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Could someone please give me and Idea of what HP I can exspect??

5K views 23 replies 6 participants last post by  nastynova 
#1 · (Edited)
Could someone please give me and Idea of what HP I can expect??

I just purchased a baja truck for parts and I am trying to figure out what I've got.. it has a 383 sbc with:

Dart II 64cc sportman 200 iron heads, angle plug, w/crane roller rockers
.15 dome pistons...don't know the CR
Weiland x-celerator intake
750 vac carb
Cam specs: Advert. Dur: In-228 Ex-234 Dur. @ .050”: In-284 Ex-290 Lift: In-.480 Ex-.494 Lobe Sep. Angle-106°
MSD Box and Distrib.
open headers

what do you think it will make for HP?

feels pretty strong and a blast to drive... almost hate to part it out...

also what program do you guys like the best to do this and what do they cost..?

thank you
Nasty
 
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#4 ·
really...thats all... seems snottier than my current motor... I was just going to sell the motor and trans to get some money back out of it but after playing with it thought about putting the 383 into my nova... thinking i may be a little quicker with the 383... I know my 355 is built with alot better parts and balanced where the 383 is not...maybe pull the dart heads get a intake and put them on my 355...it has GM vortecs now... heres the list....

current motor specs:
350 30 over - balanced, forged crank, main studs,diamond stripper
windage tray, forged H-beam rods, Keith Black KB 180 pistons, GM vortec
heads, port matched and polished w/manley race flow SS valves (1.94,
1.50)'s, edelbrock torker II cam (Dur.at .050 lift, intake 232, exhaust
234, lobe sep 110) lift at valve .488, edelbrock super victor vortec
intake, Holley 650 DP w/proform 750 center,MSD Probillit Dist.\MSD
Digital 6 Box , hooker headers, elec. water pump...I've calculated a
compression ratio of 12 to 1, which should be within a tenth...desktop
dyno'd at about 400 to 450hp...best time was a 12.43 @ 112mph

would that be better than going to the work of swapping my 355 for the 383???


Thanks
Nasty
 
#5 ·
I would agree that the 355 is the better bet. The only short side is the cam. What do you mostly use the car for? What type of transmission are you using? And What gear is in the rear? If you have a manual or a larger stall accompanied with a low gear, you could go with a little bigger cam: .500 and up. This should bump your hp and torque up a very considerable amount. If it is going to be street driven alot, your cam will be fine. the 383 is a great street motor. Whatever takes your fancy, good luck.
 
#6 ·
its strip only... the cam is small due to the vortecs...they don't like anything over that .480 .490 lift (stock anyway)...currently it has a 8.5" 10 bolt posi w/3.90 gear and 27.2" MT slick. I just ordered a race tranny from a shop... manual valve body rev. pat. TH400 w/brake... 4500 stall converter... some of the parts you question are the reason I bought the truck...I bought it for the narrow 9" rear w/spool and summers brother axles...griffin alum. rad. and other misc. parts and was going to part out the rest of the truck...now im thinking i'll put my vortecs and intake on the 383 and buy a cam and intake for my 355... any suggestions on a nasty cam for the 355 with the dart heads ??

thanks
Nasty
 
#9 ·
this time with the vortech heads and that intake it made alot more tourque but a little less horse power. with the numberes being at 450HP @ 5500RPM and 474 Ft-lbs of tourque @ 4000RPM.

your welcome, i like useing that software any way! its cool. and when i built my motor i ran all the specs for it it sayed i would be making 385HP and 405 Ft-lbs of tourque and i didnt beleive it because i was building the engine for about 330 HP and way less tourque. so i brought it to my local machine shop and had it dyno'd it ran 384HP and 411 Ft-lbs of tourque! i was amazed! and my dad was pissed because this will be my first car (im 16 and my car is a 1971 chevy nova) and he wanted it to be not to powerful! but i thought it was cool because i wanted it to be way faster then my all of my freinds jap crap RICERS! :spank:
 

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#10 ·
kuel...wish I had the software... but its kind of spendy.....

could you run my 355 through it with the components above except use the dart heads and a super victor intake... and these cam specs...

Advertised Duration IN/EX: 308/316
Duration @.050 IN/EX: 276/284
Gross Valve Lift IN/EX: .640"/.645"
Lobe Sep Angle / Intake Ctr Line: 106/102
Valve Lash IN/EX: .025"/.027"
RPM Range: 4400-7800

Thanks
Nasty
 
#11 ·
As an answer to the first post, I would look at Combo 9, and combo 42(especially). Based in these two I would say you are probably around 415-425 hp and ~450 ft lbs. I would not recommend the last combo you suggested dynoing. That cam is much larger than what those heads are designed for, and it will probably not work very well with 11:1 compression. I had a cam pretty much identical to that in a 358, but it had 14.7:1 and ported 230cc heads; It made 608 hp at 7900 RPM. For a strip vehicle with the 200cc heads, I would recommend a cam with a max of high 240's to low 250's@.050 duration and as much lift as you can get. In a 350, a cam like that is probably going to want to work close to 3000-7000 RPM. It is best you match your cam to the powerband of your heads, and those 200cc heads, on a 355, will probably want to work until around 6500 RPM so the cam I recommended will be pusing it. I think the 4500 stall should be about right for that setup.

http://www.ryanscarpage.50megs.com/combos2.html

Adam
 
#13 ·
Thanks guys...for all of your input....

I think I'll sell the 383 with the vortecs to finance parts for the 355....

whats a slightly used (less than 3000 miles) 383 worth...I do have a TH400 that could go with it...

what is a reasonable price to start with...

Thanks
Nasty
 
#16 · (Edited)
I dont want to be negative, but I have some real doubts about that motor making that much hp. As a rule of thumb on a motor like you are building, with 10-11:1 compression, you can figure around 2 hp/cfm max flow on the heads. According to the CHP cylinder head flow bench database, A set of heads like yours will flow around 236 cfm at .600 lift. That would put the hp capeability at around 472hp max, but I think you would be lucky to get that with them on a motor as small as a 350. I just dont want you to be dissapointed. Also, the numbers will probably be even lower with a cam that large and only high 10:1's for compression.

If possible, I would like to see what the desktop dyno says about the comp XS290S with some 1.6 rockers (252 260 @.050 / .570 .588 lift 110 lsa) as well as the comp XS282S with 1.6's (244 252 @.050 .550 .570 lift 110 lsa). the xs282s really matches the heads the best, but if you wanted to go larger, I would not go with anything bigger than the xs290s.

flow
http://www.chevyhiperformance.com/techarticles/41598_cylinder_head_flow_bench_database/photo_46.html

Adam
 
#17 ·
no negativity taken....I am getting unsure that we are talking about the same parts on the right motor... The reason I think I will stay with the 355 is that I built it... I know what went into it... it has been balanced and has better components... my loosely put together plan would be to take the dart heads off of the 383...and replace them with the vortecs and the super victor vortec intake... sell that motor...put the darts on my 355...they are the same cc (advertised anyway) which would keep me at 12 to 1 compression... and buy a new intake / cam combo that would work the best together... are we on the same pege??

Thanks for the help...
Nasty
 
#18 ·
OK, I did not realize that you were going to have 12:1 compression. I would still be carefull how much cam you run, but compression should not hold you back with 12:1. It may be worth calling comp to see what they recommend with those heads.

Adam
 
#19 ·
think I have changed my mind again...sell the 383 like it is....sell my vortec's...and use the cash for a set of AFR's... so the question would be which AFR's and i would be getting a whole new package cam/intake/heads...
whats the best way to figure out the best combo to go with the rest of my components...can't really ask here with every combo...
 
#20 ·
383 /355

If you've got a built 355 and are trying to go faster, go to more cam and bigger , more efficient heads like AFR 195's. The trade off is always cubic inches (with lower rpm power) vs. smaller displacement higher rpm power
at the sacrifice of torque. Being that you are running a 4500 stall converter, I think the question is already answered ..... 355 built to make high rpm power ....
 
#21 · (Edited)
I think the AFR's are a really good idea. The size will depend on what you want your RPM range to be. If you are looking at ~2500-6500, i think the 195's would be a good choice. If you want to run closer to the 3000-7000+ range, I think the 210's would be a good way to go. You just need to remember that with a high RPM motor, the quality of all of your components becomes more important. If you want the higher RPM range, I would recommend the AFR 210cc street heads with something like the comp xr292r cam (mech roller) with 1.6 rockers on the intake (254 260 @.050 .612 .588 lift 110 lsa) along with a victor Jr intake.

AFR 210cc heads
http://www.airflowresearch.com/210sbc_rh.php

Here is an article about a 10:1 355 with the old style street 195cc heads and a 242 248 @.050 mechanical roller cam. It made~520 hp at 6600 RPM and 454 ft lbs at 5200 RPM. Your motor would have much better heads, and a higher RPM range. Based on this article, I dont think 550-575hp would be out of the picture for the setup I recommended above.
http://airflowresearch.com/articles/article054/A-P1.htm

Here is another 355 with the AFR 195cc heads that made 527 hp on pump gas. It has quite a bit bigger cam than in the previous article, but does not make a whole lot more power. This could be an indication that with a cam too much bigger than in the previous article you reach a point of diminishing returns for the 195cc head. In other words, this cam is probably a little too big for the 195cc heads. As you can see on the dyno chart, it made pretty much the same hp at almost exactly the same RPM, and made about the same torque but at a higher RPM, 5600. That shows that from the smaller cam to the larger cam, you may actually will end up with a slower motor because of a reduction of low end torque due to the max torque being shifted upward in the RPM range with the larger cam.
http://airflowresearch.com/articles/article096/A-P1.htm

Adam
 
#23 ·
ya 4000 + 600 in shipping! and he also has a th-400 that can go with it! that alone is worth $400. ya i might have been a little over by saying 7K but now that i think about it probly around 5.500 for the two! and its been run! and the crate engines dont come with any other thing but the long block and valve covers and oil pan! but with the carb, intake, pullies, probly a flywheel/flexplate and torque converter! all that stuff adds up! :thumbup:
 
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