Revised engine combo

bigwhitecobra · 01-30-2001, 04:56 PM

Ok, I've thought about it, and I have decided to go with a 351, alum Edelbrock Victor Jr heads,(2.02 and 1.60) and a Eaton/ Saleen blower/intake. I figure that I need more off the line grunt, seeing as then 351 will make plenty of power on the top end.

Now here's the question, for that high end power, which cam would be better, a FMS E-303 or F-303? And still pass emmissions?

------------------
1989 GT- Vortech blown 306, Anderson 3" power pipe, Vortech S-Trim 14# boost, MSD-6BTM, black wrinkle finish Cobra valve covers(woohoo), world class T-5, 3.55 gears, custom sub-frame connectors, Cobra grille insert and rear valance, Saleen "whale" wing, 4 wheel disc conversion, 11.1@124
1994 Cobra- MAC cold air fender kit, Motorsport underdrive pulley's, MAC 21/2" off-road H pipe, SVO mufflers, 3.73 gears, E-303 cam, 13.417@101.335mph

84_GT350 · 01-30-2001, 06:29 PM

Well...I dunno if it'll pass emissions, but the F-303 is better for a blower. Come to think of it, is the E303 even street legal? I always get the E and B cams mixed up. But that Eaton blower will make it pull hard off the line and the F303 will keep it going till the limiter.

------------------
1984 1/2 GT350 (#842 Hatchback w/ T-tops), 302HO, Comp cams Xtreme Energy cam, Carter 625cfm carb, Weiand Stealth intake, MSD distributor, MSD coil, FMS 9mm wires, 1 5/8" MAC unequal shorties, 2 1/2" MAC Prochamber H-pipe, Flowmaster 2 chambers, KYBs, 16"x8" 4 lug Cobra Rs, Falken 245/45ZR16s

Skankin · 01-30-2001, 06:47 PM

You'd be better off getting a blower cam.

They typically have more lsa, which is also good for emmissions. (you wanna keep the lobes apart). Here's a handy, generalized rule:

(intake duration@0.05"/2)+(Exh Dur@0.05"/2)-2*LSA = ?

If the number is positive, there's no overlap. The more positive it is, emissions are typically better. A negative number indicates overlap, which is bad (for blowers & emissions).

If the lobes aren't very aggressive (Long advertised durations), the emmissions are gonna be worse than what the general number indicates. Also, if the lobes are asymetrical... forget the formula.

A split duration favouring the exhaust might be a consideration. Are you gonna run 14#?

To make more top end power, and utilize the added displacement, you'll wanna go with a longer duration. Problem is, if you go too long, you either loose cylinder pressure (and power), or you have to shorten the lsa.

Maybe look into a comp cams extreme grind, they've got really agressive lobes... you could really push the "Magic number" down to zero, and be alright.

------------------
'89.5 5L LX, hatch, Medium Canyon Red, 155K Km (No winters), 5sp, 3.08, GT interior, a/c, Alpine CD, K/N, Crane PS91, Walbro 190 LPH, March Pulleys, Mr. Gasket 180 therm (HP balanced), 3 core rad, MarkVIII fan, Variflow controller, Polygraphite front bushings, FMS-5300B springs, 6 KYB's, 73mm Calipers, Maximum Motorsport 4pt chassis brace, Western Motorsport Racing's Sub-frame connectors. Re-ringed bottom end, conv. motor mounts, melling oil pump, FMS-C50 waterpump, GT40P heads (blended, polli

Skankin · 01-30-2001, 06:56 PM

um... oops... that's backwards... should be:

2*LSA - [(ID/2) + (ED/2)] = ?

Ecam= 2(110)-220 = 0
Fcam= 2(110)-226 = -6 ...'Not gonna do it' - Bush

93CobraR · 01-30-2001, 07:30 PM

If I were you I would picka different blower then that. It is a roots type, and with that 351 your going to get alot less boost then if you were to go with a 302. My point being those things can only spin so fast before you spin a bearing. So why not just go with a S-trim where you can crank it up to your needs?

------------------
87 GT, 4 inch cowl hood,17x9 Cobra R's/255/45's,GT-40 heads,long tubes headers,h-pipe,Flows,BBK cold air, Mass air,70mm MAF, 1.7's, 1" spacer,underdrive pulleys,Pro 5.0, King Cobra, Adj. fuel Reg., Lakewood Lift Bars,50/50's,subframes, 4.10's.
Best time 13.012
Best MPH 104
Best 60' 1.816

Visit my site at:
http://www.geocities.com/cobrar93_2000/MyPage.html

bigwhitecobra · 01-31-2001, 12:30 AM

Skankin, thanks for that equation(sp). I have to admit, You lost me there for a second, but I figured it out after a minute.

93CobraR, I only want the possitive displacemnet because I already have an S-trim making 14#. And let me tell you, traction is hard to come by. If I don't shift by 3500 in first and second on the street, it gets pretty damn scarey. My life begins to flash before my eyes and my balls pack up and take a trip to my throat.(not a good thing) I just want to run a solid 12.5 and still make the daily drive to work and home. This car will not likely see very much track time. Although, I would like to run the true street challenge. Besides, I already have one gas guzzeling, fire breathing, widow maker of a car now, why on Gods green Earth would I want to have a photo copy of the same car?

Ok, that sounded mean, and I didn't intend for it to, so please do not take offence by it.

------------------
1989 GT- Vortech blown 306, Anderson 3" power pipe, Vortech S-Trim 14# boost, MSD-6BTM, black wrinkle finish Cobra valve covers(woohoo), world class T-5, 3.55 gears, custom sub-frame connectors, Cobra grille insert and rear valance, Saleen "whale" wing, 4 wheel disc conversion, 11.1@124
1994 Cobra- MAC cold air fender kit, Motorsport underdrive pulley's, MAC 21/2" off-road H pipe, SVO mufflers, 3.73 gears, E-303 cam, 13.417@101.335mph

01-30-2001, 04:56 PM	#1
bigwhitecobra Huh? Whatcha said? Join Date: Oct 2000 Location: Fayetteville, NC Posts: 1,073	Revised engine combo Ok, I've thought about it, and I have decided to go with a 351, alum Edelbrock Victor Jr heads,(2.02 and 1.60) and a Eaton/ Saleen blower/intake. I figure that I need more off the line grunt, seeing as then 351 will make plenty of power on the top end. Now here's the question, for that high end power, which cam would be better, a FMS E-303 or F-303? And still pass emmissions? ------------------ 1989 GT- Vortech blown 306, Anderson 3" power pipe, Vortech S-Trim 14# boost, MSD-6BTM, black wrinkle finish Cobra valve covers(woohoo), world class T-5, 3.55 gears, custom sub-frame connectors, Cobra grille insert and rear valance, Saleen "whale" wing, 4 wheel disc conversion, 11.1@124 1994 Cobra- MAC cold air fender kit, Motorsport underdrive pulley's, MAC 21/2" off-road H pipe, SVO mufflers, 3.73 gears, E-303 cam, 13.417@101.335mph

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01-30-2001, 06:29 PM	#2
84_GT350 Registered Member Join Date: Apr 1999 Location: Overland Park, KS, USA Posts: 1,631	Well...I dunno if it'll pass emissions, but the F-303 is better for a blower. Come to think of it, is the E303 even street legal? I always get the E and B cams mixed up. But that Eaton blower will make it pull hard off the line and the F303 will keep it going till the limiter. ------------------ 1984 1/2 GT350 (#842 Hatchback w/ T-tops), 302HO, Comp cams Xtreme Energy cam, Carter 625cfm carb, Weiand Stealth intake, MSD distributor, MSD coil, FMS 9mm wires, 1 5/8" MAC unequal shorties, 2 1/2" MAC Prochamber H-pipe, Flowmaster 2 chambers, KYBs, 16"x8" 4 lug Cobra Rs, Falken 245/45ZR16s

01-30-2001, 06:47 PM	#3
Skankin Registered Member Join Date: Dec 1998 Location: London, Ontario, Canada Posts: 1,349	You'd be better off getting a blower cam. They typically have more lsa, which is also good for emmissions. (you wanna keep the lobes apart). Here's a handy, generalized rule: (intake duration@0.05"/2)+(Exh Dur@0.05"/2)-2*LSA = ? If the number is positive, there's no overlap. The more positive it is, emissions are typically better. A negative number indicates overlap, which is bad (for blowers & emissions). If the lobes aren't very aggressive (Long advertised durations), the emmissions are gonna be worse than what the general number indicates. Also, if the lobes are asymetrical... forget the formula. A split duration favouring the exhaust might be a consideration. Are you gonna run 14#? To make more top end power, and utilize the added displacement, you'll wanna go with a longer duration. Problem is, if you go too long, you either loose cylinder pressure (and power), or you have to shorten the lsa. Maybe look into a comp cams extreme grind, they've got really agressive lobes... you could really push the "Magic number" down to zero, and be alright. ------------------ '89.5 5L LX, hatch, Medium Canyon Red, 155K Km (No winters), 5sp, 3.08, GT interior, a/c, Alpine CD, K/N, Crane PS91, Walbro 190 LPH, March Pulleys, Mr. Gasket 180 therm (HP balanced), 3 core rad, MarkVIII fan, Variflow controller, Polygraphite front bushings, FMS-5300B springs, 6 KYB's, 73mm Calipers, Maximum Motorsport 4pt chassis brace, Western Motorsport Racing's Sub-frame connectors. Re-ringed bottom end, conv. motor mounts, melling oil pump, FMS-C50 waterpump, GT40P heads (blended, polli

01-30-2001, 06:56 PM	#4
Skankin Registered Member Join Date: Dec 1998 Location: London, Ontario, Canada Posts: 1,349	um... oops... that's backwards... should be: 2*LSA - [(ID/2) + (ED/2)] = ? Ecam= 2(110)-220 = 0 Fcam= 2(110)-226 = -6 ...'Not gonna do it' - Bush

01-30-2001, 07:30 PM	#5
93CobraR Registered Member Join Date: Oct 1999 Location: Cincinnati, Ohio Posts: 1,575	If I were you I would picka different blower then that. It is a roots type, and with that 351 your going to get alot less boost then if you were to go with a 302. My point being those things can only spin so fast before you spin a bearing. So why not just go with a S-trim where you can crank it up to your needs? ------------------ 87 GT, 4 inch cowl hood,17x9 Cobra R's/255/45's,GT-40 heads,long tubes headers,h-pipe,Flows,BBK cold air, Mass air,70mm MAF, 1.7's, 1" spacer,underdrive pulleys,Pro 5.0, King Cobra, Adj. fuel Reg., Lakewood Lift Bars,50/50's,subframes, 4.10's. Best time 13.012 Best MPH 104 Best 60' 1.816 Visit my site at: http://www.geocities.com/cobrar93_2000/MyPage.html

01-31-2001, 12:30 AM	#6
bigwhitecobra Huh? Whatcha said? Join Date: Oct 2000 Location: Fayetteville, NC Posts: 1,073	Skankin, thanks for that equation(sp). I have to admit, You lost me there for a second, but I figured it out after a minute. 93CobraR, I only want the possitive displacemnet because I already have an S-trim making 14#. And let me tell you, traction is hard to come by. If I don't shift by 3500 in first and second on the street, it gets pretty damn scarey. My life begins to flash before my eyes and my balls pack up and take a trip to my throat.(not a good thing) I just want to run a solid 12.5 and still make the daily drive to work and home. This car will not likely see very much track time. Although, I would like to run the true street challenge. Besides, I already have one gas guzzeling, fire breathing, widow maker of a car now, why on Gods green Earth would I want to have a photo copy of the same car? Ok, that sounded mean, and I didn't intend for it to, so please do not take offence by it. ------------------ 1989 GT- Vortech blown 306, Anderson 3" power pipe, Vortech S-Trim 14# boost, MSD-6BTM, black wrinkle finish Cobra valve covers(woohoo), world class T-5, 3.55 gears, custom sub-frame connectors, Cobra grille insert and rear valance, Saleen "whale" wing, 4 wheel disc conversion, 11.1@124 1994 Cobra- MAC cold air fender kit, Motorsport underdrive pulley's, MAC 21/2" off-road H pipe, SVO mufflers, 3.73 gears, E-303 cam, 13.417@101.335mph