2 replies to this topic

[lcgtr1970]

Hi Guys

I have a 253 running a Crow Cam 5666-8 cam. On top is a 4 barrell Holley 465 that I bought rebuilt. 

This set up seems to run quite rich...

It uses about 21L/100kms and leaves the spark plugs black...also has a few dots of soot on rear of car.

 

The current jets are 58s and the powervalve is 65.

 

What do you think would be a good jet size to drop to for this set up? And what would be a more appropriate powervalve?

 

Thanks 

 

[Rockoz]

Thats a how long is a piece of string question.

Its a mild cam so economy from standard shouldnt be much higher.

But given those numbers its using about 50% more fuel than I would consider reasonable.

My comparison is a VB Commodore with a 253 that I used to get no worse than 14l/100km.

That was usually spirited driving for the most part too.

A 2 barrel 350 Holley was usually the go to for a 253 back in the day.

A 4 barrel was really only going to affect your wallet rather than performance.

Jets and Power Valves probably arent that expensive.

Buy a few different sizes and play, unless you want to spend time and money on a dyno with a good tuner.

 

Cheers

 

Rob

[yel327]

I'd be looking to a Quadrajet setup right for a 4.2, off a blue 4.2.