Holley Sniper

[Green411]

Hi all, new member here with first post. It's so exciting..... I've recently bought a 411 S3 and am beginning to get over the shock of the fuel consumption. There's plenty of play in the carb throttle shaft yet it runs very rich so am assuming the carb is well worn.
Am probably going to get a Holley Sniper master kit, as I want the driveabilty of efi. So am very interested in anyone's experiences, good or bad, of them - particularly if you did it yourself, as I plan to do.
If you have one, what was fitting it like? Did you choose an in-tank or in-line pump? If in-line, what did you do for a fuel reservoir? What driveability difference did fitting it make? Etc etc.
Sorry if I've missed an existing thread about this topic.
Thanks in anticipation
Cheers Mark

[dwomby]

Welcome! Sorry, I can't help you but I have a 408 with non-standard 360 and performance camshaft that gets horrible mileage and am considering the Sniper too. I will be interested to see how people propose fitting the fuel return into the tank.

David

[peter dowdle]

I too am dismayed by the fuel my 411 & 412 use, so to that end I made a study of various fuel injection systems . Many U TUBES and articles latter these are my conclusions comparing a well set up carby verse an after market efi

1/ Your fuel economy will not improve
2/ Your motor will run more reliably(starting hot and cold, no choke issues and perform more smoothly )
3/ The cost and issues of setting it up isnt as easy as it looks
4/getting it tuned and set once again isnt that easy.
5/ Given the miles I travel in my Bristols and the cost of an EFI i decided to stick with what I have.

Do your research there is a lot on U TUBE and the US forums . Keep us informed.

[dwomby]

Originally Posted by peter dowdle

I too am dismayed by the fuel my 411 & 412 use, so to that end I made a study of various fuel injection systems . Many U TUBES and articles latter these are my conclusions comparing a well set up carby verse an after market efi

1/ Your fuel economy will not improve
2/ Your motor will run more reliably(starting hot and cold, no choke issues and perform more smoothly )
3/ The cost and issues of setting it up isnt as easy as it looks
4/getting it tuned and set once again isnt that easy.
5/ Given the miles I travel in my Bristols and the cost of an EFI i decided to stick with what I have.

Do your research there is a lot on U TUBE and the US forums . Keep us informed.

I suspect you are correct and that not much, if any, economy improvements would be had and one would, at best, have to drive a lot to recoup the cost via fuel savings.

A friend of mine has suggested that I might improve my car's economy (and horrible muscle car-like idle) by reverting to a stock camshaft but I think that would be too intimidating for this home mechanic!

David

[peter dowdle]

David my brother Geoffrey had a 411 mk 1 with the 383 motor which had been set up by a friend of ours in Sydney, Keith would know more about Chrysler cars and motors than any one in Australia .Geoff fitted an alloy manifold and had made a set of extractors . This car with a very mild sports cam would go like the wind and return 18 to 20 mpg.

I have spoken to Keith about my 411 and he has suggested reverting to a standard sports cam as supplied by Bristol and use either a 600 or 650 Edelbrock carbie. Edelbrock have a new range of carbies which are meant to improve economy and performance.

I had a hotter cam fitted to my car and wish I hadnt

Your car being a Mk3 had a slightly detuned motor than the Mk 1 and 2 but I have no idea what cam was used. Chrysler at the time were detuning their motors in the 70s and eventually upgraded them to the 400 motor which had low compression and no go. My 412 is very slow compared to the 411.

[AndrewA]

Morning Mark - congrats on your new acquisition - apart from the fuel consumption I hope you're pleased with your car?
There's an interesting thread on here titled Fuel Consumption where you can see what different cars are achieving.
12/13 MPG seems achievable on a big block with a new carb and everything else bang on - I'd imagine the only thing that's going to alter that dramatically is an LPG conversion.
EFI + LPG would be great and a nice winter project for you!
Cheers
Andrew

[dwomby]

Originally Posted by peter dowdle

I had a hotter cam fitted to my car and wish I hadnt

My 408 came with it. The car lost its original engine sometime in its history and the 360 from a 1978 Dodge Monaco was rebuilt by a Mopar performance expert and fitted. He fitted the following (all I can make out from the 1992 photocopy of a handwritten receipt!):

Mopar Performance Cam 4452761.
Lifters unknown.
Mopar Performance Intake Manifold P4529116.
Piston rings 4.030"
Pistons unknown
Exhaust valve 1863

It is now fitted with:

Summit Racing Carb SUM-M08600VS. 600cfm
Distributor Pertronix PNX-D141701.
Coil Pertronix PNX-45001.

The exhaust manifolds are stock cast iron things.

The cam gives the car a bit of a Muscle Car-like performance and sound. I think I'd be happier with a stock cam as I am told it would quieten the idle and improve economy but the car can certainly pick up its skirts and shift itself!

David