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Discussion Starter · #1 · (Edited)
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.
 

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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.
 

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FKR said:
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
 

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Discussion Starter · #4 ·
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).
 

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Discussion Starter · #5 ·
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.
 

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Discussion Starter · #6 ·
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.
 

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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
 

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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..
 

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Discussion Starter · #10 ·
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!
 

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Discussion Starter · #11 · (Edited)
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.
 

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Discussion Starter · #12 ·
A little more update for everyone. I have the engine back out and did a little more port work to the heads (184cc intake/69cc exhaust) and intake now a 1206 gasket, while I wait on my new mechanical roller cam and the machining for the new springs and 54cc chambers for 10.8:1. Also looking into running a 750 carb with alcohol. Still looking into a better rear. Spending a lot of time learning as much as I can to make this engine work and the car to put the power to the ground for fast good consistent times. If a 305 can make 394hp n/a with stock rotating assembly (engine master challenge) Then there is no way my build can't be close or even better. I am really hoping to make over 550hp with nitrous. Some how 10.99 here I come! :thumbup:
 

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Discussion Starter · #14 ·
To each there own and its tiring to always see the same engines. I'm one of those guys that really likes to be different. Look at all the people with T-Types and Grand Nationals with the turbo V-6's that make some serious power but for a Ton of money, same with imports. Mine is just a nitrous fed 313ci small block. Not really a ton of money like so many think. Really different and awesome! Look at all the 305 class now.
 

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Discussion Starter · #16 ·
I get that, I just see so many people with these crate engines then they through nitrous on them and make the same power I am for even more money. I have only paid for parts, I did all the work myself on my free time in the machine shop. I have only had to pay for parts, Less than a base performance crate engine cost. If you had to pay someone else for all of this then you are more than right, this would cost an arm and a leg for only 400hp or so naturally asperated.
 

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Discussion Starter · #18 ·
Now that's expensive. Parts cost triple or even more than what I have spent and then another five time that for the rest of the driveline to hold that kind of power. I didn't say I had $30k to spend.
 

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My motto is 'Do what you can with what you have where you are.' I have it hanging up in the office part of my shop at work. I think you did pretty well with what you started with. I'm not a big proponent of small cube motors but this a solid build that shows the capabilities of one of the less-loved SBCs. Good on you for taking good advice when it's given as well.
 

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Nice project :thumbup:

Are you using a 7.5" rear or an 8.5"?
I would definitely get rid of the 7.5, broke 3 of them myself not launching harder than 1.88-1.92 60'.
It would be interesting to see some timeslips if you ever get it to the track.
 
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