42lb injectors ?
 

wasup peoples

i am on a mission to make about 500hp at the rear wheels of my car.i know that a chasis dyno take a way a lot of power.here is my setup.

engine
400sbc bored 0.080,

heads
aluminum cnc ported,2.08 in\1.99ex valves,220cc runner,68cc chamber,5 angle valve job,angle spark plugs

cam/rocker arms
comp xfi 292 exreme efi cam/1.65 full roller rocker arm
cam spec are below

Basic Operating RPM Range2,800-6,800Intake Duration at 050 inch Lift248Exhaust Duration at 050 inch Lift253Duration at 050 inch Lift248 int./253 exh.Advertised Intake Duration292Advertised Exhaust Duration302Advertised Duration292 int./302 exh.Intake Valve Lift with Factory Rocker Arm Ratio0.584 in.Exhaust Valve Lift with Factory Rocker Arm Ratio0.579 in.Valve Lift with Factory Rocker Arm Ratio0.584 int./0.579 exh.Lobe Separation (degrees)113Computer-Controlled CompatibleYesGrind Number292XFI


42lb injectors venon

rhode island variable lifters

ign and ecu
efi connections 24x/ls1 ecu

elderbrock pro flo xt with ported ls1 tb

maf sensor

my question is should i move up to the 60lb or stay with the 42lb to get near 500 hp or higher. range on a chassis dyno

Re: 42lb injectors ?
 

Lets start with this.
I hope your not planning to bore a factory 400 block to .080.. :eek:

Re: 42lb injectors ?
 

the engine is together and is running with everything that is listed above.its a 408 sbc.

Re: 42lb injectors ?
 

If its a 408 then its bored .040 over.
If you went much more your reeeeeally pushing it with a 400 block, even with sonic testing shes getting thin unless you got super lucky..

I haven't got mine to the dyno yet but I'm going with 60s

Re: 42lb injectors ?
 

Maybe it's a Rhode Island block ? :confused:
I mean aftermarket block.

At any rate, 42 lb injectors are more than enough to handle 500 rwhp.

Re: 42lb injectors ?
 

she is built by a professional.400 block are more sturdy than what people actually knows.do you have a 400sbc.

Re: 42lb injectors ?
 

rhode island is a after market company that make lifters.they have been around for such a long time. but the block is stock gm block

Re: 42lb injectors ?
 

Yes I have a GM 400, 509 2bolt block with splayed 4bolt mains. I've even broke a few 509s.
I have some crete in it to stifen the walls.
Forged crank eagle rods and JE pistons.

Did you sonic check the thrust side of the bores??
Nuthing wrong with a 408 at all as long as the walls are thick enuff for proper ring seal even after several thousand miles. :)
I had a guy going from a .030 over to .040 over and he cracked 2 cyls boring them. They were super thin.

I know of rhodes lifters.. http://www.rhoadslifters.com/ I didn't know they were still around.
Never heard of rhode island lifters???

Re: 42lb injectors ?
 

the engine was professional built.

Re: 42lb injectors ?
 

is there any one running 42lb injectors their setup if so what type of power are you guys getting.any feedback would be greatly appreicated

Re: 42lb injectors ?
 

I dunno much but Im aiming for 490 at the fly. Do a Google search for fuel injector size calculator. It is based off of several things including HP. Plug in your variables and it should give you a fairly accurate number on the injector size that is required for your setup. If that size isnt available, round to the nearest size injector that is.

Re: 42lb injectors ?
 

One more time. 42 lb/hr injectors are WAY more than enough to produce over 500 horsepower at a reasonable RPM - 6000.
Sizing injectors for a max of 80% DC is overkill in the first place.
On top of that you have the freedom to up the fuel pressure as/if needed should the situation arise.

Re: 42lb injectors ?
 

other inputs besides yours sir thank you

Re: 42lb injectors ?
 

My friends 406 victor EFI motor is making 521whp thru a 6spd. He is using 42lb injectors but they are at 55psi base pressure and about 85-90% cycle duty now.

If you can get 60's that will leave more room for error, but then again, you may be ok with 42's at higher pressure. I dont see your combo making quite 500whp if an automatic with that cam. It will be alot, mid high 400's if good compression/ring seal in that motor but it needs abit more lift and duration to really make 500whp. Whose heads? That intake may need some serious port work to help flow up top end too

Re: 42lb injectors ?
 

You didnt say if you tried my suggestion or not. heres a link...
http://www.witchhunter.com/injectorcalc1.php4
Try that.

Re: 42lb injectors ?
 

tried the link and it not working

Re: 42lb injectors ?
 

Re: 42lb injectors ?
 

Calculator seems to predict about the same as my buddy's 406. Figure 620 crank hp, 0.55 bsfc and 90% cycle duty, need about 42 lb injectors if you run them at 55 psig pressure.

If you wanted to use regular TPI 43psi fuel pressure, you should look into 48-55 lb injectors, whatever is available in that range.

Re: 42lb injectors ?
 

ALOT of misinformation going on here. You got some research to do. And 42's even sounds overkill for that combo.

Re: 42lb injectors ?
 

Even the GM Bowtie block only allows a max 4.185 bore(.060 over factory 400). The correct terms are Edelbrock, Rhodes Lifters(I don't of any serious engine builder today that uses them, although Gale Banks used to endorse them, so whatever), the 1.99 exh vales must be a misprint. Noone makes a small block head that takes 1.99 exh valves.

If you actually have this engine, and it was professionally bulit, you just spent alot of money on an engine you know very little about. As far as injector sizing is concerned, the size of the nozzles is a small part of the equation. I run 24 lb injectors and make over 450hp at the flywheel. I of course run the nozzles at 70 psi. More important is knowing your engine's peak fuel requirement and sizing injectors to provide that need when operated at at 80% duty cycle. That's why you need to use the injector size calculator. Try TPIS. They should have a calculator on their website.

Do your homework.