LB7 Guys:PLEASE TAKE ME TO SCHOOL!

[1stgensleeper]

I have a lot of unanswered questions regarding the performance of my federal LB7 I plan to swap into my dodge truck. All advice is appreciated guys.

1. I want a set of 40% over nozzles or somewhere around there but don't know where to go. Option 1 is to send my nozzles to Extrude Hone and for about $300 get them enlarged. Option 2 is buying a used set of Exergy 40% overs for $800, they only have 10 hooks on them and no street miles. I know the Exergys are balanced better but how much does that really effect the engine?

2. How many issues arise with cylinder pressure blowing injector cups out or causing them to leak? I was planning on using an 80mm single and have heard that the added pressure will most likely cause issues. Is it difficult to weld or thread the cups into the head? Will billet hold downs help? I've been thinking and I'd also assume an aftermarket cam and thicker headgaskets would help to lower cylinder pressures would it not?

3. Has anyone ever used a diverter valve and a big single together? In theory it would work great but drive pressures could get a little high. Just curious.

 

[MAXX IT OUT]

For question 1, if your not getting the hole injector balanced by energy it would be better off extrude hone. As for your cups if would look at getting screwed in cups, http://www.duramaxdiesels.com/forum/showthread.php?t=51379&highlight=Screw+cups. But running the stock cup and hold downs will work or with billet it hold downs.

 

[DIESELMAFIAPER.LB7]

Imo billet holds aren't going to stop cups from pushing do threaded cups and call it a day.

The extrude hone will work fine but if the budget allows go exergy

I couldn't say on the diverter valve never ran one

 

[Dirtymaxx03]

1) pony up the extra $500 for a set of flow balanced sticks. That's a killer deal and a no brainer.
2) stock rods? If so I wouldn't worry about the cups. You will most likely chunck a rod through the block and into orbit before you lift a cup. And with that 80mm drive pressure should be perfect, so I really wouldn't worry about crazy high cylinder pressures.

3) the higher rpm power band of a big single, in your case a big 80mm, will help keep the rods somewhat happy. The sooner you make that 80mm light the greater the chance of causing some serious carnage. I would bolt that s480 on and run it without a valve and if it's unbearable, try a spool valve, or sell it for a more appropriate option.

 

[Bustedknuckles]

The guys saying go exergy arent understanding that you are just buying nozzles and putting them on your injectors. The extrude hone nozzles are just as good as the exergys. where the exergys shine is when you by the whole balanced injector through them, the magic is not in the nozzle. The guys at ATP trucks said extrude hone is great up to 45% over, then they recomend full exergy injectors. Billet hold downs aren't necessary.

 

[DIESELMAFIAPER.LB7]

I need to find my sheet with the extrude flow rates

Edit found it I'm not saying don't use them as I liked them made good power and for someone on a budget they are great mine cost like 400 bucks back in day I Got them dialed in fine even with the flow rates being the way they are

 

[1stgensleeper]

The guys saying go exergy arent understanding that you are just buying nozzles and putting them on your injectors. The extrude hone nozzles are just as good as the exergys. where the exergys shine is when you by the whole balanced injector through them, the magic is not in the nozzle. The guys at ATP trucks said extrude hone is great up to 45% over, then they recomend full exergy injectors. Billet hold downs aren't necessary.

Yeah these are nozzles only. I'd like to save money if I can but don't want to destroy something or hurt performance a lot. Right now I'm thinking about extrude honing them to 40-50% over and running the 80 with the diverter valve. Then I'll tune the bottom end torque out of it and use balance rates to get the injectors running evenly. How does that sound to you guys?

 

[SmokeShow]

The guys saying go exergy arent understanding that you are just buying nozzles and putting them on your injectors. The extrude hone nozzles are just as good as the exergys. where the exergys shine is when you by the whole balanced injector through them, the magic is not in the nozzle....

This!



and it's been a while since I've even opened EFI Live (set it and forget it with my tunes ) but I don't remember being able to do any individual injector tuning to help achieve a more balanced fire. That is actually what the computer itself tries to do which is what you are seeing when watching the balance rates - the computer trying to balance the fuel at each injector.

 

[1stgensleeper]

This!



and it's been a while since I've even opened EFI Live (set it and forget it with my tunes ) but I don't remember being able to do any individual injector tuning to help achieve a more balanced fire. That is actually what the computer itself tries to do which is what you are seeing when watching the balance rates - the computer trying to balance the fuel at each injector.

I see. That makes sense. It looks like I'll just send them to extrude hone and get them opened up then. Does anyone have the contact info for them?

 

[zf>allison]

I have a question to add. Running a big single and moving the power to a higher rpm helps rods. So could you run a adjustable cam gear valve springs anything you would need to make it rev up high like a secret squirrel pulling truck say 5 to 6000 rpms and it would preserve rods and give you more usable rpm after spoolup?

 

[Xternal]

At that rpm a cam is certainly needed. Welded water pump cam and crank etc. Valve springs should already be included as the seat pressure stock won't like that 80 if he starts pushin it with some nozzles. Sounds like he has the right plan. Can't wait to see the finished product