Anyone ever ran a Holley Sniper EFI on a stock 400? It’s rated for a minimum of 250 hp. I was wondering if the engine would be able to run with this and peoples experiences with this setup? It’s a stock motor, msd hei with a al6 control box and dual 3” exhaust uncrossed with 40 series mufflers. Headman long tube headers.

 

Call Holley's Tech Line;

...And for general information regarding HP:

"In the United States, the term bhp fell into disuse in 1971–1972, as automakers began to quote power in terms of SAE net horsepower in accord with SAE standard J1349. Like SAE gross and other brake horsepower protocols, SAE net hp is measured at the engine's crankshaft, and so does not account for transmission losses"

 

In my opinion, they're more trouble than they're worth. Nothing runs better than a naturally aspirated (carbed) engine with the timing curve set just right, etc, etc. Why would you want to go EFI with all the sensors, etc, and junk when you have a perfectly fine engine?

With that being said, you'll need to weld up an O2 bung on one header collector...a new fuel tank and in tank pump, rated for 60 psi (or so), 3/8" fuel feed line and a 5/16" return line, a dedicated electrical coolant temp sensor (as the Sniper will read stuff starting at 160*F, dedicated POS (+) and NEG (-) cables/wires from the Sniper connections to the battery, 86 the ballast resistor circuit such that yer coil runs on 12 VDC (the HEI setup), a hole through the firewall for the LED tuner to fit/set in the cabin, and a host of other wiring.

Then there's the initial tuning setup which can be a daunting task....especially if the O2 sensor Holley sends you with all the associated stuff...doesn't work right. Then you'll have to jump through some Holly hoops for them to send you a new one.....

I'm sure there are folks out there that have 'em........mebbe love 'em....but not for me.

....And a stock 400 doesn't have that kind of horsepower at the crank or wheels.....mebbe 160 Hp.

 

Well, just the self-adjusting characteristics during altitude changes is enough reason for me. All by itself.

Not sure why they bother posting minimum power recommendations. Seems strange and an engine sucking 400 cubic inches should be fine with this setup. But it's still good advice to call Holley to double check.
For comparison though, we sell them (Sniper, FiTech, MSD, etc) with the expectation that customers will be installing them on stock 150-175 crank hp 302's in their Early Broncos. Same for their stock and stock-ish 351M's and 400's in their full-sizes.

We sell a lot of the FiTech 400hp and 600hp throttle body EFI setups as well. And nobody has ever had trouble that I'm aware of because of the engine being too small or weak.

Now, problems due to poor original wiring, or improper installation techniques... Absolutely!
And of course a few of them even had trouble with the systems themselves as FB was saying. Most of which have been easily resolved. And not just from FiTech, but also MSD with their Atomic, and Edelbrock with their unit too. So far, not any of the Snipers that I've heard. I'm going to check on that though, just to see if I've missed something.

Regarding the HP recommendations again, I think FiTech did themselves a disservice by naming their units after their HP support-ability. Most of our customers use the 600HP on their little 302's. Not because they want, or expect to ever build 600 horsepower, but because for the extra $200 bucks ($800 vs $1000) your unit's computer will control the ignition timing as well.

I'm running a stock Ford Explorer DIS engine in my '68, but am still a huge fan of the TBI units mentioned. We have employees and many customers that love their setups. Only reason we don't sell many (if any?) of the MSD units anymore is that, at $2000 bucks a pop, once the FiTech came out at $795 and the Sniper not long after that, it's hard to sell one that's double the price without some really good reasons.
All three units mentioned have all but the ECT (engine coolant temperature) sensors mounted right to the throttle body. And most (if not all) use standard, easy to find just about anywhere GM-based sensors.

I don't dispute your reasoning that a perfectly tuned carburetor and ignition combination is a good running setup. But I have no doubt that an equally properly tuned TBI and ignition is superior in enough ways as to make them well worth the price of admission. At least for some of us.

In fact, for some of us they might even get rid of your "overheating" problems permanently by controlling the fuel and spark more precisely.
Maybe... In theory... And all the other vague words I can think of. But it is still entirely possible.

Paul

 

Great for a true get-in-and-go every day driver, but a well set up carburetor should do the same thing! My '78 F350 with a Cleveland 351 starts with one pump of the accelerator every time, no choke required just that one initial pump. Sub zero (Celcius) temps it does need choke but only until the end of the block and then its fine.

Things that I see the Fitech/Sniper/Atomic units being great for, though, is great fuel economy and ease of use once set up. They're basically set-and-forget style units and will rarely (if ever) go 'out of tune' unless there is some sort of catastrophic failure... which is unlikely.

If it is a shared family car, though, or a project for the wife then I would definitely be inclined to get the injection unit. Key on, hit start, begin driving - that's what the majority of people are expecting from a car and that's what you get with injection.

- boingk

 

I have been looking into the Sniper and Dual Sync for my 400 after I finish the rebuild.

 

I think the jury is still out on the compatibility of the Duraspark with the FiTech. They don't "recommend" them, but they don't know if they'll work or not. Just that they know the other stuff better.
But they state initially that you can use the timing control with "a 2-wire distributor" which the Duraspark actually is.
In spite of it having a third wire, that wire is just a simple ground and only the other two are actually trigger wires. So in theory it should work.
Several customers are going to try theirs, but have not gotten to that point in their builds yet.

Paul

 

Interesting. I would like to hear the results of that. I do know that some people have had trouble with the Sniper and the previously recommended HEI in other applications causing electrical noise. The signal interference causes idle problems.

 

That makes sense. They were kind of finicky with computers all along I think I remember hearing.
And they're just a 1-wire thing anyway, so maybe not sending as clear a link to the ECM as needed.

I prefer a Ford ignition just for looks, but there's no arguing the performance that people are getting from their HEI's. Only argument you get is how long the cheap ones will last before they start giving you trouble.

What are you running now? Stock?

Paul

 

We are kind of hijacking the OPs thread but mine is a very tired stock 400, 2 barrel, Duraspark engine. I am working on another engine that will be mild .030 over with TMI pistons and stock heads. I will rebuild the 2 barrel core I mentioned before and install that on a 4 barrel manifold until I get enough saved for the Sniper. The Dual Sync will be added later. If I see any improvement in MPG I will be happy. If not, at least I won't flood out at stop lights anymore. I saw an interesting thread on swapping a 4r70w that would probably help the mileage more than the EFI will.

 

Yep, but if he comes back we'll let him have it right back.

Yeah I hope to see at least a slight improvement. My Explorer engine'd EB only sees about 12-13 around town (which is still pretty good compared to stock!) but will get 20 on the open road with not to many hills and keeping the speed below 60.
I bet the taller gearing will help even more when I test the 4.11 over the current 4.56's.

I have an Edelbrock TBI to go on the 400, but don't have any time-frame for when that will get done yet.
And with the Edelbrock being more finicky than the rest, I'm not sure I won't have to do a lot of fiddling (they call it tuning now) to get it running correctly.
We will see.

Getting enough feedback yet ajg?

Paul

 

Holley is currently doing a give away for $1000 a week to spend with their companies. The certificate would cover the base Sniper system.

https://www.holley.com/blog/post/enter_holley_power_sweeps_for_a_shot_at_1000_in_ne w_parts_/

For those who are interested.

 

I literally talked to a friend today about his Holley Sniper EFI on his truck. But he has a '72 C10 Chebby with a 396 with a street/strip cam, around 425hp. He said it was fairly easy to install, just follow instructions. It is self learning but he is having troubles with off-idle take off (from a dead stop), it tends to supply more than desired fuel causing unwanted tire spin. Also, the computer controls the dizzy curve, making it hard for him to adjust. He did mention that he misses his Holley 750 DP. He plans to replace the cam for a more streetable cam, in hopes to keep his EFI and hopefully will operate better. It's an expensive investment, not just the EFI, but the other stuff that is needed to make it operate, right at $2000.

 

Your friend could try playing with the fuel enrichment a little. The systems are self learning, but can still be adjusted to perform better.

 

I imagine he knows that. He's very mechanically inclined. He's not happy with the cam he has now anyway, so once he changes that he will reset the ecm. I'm not sure if the Sniper is designed to work with big lopy cams, or if that even matters at all.