Holley Sniper

[dezelsky]

Thank you Mr Green411 for sharing your experiences with the Holly setup.

I am currently on the return leg of a trip to Italy in my 411 S4, It is not directly comparable to yours - with the later series 400ci engine + torqueflite. It also has a 603 rear axle with longer top-gear ratio, and MSD ignition kit both fitted by Martin Barnes several years ago. I bought an Edelbrock ‘Performer’ 750cfm from Summit to replace the worn out Thermoquad with electronic choke. This worked pretty well immediately out of the box, and fits with the original air-cleaner. I took it for a rolling-road tune up but no adjustments were required. Almost certainly over-carbed, but seems to suit it well, with easy starting and good kick-down when needed.

I had not bothered to check fuel consumption up until now, fearing the worst. However having covered 1700 miles on this trip so far, my back-of-fag-packet calculations tell me it is returning just over 16mpg. This is using regular 95 fuel and sometimes 98 super when conveniently available. Whilst It is still undoubtedly a very thirsty machine, it is slightly better than I was expecting. Seems happiest on long motorway runs between 2500-3000rpm where it averages 17-19mpg. On days with more stop/start and mountain driving it returns 12-13mpg.

I have occasionally flirted with the idea of fitting an LPG conversion, but based on other forum comments the downsides appear to outweigh the upsides, unless the car is used for everyday substantial mileages, so have rejected that idea.