Can a built 5.3 from a 99' sierra run e85 normally?

[Mario Marquez]

So, I have a 1999 sierra with mods such as New rod bearings, main bearings, Stage 3 TSP cam 216/220 .550 lift, Lr4 high compression pistons and new rings, ls7 valve springs, LS7 intake valves, polished/ported heads, LS1 long tube headers with a tune and was wondering if it can use e85 without blowing a rod. Would like more hp but wanna make sure before any steps are taken. Thanks in advance.

[swathdiver]

1 hour ago, Mario Marquez said:

So, I have a 1999 sierra with mods such as New rod bearings, main bearings, Stage 3 TSP cam 216/220 .550 lift, Lr4 high compression pistons and new rings, ls7 valve springs, LS7 intake valves, polished/ported heads, LS1 long tube headers with a tune and was wondering if it can use e85 without blowing a rod. Would like more hp but wanna make sure before any steps are taken. Thanks in advance.

 

The hardware can certainly handle the additional horsepower of E85, question you should be asking, can your fuel system?  Is this an LM7 or L59?  The latter is a FlexFuel engine with the alcohol sensor and larger injectors and fuel pump capacity, FlexFuel tables, etc.

[Mario Marquez]

8 minutes ago, swathdiver said:

 

The hardware can certainly handle the additional horsepower of E85, question you should be asking, can your fuel system?  Is this an LM7 or L59?  The latter is a FlexFuel engine with the alcohol sensor and larger injectors and fuel pump capacity, FlexFuel tables, etc.

I believe it's an LM7. I was originally thinking about upgrading fuel pump, injectors and possible lines to accommodate but I'm not sure if I need anything else other than that. 

[swathdiver]

23 minutes ago, Mario Marquez said:

I believe it's an LM7. I was originally thinking about upgrading fuel pump, injectors and possible lines to accommodate but I'm not sure if I need anything else other than that. 

https://help.summitracing.com/app/answers/detail/a_id/4820/~/upgrading-the-lr4%2C-lm7%2C-and-l59-engines

 

https://help.summitracing.com/app/answers/detail/a_id/4816/related/1/session/L2F2LzEvdGltZS8xNTY5NTU5OTI2L2dlbi8xNTY5NTU5OTI2L3NpZC9mVWlJMWhLelJrel9hcHVVbGNuUkt5dXY0dkJPZWJNRkYxRHFSa0VKal9rejVvS1Z0OGhERXIlN0VQJTdFUDlQY3c3TWtuRkd2WGF6REQ3bXFzQm1mckhoOTJGRzNDZl9zeDBvdXVaY3FPenRvaDZLVlk2YXNQelYzMVRRJTIxJTIx

 

https://help.summitracing.com/app/answers/detail/a_id/4821/related/1

[Mario Marquez]

8 minutes ago, swathdiver said:

https://help.summitracing.com/app/answers/detail/a_id/4820/~/upgrading-the-lr4%2C-lm7%2C-and-l59-engines

 

https://help.summitracing.com/app/answers/detail/a_id/4816/related/1/session/L2F2LzEvdGltZS8xNTY5NTU5OTI2L2dlbi8xNTY5NTU5OTI2L3NpZC9mVWlJMWhLelJrel9hcHVVbGNuUkt5dXY0dkJPZWJNRkYxRHFSa0VKal9rejVvS1Z0OGhERXIlN0VQJTdFUDlQY3c3TWtuRkd2WGF6REQ3bXFzQm1mckhoOTJGRzNDZl9zeDBvdXVaY3FPenRvaDZLVlk2YXNQelYzMVRRJTIxJTIx

 

https://help.summitracing.com/app/answers/detail/a_id/4821/related/1

Okay, its definitely an LM7 Vortec 5300. My 8th digit of vin is a T.

[swathdiver]

13 hours ago, Mario Marquez said:

Okay, its definitely an LM7 Vortec 5300. My 8th digit of vin is a T.

I hope this links help inform you better about these different engines, their capabilities and how to modify them.  Have fun!

[CamGTP]

Your 1999 computers operating system can't see alcohol content so keep that in mind. You would have to run it from a barrel or something and leave the stoich setting exactly the same for it to be super accurate for the fuel.

 

Or you will have to change operating system to a 2002 file from like a tahoe/suburban that can run a flex fuel sensor and will do real time content readings to adjust the fueling on the fly. If you own a tuner, this can be done but it will cost you several more credits to get there. Then it's the time to dial the tune in.

 

I'd suggest injectors in the 40-50lb/hr range for the mods you have and E85.

Edited September 27, 2019 by CamGTP