I hope this is an advanced enough question for this board, I figure you guys will have the experience to answer this question. Basically, I am looking to the future, and the next motor I build is going to be the motor I want to run for a while to come. I have mid 12's at the moment, I should have low 12's/high 11's by the end of the season, and my next motor I would like to be somewhere in the 10's (as fast as i want to go for now). I am hoping to reuse my 350 block since i just shelled out 2200 for the crate motor a little over a year ago.

My question is, do you guys think a 6" rod, gen 1 sbc 383 could power a 3050 lbs (without driver) car to mid to high 10's n/a? Lets say the car can cut 1.5-1.6 60 foot times with the new motor to take the traction variable out of the equation, I am just interested in the motor itself.

My only stipulation for the motor would be that it would need to run on pump gas, that is "streetable" to me. I dont care if it has to idle at 2 grand or if I have to run a 4500 converter, I want to be able to put pump gas in it and run it detonation free.

So what ideas do you guys have for me? Here is my buildup in my mind so far:
383ci motor (6" H beam manley rods, undecided forged pistons, probably an Eagle 4340 3.75" stroke crank)
I'm thinking 11.5:1 compression or less depending on cam and heads
Cam will be a solid roller something like the following crower I found:
(254/264@.050), .638/.650 lift w/ 1.6, 106* LSA
Cylinder heads: Maybe some 18* trick flows or GM 18* high port heads?

Anyways, do you guys think this is possible? Feel free to point out anything that you think that you would like to see changed. Are 10's possible for my next motor?

 

posible? sure!

I'd go with a point higher compression and a longer stroke though. A whole lotta nitrous wouldn't hurt either!

 

Yes it is definately doable, but really a buildup question like this should be posted in a gen spacific forum... moving to correct one. Thank you.

 

So nobody else has any suggestions for me?

 

I would try running low shots of nitrous (less then 100) and see what that does for your ET. If you've got forged pistons/rods you could run even higher doses safely, and drop your time considerably without further engine modification.


On a side note, not relating to this thread, what 350 HO crate motor did you use to drop you into the 12's? I just got a new project, an '86 firebird with a 305 4 bbl in her... She's running high 15's, as is (prior to gears). I wanted to pull it and drop in a decent crate motor... something built solid enough to take abuse and run fast, but not tank my fuel economy. I was interested in which one you have.

Thanks

__________________________
'86 Firebird 305 4BBL
Stage II 700R4
295-50/15's
Open Element Filter
4:11 Posi-traction Rearend

 

i hope youll run aluminum heads with that...if not youll have no chance in hell running 11.5 on pump gas...that may be a little high even with aluminum heads

my buddy runs 11.4's with a 10.5 aluminun headed 350..
but his isnt a daily driver..
my advice would be...
10's on a n/a 383 will be quite radical for a daily driver..
id shoot for mid 11's then snort it for that 10
a mid 11 to a high 10 is about 75-100 hp..

if thats the cam your gonna run then id double check my triple check on the piston to valve clearence

 

Its the $2200.00 350HO GM crate engine, I got a 12.88 @ 105.X and a 12.93@106.1 out of it with a performer intake and a demon 650 carb. I would like to run 10's completely N/A.

 

Its not my daily driver, I just want 10's N/A. Nobody has any ideas for me?

 

Why do you want so much power out of the N/A motor? Nitrous or a blower would drop your times just like you wanted them to be. Friends of mine have had good luck with Powerdyne blowers... pisses away an alarming amount of gas, but if its not a daily driver I'd go the nitrous route.

 

12Second3rdgen - I think the combo you listed would easily put you in the high 10's. For your car 3050+200lb driver it would only take about 525HP to do that with the slippery 1.5-1.6 short times. I had a 11:1 383 with a comp 242/248 cam and ran 36 degrees timing on pump gas. Your motor will be a little stronger so you could always just back it down to like 32 degrees and cruise and keep a good eye on your plugs.

I don't think you need the 18 degree heads you listed. A good set of 23 degree heads will easily make the power to go 10's N/A. Trac1, Dart 220, AFR all will flow 300 with a good port job and thats all it will take. Unless you are just wanting to spend the bucks for shaft rockers and off set lifters I would go with a 23 degree head. After all this motor will probably only go to 6500 and fall on its face after that.

 

I agree with 1994B4C. You don't necessarily need the 23* heads. I am not sure what transmission you are running but i would guess a TH350 or 400. Match a converter that will foot brake to 4000 RPM and a 4.11 gear should get you the 60' with good traction. I am sure you can hit 10's N/A on a pump gas motor with some money.

 

People have gone 10's with ported LT1 heads around here....LOW LOW 10's like 10.0...hehe Money is the magic in getting them to work just like any other head.

That Crower cam is huge Sounds good though. I don't know of many companies like them but I like to check out www.weldtech.com and see what they do with their heads. Some of their prepped Track1 heads would be enough for 10's probably setup correctly on a 383 in a light car. AFR 210's or 220's I've seen in the 10's in HEAVY street going F-bodies. Dart makes a nice 230cc alum. head that would be really cheap and effective. I'm still thinking but goodluck!

 

Yes its possible, dont even need 11.5:1 to do it, I hate those people who say "gotta run high compression to make power" - 10.5 is good enough and alot safer for your pump gas requirement.

A set of 23 degree heads will do it, but 18 degree is better if u wanna spend the money. That cam is huge, about the size I'm gonna be running in my 383. I'll be spraying 300hp of nitrous to get hopefully into the 9's, but i'm hoping 10.8-11.3 on motor. I'm using a tunnel ram with a pair of 660 center squirters race prep'd, 4800-5000 stall converter, and a back half'd car with 12 point cage and front motor plate with custom 1-7/8" to 2" step tube headers. Hell www.zee28.com go there n click on Engine. Got some Hoosier QuickTime Pro's 33x18.5 going on there on 15x15" rims, I know they are "too big" for a small block, but they look effin cool n I won't have any traction problems there either.

All you "get nitrous" people, he wants to get into 10's n/a, and THEN shoot it with nitrous.

Bare in mind, your stock rear will be toast once u get past the mid 11's but I'm assuming you're gettin a good transmission and a good rear end to hold up.

The key is - it takes money to go that fast, and once you go that fast, it's gonna cost more money cuz ure butt will get kicked off the track with a list of 1000 NHRA rules you haven't met Unless ofcourse there's something you're not telling us.

 

Yeah i forget if its when you break into the 10's or break 10 flat and dip into the 9's but a ton of rules fly at your head ie roll cages, cut off switches, and a ton of other fun stuff.

Just out of curiosity whats the highest compression you could run on 91 octane without problems?

 

it depends on what cam you are running , ect.

check out....

http://members.uia.net/pkelley2/DynamicCR.html

he does a good job of explaining dynacmic compresion ratio, and also has a very nice DCR caculator for download.