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347 Ford Sniper EFI cam specs

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JES
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347 Ford Sniper EFI cam specs

Post by JES » Thu Nov 07, 2019 6:20 pm

Hello gentlemen.

I am looking for ideas on camshaft specifications for a 10 to 1 347 build. 57 Ford Fairlane 3500lb ?
Toploader 4 speed with 325 rear gears. Of course the customer wants as much of a Lopey sound as he can get but also wants it to start and run for everyday driving. The plan is for Sniper EFI system. The engine will have flat top pistons with ProMaxx aluminum heads. The camshaft needs to be hydraulic flat tappet for this application. 1.6 rockers.


THANKS

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Re: 347 Ford Sniper EFI cam specs

Post by Walter R. Malik » Thu Nov 07, 2019 6:59 pm

JES wrote:
Thu Nov 07, 2019 6:20 pm
Hello gentlemen.

I am looking for ideas on camshaft specifications for a 10 to 1 347 build. 57 Ford Fairlane 3500lb ?
Toploader 4 speed with 325 rear gears. Of course the customer wants as much of a Lopey sound as he can get but also wants it to start and run for everyday driving. The plan is for Sniper EFI system. The engine will have flat top pistons with ProMaxx aluminum heads. The camshaft needs to be hydraulic flat tappet for this application. 1.6 rockers.


THANKS
Does he have an intake manifold and RPM range in mind ...?
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Re: 347 Ford Sniper EFI cam specs

Post by JES » Thu Nov 07, 2019 7:49 pm

Yes,it will have a dual plane air gap style intake and NEVER past 6500 RPM, and that would be very seldom.

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Re: 347 Ford Sniper EFI cam specs

Post by Walter R. Malik » Thu Nov 07, 2019 9:33 pm

JES wrote:
Thu Nov 07, 2019 7:49 pm
Yes,it will have a dual plane air gap style intake and NEVER past 6500 RPM, and that would be very seldom.
I would use a custom "street rod" style camshaft. Lower duration, tight separation with as much lift as that size lobe can have.
It probably would not be the best power maker but, would fulfill what you want it to do.
Something about 226/232 @.050" - around .325"/.330" lobe lift and 106 separation would be my choice.
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Re: 347 Ford Sniper EFI cam specs

Post by JES » Thu Nov 07, 2019 11:10 pm

Thank you for your suggestion Walter.

Do you think that the EFI will get the signal/vacuum that it needs with the 106 lobe separation angle?

I do realize the short duration cuts down on overlap.

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Re: 347 Ford Sniper EFI cam specs

Post by My427stang » Fri Nov 08, 2019 8:48 am

It'd be handy to see calculated compression numbers and quench distance, but although I think the above cam recommendation is spot on for a carb, it could be fussy with the Sniper, but to be honest I haven't used their software.

Depending on overlap, sometimes you need to trick the system to go open loop at idle and even sometimes at WOT with a snotty cam. not sure if you can do that with a Sniper. With the EFI and a SBF I'd prefer to stay as narrow as I can, but would likely limit .006 overlap to about 58-60 degrees by spreading the centers

It maybe a little tighter if the software is friendly. May not be as rowdy as he wants, and of course the rest of the cam specs are more important to making power, but keeping as much raw fuel off the O2 sensor at idle is why I am recommending treading more lightly.
70 Mustang, 489 FE, TKO-600, Massflo SEFI, 4.11s
71 F100 SB 4x4, 461 FE, 4 speed, port injected EFI, 3.50s

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Re: 347 Ford Sniper EFI cam specs

Post by Walter R. Malik » Fri Nov 08, 2019 9:22 am

My427stang wrote:
Fri Nov 08, 2019 8:48 am
It'd be handy to see calculated compression numbers and quench distance, but although I think the above cam recommendation is spot on for a carb, it could be fussy with the Sniper, but to be honest I haven't used their software.

Depending on overlap, sometimes you need to trick the system to go open loop at idle and even sometimes at WOT with a snotty cam. not sure if you can do that with a Sniper. With the EFI and a SBF I'd prefer to stay as narrow as I can, but would likely limit .006 overlap to about 58-60 degrees by spreading the centers

It maybe a little tighter if the software is friendly. May not be as rowdy as he wants, and of course the rest of the cam specs are more important to making power, but keeping as much raw fuel off the O2 sensor at idle is why I am recommending treading more lightly.
I have done pretty much the same thing with a Chevrolet 350 without any problem using the MSD Atomic and when the interfaced distributor is used with the Throttle body Injection also controlling the ignition timing.
The Holley "Sniper" injection is supposedly a better unit than the MSD unit with high pressure "below the plate" injection.

That camshaft is a slightly larger short oval track cam, even.
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Re: 347 Ford Sniper EFI cam specs

Post by JES » Fri Nov 08, 2019 7:52 pm

Thank you all.

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Re: 347 Ford Sniper EFI cam specs

Post by My427stang » Sat Nov 09, 2019 8:31 am

Walter R. Malik wrote:
Fri Nov 08, 2019 9:22 am
My427stang wrote:
Fri Nov 08, 2019 8:48 am
It'd be handy to see calculated compression numbers and quench distance, but although I think the above cam recommendation is spot on for a carb, it could be fussy with the Sniper, but to be honest I haven't used their software.

Depending on overlap, sometimes you need to trick the system to go open loop at idle and even sometimes at WOT with a snotty cam. not sure if you can do that with a Sniper. With the EFI and a SBF I'd prefer to stay as narrow as I can, but would likely limit .006 overlap to about 58-60 degrees by spreading the centers

It maybe a little tighter if the software is friendly. May not be as rowdy as he wants, and of course the rest of the cam specs are more important to making power, but keeping as much raw fuel off the O2 sensor at idle is why I am recommending treading more lightly.
I have done pretty much the same thing with a Chevrolet 350 without any problem using the MSD Atomic and when the interfaced distributor is used with the Throttle body Injection also controlling the ignition timing.
The Holley "Sniper" injection is supposedly a better unit than the MSD unit with high pressure "below the plate" injection.

That camshaft is a slightly larger short oval track cam, even.
I was afraid it sounded like I was poking, I apologize if it sounded that way. There are camps out there that "EFI can't handle overlap" and others that don't care and tune around it, I am closer to the "don't care guys"

My own car below is a narrow band port injected system with 72 degrees overlap and is happy from 1500 to 6500, but I am also able to tune everything, injector timing to valve events, open/closed loop, timing, etc. I am doing a 461 for my truck right now with a less adjustable port injection, but only 60 degrees of overlap and a wide band O2 sensor. (Cam specs match the use, I am just referring to overlap because it affects both vacuum and fuel in the exhaust), I expect it will be gentle

I certainly would hope the Sniper has some ability to manage things, being a TB it's a little more limited than port injection, but admittedly some systems can go overboard, and if it is happy, what a fun 347 that would be with a tight LSA cam. The reason I get concerned with the EFI though, is even with a wideband O2 sensor, if system doesn't have an input or a control to manage raw fuel hitting the O2 sensor during overlap, the O2 sensor thinks it's rich.

I am in no way saying it wouldn't work, and a wide band informed system can be smarter, especially when it comes off idle and has some heat with it, I just have found that it's a bit easier with the TB systems to go a little more conservative. I have used and worked on quite a few but never an MSD or a modern Holley

That being said, if the guy wants a rowdy street rod, my idea of 58-60 degrees of overlap will have some chop, but isn't going to cause the crowds to walk over and moms to grab their kids LOL
70 Mustang, 489 FE, TKO-600, Massflo SEFI, 4.11s
71 F100 SB 4x4, 461 FE, 4 speed, port injected EFI, 3.50s

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Re: 347 Ford Sniper EFI cam specs

Post by Walter R. Malik » Sat Nov 09, 2019 10:26 am

My427stang wrote:
Sat Nov 09, 2019 8:31 am
Walter R. Malik wrote:
Fri Nov 08, 2019 9:22 am
My427stang wrote:
Fri Nov 08, 2019 8:48 am
It'd be handy to see calculated compression numbers and quench distance, but although I think the above cam recommendation is spot on for a carb, it could be fussy with the Sniper, but to be honest I haven't used their software.

Depending on overlap, sometimes you need to trick the system to go open loop at idle and even sometimes at WOT with a snotty cam. not sure if you can do that with a Sniper. With the EFI and a SBF I'd prefer to stay as narrow as I can, but would likely limit .006 overlap to about 58-60 degrees by spreading the centers

It maybe a little tighter if the software is friendly. May not be as rowdy as he wants, and of course the rest of the cam specs are more important to making power, but keeping as much raw fuel off the O2 sensor at idle is why I am recommending treading more lightly.
I have done pretty much the same thing with a Chevrolet 350 without any problem using the MSD Atomic and when the interfaced distributor is used with the Throttle body Injection also controlling the ignition timing.
The Holley "Sniper" injection is supposedly a better unit than the MSD unit with high pressure "below the plate" injection.

That camshaft is a slightly larger short oval track cam, even.
I was afraid it sounded like I was poking, I apologize if it sounded that way. There are camps out there that "EFI can't handle overlap" and others that don't care and tune around it, I am closer to the "don't care guys"

My own car below is a narrow band port injected system with 72 degrees overlap and is happy from 1500 to 6500, but I am also able to tune everything, injector timing to valve events, open/closed loop, timing, etc. I am doing a 461 for my truck right now with a less adjustable port injection, but only 60 degrees of overlap and a wide band O2 sensor. (Cam specs match the use, I am just referring to overlap because it affects both vacuum and fuel in the exhaust), I expect it will be gentle

I certainly would hope the Sniper has some ability to manage things, being a TB it's a little more limited than port injection, but admittedly some systems can go overboard, and if it is happy, what a fun 347 that would be with a tight LSA cam. The reason I get concerned with the EFI though, is even with a wideband O2 sensor, if system doesn't have an input or a control to manage raw fuel hitting the O2 sensor during overlap, the O2 sensor thinks it's rich.

I am in no way saying it wouldn't work, and a wide band informed system can be smarter, especially when it comes off idle and has some heat with it, I just have found that it's a bit easier with the TB systems to go a little more conservative. I have used and worked on quite a few but never an MSD or a modern Holley

That being said, if the guy wants a rowdy street rod, my idea of 58-60 degrees of overlap will have some chop, but isn't going to cause the crowds to walk over and moms to grab their kids LOL
No Issue here; everyone has a different scope of what they can live with ... I would not have answered at all except that I have already done a similar conversion with a low pressure above the plate fuel injected throttle body unit.
High pressure, below the plate fuel injected throttle body systems are supposed to be so much better but, that is only advertising.

Just for information, there are flat tappet hydraulic lifter camshaft lobe profiles available from a lot of places which offer about 226 degrees at .050" with only 268 degrees or less at .006" and 232@.050 with only 276@ .006" ... that is merely 60 degrees of overlap @106 separation, which was my target. Less would certainly idle smoother which I don't believe would be a necessity.
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Re: 347 Ford Sniper EFI cam specs

Post by Calypso » Sun Nov 10, 2019 3:16 am

My427stang wrote:
Sat Nov 09, 2019 8:31 am

The reason I get concerned with the EFI though, is even with a wideband O2 sensor, if system doesn't have an input or a control to manage raw fuel hitting the O2 sensor during overlap, the O2 sensor thinks it's rich.
Overlap flow from narrow LSA will show lean on the WB Oxygen sensor. The sensor measures oxygen content, which is increased. It has no idea if there's raw fuel in there or not.

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Re: 347 Ford Sniper EFI cam specs

Post by JES » Sun Nov 10, 2019 11:42 pm

I do believe that overlap is the key equation.

Currently running 71 degrees overlap with Sniper EFI on a 408 mopar and it runs very nice. Basically tuned AFR parameters like you would a carb. But you guys already knew that. I definitely had a learning curve, as I have never played with EFI before.

I have narrowed my cam choice down to 59 to 63 degrees overlap for this 347. I should know more in a few weeks.

I will try and update. Thanks

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