[FKR]

I got it done. I built a really nice 307 sbc .040 over. The intent is an all strip small cube engine. Built sheet: 081 full port Extremely worked superstock style heads. 0 Deck block. Ultra light crank and rods. 10.3:1 compression. Cam specs are .503/.523 duration 237/247 and 108 lsa. Full Port Hurrican intake. Edelbrock 1405 carb moddified. Custom 1" swirl port spacer (may come off because of nitrous). What kind of power should it make or what kind of ET's should I hope for? 86 Monte weighs 3236 with me in it (looking to get rid of more weight). Th350 3500 stall stage 2 shift kit 4.10 gears 275/60 drag radials. Starting with single stage nitrous but will hope to go to a two stage (125 or 150 then 250) later. Starting with 100 shot for now. Any Ideas. Thank you! Will try to upload pics of engine.

[FmrStrtracer]

600 cfm is not going to supply what you want to do.
Flat tappet or roller, hyd or solid?

Head studs?

Whats holding the crank in? Splayed four bolt caps with ARP hardware?

Flow numbers?

Exhaust? header size"

Personally, I'd run a progressive controller. Launch with what ever the track/car will hold, and ramp up from there up to max setting as fast as the car will put it to the track.

[zildjian4life218]

Originally Posted by FKR

I got it done. I built a really nice 307 sbc .040 over. The intent is an all strip small cube engine. Built sheet: 081 full port Extremely worked superstock style heads. 0 Deck block. Ultra light crank and rods. 10.3:1 compression. Cam specs are .503/.523 duration 237/247 and 108 lsa. Full Port Hurrican intake. Edelbrock 1405 carb moddified. Custom 1" swirl port spacer (may come off because of nitrous). What kind of power should it make or what kind of ET's should I hope for? 86 Monte weighs 3236 with me in it (looking to get rid of more weight). Th350 3500 stall stage 2 shift kit 4.10 gears 275/60 drag radials. Starting with single stage nitrous but will hope to go to a two stage (125 or 150 then 250) later. Starting with 100 shot for now. Any Ideas. Thank you! Will try to upload pics of engine.

stock rearend?
x2 on the progressive controller

[FKR]

stock rebuilt rearend all parts are new. 1 5/8 headers. ARP throughout, rods,mains and heads. No flow numbers but intake ports are 177cc and were shaped to look identical to enginequest 180cc vortec heads. Here is a pic of the engine. I have done everything 100% from beggining (tearing old down) to end (All machining,porting custom work and assembly).

[FKR]

All the custom work to the carb should flow a bit more around 630cfm's give or take. VE at 100% to 6500rpms shows 588.686 cfms. Cam range is 28-6500, intake range 25-7000. Both intake and heads are largely ported and port matched. I am hoping for around 325-350HP at the crank naturally aspirated. Don't want hopes to high. Looking to get close to 500HP on nitrous safely.

[FKR]

I have driven the car and its almost complete. I will have the nitrous and everything done by spring. I will be testing on engine first then the nitrous. I turned 8300 rpms with no problem but I let off as soon as I seen it. If I didnt see it for myself I would say bull crap but I did. If interested in seeing pic's just google SBC 313 nitrous. This thing really surpised me, its fast. I would say it should be low 13 or better et's on engine alone and mid to low 11's on nitrous. Eventhough I am hoping for better. I believe I am going to need to go to 4.56 gears because the power is just starting to come on around 3500 rpms. Still trying to get more weight out of it too. I plan to put videos up in the spring from the track.

[vinniekq2]

it should go 13s on the motor,maybe 12s on no2,depending how much. Yes a new motor can go 8300 rpm a few times,should be reliable over 7 if the valve train is all good. I think fkr is close on the power,,,depends what the heads flow?
I was thinking of a 292 for fun,same kind of goals,350 horse (292=060, 283,not a 6 cylinder)I was thinking darts, cast iron 202 heads

[F-BIRD'88]

Looks like a really fun package. it may rev up that high but you probabily are over reving it a bit.
It will need two different gear ratios for N/A and nitrous.
The best thing to do is to use a short tire for N/A and a 2" taller tire for nitrous

N/A will want big gears 4.56+ (4.56 and short 26" tire) (the lil engine wants to rev up as you foundout LOL))) On nitrous it will MPH so use a tall 28" to 30" tire
with the 4.56's. The motor will not need to be reved up so much on the shift when using nitrous.
7000 rpm on the 1-2 2-3 shift should be plenty. (over reving on the shift, on nitrous will slow you down)
Tighten the valve lash up. The cam is small.

the carb is way too small. get a 750.
The more converter stall speed,,, the better .. find a 8" full race converter. (especially with nitrous, especially with that hurricane manifold) RPM is your friend.
It will drive well on the street with the race converter, don;t be shy.

Do you have any pics of your cylinder head port work? or flow bench data?
The potential is 400 hp but it all depends on how the heads turned out.

Very cool keep us posted on your progress.

[F-BIRD'88]

if this is a hyd cam , not a solid lifter cam.... that will be your undoing. (on nitrous) Don;t care how it seems to "rev up" Little motors that like to rev up, need a solid lifter cam. X2 when nitrous oxide injection is in the picture.

EG Crane Cams F-278-2 crane F288-2 Crane F-280-2 for nitrous, all off the shelf cams for this cool lil nitrous motor.
something for you to consider when you find you cannot get the end of the track, on nitrous
at high rpm (with 4.56's) without it going flat on you. 7000+ rpm under nitrous power, thru the traps.
with a hyd cam. you will see.
The only way you will be able to do this is to keep the thru the trap rpm down (4.10's and tall tires)
but this will not allow the little motor to rev and ET hard like you want.
This has as much to do with making big safe reliable power on nitrous at high rpm as
getting a good ET.

Think about what will happen when both valves are held off seat (hyd lifter pump up) at 7000+rpm while big nitrous is in the motor.... The only way to avoid that is to run the hyd lifters as solids with .001-.003" valve lash. All hyd lifters have a pump up rpm limit. You don;t want to find that point ,,,on nitrous.

www.cranecams.com

again very cool... FKR... Big Thumbs Up!

[E.Furgal]

kiss that stock rear end good bye..
I'd change it out now.. before you have to pick it off the track

[F-BIRD'88]

Originally Posted by E.Furgal

kiss that stock rear end good bye..
I'd change it out now.. before you have to pick it off the track

thats not true as long as its set up right, wheel hop is avoided and you DO NOT USE A SPOOL in it. Use Eatons posi or a aftermarket Auburn posi.

wheel hop kills these rears in G bodys.
Wheel hop is easily avoided with correct G body rear suspension set up.
Get some Air Lift Air Bags for it (Drag Bags) . and some lower control arm relocation brackets.
Replace all the OEM control arm bushings. Box in rear lower control arms
or replace.

Do not use a spool, ever, in this rear end.

[E.Furgal]

Originally Posted by F-BIRD'88

thats not true as long as its set up right, wheel hop is avoided and you DO NOT USE A SPOOL in it. Use Eatons posi or a aftermarket Auburn posi.

wheel hop kills these rears in G bodys.
Wheel hop is easily avoided with correct G body rear suspension set up.
Get some Air Lift Air Bags for it (Drag Bags) . and some lower control arm relocation brackets.
Replace all the OEM control arm bushings. Box in rear lower control arms
or replace.

Do not use a spool, ever, in this rear end.

I snapped the pinion shaft in 2 on a 1 -2 shift.. no hop .. with a 305
also.. it's a c clip rear.. unless he plans on drag street tires..

[FKR]

I think a 750 carb is really needed too. Thank all of you for your posts. It is a very well built rear end with 4.10's with auburn posi right now with a 275/60 rear tire (27.6 inches) M/T drag radials. I beleave it will need more stall, it stalls at 3700 right now. I have a great valve train and the lifters are set at .008 on oil clearence. I built it with alot learned from the david vizard books. I will be using 150 shot to start. I talk to Ron Hutter of Hutter racing engines and he thinks I have done a great job. The heads are ported very well with a lot learned from super stock engines they're amazing. I would say they flow around the 240 range at .500 or better but great swerll and volocity. (sorry for my spelling). I think all of you are right, It did pull really hard all the way to 7400 and seamed to slow a little after that. I am putting a full drag suspension in, but keeping stock location. This thing is so cool. I did it because everyone told me not to. I want to get the weight down to under 3100 with me in it. I am very proud of this car. Thank Everyone for not dogging me. I had it alot since the built started. Again Thank You!

[FKR]

I also forgot to mention that I plan to put a mach. roller in, in the future and up the compression with trick flow heads ported. Less weight LOL! Electric water pump and fan also. Is it okay to eliminate sway bars? Would a 8.5 10 bolt with 4.56's be good with the nitrous? I have a ton of questions but dont remember them all. Please any advice will help a ton and I will be thankful! I will be trying to start a GM 5.0 class at the track.