Snap,

I’d think it would get pretty hot while running, but it would probably cool off reasonably quickly after shutting down. That said….

I’ve gone to the effort of designing and building a jacketed riser, dammit. I’m gonna make it work!

Thanks. Brad.

Guys,

Thinking about how to purge the bulk of the air out of the fuel lines for initial population….



As can be seen, I am returning the regulator bleed-off to the filter head. I have explored the option of adding a return bung to the tank, or teeing to the fuel fill tube, which would obviously make this an instant non-problem, but I just don’t see it happening. I don’t have that level of commitment to what is involved. The hose at the fill port is all but inaccessible, and getting it off at the tank has proven impossible. I could maybe tee into the vent tube, but I could see that as being problematic. If not, do tell. Otherwise….

I’m thinking about replacing this elbow with a tee, allowing for a purge line to be attached that will allow the air to escape without having to run it through the filter, continuously recycling it until the injectors consume it. I know some air will have to go through the injectors, but I’m just trying to minimize the process. Obviously the tee would be capped once purging is done.

My question is this:

With this tee open, will the pump pull fuel through it instead of from the tank? I could see it doing so at first, when the entire fuel tract is dry, so I’d plan on capping the purge line (which would be at a vacuum at this point, until we get fuel to the regulator. I’d think the pump would then put the purge line at a higher pressure than the vacuum being drawn on the tank, and the flow would reverse, flushing fuel and air out until “all” the air was gone. From that point on, at least until a fuel filter change, which would require a repeat of the purge process, the fuel tract would be fully populated and devoid of air.

Yes/no? Thoughts?

Thanks. Brad.

do you have a provision to mount a fuel pressure gauge on the fuel rail?your gonna want to watch rail pressure and make sure its steady and not bouncing.bouncing means air up there in the rail.

Sutphen,

It has been discussed, but no, I don’t have a gauge port on the rail. I have since teed the gauge port on the regulator and included the pressure sender, but the gauge is still on the regulator. Will this not reflect the pressure at the rail?



The OEM fuel rail doesn’t even have a return line, so I know the injectors will eventually consume all the air in the system. I’m just trying to expedite the process a bit.

Thanks. Brad.

you think that would be the case,,we saw differently.after days of running,we finally sent the return to the tank and rail pressure was perfect.this happened on 47excalipers whippled 496's.we tuned his engines on the dyno and we knew the afr's would change,,but the swings were crazy.put the gauge on the rail and it was bouncing.
hope your situation is different,,just keep an eye on it.

Sutphen,

I am not at all opposed to running the return back on the tank, but I’m not, at this point, willing to commit to breaching the tank to install a bung, and have yet to find a feasible way to tee to the fill hose. I can get to the top of the tank, and get the fill hose loose, so that I can move it, but at about 1/4” of movement, it just hits a wall and won’t budge. I can get to the fill hose at the fill port under the gunwale, but getting it loose is going to be next to impossible. I’m pretty sure I can tee to the vent line at the top of the tank. Thinking about it, the tank should always be at neutral or negative pressure, with the tank drawing however much air the injectors are consuming through the vent. Is this a viable option?

Thanks. Brad.

Guys,

EZ Return Fittings: New Sizes Now Available - Team CPP

Anybody ever....?

Thanks. Brad.

Looking at some of the items that you have made, it's obvious that you are a craftsman at what you do,

but as somebody that has worked on these engines for many years and also have owned numerous boats with twin 496 engines I just have to ask,

496, an engine that's been for the most part trouble free and proven, are you making things overly complicated and redesign things that do not need to be redesigned?

Cool watching you make one of items,keep up the good work.

BoatNT,

It’s a curse sometimes.

No. I don’t think I’m overcomplicating things. I started the custom fuel rail because I was suspect that it was a contributor to the failure. In retrospect, I’m not totally convinced. The builder is adamant that the cylinder went lean, and I don’t disagree, but the injectors passed Smitty’s inspection with flying colors. My running theory is that a flake of paint got loose from the CoolFuel, found its way to the injector, but was too big to infiltrate, so when I disassembled the rail/injectors, it fell away and eluded discovery. We will never know. But the fuel rail was well underway, so I followed through with it. I now have a BoM, a process and a collection of fixtures I can make more with, that I intend to pursue as soon as we have the prototype that will be on my engine proven out. It also facilitate a flow-through design, which I and many others believe to be a better means of fuel delivery.

The exhaust risers were an attempt to ensure we don’t get reversion, and thought it should be water jacketed. It’s actually a very simple design.

I really haven’t done anything else that I and the builder didn’t think needed to be addressed. And let’s face it…. The 496, while a proven platform, is not the ideal platform for any kind of power adder setup. So we corrected all those issues with forged pistons and rods, and modifications of the intake to improve airflow and eliminate the PCV conflict with positive manifold pressure under boost. And, also, let’s face it…. The ProCharger, while the unit itself is perfectly viable as a power adder, the kit they provide leaves a lot to be desired, which many of the issues that need to be addressed with regard to the fuel delivery requirements under boost either band-aided or simply not addressed at all. We have corrected those ills.

I also wanted to declutter the engine. As much as it may not look like it, I am a minimalist, and I am striving for a cleaner look. So anything that didn’t need to be on the engine went elsewhere, mostly the transom.

Now it’s just a matter of ironing a couple wrinkles flat, hopefully with enough anticipation to get them out of the way before the engine is back in place of it’s going to be an issue with it in the boat.

Thanks. Brad.

Going back to the filter head will be fine and works. I believe the 700s are plumbed the same way .
I`d put a fuel cooler in that line to prevent hydrolock.. not sure what youre talking about injectors and air ?? What air?