BBC ideas

[cobb]

Hey guys im new to the forum and i been reading around and haven't seen many trucks built with 396 bbc. I just bought a 78 swb with a 67 chevell 396 bored .030 over besides that i have been told it has comp cam in it as well as comp valve springs retainers adjustable cam gear. Has a HEI distributor, long tube headers with a 350t behind it all. Im wanting to drag race the truck and try to achieve 12 second truck. I was just wondering what some of you guys would advise me to do or give me some options of what i can do. Plan to spend money because i hate breaking stuff lol. But i like good deals too. Any advice would be appreciated.

[383Ram]

Unfortunatly, the information given is very vauge. So its really hard to answer your question. By the sounds of it, you are not sure what the static compression is, what the specs of the cam are, things also like intake and carb size would be helpful too. Then above all else, just building the engine is only part of the equation. Getting it down the track is another.

Can you do at least a cranking compression test? i like to see numbers in the 160 range for a good motor--but sometimes long duration cams will mask this number. But its at least something we can go off of if you dont know for sure of your engine internals--and i wouldn't take the previous owners word on whats in it.

[cobb]

Originally Posted by 383Ram

Unfortunatly, the information given is very vauge. So its really hard to answer your question. By the sounds of it, you are not sure what the static compression is, what the specs of the cam are, things also like intake and carb size would be helpful too. Then above all else, just building the engine is only part of the equation. Getting it down the track is another.

Can you do at least a cranking compression test? i like to see numbers in the 160 range for a good motor--but sometimes long duration cams will mask this number. But its at least something we can go off of if you dont know for sure of your engine internals--and i wouldn't take the previous owners word on whats in it.

well unfortunately i know None of the spec's bc i didnt build it but what im trying to figure out is what guys are doing to the 396's to get a good strong motor, plan on rebuilding it with new parts so the stuff on it will not be used. Compress is good across the board all numbers close and above 170 range. I will be buying a 750 demon carb vac secondary, msd ignition with 6al or 6al2, has a edelbrok rpm2 intake i believe. so i hope this helps some i know i dont know a lot about the motor but like i said the previous owner didnt keep the receipts so who knows what is on the inside. Thanks any additional help would be appreciated.

[BossHogg69]

Do you know anything about the heads? if they are '67 castings, they're almost certainly closed chambered, probably oval ports with small valves. I'm guessing it'll take 500hp or more to get a 1/2 ton truck in full street trim into the 12's, and i'm not too sure those heads will get you there without putting some work into them or running some nitrous through the motor. Also, knowing the cam specs would be a huge plus. Putting nice bolt ons (msd, intake, carb) may help you, but without knowing what hard parts are in there, it's kind of tough.

For a street motor, esp a 396, the oval port heads are your best bet, since they have better port velocity than the rectangle port heads, and the oval port exhaust side usually tend to flow better. Closed chambered heads will help keep a reasonable compression ratio without using a big dome piston like you'd need with an open chamber head. I have a 454, and a huge pile of parts to go in it, and i too am shooting for 12 sec timeslips. if you think it'd help you, I can list it all, it may give you some ideas on what direction you want to go.

[cobb]

Originally Posted by BossHogg69

Do you know anything about the heads? if they are '67 castings, they're almost certainly closed chambered, probably oval ports with small valves. I'm guessing it'll take 500hp or more to get a 1/2 ton truck in full street trim into the 12's, and i'm not too sure those heads will get you there without putting some work into them or running some nitrous through the motor. Also, knowing the cam specs would be a huge plus. Putting nice bolt ons (msd, intake, carb) may help you, but without knowing what hard parts are in there, it's kind of tough.

For a street motor, esp a 396, the oval port heads are your best bet, since they have better port velocity than the rectangle port heads, and the oval port exhaust side usually tend to flow better. Closed chambered heads will help keep a reasonable compression ratio without using a big dome piston like you'd need with an open chamber head. I have a 454, and a huge pile of parts to go in it, and i too am shooting for 12 sec timeslips. if you think it'd help you, I can list it all, it may give you some ideas on what direction you want to go.

Yes please this is exactly what i was looking for and it is oval ports but like i say im going to be going with a different cam like a voodoo or something of that quality but as far as the duration or lift i was hoping i would get some ideas what to go with by guys with experience, i havent been around a lot of motor building, i am a mechanic so going to be doing all the work myself and i do not care to spend the money the goal is 12 sec 1/4 on spray! I hope this helps more! Thanks

going to be running a 4.11 gear ratio

[71Dragtruck]

My old motor was a 396, closed chamber oval port heads. It has a full solid roller cam setup, heads were fully ported and polished and cut for bigger valves. It was around 10.5:1 and ran high 12's in my truck. It wasn't that streetable, ran a turbo 350 manual shift kit and a 4500 stall. To be as honest as I can I wouldn't waste my money again, i had close to $8000 Canadian into it with the original cost of the motor and sold it for $3000 after it spun a lifter. I suspect it was in the 450 to 500hp range. Starting with a 454 you can do 500hp for way less then that.

[cobb]

Originally Posted by 71Dragtruck

My old motor was a 396, closed chamber oval port heads. It has a full solid roller cam setup, heads were fully ported and polished and cut for bigger valves. It was around 10.5:1 and ran high 12's in my truck. It wasn't that streetable, ran a turbo 350 manual shift kit and a 4500 stall. To be as honest as I can I wouldn't waste my money again, i had close to $8000 Canadian into it with the original cost of the motor and sold it for $3000 after it spun a lifter. I suspect it was in the 450 to 500hp range. Starting with a 454 you can do 500hp for way less then that.

ok can you pick up a 454 cheap?

[71Dragtruck]

They are out there, just have to find them. Maybe someone on here that lives a bit closer can help? Depending what your budget is might be able to find one thats done from someone looking to upgrade and run faster, look on racingjunk.com, or look into crate engines?

[BossHogg69]

here it is from the carb down...

870 cfm Holley Street Avenger carb (4150 style)
may use 1.5 or 2" open spacer
E'brock RPM air gap oval port intake
E'brock RPM marine oval port heads, 2.25/1.89 valves, 290cc intake ports, 110cc combustion chambers
Comp Cams Xtreme energy 278 cam, 234*/244* @ .050", .564"/.575" lift, 111* LSA, flat tappet cam
Crane aluminum full roller rockers 1.7:1
comp cams magnum one piece 3/8" pushrods
Cloyes Hex-a-Just billet steel adjustable timing set
SRP forged -23cc dome piston
GM truck rods (reusing stock rods, ARP bolts)
GM steel crank (reusing stock crank)
GM block (reusing stock block, with ARP studs)

I'll be using the crank, rods, and block in the truck now, and build the motor for 10:1 compression. i'm running a TREMEC 5spd, 12" Centerforce dual friction clutch and PP. I plan to run 3.73 gears with either a Detroit Truetrac or Auburn Pro series diff, Moser 5 lug axles (swapping from 6 lug) and the driveshaft I had built with all Spicer stuff when i swapped in the 5spd. I don't want to have to use spray, but may use a 125 shot to get me where i want to be - low to mid 12's. i don't plan on drag racing the truck much, but I do want a fast street hauler. I'm shooting for a solid 530hp on motor. Here's a build on a 454 similar to mine.

http://www.carcraft.com/techarticles...evy/index.html

[BossHogg69]

Originally Posted by cobb

ok can you pick up a 454 cheap?

I know a guy in Hot Springs with a 454 HO crate motor (425hp)for sale right now, with a th350 and a 2200 stall converter in it. the motor has about 1500 miles on it.

Honestly if you have forged slugs in your 396 you could just spray it and hit 12's and still have a driveable street engine. you'll need a pretty good sized cam to hit 500hp in a 396. There's no sense in starting all the way over if you already have a solid motor in the truck now, unless you really want to make the change to a 454.

[cobb]

Originally Posted by BossHogg69

I know a guy in Hot Springs with a 454 HO crate motor (425hp)for sale right now, with a th350 and a 2200 stall converter in it. the motor has about 1500 miles on it.

Honestly if you have forged slugs in your 396 you could just spray it and hit 12's and still have a driveable street engine. you'll need a pretty good sized cam to hit 500hp in a 396. There's no sense in starting all the way over if you already have a solid motor in the truck now, unless you really want to make the change to a 454.

I agree i just didnt want to have something not worth building. That was the main point of this thread. But i left out i already have a 2000 stall as well. But every post has helped me greatly. Thanks

On the guy with the motor in hot springs do you have an idea how much he wants for the motor by any chance? I really want to c what we can squeeze out of the 396 but i also dont want to waste the money lol. This is going to be a truck that will only see the street on maybe a friday or saturday night. I just really want to have fun thats all i want.

So if i go in and replace the pistons what compression ratio should i aim for in a (NOS) application? Do i need to replace any thing like rods, i know i have to step up the cam a lot but on the carb side of the deal how big and what secondary? Stall should i go 2800 or higher? Just some other questions i have rolling around in my head.

[71Dragtruck]

If your going to spray it stay with that stall nitrous likes to be lugged, even short shifted to make the engine work, plus on the street your tranny will run cooler. I guess what I should have added to my comments is this. If your going to be happy with 12's and know that you will never want to go faster and faster then what you have will do fine. Build it for the street 9.5-10:1 forged pistons, use good bolts (ARP) stock rods are fine, good ignition system and fuel system then spray 100-150 shot. BUT if your going to get bitten by the go faster and faster bug ( like I did ) then your going to hit the wall fast with the 396. Thus why I commented on the 454, you can hit the 12's on motor with a built 454 and then if the bug bites a bit of spray can scratch the itch. Thats kinda what I meant with my comments, now that being said if that 396 is running now I would save my money spray it as is and save your money for down the road to either rebuild or go bigger. So for me I bought a 396 then built it up down the road, and wished I wouldn't have, you already have the motor but will it be enough when your done???

When I built my 396 I thought that was all I'll ever need and 12's were good, then I built a 489 thinking 650hp has to be good for low 11's, and I had all the stuff to spray it and then 10's came along, roll cage all the safety stuff to go along and now it's not enough again LOL. A all aluminum 632 BBC is next that's all I know.

[BossHogg69]

Originally Posted by 71Dragtruck

If your going to spray it stay with that stall nitrous likes to be lugged, even short shifted to make the engine work, plus on the street your tranny will run cooler. I guess what I should have added to my comments is this. If your going to be happy with 12's and know that you will never want to go faster and faster then what you have will do fine. Build it for the street 9.5-10:1 forged pistons, use good bolts (ARP) stock rods are fine, good ignition system and fuel system then spray 100-150 shot. BUT if your going to get bitten by the go faster and faster bug ( like I did ) then your going to hit the wall fast with the 396. Thus why I commented on the 454, you can hit the 12's on motor with a built 454 and then if the bug bites a bit of spray can scratch the itch. Thats kinda what I meant with my comments, now that being said if that 396 is running now I would save my money spray it as is and save your money for down the road to either rebuild or go bigger. So for me I bought a 396 then built it up down the road, and wished I wouldn't have, you already have the motor but will it be enough when your done???

When I built my 396 I thought that was all I'll ever need and 12's were good, then I built a 489 thinking 650hp has to be good for low 11's, and I had all the stuff to spray it and then 10's came along, roll cage all the safety stuff to go along and now it's not enough again LOL. A all aluminum 632 BBC is next that's all I know.

^ couldn't agree more!

The goal for my 454 is a street/strip motor, leaning more towards 'street'. I want to be able to drive it to work if i want or cruise with the wife without having an unruly beast that doesn't have any manners on the street. I spent most of my money on getting good heads/induction and didn't get too crazy with the cam, although I did want something that sounded tough, I have a/c, and power brakes and want it all to work.

Cobb, if I were you, I'd tune that motor up really good, dyno it to see where you're at hp wise, and spray that bad boy!

[cobb]

Originally Posted by BossHogg69

^ couldn't agree more!

The goal for my 454 is a street/strip motor, leaning more towards 'street'. I want to be able to drive it to work if i want or cruise with the wife without having an unruly beast that doesn't have any manners on the street. I spent most of my money on getting good heads/induction and didn't get too crazy with the cam, although I did want something that sounded tough, I have a/c, and power brakes and want it all to work.

Cobb, if I were you, I'd tune that motor up really good, dyno it to see where you're at hp wise, and spray that bad boy!

Ok thats sounds good. The way im looking at it right now is that build it, get it hopefully in the 12's, and if i ever want to go faster build a different motor. But Thanks guys you have been very helpful with the next steps i need to take with my build i will be posting a build thread soon and show the progress of the truck. I am still open ears to any more advice on places to get the parts and ways to find good deals.

I still have one question in regarding the turbo 350 whats is the best route to take with it? What kind of shift kit should i buy and so forth?

[cobb]

Originally Posted by 71Dragtruck

If your going to spray it stay with that stall nitrous likes to be lugged, even short shifted to make the engine work, plus on the street your tranny will run cooler. I guess what I should have added to my comments is this. If your going to be happy with 12's and know that you will never want to go faster and faster then what you have will do fine. Build it for the street 9.5-10:1 forged pistons, use good bolts (ARP) stock rods are fine, good ignition system and fuel system then spray 100-150 shot. BUT if your going to get bitten by the go faster and faster bug ( like I did ) then your going to hit the wall fast with the 396. Thus why I commented on the 454, you can hit the 12's on motor with a built 454 and then if the bug bites a bit of spray can scratch the itch. Thats kinda what I meant with my comments, now that being said if that 396 is running now I would save my money spray it as is and save your money for down the road to either rebuild or go bigger. So for me I bought a 396 then built it up down the road, and wished I wouldn't have, you already have the motor but will it be enough when your done???

When I built my 396 I thought that was all I'll ever need and 12's were good, then I built a 489 thinking 650hp has to be good for low 11's, and I had all the stuff to spray it and then 10's came along, roll cage all the safety stuff to go along and now it's not enough again LOL. A all aluminum 632 BBC is next that's all I know.

One quick question. What nitrous brand do you recommend and fuel wise do i need to step up to a electric pump i will be getting a fuel cell bc my tank is junk.

[cobb]

Ok i got a hold of the P.O and got him to call summit and get the invoice number so ive got all the parts that he bought and found the cam specs and i wanted to throw it in here and see what yall thought about it for the application.

Hydraulic Flat Tappet, Advertised Duration 270/270, Lift .510/.510
Basic Operating RPM Range 1,500-5,800

[crackerbuzz]

Hey there,

Fairly new here and yes I sell engines, but not necessarily here to do that!

Pretty sensible comments there by the other posters.

Getting a truck to hit 12's requires a few horses and a 396 would need to be reasonably worked to do it unless you sprayed it.

I say jump on the track and see what she does now to give you a better idea of what you have under the hood. If you are happy stick with or make a decision form there.

One of our 505 trucks hits late 11's but needs 650HP and truckloads of torque to get there.

Give it a bash!