Sniper with RobbMC Surge tank install - fuel return and other questions (1 Viewer)

[jhynesrockmtn]

I am hoping you all will indulge another Sniper related thread. I am gathering parts to replace the Empi weber copy on my 77 FJ40. My engine is in good shape and generally runs well when the carb is behaving. I'm wanting better drivability, better cold weather performance and anticipate some higher altitude overlanding trips with my son and his Samurai. I also just like projects.

I decided on a surge tank from RobbMC to simplify some things and retain the mechanical pump should I want to go back to the carb in a pinch.

My rig has dual tanks with a Pollack switch over valve that is capable of handling the tank return. However, the rear aftermarket tank currently has no provision for a return. I'm also thinking for now I will simplify some of the plumbing and just fill the main tank from the reserve.

One of my questions is how to do that. Should I run a T at the main tank return so the fuel return from the surge tank bypass regulator I'll run and the fill from the reserve both go to the return port with check valves OR fill the main from the reserve with a T into the vent pipe?

Another question is which manifold adapter to use? I like some of Red Line Cruisers stuff. Their manifold adapter is out of stock currently. My carb sits on a Man a Fre adapter now. Other options?

I want to add back a charcoal canister. That is missing from my setup now. I'm reading threads on aftermarket solutions for that. I found a nice rodent nest under the fuel separator when I starting taking things apart. Luckily no current residents.

My engine bay is a bit stuffed due to the dual battery setup. I think I'll move the radiator overflow to the driver side and locate the surge tank in that spot. I then need to find room for the charcoal canister.

Parts should start arriving this week.

 

[rlong]

No expert, but in the design stages as well. Your drawing looks functional. Goes without saying (maybe) I would not fill from rear tank and run the engine (surge tank pump) at the same time, as the two streams of fuel (new fuel from auxiliary, and return fuel from regulator) will “dead head” into each other in the “tee”; and likely mess with your regulated pressure to throttle body. I say run it!

 

[jhynesrockmtn]

No expert, but in the design stages as well. Your drawing looks functional. Goes without saying (maybe) I would not fill from rear tank and run the engine (surge tank pump) at the same time, as the two streams of fuel (new fuel from auxiliary, and return fuel from regulator) will “dead head” into each other in the “tee”; and likely mess with your regulated pressure to throttle body. I say run it!

Thanks. That was the plan. Only fill from the reserve when the engine is off.

 

[Skreddy]

I would probably just run the return back to the surge tank. I’ve never used the surge tank but the setups I’ve seen usually just feed the surge tank and dump return fuel back into the surge as well.

 

[Skreddy]

Meant to comment on the adapter too. I am running the Mr gasket adapter and my own spacer to fit the sniper to original air filter and my carb is already cable actuated so reused that. I know people are very happy with the adapter from Mosley.
I strongly recommend the throttle lever extender. Before it, driving the sniper was like an on/off switch, the arm smooths it out and gives you more pedal travel. However; my setup can only get to 85% on the TPS with the added arm but I’ve never had an issue with that.
There are knockoff versions for about $10.

https://www.holley.com/products/fuel_systems/fuel_injection/sniper_efi/ignition_and_fuel_systems/sniper_efi_service_components/parts/20-16?utm_term=&utm_campaign=Performance+Max+-+Sniper+EFI&utm_source=google&utm_medium=cpc&hsa_acc=7848552874&hsa_cam=20996530552&hsa_grp=&hsa_ad=&hsa_src=x&hsa_tgt=&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3&gad_source=1&gbraid=0AAAAAD1FzSqCMrw6RwMb_nWZfNRN2eZaj&gclid=CjwKCAiA74G9BhAEEiwA8kNfpTGJc46RBta-FnaJeVkRntu1tiQyuv6rnIYZ6c4PIU1HvtBCCBEWAxoCKXMQAvD_BwE

 

[jhynesrockmtn]

I would probably just run the return back to the surge tank. I’ve never used the surge tank but the setups I’ve seen usually just feed the surge tank and dump return fuel back into the surge as well.

I have been emailing back and forth with Robb who makes the surge tanks. That is not the setup that he advises. He wants the fuel feed to go to a bypass regulator which has a port for the return back to the tank. That can either be at the sniper itself, using the built-in one, or in my case I'm going to have one he makes coming right off the surge tank so I'm not running the return line back from the hot side of the engine.

 

[Skreddy]

Good to know they don’t want the ST itself to take the return (I’m debating on in tank pump or the ST when I EFI my 60).
I would run the return from the sniper. I think Holley recommends this. I’m not sure if there are issues returning before the sniper (I know a lot use the corvette style regulator with return), it just seemed to me the return from the regulator at the end of the line was best. But, again, there’s lots of other rigs out there problem free other ways.

Will you add a cat to the exhaust or anything? I don’t have one but when I do the stainless exhaust on my 40 I’ll add one and likely a charcoal canister too. Not for any specific reason.

 

[jhynesrockmtn]

Good to know they don’t want the ST itself to take the return (I’m debating on in tank pump or the ST when I EFI my 60).
I would run the return from the sniper. I think Holley recommends this. I’m not sure if there are issues returning before the sniper (I know a lot use the corvette style regulator with return), it just seemed to me the return from the regulator at the end of the line was best. But, again, there’s lots of other rigs out there problem free other ways.

Will you add a cat to the exhaust or anything? I don’t have one but when I do the stainless exhaust on my 40 I’ll add one and likely a charcoal canister too. Not for any specific reason.

I haven't seen where Holley prefers their return necessarily. Several of their units lack a bypass return at the throttle body. The 2300 does have one. This is from their site.

Fuel Pressure Regulator: The majority of Sniper EFI systems come with a pre-installed fuel pressure regulator that will work great for all naturally aspirated, nitrous and roots supercharged applications. Blow-through applications will require the use of an external boost referenced regulator (example: 12-848). Below is a list of systems that will require an external fuel press regulator :

• Sniper EFI Stealth 4150
• Sniper EFI Stealth 4500
• Sniper EFI Quadrajet
• Sniper EFI 4150 2X4
• Sniper EFI X-Flow

There are some threads on MUD that talk about trying to keep the fuel return away from the hotter side of the engine or going over the engine to keep fuel temps down at the tank. I like the idea of reducing fuel line runs as well.

My exhaust is fairly new, from the previous owners work. I smoke tested the exhaust and the vacuum lines and carb setup yesterday. All looked good with the exception of a small leak at the PCV. I won't add a cat, but will need to add back a charcoal canister. The fuel separator on mine is plugged at that port.

 

[jhynesrockmtn]

Parts are arriving for this project and I've made a bit of progress with getting the surge tank mounted. I fabbed up a mount from some scraps I had lying around. Once again, hoarding pays off! I've decided to pull the aux tank to simplify things. The fuel coming from that tank has a color that suggest rust in there. These two fuel filters were installed at the same time. The yellow colored one is the aux tank fuel. I'll set up the fuel lines so I can add it back later but may just go with a couple of Jerry cans for extra fuel.