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383 numbers


Guest zfan

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Well I am jumping off the deep end and building a sbc 383. My desk top dyno is not working properly. What I am trying to do is compare my build vs. new build.

 

current is a 350 4 bolt 30 over

10.3 to 1

comp cams xr276hr 224/230-502/510 with 110 lobe separation

1.50 roller rockers

Edelbrock rpm heads 64cc, 170cc runners,1.60-2.02 valves

Weiand dual plane stealth intake

holley 750 dp 69 primaries and 76 secondary jets

msd pro billet distributor

msd 6a

1 5/8" hooker long tubes

2 1/2" exhaust

 

New build is a 350 4 bolt 40 over

400 crank

10.7 to 1

comp cams xr276hr 224/230-502-510 with 110 lobe seperation

edelbrock rpm heads 64cc, 170 runners

weiand dual plain stealth intake

holley 750 dp

all msd ignition

1 5/8" hooker super comp long tube headers

2 1/2" exhaust

 

If someone out there is bored and has nothing better to do? Could you please run the numbers for a comparison.

 

I am currently getting the part together for the build.

I have the block, crank, fluid damper and looking at 5140 I beam rods with arp rod bolts and keith black hyperutectic pistons.

 

Mike

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my computer only shows these results

rpm.........350...............383 ...............afr/crower/edelbrock

2000......151/397.........171/448 ...........157/412

3000......242/423.........269/470............256/447

4000......337/442.........365/479 ...........376/493

5000......405/425.........422/443 ...........473/497

6000......404/354..........396/346...........503/440

 

but in the real world a 40hp/40ft lb gain over most of the rpm range is quite common

btw those heads and cam/intake are holding you back,look at the results for a super ram intake,crower 00471 cam and afr95cc heads

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.., btw those heads.., are holding you back, look at the results for a.., and afr95cc heads

 

Grumpy,

 

For clearification sake I am assuming your reference to afr95 was suppose to be afr 195: yes/no? I agree that those heads, the 170cc runners will reach their maximum efficiency prior to 383 cubic inches having an opportunity to reach their maximum efficiency.

 

If maximum effieciency is not your goal then you dont really need a 383 and you can get by w/a stout 350 build. If maximum performance is your goal then consider Grumpy's suggestions.

 

I was also thinking cylinder heads w/larger intake runners are more appropriate for a 383: the larger intake runners will delay the point at which maximum efficiency is reached-thus giving your car & its gearing a chance to move the car down the road as this will momentarily delay wheel spin & allow the engine to run in its maximum efficiency...after the car is already moving-remembering that our Z's are somewhat traction limited at times from a dead start.

 

As far as the cyl.heads, intake, and cam choices....I would want to know what your goal is for your car prior to making any changes. Regardless of your need-those 170cc cyl.heads are considered "small": especially for a 383. They're great for a true street 350 or smaller...but not so great for a performance 383.

 

As far as gearing is concerned in any car: more tq/hp will require less gearing while less tq/hp requires more gearing.

 

What are your goals:

 

1) Pure Streetability/No 1/4 mile time

2) Heavy Street/Mild Strip

3) No Street/All Strip

 

Kevin,

(Yea, Still an Inliner)

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I am currently looking to go street/strip. the current build runs 12.30's and I would like to go mid 11's. I have another cam in my garage, it is a Comp cams xr288hr-10..part#12-433-8. The cam specs are 236/242-520/540 with 110 lobe seperation.

 

I don't want to spend alot on heads. That said what would be better but inexspensive? Iron heads if need be.

 

Mike

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Guest Phil1934

I went to http://www.edelbrock.com and got better flow #'s.

350 HP TQ 383 HP TQ

4000 307 402 326 428

4500 346 403 363 424

5000 377 396 389 409

5500 390 372 393 375

6000 387 339 379 331

You can see the bigger motor doesn't gain you anything with these heads. The cam is as big as I would care to go with a street cam. I ran these numbers with small tube headers with mufflers. I ran both through desktop drag and dropped e.t. .04 seconds with same MPH.

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Guest billy383Z

Based on my own personal experience, I completely agree with everybody else on the cylinder heads. My 383 currently has World Products S/R Torquer 305 cylinder heads with 58cc chambers, 170 cc runners and 1.94/1.50 valves. I chose these because the KB pistons in my motor have either a 24 or 26 cc dish, (I can't remember which now since I built this engine 6 years ago) to get my compression up around 9.6 to 1. Produces MASSIVE torque down low, but will only go to 5800 rpm (I don't have a rev limiter, the heads take care of that!). My motor is purely a street motor because it is a true daily driver. I drive it to work 6 days a week and everywhere else on Sundays. My '67 Ford Fairlane 500 with 48,000 original miles is an antique and only gets to go out on the street once or twice a month just to keep everything from deteriorating due to lack of use. If I were to use the Z for more than just a daily driver, I would certainly choose a set of heads with characteristics like the afr 195's, and change my cam to suit them.

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Well maybe before I jump in over my head I should just go with a 100 shot of juice. My good friend said he would buy what I have already put together for the build :(

 

If I was to score another set of heads what would you all recommend. On a budget of course!!!!!!

 

Mike

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Here's another option... Buy a pair of AFR 190 heads and Ebay your current heads. Try to get the quench area

to about .040" when you reassemble. This should get you into the 11's with your 350 without going broke.

 

:cheers:

Don

 

PS: If you don't already have a line-lock, get one.

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I have decided to go ahead with the 383 build and will use the Edelbrock RPM heads for now. As soon as I can afford to I will buy a set of AFR 190's or 210's.

 

I am also going to go with the bigger hydraulic roller cam xr288hr-10 with approx. 11 to 1 compression I should be ok with that cam.

 

Thanks for all your imput!

 

Mike

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