What size do i need?!!!!
- Thread starter SMOKEDYA
- Start date
Vipersix
Founding Member
68stang351
Founding Member
If you want 30's on the cheap you can rob them off a couple of Thunderbird Supercoupes or early non-SVO Turbo 2.3's.
I did see an ad for a set of them though for only like 239$ new!
I did see an ad for a set of them though for only like 239$ new!
+1 on the 30# injectors. However, I say a 75mm TB and EGR spacer at a minimum. I'd be half tempted to go even bigger, but that would require hogging out the intake opening on most aftermarket intakes, and since you are running 185s, it would probably not be worth going 80mm+. Going a little bigger with the TB certainly won't hurt, but going too small will.
why do you say this? do you know someone running what i am? just courious everyone else seems to think 30's will work! also how do i determine my throttle body size i have now! peace
john
You said you're doing a "healthy" 351. I have a healthy 347 with 100% maxed out 30lb injectors so I speak from personal experience. Go with the bigger injector and a 75mm tb at least. I see 96% duty cycle before I hit my shift point.
What A/F are you getting? Power? RPM? I'm not trying to call you out, that just seems pretty extreme for an N/A 347.
42s seem really big for an N/A 351... If you go by this method:
Injector Flow Rate (lb/hr) =
(HP x BSFC)/(Number of Injectors x Injector duty cycle)
And use these numbers:
HP=400 (guessing he might make this with a "healthy" 351)
BSFC=.5 (about normal for an N/A engine)
8 injectors (duh)
80% duty cycle (ideal)
... You result with a 31.25 lb/hr injector.
Using the same formula and numbers, a 42lb/hr injector would be feeding a 537hp motor!
Ok heres my combo. 351 .40 over AFR 185's trick flow R intake and this cam Voodoo Hyd Cam Kit - Ford 351W 302HO 262/268 - Lunati Power also will have l/t's so going off this will it help determine my injecter size? peace
john
john
Dude go with a custom cam. You have potential to make a good combo, don't ruin it with a guessing game junk cam! Go with 42's.
NikwoaC- I tuned the car myself with a PMS and a wb 02 meter. The a/f starts around low 13's and works its way into the uppers 12s up top. It goes just under 7,000 rpm. No clue on power, dynos are for tuning and I do my own tuning on the street. I would throw 42s on my own car but I don't drive it enough to worry about the high duty cycle for now.
NikwoaC- I tuned the car myself with a PMS and a wb 02 meter. The a/f starts around low 13's and works its way into the uppers 12s up top. It goes just under 7,000 rpm. No clue on power, dynos are for tuning and I do my own tuning on the street. I would throw 42s on my own car but I don't drive it enough to worry about the high duty cycle for now.
who would i contact to get a custom cam ground? i talked to a speed shop here and he also said all the 351's he's done needs 42's. so thats what i'll do. will have to chip it but big deal! peace
john
joel5.0
Member
who would i contact to get a custom cam ground? i talked to a speed shop here and he also said all the 351's he's done needs 42's. so thats what i'll do. will have to chip it but big deal! peace
john
Do suggest Camshaft Innovations for the best custom cam for your setup. Great service, products, and most important, results.
Sometimes I wonder how much commission some of these guys are getting for promoting one guy as the "best." 
There are several options out there that will give you everything you are looking for:
Ed Curtis, Buddy Rawls, Jay Allen, etc.
There are several options out there that will give you everything you are looking for:
Ed Curtis, Buddy Rawls, Jay Allen, etc.
joel5.0
Member
Assumptions, assumptions.....Sometimes I wonder how much commission some of these guys are getting for promoting one guy as the "best."
.... yet, the best model of a pharisaical statement....just courious? what does your 347 make at the wheels? whats your combo N/A power adder. peace
john
Sounds like your motor is a screamer! Like I said before, I wasn't trying to call you out on anything, it just seemed to me that 42s are a little on the big side for a 351. They would allow for some growing room, though, so with a good tune it probably wouldn't be a big deal.
I know you don't Dana. You put the recommendations when they are needed, not every time you hit the reply button, nor do you say that CI is the "best" without having several experiences.
To answer your question honestly, probably not in THIS thread. There are factors I take into account.
