Sugestions needed(fuel injection)
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 5,779
Likes: 0
From: Peoria AZ.
St. Jude Donor '05
Sugestions needed(fuel injection)
I am almost done with my engine
86 350 bored .030 over
Comp Cam part # 12-256-4
112° lobe sep.
0.449" Intake @ 0.05
0.456" Exhaust @ 0.05
Comp Cams 1.6 roller rockers
Im running the stock intake and runners for now.So with the cam and 1.6 rockers I figure I 've added sbout .060 of lift over the stock cam.(I still want to be able to drive it daily)If I'm correct It came with 24 lb injectors,which I plan on replacing with new set of Accels.
Now here's what I need help with,should I install 30 lb. injectors,or put 24 lb.ers back in and and a adjustable fuel pressure reg?
Any other sugestions would be greatly appreciated.
86 350 bored .030 over
Comp Cam part # 12-256-4
112° lobe sep.
0.449" Intake @ 0.05
0.456" Exhaust @ 0.05
Comp Cams 1.6 roller rockers
Im running the stock intake and runners for now.So with the cam and 1.6 rockers I figure I 've added sbout .060 of lift over the stock cam.(I still want to be able to drive it daily)If I'm correct It came with 24 lb injectors,which I plan on replacing with new set of Accels.
Now here's what I need help with,should I install 30 lb. injectors,or put 24 lb.ers back in and and a adjustable fuel pressure reg?
Any other sugestions would be greatly appreciated.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
That is a good reasonable, streetable, cam. With the stock manifold, you should stick with the stock size injectors. If it turns out that you need a little more fuel (unlikely with this combo) you can jack up the fuel pressure a little.
You have over estimated the lift gained by the 1.6 rockers, however. The .449" intake valve lift comes from a lobe lift of .2993". The 1.6 rocker ratio multiplies it out to .489", valve lift. That equals a gain in lift of .479" - .449" - .030", or 60% of what you were guessing. The exhaust becomes .486", a .030" increase, also.
The @.050" designation is for the duration, not the lift. The "@ 0.05" doesn't apply to the lift, only, specs you supplied. BTW, that cam has 212° duration @.050" lift for the intake, and 218° duration @.050" lift, exhaust. The "advertised durations are 256° intake and 268° exhaust. I hope that clears some things up for you.
RACE ON!!!
You have over estimated the lift gained by the 1.6 rockers, however. The .449" intake valve lift comes from a lobe lift of .2993". The 1.6 rocker ratio multiplies it out to .489", valve lift. That equals a gain in lift of .479" - .449" - .030", or 60% of what you were guessing. The exhaust becomes .486", a .030" increase, also.
The @.050" designation is for the duration, not the lift. The "@ 0.05" doesn't apply to the lift, only, specs you supplied. BTW, that cam has 212° duration @.050" lift for the intake, and 218° duration @.050" lift, exhaust. The "advertised durations are 256° intake and 268° exhaust. I hope that clears some things up for you.
RACE ON!!!
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Stock size is 22lb/hr for 86s.
I would either stick with that or get Ford SVO #24s, NOT Accels. I would ask a tuner for their recommendation on injector size, since a chip should be done for that cam change. Get the AFPR either way.
I would either stick with that or get Ford SVO #24s, NOT Accels. I would ask a tuner for their recommendation on injector size, since a chip should be done for that cam change. Get the AFPR either way.
