Need Ideas for a 393 stroker build

ChaseTruck754 · Post by **ChaseTruck754** » Tue Dec 06, 2011 10:38 am

Silverslk wrote:
BajaBronco13 wrote:Andy, you seriously considering an LS engine?

uh.....no.....

Man up & admit it Andy - there's nothing to be ashamed of.

I'm considering it for sure. That and a 4bt cummins are the current debate in my mind...

Silverslk · Post by **Silverslk** » Tue Dec 06, 2011 10:53 am

ChaseTruck754 wrote:
Silverslk wrote:
BajaBronco13 wrote:Andy, you seriously considering an LS engine?

uh.....no.....
Man up & admit it Andy - there's nothing to be ashamed of.

I'm considering it for sure. That and a 4bt cummins are the current debate in my mind...

Not ashamed. haha

Just no plans on formal announcement until I was closer to actually pulling trigger.

My plans are clear LQ9/ 4L80E (or hopefully 6L80E). Already have line on items needed to do swap (Dakota Digital adapter for speedo and tach to keep factory gauges), Also deciding if I keep push button 4wd or manual shift.....that will settle on which TC. All CARB approved and smog legal. IF that falls through......I have an address in AZ too!!!

Actually discussed it more this weekend with a guy who has 5.3 in his YJ.

ChaseTruck754 · Post by **ChaseTruck754** » Tue Dec 06, 2011 11:02 am

Just talked to a buddy last night who grabbed an LQ9 with 4L80E attached with 37k on the package for $1,100. He stumbled across it (went to buy a tool box & ended up with tool box & motor) & then sold it to another buddy. I told him if he ever lands on another like that CALL ME 1st!!!!

Agui-E7TE · Post by **Agui-E7TE** » Tue Dec 06, 2011 2:25 pm

Anyone have any ideas on what size injectors would be good for a 393 stroker? I don't want to run the biggest available since it probably would have issues idling. I'm guessing the stock injectors are the 19 lbs/hr. I'm thinking the 24 lb/hr. injectors might be the suitable choice.

Seattle FSB · Post by **Seattle FSB** » Tue Dec 06, 2011 5:18 pm

Agui-E7TE wrote:Anyone have any ideas on what size injectors would be good for a 393 stroker? I don't want to run the biggest available since it probably would have issues idling. I'm guessing the stock injectors are the 19 lbs/hr. I'm thinking the 24 lb/hr. injectors might be the suitable choice.

Time for you to start your research.

Your 19lb fuel injectors may be an issue on a 393 Stroker. I run 42lb injectors at 42.5 psi fuel pressure on my 6.7L. These were estimated at 500 HP with a .50 Brake Specific Fuel Consumption and 80% Duty Cycle. If you estimate 300 HP, I would think you would be starting at 24 lb injectors. 300 hp at the flywheel would require 24 lb/hr injectors to stay within safe parameters. This is at the standard .50 BSFC, .80 Duty Cycle and Industry Fuel Injector Test Pressure of 43.5 psi. 19 lb/hr injectors show a hp potential of only 243 hp.

Crunch the numbers for yourself at RC Fuel Injection or WitchHunter Performance or Marren Fuel Injection or Injector Size Calculator. Sure you can increase your Duty Cycle or Fuel Pressure for more performance, but why risk going lean at WOT?

Also consider the following:

The fuel system on your EFI includes a fuel pump, fuel lines, fuel filter, fuel rail, fuel pressure regulator and fuel injectors. When upgrading to a high horsepower engine with large fuel injectors all variables must be considered or you may risk running one or more cylinders lean potentially causing serious engine damage.

Ensuring equal fuel pressure across the fuel rail is critical. Most stock fuel rails are designed for stock fuel injectors by the bore diameter of the rail and whether it is a single-feed or a dual-feed design. Even if it is a dual-feed type, it may not be able to keep up with larger than stock injectors and will drop fuel pressure to different parts of the rail at WOT.

After market fuel rails tend to have much larger bores that will equalize pressure to all fuel injectors, even with a single-feed design. A quality after market fuel rail, adjustable FPR and high flow fuel pump may in order for a 393 or 408 Stroker with increased Injector sizing.

Also consider most 5/16" stock fuel lines are good for around 400 hp. When exceeding these demands one may have to upgrade to 3/8" diameter fuel lines. Additionally, the stock fuel filter can also be restrictive, especially when contaminated. Service it regularly or replace it with a aftermarket high flow fuel filter.

Agui-E7TE · Post by **Agui-E7TE** » Tue Dec 06, 2011 7:10 pm

I have thought about replacing the fuel pumps as well as the fuel rails and adding an adjustable fuel pressure regulator. I did check out the links you posted and it looks like 36 lbs/hr injectors might be the perfect match for my 393. I'm thinking it will produce under 500 horsepower since I want to keep the compression low(10 to 1) to be able to run pump gas.

BajaF250 · Post by **BajaF250** » Tue Dec 06, 2011 7:29 pm

Hey Aqui,
I compiled a listing of potential stroker kits for comparision... thought you might find it of interest. The prices may be a little dated as this table is a few years old now.

Agui-E7TE · Post by **Agui-E7TE** » Wed Dec 07, 2011 1:08 am

Thanks Tom! That's a great way to compare the various kits available. I was leaning towards a stroker kit from Coast High Performance since they seem to be reasonably priced and seem to work really great for the Mustang crowd but I totally forgot about DSS and there stroker kit is just over $1000 and comes with a nodular iron crank, forged pistons and forged I-beam rods.

robertcrav · Post by **robertcrav** » Wed Apr 18, 2012 12:05 pm

Seattle FSB wrote: BBK 56mm Twin Throttle Body

Is there a reason you went with the Dual 56mm instead of the Dual 61mm? I would think the 393 would make use of the extra cfm, no?

Seattle FSB · Post by **Seattle FSB** » Mon Apr 23, 2012 2:22 pm

robertcrav wrote:
Seattle FSB wrote: BBK 56mm Twin Throttle Body
I would think the 393 would make use of the extra cfm, no?

Mmmm.... no. At least not any more cfm that I could effectively use. Your air flow restrictions are elsewhere.

I already had a BBK 56mm Twin Throttle Body which can support up to 570 hp and can flow approximately 850 cfm. I do have a standby BBK 61mm which can support up to 670 hp and can flow approximately 1000 cfm. I may throw it on when I retune the PCM, but this will require port matching the Throttle Body to the upper intake.

Throttle Body Sizing and Horsepower Level
Dual 51mm = single 72mm = 470 HP
Dual 56mm = single 79mm = 570 HP
Dual 61mm = single 86mm = 670 HP

Seabass · Post by **Seabass** » Mon Apr 23, 2012 10:08 pm

What is the stock t-body size?

AussieRod · Post by **AussieRod** » Tue Apr 24, 2012 1:40 am

Seabass wrote:What is the stock t-body size?

High-lighted in yellow.... dual 51 mm

Seabass · Post by **Seabass** » Tue Apr 24, 2012 3:34 pm

LOL thanks

Seabass · Post by **Seabass** » Tue Apr 24, 2012 3:37 pm

Now that I've looked at the chart I have another possibly equally dumb question. Is the 5.8 t-body the same?

And one more for good measure... Hows the 460 t-body compare? I've seen them installed on the 6's as an upgrade.

AussieRod · Post by **AussieRod** » Tue Apr 24, 2012 5:06 pm

I believe the throttle body is the same size for all 3 EFI truck engines (5.0, 5.8 and 7.5L).

Seabass · Post by **Seabass** » Wed Apr 25, 2012 3:20 pm

Gotcha. Seems when researching sbf stuff it's all mustang tech. Great thread hope to see it grow.

I'm hunting for heads now myself. Any one care to chime in on runner volume that would work on a stock 351 and a 393 maybe even a 408. I hate spending money twice

What compression ratio are you guys aiming for? I was hoping 11:1 but everone on mustang forums says thats asking for trouble with a heavier car.

Hey mods what do you think about adding a sub forum just for engine tech?

Our builds are differant enough from mustangs it may be a hit....

ChaseTruck754 · Post by **ChaseTruck754** » Wed Apr 25, 2012 3:31 pm

I typically aim to keep compression lower - like 9.5:1 max if I can since my trucks will see Pemex and I never really trust what that is octane wise.

Seabass · Post by **Seabass** » Wed Apr 25, 2012 4:22 pm

Is 11:1 to agressive for good 91 octane?

I've heard that pmex is actually good stuff (if your not getting swindled at the pump). I don't know this to be fact but came from an oldtimer that's spend some time down there.

ChaseTruck754 · Post by **ChaseTruck754** » Wed Apr 25, 2012 4:41 pm

I'll defer to others on the 11:1 w/ 91 but from what I remember reading - that is pushing it.

As for Pemex - it's just more of a "you never know - it is mexico afterall" type deal for me. It's the same reason I plan on running a large, removable can (cleanable) fuel filter on my truck.

MOSS2 · Post by **MOSS2** » Wed Apr 25, 2012 5:35 pm

Your compression ratio kind of depends on the cam you want to run. If you run a mild computer FI friendly cam with low overlap that is going to build a ton of cylinder pressure and probably not like 11:1 to go with it. If you run a high overlap cam rough idle and computer unfriendly you can get away with higher compression as it loses some pressure with the cam. I would probably keep it 10:1 or less unless it is a race motor.

Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build

Re: Need Ideas for a 393 stroker build