Injector size for a 351? Guys with 351's get in here....

[nmcgrawj]

Whats up guys? Im building a 351 with tfs twisted wedge heads with a stage 1 port job, compcams 35-518-8 cam(similar to tfs stage 2) or maybe a custom cam, tfs 351 intake, long tubes, 5-speed, daily driver, etc.....

What size injectors should i run? Im thinking 30lb but some people tell me 36 and others say 24.

Which do you think?

 

[AznStanger3v]

i think you should swing well with 24s and up the fuel pressure a bit. or go with 30s and play with the fuel pressure as well. 36s and up are kinda the forced induction territory

 

[nmcgrawj]

Thats what i was thinking.....30s seem to be good. I dont wanna come close to being lean with the 24's

 

[Grn92LX]

Just like I said on corral, 30's at least and 42's if your planning on getting a bit more wild. I run 30's on my n/a 302.

 

[nmcgrawj]

haha thanks man. Like i said over there, it wont be wild for another couple years. This will not be supercharged or used with nitrous, just all motor.

 

[Rootus]

All motor, 30's should take you to around 450 bhp. Could go a little higher if you want to cut the safety margin down.

 

[nmcgrawj]

So thats about 382 rwhp right? If i did go with 36s, would it run terribly rich?

Would the 30s be easier to tune since it will be in the middle of its power band?

THANKS SO FAR!

 

[Grn92LX]

When I said 'wild' I meant like a properly designed custom cam(possibly a solid cam), spinning it high, high flowing intake. I think 30's are fine for what you have, but IMO, their close to borderline. Who did the 'stage 1' port work and what do they flow?

 

[Rootus]

So thats about 382 rwhp right? If i did go with 36s, would it run terribly rich?

Would the 30s be easier to tune since it will be in the middle of its power band?

THANKS SO FAR!

Unless you go with far bigger injectors, it's not going to make you run any richer. As long as the EEC has been told what you're doing, it can deal just fine with larger injectors. I don't think it would be any easier to tune either way, as long as the injector is big enough go with it.

Dave

 

[Joes95GT]

Unless you go with far bigger injectors, it's not going to make you run any richer. As long as the EEC has been told what you're doing, it can deal just fine with larger injectors. I don't think it would be any easier to tune either way, as long as the injector is big enough go with it.

Dave

I'd go with a minimum of 36. 382 RWHP is going to come very easy for a 351, and the 30's will be maxed. You could use any stock type high impedance injector and not run terribly rich; that includes 42's.

Joe

 

[nmcgrawj]

I'd go with a minimum of 36. 382 RWHP is going to come very easy for a 351, and the 30's will be maxed. You could use any stock type high impedance injector and not run terribly rich; that includes 42's.

Joe

You think a stock shortblock 351 with tfs twisted wedge heads ported by Fox Lake- stage 1(pretty sure thats the name) , most likely a custom cam if not TFS stage 2, tfs 351 intake and the other parts to go along with it will get 382rwhp? I wasn't expecting that much but hey i will take it.

I dont have the flow numbers of the port work, i bought the heads used.

Thanks for all the help so far guys...

 

[Grn92LX]

With a good streetable custom cam, thats easily 400+rwhp. Unless you have some weak blower compression? I'd use that tfs r 351 intake or a victor 5.8. If you dont have the injctors yet, I think im gonna have to recommend 42's. I cant believe people would recommend a 24lb injector for that combo!

 

[Joes95GT]

With a good streetable custom cam, thats easily 400+rwhp. Unless you have some weak blower compression? I'd use that tfs r 351 intake or a victor 5.8. If you dont have the injctors yet, I think im gonna have to recommend 42's. I cant believe people would recommend a 24lb injector for that combo!

Yup.

nmc - Go with 42's. I thought you were using the stock camshaft, hence the recommendation for 36's.

Joe

 

[nmcgrawj]

WHOA, i havent seen anyone of the 351's (non stroked) run 42's, but i haven't seen that many. That seems like a whole lot of fuel. I thought this combo would be tough but you guys make it sound like a beast. I still cant see getting that much power out of the parts.

The most popular i have seen with 351 combos are 30 and 36's. Feel free to shed some light on my ignorance.

Thanks

EDIT: What is blower compression? (When no blower is being used?)

 

[Jo_885o]

Nate u already got the heads? U did'nt tell me that.

 

[nmcgrawj]

ummmm oh yea.......Joe i got some heads. LOL

SHHHHHHHHH!!!! No one else knows in our area.

 

[Joes95GT]

WHOA, i havent seen anyone of the 351's (non stroked) run 42's, but i haven't seen that many. That seems like a whole lot of fuel. I thought this combo would be tough but you guys make it sound like a beast. I still cant see getting that much power out of the parts.

The most popular i have seen with 351 combos are 30 and 36's. Feel free to shed some light on my ignorance.

Thanks

EDIT: What is blower compression? (When no blower is being used?)

Assuming the heads are what the person claims they are and you buy a sufficient manifold and camshaft, the car will probably make 1.2-1.3 hp/cube at the flywheel. Cripe, I have a Hot Rod magazine where they pulled 380 horsepower out of a 351 with GT40P heads and some kind of small OTS cam. Horsepower becomes much easier to make when using a 351 instead of a 302 as a base.

Remember, fuel pressure can be regulated. This isn't like putting too much carb on a car. You could run 24 lb/hr injectors if you wanted; just crank up the fuel pressure. 36's or 42's will work well, however, I'd just use the 42's just in case.

He meant blower compression meaning low compression. Guys who use superchargers and turbos use lower compression pistons because it allows them to run more boost with that specific combination. I define low compression for anything less than 9:1.

Joe

 

[nmcgrawj]

oh ok i got it. Hmmm are 42's much more expensive then the others? Who makes 36's? It seems like i have only seem FRP go from 30 up to 42 and nothin in between.

BTW, i will be running the TFS 351 Intake and whatever ED comes up with the cam.

 

[Jo_885o]

o u trying to keep it on the down low huh? Are they on the car? and how much did u pay for 'em?

 

[Jo_885o]

man u gotta keep me posted. I feel like u trying to keep secrets. lol