which injectors? 24# or 30#

[1991vert]

i have a 347 stroker. 8.5:1 compression, AFR185 heads, crappy crane 2040, 1.6 rockers, trickflow R-intake.

can i get by with 24's? or should i get the 30's?

 

[bob331T76]

yeah 24's will work fine!

 

[1991vert]

ttt anyone else?

 

[Ozz]

Injector HP ratings: divide flow rating by.5 and multiply the result by the number of injectors. This uses a 100% duty cycle. These ratings are for naturally aspirated engines. See my comments on pressurized induction in the paragraphs following this one.
Example:
19/.5 = 38, 38 x 8 = 304
24/.5 = 48, 48 x 8 = 384
30/.5 = 60, 60 x 8 = 480

The preferred duty cycle is about 85% maximum, so for a safety factor mulitply the final figure times .85.

Remember that the above ratings are at 39 PSI. Increasing the pressure will effectively increase the flow rating. Example: a 19 lb injector will flow 24 lbs at 63 PSI, and a 24 lb injector will flow 30 lbs at 63 PSI.

So, if you're expecting more than 384HP on the NA setup, go with 30s. Otherwise 24s will work according to this info by the man himself If you want my 24s, get in touch quick

 

[04sleeper]

His car has a Novi 2000 Dave.

With your 347 combo you could easily push 600+ RWHP with the Novi.

I would go with a set of 60's.

 

[Ozz]

(The Novi isn't in the mix at this point)

 

[04sleeper]

(The Novi isn't in the mix at this point)

Oh. OK. I saw it in his sig.

In that case he could get away with the 24's for now.

60's down the road.

Or just buy 60's now and tune it for N/A and be done!

 

[N8Miller]

30s for peace of mind.

 

[Thomas302]

I think you would be safer with 30's.

 

[S&B]

30's

 

[5spd GT]

You can "get by" with 24's...and go with them if you get a better deal on them.

Go 30's if you plan on keeping it for a while N/A...

 

[gcwh02]

30's

 

[superhuaman]

You can "get by" with 24's...and go with them if you get a better deal on them.

Go 30's if you plan on keeping it for a while N/A...

lol, ive never seen 24's for cheaper than 30's... i got 30's for my 306 because they will work...everyone on ebay was after the 24's like a starving squirrel after the last nut on earth. i guess since 24's are good on a mostly stock engine, lots of people switch to them

 

[FullAuto]

30s and I said that on mustangforums.com also.

I don't care if the compression is only 8.5:1. That AFR headed stroker should make enough power N/A to need 30s.

 

[5spd GT]

lol, ive never seen 24's for cheaper than 30's... i got 30's for my 306 because they will work...everyone on ebay was after the 24's like a starving squirrel after the last nut on earth. i guess since 24's are good on a mostly stock engine, lots of people switch to them

Lol.

I was saying if he could get them for cheaper, would be the only reason to get them.

I have a 306, I know for a fact 24's would not be starving my car for fuel.

The 30's I have now are drowning my car.

19's are good on a "mostly stock engine"...not 24's.

 

[superhuaman]

well yeah...i guess i was thinking of stock bottom end...with h/c/i...then you would probably want 24's

 

[MatthewP]

Assuming this car is actually going to run the supercharger, I would suggest at least 42# injectors. Save yourself the trouble of having to buy another set of injectors once you hook the supercharger up.

I ran 30's on an N/A 351W setup with a solid roller and TFS Track Heat heads. At 3500 ft it worked ok, but at a 2200 ft track it would occassionally run short of fuel. 30's were right at the limit for that combination, and probably will be with yours too.

-Matthew