To Sniper or not to Sniper...?

[Steeveedee]

Cliff doesn't personally rebuild carbs anymore, I understand that he is retired. I bought a kit from him many years ago and it worked fine. It's up for rebuild again, and that's the way I'd go. The only real adjustments a carb needs is from winter to summer and back. My take is that vehicles sitting long enough for the fuel to evaporate out of the float bowl have problems. I know mine does. But if I start it even every other day, all I have to do is pump the pedal once and turn the key until it starts, and that may be as short as turn and release. As usual, one's mileage may vary.

FWIW, given the number of miles I drive my truck per year (~1000), I don't think that I'd ever recover the installation cost, even if I provided the labor for free.

[pjmoreland]

As others have already said, the main benefit of the Sniper I installed on my truck has been easy starting all year. Probably not worth the expense and effort just for that. Here a few other built-in Sniper features I like:

1) Idle RPM stays steady when the A/C kicks on

2) A/C shuts off at WOT

3) Temperature based dual electric fan control

4) Optional ignition timing control

The Sniper 2 offers optional electronic automatic transmission control.

[dmjlambert]

Originally Posted by pjmoreland

...
4) Optional ignition timing control

How does the ignition timing control work? Does it require a special distributor with electronic gizmos in it, or does it control the timing by varying vacuum going to the can on the distributor? Some sort of knock sensor required?

[pjmoreland]

Originally Posted by dmjlambert

How does the ignition timing control work? Does it require a special distributor with electronic gizmos in it, or does it control the timing by varying vacuum going to the can on the distributor? Some sort of knock sensor required?

Holley sells a distributor called the Hyperspark that is designed to work with the Sniper. It is actually a very simple distributor with no vacuum advance or mechanical advance. It just has a sensor that detects the orientation of the rotor and sends its readings to the Sniper. The Sniper adjusts the timing as it sees fit by controlling the angle at which a spark pulse is sent through the ignition system. The rotor/cap can conduct spark pulses within a fairly wide angle range (the rotor doesn't have to be perfectly aligned with the cap contacts). There is no knock sensor.

[MikeB]

Originally Posted by jocko

Kootenay, you sound undecided in your first post (EFI vs carb). If it's just the frustration of tuning the carb, have you considered replacing your carb for a professionally rebuilt q-jet? Or perhaps sending yours out for a rebuild?

Well said. Q-jets might just be the best carbs ever.

[1970cstblazer]

Originally Posted by MikeB

Well said. Q-jets might just be the best carbs ever.

Definitely best overall street carb. For super high performance race applications, the Holley Dominator ranks highly.

Every single vintage hobby vehicle I own has a Q-Jet, and all perform well no matter the weather. You have to be good with setting them up, as well as timing and other adjustments to get great results.

[Burnsy01]

Originally Posted by pjmoreland

Holley sells a distributor called the Hyperspark that is designed to work with the Sniper. It is actually a very simple distributor with no vacuum advance or mechanical advance. It just has a sensor that detects the orientation of the rotor and sends its readings to the Sniper. The Sniper adjusts the timing as it sees fit by controlling the angle at which a spark pulse is sent through the ignition system. The rotor/cap can conduct spark pulses within a fairly wide angle range (the rotor doesn't have to be perfectly aligned with the cap contacts). There is no knock sensor.

Also adding that if you have a MSD distributor you can convert it over fairly easy

[Rust_never_sleeps]

Failed to mention in my previous post that swapping a 'lectric choke onto a q-jet can simplify things, particularly since you mention cold start problems

[suburban99]

With the price of fuel up here at $1.60+ liter some sort of fuel injection makes sense. My '72 went from 13mpg to 19mpg when I LS swapped it. I thought about the sniper before I took the plunge. I saved the 350/350 in case I ever sell it. (unlikely)..

[IT Cowboy]

Originally Posted by my67c20

Well it was a lot of work / time to install. Had to splice and lengthen some of the harnesses so it would not look like a snake pit. Needed a few extra fittings to route the fuel lines. Installing the O2 sensor was a battle in itself. Had to make a bracket to mount the fuel pump. Still need to add some isolators cause that pump is loud.

Could one person install the system on a Saturday, yes. It took me longer cause I wanted to make it a clean install. The install instructions are easy to follow and the start-up wizard walks you thru the initial set-up. Had my doubts, but it fired up right way. No pumping the gas, no half throttle while waiting for it to warm up to idle, basically none of the start-up fun from a carb set-up. Also no more leaky gaskets drying out from the desert heat.

I had my carb pretty well tuned or so I thought. This system woke my engine up. Was it worth it, hell yes. Could I have done a cheaper set-up to achieve the same results, sure. The only problem I have had is my O2 sensor crapped out on me after a year, which then lead to crappy performance. It was easy to change and now she runs like a beast.

Does the external in-line pump for the holley efi pull fuel from your in-cab tank via the stock sending unit?

[weq92f]

Originally Posted by pjmoreland

...<snip>... [Sniper Features]

1) Idle RPM stays steady when the A/C kicks on
2) A/C shuts off at WOT
3) Temperature based dual electric fan control
4) Optional ignition timing control

The Sniper 2 offers optional electronic automatic transmission control.

.

Good point. These features are often overlooked. My MSD Atomic EFI has all the same features with the possible exception of the A/C off at WOT and there are tranny control units/modules as addons.

A possible drawback to these systems (mine for sure) is that a few of the sensors embedded into the throttle body are not serviceable. All the normal computer control data is gathered with these systems and a lot of that is in the throttle body. The only external sensors on the MSD are O2, coolant temp, and A/C on trigger. The others are integrated: MAF, TPS, IAT, MAP and Fuel pressure.

I'd be interested to hear of anyone on the board here if they've enabled the computer controlled timing on one of these systems. I have not opted to do that just yet and may not. For what I do with the thing, I don't think it's necessary.

-Kevin

[IT Cowboy]

I am over researching for if I decided to install a Sniper system. Here is the fuel delivery and return system as I think should work. I am unsure if the in-line pump will be able to pull from the tank with this. I beleive the pump should act like a siphon once it starts?

[my67c20]

To answer your question, yes the inline fuel pump will pull from your tank. You will need to add another hole for the return line. Since I was needing to drill a hole, I took the opportunity to buy a new sending unit so if I screwed things up I at least still had one. Look at my post #17 as to how I mounted things.

https://67-72chevytrucks.com/vboard/...5&postcount=17

Originally Posted by IT Cowboy

I am over researching for if I decided to install a Sniper system. Here is the fuel delivery and return system as I think should work. I am unsure if the in-line pump will be able to pull from the tank with this. I beleive the pump should act like a siphon once it starts?

[pjmoreland]

Originally Posted by weq92f

I'd be interested to hear of anyone on the board here if they've enabled the computer controlled timing on one of these systems. I have not opted to do that just yet and may not. For what I do with the thing, I don't think it's necessary.

-Kevin

I went with the HyperSpark distributor, and the Sniper controls the timing. I just went this way because I thought it would be a cleaner overall setup. I just configured it to act the same as the HEI it replaced. It didn't make any functional difference other than now I have a rev limit. Other than that, an HEI can be adjusted in all of the same ways.

[IT Cowboy]

I wish someone made a kit for the pump in the in-cab tank. If anyone has any contacts in the industry tell them to do that, please.

[IT Cowboy]

Originally Posted by pjmoreland

I went with the HyperSpark distributor, and the Sniper controls the timing. I just went this way because I thought it would be a cleaner overall setup. I just configured it to act the same as the HEI it replaced. It didn't make any functional difference other than now I have a rev limit. Other than that, an HEI can be adjusted in all of the same ways.

A mechanic I know says the hall-effect pickup distributors are crap and not reliable? I am considering the Sniper system and thought it would be nice to have my timing self-adjust, especially with the elevation changes here in AZ but now I don't know.

[PbFut]

That is because your mechanic does not understand hall pickups. They are very sensitive to EM noise. Be it in the power source or proximity of leads to one another. Magnetic pickup that Sniper and EFI use are way less sensitive. But all the ECUs need clean power as stated in the instructions. Our trucks do not have good clean power. You must connect directly to the positive and should also do negative direct to the battery. I even had to relay the switched power lead on my aces ecu. Dirty or noisy power will greatly degrade the ability of the ecu to learn.

[IT Cowboy]

Originally Posted by PbFut

That is because your mechanic does not understand hall pickups. They are very sensitive to EM noise. Be it in the power source or proximity of leads to one another. Magnetic pickup that Sniper and EFI use are way less sensitive. But all the ECUs need clean power as stated in the instructions. Our trucks do not have good clean power. You must connect directly to the positive and should also do negative direct to the battery. I even had to relay the switched power lead on my aces ecu. Dirty or noisy power will greatly degrade the ability of the ecu to learn.

Is using the Holley power controller / relay OK or is some type of power conditioner inline recommended?

Please tell me about the Aces system and how it compares and performs.

[PbFut]

I have never used Sniper. I've used FiTech (I have a habit of calling them EFI) briefly but had issue with an associated Speedmaster 8 stack that used the FiTech EFI system. The FiTech worked good was easy to set up and ok support. The Speedmaster 8 stack is not unexpectedly, pretty bad. I was prepared for issues with the Speedmaster parts, but it was surprisingly bad. No provisions for some of the sensors. Nothing a good drill press and tap couldn't fix. I questioned the fuel rail set up, but not enough I guess. Three weeks after getting things running pretty good, 8 stacks are a hand full, #8 injector herniated it's oring out of the fuel rail. By the third attempt to fire the engine, (think 9 full seconds of 60 lbs of fuel spraying the engine compartment during 3 start prime cycle, flames erupted from under the hood and I burned down 18 months of restoration work. Everything forward of the seat was pretty bad.
With that said, the easiest way to get clean power in our truck is to wire directly to the battery and relays. I have an RV battery set up so it makes it easier. You want go direct to the battery post. Not to a junction. I made that error for you already. 50 year old motors, radios, alternator design, and just corroded grounds will cause enough static and or voltage dips and spikes to overwhelm the ECU filters or create errors and false sensor inputs. Even things like driving relays with dirty power can get you. There are provisions to trigger electric fans. The trigger on FiTech and Aces is negative. Meaning you need a positive 12v on the other side of the coil in your relay for things to work. Seams easy. Use the relay to switch a 12V feed to your fan, and jump the hot pin on the fan circuit for the positive feed to the relay coil. The ECU trigger lead to the relay complets and circuit and trips the relay and the fans start running. But the fans now induce noise into the 12v line, which you jumped to the relay coil for easy of wiring and that noise back feeds up the negative fan trigger lead and into the ECU. Was the trigger lead isolated in the ECU, or will it cause issue? All that to say, there are many ways for noise to get into the ECU and cause it to not work at 100%. Engine may still run and ECU not indicate an issue, but it can be just off for someone to say, it's not as good as a carburator. Properly wired, and just using the ECUs lean ability, 60 year old engine design runs like a modern engine. Very smooth and reliable across the RPM range and at any altitude or temperature. The ECU looks at all those elements to adjust fuel ratio and spark timing.

[dmjlambert]

Originally Posted by IT Cowboy

I wish someone made a kit for the pump in the in-cab tank. If anyone has any contacts in the industry tell them to do that, please.

There is such a thing as EFI sump fuel system that pumps from the existing tank into a very small package, and from there pumps at high pressure for EFI, and return is to the sump device. I don't think at this time I am interested in EFI, but if I become interested I will probalby explore this option since I am a little odd and like the in-cab tank and like leaving the fuel storage system alone (and having no return to the tank). Not endorsing, just noticed it exists. https://www.summitracing.com/parts/edl-36032

[PbFut]

Yes but the sumps are not as small as you would think. Nothing wrong with a inline pump. Speedmaster, as bad as they are, has a inline that uses a emerged style pump in a relatively small housing to keep cool. Place a return style regulator, not speed master, after the pump and you are good. It's a smaller version of same idea
In photo, logo upside-down. Not issue as the device is below tanks and so inner pump intake is always submerged.

[weq92f]

Originally Posted by PbFut

Yes but the sumps are not as small as you would think. Nothing wrong with a inline pump. Speedmaster, as bad as they are, has a inline that uses a emerged style pump in a relatively small housing to keep cool. Place a return style regulator, not speed master, after the pump and you are good. It's a smaller version of same idea
In photo, logo upside-down. Not issue as the device is below tanks and so inner pump intake is always submerged.

.

Can't find that piece Online at all. Even a google image search fails. Got a link?

-Kevin

[PbFut]

Originally Posted by weq92f

.

Can't find that piece Online at all. Even a google image search fails. Got a link?

-Kevin

Here you go. Lots of choices. Some good some not so. At the time I wanted the smaller pump but it was during supply chain issue time. The one I have is really too big and a bit noisy. Works good. Probably stressing the regulator some. https://www.speedmaster79.com/air-fu...ctric-external

[weq92f]

Originally Posted by PbFut

Here you go. Lots of choices. Some good some not so. At the time I wanted the smaller pump but it was during supply chain issue time. The one I have is really too big and a bit noisy. Works good. Probably stressing the regulator some. https://www.speedmaster79.com/air-fu...ctric-external

.

Must not be a real thing anymore. I walked through that page already.

The one you pictured is a wet fuel immersed pump inside a small housing mounted to the frame? I was thinking you were saying that picture was of a product that suspends a pump in a pool of fuel for cooling (and noise) purposes. Is that not right?

Sorry I'm confused I guess.

-Kevin

[68 P.O.S.]

Holley also makes a Q-Jet Sniper, so no fiddling with spread bore to square bore adapters or buying a new intake.