540hp 383 in this month's Car Craft

[Guest the_dj]

Anyone seen the June issue of Car Craft with the 540hp 383 stroker for $4800? I am HIGHLY interested in this motor and need opinions.

 

I have a TPI crate motor with SLP runners and the Holley Commander 950, as many already know.

 

I am thinking of selling my heads, cam, Computer (with laptop) and TPI setup and the rotating assembly from my motor and building the 383 out of it. What do you guys think? How will this motor be on the street? Can I expect any reliability out of this motor?

 

I am trying to convince my Dad that carbs are not the Devil, but it's not working. Will the 383 turn out to be an evil motor that can't be tuned or will it be friendly for just driving around Houston?

 

If you were in my position with little money, would you keep the TPI setup with 270hp or trade it for the 383 with 540hp? Thanks guys.

 

Sam

[grumpyvette]

first thing is that the EFI will produce even better power, its only the lack of air flow useing the TPI intake that keeps the EFI from making 500- 600hp, swap to a HOLLEY STEALTH RAM INTAKE, keep your EFI and lap top computer controls, they have far more mixture control,streetablity and mileage potential, the HOLLEY STEALTH RAM INTAKE and FUEL RAILS SELL FOR ABOUT $460 from summit, sell your TPI intake that should cover some of the expense, next you will need about 30lb-36lb injectors (30lbs will work but 32lb or 36 lbs are better choices, yes you will need the better heads, and btw one of the guys on chevytalk had already built that identical carbed engine and only got about 497hp so that build-up may be somewhat suspect or the dyno on one of the two engines was (OFF). DOUG over at CHEVYTALK/EFI forum can help you tune it also, (DOUG works with PAT MUSSI and gets well over 500hp useing a single plane EFI intake and says the STEALTH RAM will produce even more hp as it flows even better)plus with the stealth ram youll be able to tune to pass emission tests, something that carb will never do.what it basically comes too is that a 383 of about 1.5-11:1 compression with those heads or the 210cc AFR heads and that roller cam can make good power, but don,t sell your EFI short its good for even more power that the carb, its the TPI intake that SUCKS to give you an idea of what Im talking about one of the guys at the vette site had a stock tpi and standard vette heads flow tested and they flowed 180 cfm, a highly modifyed tpi can flow 230cfm, but the stealth ram flows 300cfm that enough for 600hp. the formula for potential hp from airflow is (.257 x airflow x 8=max potential hp) so the MOST a stock TPI intake can support (180 x .257 x 8=370hp)(modifyied 230 x .257 x 8=472hp)( stealth ram 300 x .257 x 8=617hp) see the differance now the 195 cc heads flow about 280 cfm so they not the stealth ram get you about a 575 hp limit, go to the 210cc AFR heads and your back to over a 600hp limit but the 383 displacement allows either head to work well, on a stroker 427 small block the 195cc heads would be a restriction.

[Guest the_dj]

Thanks for the reply grumpy. I have a couple of question though regarding my EFI setup.

 

1) What do I do about my hood and the Stealth Ram clearance issue? There is no way a 10 inch tall intake will fit with the hood.

 

2) If I went to 36lb injectors, the AFR 195cc heads and a solid roller cam of about 250 degrees at .050 and .525-.560 lift on a 9.4:1 engine, what kind of power would it make?

 

3) Who makes a good fuel pump for that type of engine at a good price?

 

Thanks guys

Sam

 

PS....I'm sure I'll have more questions.

[grumpyvette]

(1) your going to need a hood bulge/scoop just like Im going to on my vette

 

(2)now you need about a static 11.5:1 compression to get a dynamic 9:1 compression with a cam like that but assumeing you have a dynamic 9.4:1 compression (youll need high test gas) you can get about 530hp/530 tq if its tuned correctly according to the computer but with a wider torque curve than the magazine engine

 

(3)

GET ONE out of almost any EFI 8 cylinder mercedes benz from a salvage yard they normally produce 80psi and more flow than domestic pumps and Ive bought them for $78 in salvage yards

[Guest 1fastz]

Unless you have a ton of time to invest in tuneing a custom programed efi and acess to a chassis dyno the carb is by far easier to work with..

 

seat of the pants is no way to tune a efi system from scratch

 

i can atest to that from 15 years of use of both efi and carb systems.. and yes im qualified to coment as i have built several low 7 second cars with a 347 small block and a single turbo useing efi..

and more nine second cars then i can remember useing both efi and carb.

 

i have built everything from mild to outrageous and if someone is on a budget you simply can NOT beat a carb for performance per dollar invested.

 

and I am a fast and dfi dealer so im not knocking EFI in any way .

 

In any state that you are required to have a sniffer test run on your car at the tailpipe .. You will fail the emisions test long before tuneing is a issue due to the strict regulations on other items and the visual inspection..

 

You simply are not going to make 500 naturaly aspirated small block chevy horses and still have all required emissions equipment for a fuel injected vehicle in any state that requires a taill pipe sniffer for inspection.

 

Not without spending huge amounts of money.

 

Also if you are going FI forget the mecedees pump and go with a ford truck heavy duty external pump it can suply 650 horses at up to 95 psi..

 

its the pump most aftermarket bolt on booster pumps that come with blower kits is built on. and is rated at 194 liters per hour

[grumpyvette]

more options

http://www.bob2000.com/carb.htm

 

http://www.dakotadigital.com/tech/ODY-13-2.htm

 

http://www.techedge.com.au/vehicle/wbo2/default.htm

 

http://www.scuderiaciriani.com/rx7/AF_meter.html

 

http://www.nastyz28.com/perftune.html

 

http://www.nastyz28.com/fuelie.html

 

http://www.centuryperformance.com/vacuum.htm

[Guest]

Hey Grump!!! At your advice before I went with TPIS mini-ram set up on my L-98,and intend to build everything around Myron`s specs.He is expensive but he`s got the test to prove he`s the TPI GOD!! Also the mini-ram set up is like 4 inches shorter than stock plenum and has ENDLESS hp configurations.No offense 1FASTZ but the TPIS mini-ram will out perform any carb.BAR NONE!!

[Pop N Wood]

I am a converted disciple of Grumpyvette

 

I follow his advice like Pee Wee Herman searching for his remote.

 

But 1fastZ is giving some good advice too.

if someone is on a budget you simply can NOT beat a carb for performance per dollar invested.

I am coming to the same conclusion. That is why my initial V8 conversion will either be carbureted or a near stock FI motor. The ultimate engine will have an aftermarket FI that is professionally tuned.

 

zoncr is probably right too:

the TPIS mini-ram will out perform any carb.BAR NONE!!

BUT that was not 1fastZ's contention. The question is "per dollar invested" and the ability of the average (or beginner) backyard mechanic to tune it. Seems like good advice

 

Also the comments concerning smog legal and visual inspections are probably true, especially if you live in a state like California where aftermarket parts need a CARB number.

 

This is why I value this site, lots of good information.

[Guest Anonymous]

Which came first! The chicken or the egg? My project is unfinished because I am always coming up with some new modification of the proverbial egg, Get that motor you have installed and later if you want ..... put in a whomping stomping pavement pounding high horse 383.

[fl327]

dollar for dollar you wont beat a carb, no way, no how.

[Guest 1fastz]

try to make 750 horses on the motor with your tpis mini ram..

 

guess what my new motor does that with one carb..

 

try to make 300 foot pounds of torque at 1500 rpm

guess what i have built carbed motors with long runer dual plane intakes that do it all day.

 

so I hate to say it but yes there are plenty of situations where the mini ram gets owned by carbs.

 

A properly setup carb and etintake when tuned right will perform as good as any Fuel injection system from a power standpoint..

 

however they wont hang when it comes to part throttle fuel millage and emisions..

 

the reason for this is the tune ability of the injection the reason the carb can hang and in most cases out do fuel injection for utmost power is also in part to the convection cooling that takes place when the air passes through a carb and into the intake.. the air drops a good 15 degrees in temperature giveng the carb a starting advantage..

 

How much faster does your car feel when its 65 out then when its 80 ?

 

Where as the injection of fuel directly into a intake port has a far smaller amount of time to affect any cooling and it does nothing to cool the manifolds inner walls as well because they are dry ..

 

most tests you see in magazines where someone swapped fuel injection for a carb and gained power they

 

1. had to small a carb for ideal power and a intake wich was not correct for the aplication

 

2. simply jetted the carb until they had a good power reading and said OH ok its tuned.. Guess what you need to tune air bleeds in a carb to get the maximum out of it not just jets.

Why do you think you can pick up 30 or more horses by swittching to a good aftermarked carb like a bary grant etc vs a stock holley even when the cfm is the same between the two .

 

3. they used different intakes for the fuel injection vs carb setup .. and the intake and carb setup that they compared it to was not ideal.

 

4. they used a converted single plane style intake wich had a throttle body on it and then replaced the throttle body with a carb and then said look it has worse power..

 

Well yes it will because the intake for the single plane FI was not desinged to flow wet fuel and there for you have suspension issues in the runner designs.

 

they are prety much on par with each other for maximum horsepower potential the FI can have the intake be much more varried in design because it has no need to carry wet fuel suspended in the air charge.

 

While the carb has the advantage of cooling the air charge as it comes in via convextion.

[pparaska]

1fastZ, your point about the convective cooling is interestng. Would this mean a TBI system like the Holley Projection (950 commander model) would actually have a benefit over the TPI version?

 

I'm still on the fence as to whether an extra $1000 over the TBI version is justified for the TPI.

[Guest the_dj]

1fastZ: I think I'm going to switch to a carb after what you said. Maybe I can even meet up with you to get it tuned.

 

Do I need to get a new distributor? I have a small cap GM HEI ignition with a separate dual pickup coil. I think I want to go to a coil on top of distributor design with a new distributor.

 

If I sell my EFI system, it would be sold complete and include the following:

 

Holley Commander 950 ECU w/ all sensors and manual

GM TPI manifold, plenum, and throttle body

SLP high flow runners

cold air intake with K&N cone filter

Laptop computer for programming the ECU

GM HEI distributor and coil for digital control from laptop

Fuel rails

Accel 24# aftermarket injectors

 

What do you think the package will be worth, say if I sold it on Ebay? Should I finalize my plans to switch to a carb, would anyone here be interested in the package?

 

My switch would be:

AFR 210cc heads, ported and polished, stainless valves with 3 or 5 angle valve job

High pressure springs for up to 8000rpm

Cam with a duration of about 255 degrees at .050 and .550 lift

Solid roller cam

Victor Jr. intake

carb spacer

Holley 750 HP carb

Edelbrock pro-flo or similar air filter

 

Desktop dyno says the numbers would be good, around the 500ish hp mark and make good power from 3000-7000rpm.

 

Sam

[Guest 1fastz]

the tbi verson has all the benifits of a carb yes but it also has it drawbacks..

 

1 .. the fuel still has to flow through the intake so you still are limited in your intake designed due to the fact that you must keep the fuel in suspension ..

 

2. the fuel is no where near as well used as when it is ust sprayed at the back of a valve and therefor you will have better economy with a multiport system.

 

a tbi system will still have increase milage comapred to a carb because of the precise meetering of the fuel and the easier tunability of a comptuer as compared to air bleeds.

[grumpyvette]

zoncr

 

"Hey Grump!!! At your advice before I went with TPIS mini-ram set up on my L-98 "

 

?????? I have never advised the mini ram for any engine at any time, I have advised the HOLLEY STEALTH RAM EFI INTAKE SYSTEM

 

1fastz

"try to make 750 horses on the motor with your tpis mini ram" thats on nitrous Im presumeing?? well theres lots of guys running nitrous or turbos makeing that much hp and more with EFI intakes on sbc engines

 

http://www.montygwilliams.com/

 

http://www.callawaycars.com/Corvette/Sledgehammer/sledgehammer_article.htm

 

http://www.andrew.cmu.edu/~mjr2/cars/supernatural/

 

and you can easily add nitrous to most of these efi engines, pat musi gets over 700hp from nitrous EFI engines, this is his bbc but he also builds sbcs http://www.holley.com/HiOctn/TechServ/TechInfo/TchArtcl/Artcl06.html

 

btw the newer EFI systems even allow air fuel ratio changes by individual cylinder and rpm range plus ignition timeing and exhaust gas temp tuneing per cylinder, there no way a carb can match hp with a efi system, yes its totally true carbs work well and are cheaper but as far as total power , no, EFI wins, in any max power race where the efi is tuned correctly, they have not used carbs for years in formula 1, or at indy where power not cost is the goal and NASCAR won,t run EFI simply because they want to keep the change-over costs to the teams and speeds down and they know the EFI would boost power!

[Guest the_dj]

Grumpy: I would love to keep EFI, upgrade to a better ECU and still get heads, cam, intake, new injectors and a new pump. But I just don't have the money and won't for a long, long time.

 

I was thinking about switching to a carb'd system because I could afford a 500ish hp carbed system whereas I just couldn't with EFI. In the future, once I'm out of college and making a little more money, I'd switch back to the latest and greatest in EFI and spend some real time on the dyno and at the track getting it wonderfully tuned. I sounds great but the $$$ is really setting me back.

 

Sam

[Oltmann]

Originally posted by 1fastz:

While the carb has the advantage of cooling the air charge as it comes in via convextion.

I am dubious about this. Where does the heat go? I think that any heat that the fuel takes on as it evaporates goes down into the combustion chamber.

[Pop N Wood]

I have never heard or read anything about a carb cooling the intake charge. But the idea is sound. Water Methanol Injection is a common way to cool the intake charge to prevent detonation (thus allowing higher compression/boost for a given octane).

 

In thermodynamic terms, the liquid is "evaporated" as it is sprayed into the incoming air. This causes the liquid to absorb heat. The amount of heat required to convert a liquid into a vapor is called the latent heat of vaporization. Typically this number is very high for a hydrogen based liquid (such as water or methanol). Conversely, the heat capacity of air is relatively low. This means a large drop in air temperature is required to vaporize a relatively small amount of liquid.

 

And as any hotrodder knows, cooler air is denser air. Thus you have the dual benefit of forcing more oxygen into the cylinders while reducing the chance of premature ignition (detonation). Hence allowing more boost or compression or timing advance. And like I have said in the past, this type of thing was used heavily in WW2 aircraft.

 

I guess one question I have is if both a carb and FI are injecting gas into the air stream, they why wouldn't they both experience the same cooling effect?

 

About time for Grumpyvette to chime in with some links!!!

[grumpyvette]

here this will get you started,

 

http://oldsci.eiu.edu/physics/DDavis/1150/14Thermo/ToC.html

 

http://epics.aps.anl.gov/asd/me/FilmPressureDrop.html

 

http://www.taftan.com/thermody.htm

 

http://www.engr.colostate.edu/~allan/engines.html

 

http://biotsavart.tripod.com/ice.htm

 

http://tigger.uic.edu/labs/trl/AllLiquidsVaporPressureEqn.pdf

 

http://www.techfak.uni-kiel.de/matwis/amat/def_en/kap_2/advanced/t2_4_1.html

 

http://www.engr.colostate.edu/~allan/heat_trans/page1/page1.html

 

http://www.dakotadigital.com/tech/ODY-13-2.htm

 

http://www.engr.colostate.edu/~allan/heat_trans/page3/page3.html

 

short answer , most fuel injection systems have the potential to cool better than carbs due to a more highly pressureized fuel supply,faster fuel atomization and better percentage of fuel/air mix held in suspension due mostly to smaller fuel droplets haveing a faster heat transfer, here reading material.

 

http://www.amazon.com/exec/obidos/ASIN/0891163921/inktomi-bkasin-20/103-8602806-0179837

[Guest 1fastz]

No grumpy thats 750 horses NATURALY ASPIRATED .. 1098 on the bottle thank you

 

try that with a miniram .

yup you can do it with injection but you will need a custom sheet metal intake manifold this was with a ported off the shelf cast aluminum bowtie piece...

 

Dollar for dollar a carb is by far king for power.

 

unlimited budgets alow for fuel injection to rival it though.

 

the heat is removed via the change of the gass to a vapor state..

 

it is the same principle that misting systems use to keep outdoor patios cool ..

 

even grumpy posted examples of the actual phisics involved.

however i wish he had thought more before he made his comments..

 

1 presure involved is not notworthy. Yes it atomizes the fuel better but it does not allow for time for the fuel to evaporate .. its the conversion of the fuel to a gas state that does the cooling. and as the gass in its suspended state travels through a intake that is designed for wet fuel flow more and more evaporates as it moves. causeing more cooling. also the wetness on the walls of the intake cool it as well causineg less heat transfer there...

 

the fuel injector is to close to the valve in most multiport systems to alow time for the cooling to take place and there is no cooling of the runners ..

 

there have been tests and I will find some links for you where the intake charge has been measured on a carbed system at the valve and it was substantialy lower iE : more then 10 degrees lower then a fuel injection system on the same motor..