Ok guys, I am new to the diesel thing but have been working on cars for a long time. I have 7.3 Ex and have done a few simple mods to it as seen by my signature. Today, I drilled out the banjo bolts on the ends of the heads. After I got it buttoned up, it wouldn't start. I charged the batteries and it finally started but it running rough. I have no codes and no other mods than the ones in my signature. During the no start period, this guy was making a whole lot of noise. I have no idea what is, again, new to the diesel thing. Should I not have drilled those banjos out? Any idea why this pump was so noisy? Any advice or direction you can offer would be great. Thanks!

 

Drilling banjo is ok as long as you de burr and that is a vacuum pump

 

Yes I did deburr, they were both nice and clean and smooth. I thought it was the vacuum pump but I expected something...bigger lol.

So would the rough running be a coincidence and not the result of the banjo drilling?

 

Air in system

 

That makes sense! Told you I was green with this but am learning. I appreciate your quick response.

 

SO did drilling the banjo help, hurt or do nothing you can tell.

 

So I drove it for about a week or so on the drilled banjos. It seemed to run a bit "choppier" if that makes any sense. It just wasn't as smooth at idle. So I ordered the redesigned banjos from Riff Raff and it set everything right. It smoothed out a ton and whatever performance benefit I got from the drilled banjos remains. I am not sure what that benefit was since I went from choppy to the Riff Raff ones but it didn't hurt either.

The other thing I didn't consider was that drilling the banjos weakens the bolt and it could break off inside the head upon tightening. So you really gotta be careful. The Riff Raff ones are way strong, no worries with them.

 

As you are new to diesels, I would be more careful about the mods you make to the truck. I learned so much from these guys on this forum, then I went on to learn more from my incompetence as a diesel mechanic - my tools were very small before I bought "Stinky". I'm more of a troubleshooter than a mechanic - "So that's where I went wrong."

Click the "Custom Tunes" link in my signature if you want to learn more about upgrading vs. improving performance on our aging beasts. The banjo bolts are not a limiting factor on the way our trucks run, it's more internet lore than anything else. Plenty of people buy into it though, so the aftermarket is more than willing to provide the means to enable those that do. Clay at Riffraff is a straight-shooter and provides excellent products and advice - but he's also a businessman and doesn't want to miss out on the banjo-bolt craze.

 

Yea you're absolutely right. Once I drilled them and then learned more about what was actually going on, I was actually going to just replace them with stockers. Then I saw the Riff Raff ones (I think Razzi showed them to me lol sorry to call you out!) and I said well, it can't hurt. I've done a few other things to help the performance but all I can saw for the Riff Raffs, is that they're better than drilled stockers. I've learned a ton from you and the other guys here since I did this. I think I've clicked every link in your signature already lol. But yea, if I had to do it all over again, I would've just left them alone.
I appreciate that you guys all take the time to help us new guys out. I've never seen y'all be condescending or make people feel dumb when they do stuff like drilling the banjos lol.

 

Tugly is right on this. But one thing to remember is that just like people love to take statements out of context, in the forums part applications get taken out of context. This is one of those cases with the high flow banjo bolts. If you have a stock truck with maybe a tuner and you aren't going any further then it isn't something to mess with. Changing injectors, turbo, HPOP etc? Then you are getting to what they are needed for. I have installed banjos on several trucks and the one thing I can say about Riffraff's versus others or especially drilling them is how much smoother the truck runs, not to mention they won't break off on install. As with the rest of Clay's parts that they design and manufacture there is always more than meets the eye. People think it is just about the size of the hole, but turbulence is a huge factor in fuel flow. As you can seen on Riffraff's bolts they are chamfered and smoothed as well, not just a larger hole. Something tells me they have run the flow and turbulence calculation and simulations to get the end result of high flow, but especially smoother idle because you don't just randomly come up with porting like that. I also have to say Clay's honesty shows through on this one again because they sell them in pairs of two rather than in kits of four since if you are just running smaller mods you would only need the feed sides of the head and not the return until you get more flow to warrant it. Plus if Clay didn't find it worth producing and beneficial I don't think he would as I have asked for a couple parts over the years and they just won't do it if he doesn't believe it to be worth installing. Yet another reason why I love shopping at Riffraff, they will tell you straight up and help you not waste your limited funds.

 

Absolutely and I should've added some more detail to what I said. I am a Mustang guy normally until all this diesel stuff kicked off. What you're talking about is growing your mods together. You don't add a 850cfm double pumper to stock 289. It all has to work together or else you run into issues. So that's the way I see this. As you can see from my signature, I'm mostly stock. So I should've just skipped anything banjo related since I'm not at that point and I'm not sure I ever will be. But when I saw the Riff Raff ones I figured I'd give them a shot since the drilled ones weren't working for me. It's smoothed everything out but I haven't seen a performance gain from them.
And you're right, Clay wouldn't make them if they weren't worth it.

 

What is the purpose of drilling these out or upgrading to the RiffRaff bolts?

 

From Riffraff's website.

"We have engineered a high flow fuel bolt using StressProof® Steel that offers the highest flow possible. By combining a patented, high-end steel with precision flow/port testing we have been able to reduce turbulence, raise flow, and increase bolt strength all at an economically minded price point. "

Riffraff Diesel High Flow Banjo Bolt - 7.3L - Riffraff Diesel Performance

 

I have to agree with you on the flow through the RR banjo bolts vs stock bolts. in just looking at the stock and modified banjos side by side you can see the major in difference in them.

Years ago (30+) I raced motocross on a yamaha 175cc YZ. one of the shop owners was from california and knew the guys at the factory works shop for yamaha.. we were able to get the modification from the actual works bikes from two years prior.. it included some porting, polishing and smoothing the intake and exhaust area on the 2 cycle engine.

We basically allowed intake and exhaust to flow better and man the results were amazing.. low end torque was upped to where i could out pull 250 and 400 cc guys in the tight stuff as i was able to be in a higher gear with more torque to launch me out of the corner heading the the next one. man that was fun..

With all that said, i can see where the modified bolts could be better than the stock bolts just in less restrictive flow of fuel. I feel with the bolts, fuel cross over kit and hutch mod a good pre filter you have the very best fuel system for money short of a regulated system and pumps for a LOT more money, for less money..