 18 February 2012

(lack of) Choke Mechanism

With the rest of the carby back together, the only thing left was to reinstall the choke mechanism in a locked-open position to ensure that the fast idle cam isn't engaged.

The choke butterflies were removed...

...and I inserted a short piece of AT hose in the choke linkage to remove any slop...

The added bonus of the addition of the small length of hose was when the linkage was tightened, it lightly crushed the rubber which in turn held the linkage in place and ensures the choke can't "close" and engage the fast-idle cam.

John

Saturday, 4 February 2012

Carby Rebuild

Last year I sourced a rebuild kit for the Rochester 4GC carburettor from the states and now it was time to strip the carby and put the kit through it.

Joe came up and we set to work... well... Joe set to work ;-)

All parts were soaked in thinners and blown-out with compressed air.

Dimension settings were listed in the kit.

By the end of the day, the carb was back together, sans choke linkage.

While JtC rebuilt the carb, I pulled off the water pump and replaced it with a new one sourced from Rare Spares. The bottom radiator hose was severely perished, so a new one will need to be sourced before the coolant can go back in.

Once off, the old pump had it's cover removed to reveal.... perfect! The impeller looked brand new and there was no slop in the shaft! Obviously the pump was not the reason for overheating.

So the new pump stayed on and the old pump stored away as a spare.

Tuesday, 27 September 2011

Carby Back On

Decision made... carby has gone back on so we can check the timing and give it a tune.

Managed to remove the old carby to inlet manifold gasket intact (enough!) to use it as a template to make up a new one. A quick clean of the manifold and carby mating surfaces to remove any rubbish. Kept a rag in the inlet manifold to stop grit entering the engine and made doubly sure by giving it a vac. Blew out the carby with compressed air to remove any grit in it.

All went back together no probs.

I've ordered a rebuild kit for the 4GC, so when that arrives hopefully we will have tuned the engine ready for the carby to come back of for a rebuild.

In other news, it looks like I have found a 2nd hand choke (c/w internal mechanism) in the States... stay tuned.

Friday, 16 September 2011

Choke

So the choke mechanism is frozen solid on the carby; time to investigate.

First, a boring reference shot to show the original position of the choke mechanism...

Now down to business.

Cover screws came out, but she no budge. A couple of very light taps with the "gentle persuader" and voila!

Ooookay... so *that* is why the choke was frozen solid! The spring backing plate just crumbled away such was the rust.

Time to source a replacement choke mechanism.