Holly VS Edelbrock Carbs

[Guest Anonymous]

my mech says the Edelbrock carbs are alot nicer then the Holly main reason being since you can tune everything with out pulling it apart

 

the engine Im going to built for my Z is going to follow this book that I bought "how to build max performance chevy small block engines on a budget"

 

this is the list of things needed to run 390BHP "flywheel"

 

Block 4 bolt main bored +0.030 and decked (a two bolt main would have been satisfactory)

 

Pistons: Flat-top Speedpro # L2490F 30 forged

 

Head Gasket: FelPro

 

Final CR: 10.1:1

 

Crank: Stock Forged

 

rods: Stock 5.7 lightened and balanced

 

oil pump: reworked stock

 

oil pan: moroso basic pan

 

cam: comp cams 268 H on 108 LCA, 4 degrees advanced

 

Lifters: Sealed Power

 

Valve Train: comp cams magnum roller tip: R/ratio 1.6 intake 1.5 exhaust and comp cams roller timing set

 

heads: 186s with basic full porting (235cfm @ 600 lift) bronze guides; new 2.02/1.6 valve and flat milled to 64ccs

 

intake edelbrock victor jr ( required machining to allow hood clearance)

 

Carbs Holly 750 mechanical with air horn and butterflies reworked to 820cc

 

air filter: K&N

 

ignition: Stock hei with external soil: recommend accel or MSD

 

Plugs/Cables

Moroso

 

Headers: Walker 1 5/8"

 

Mufflers Walkers high flow cat and 1 x 2.5 ince dynomax

 

now if I used the Edelbrock carbs do you think I would lose any performance?

 

also the book says it was later rebuilt with a comp cams 280 hydraulic profile and it pushed 410foot pounds @ 4500 and 408BHP at 6200

 

this engine sounds like a good one for my Z

 

I use to work for ken keir race cars and he said if needed he would put subframes in my Z

 

all I need is a set of slicks to put this power down to the ground

 

any idea of what 1/4 mile times I would see?

 

 

with this engine a 1980 Camaro with muffers and on street tires did the 1/4 mile in 13.7 at 105MPH they said on slicks it would of done atlest a 1/2 sec faster

 

so if a camaro can do it in 13.2s what would my Z do =) the joys of thinking about that =)

 

atlest 12.2s Im guessing

 

any other helpful engine ideas to pass long?

 

thanks

 

Jeff 280ZXT

 

p.s any one want a turbo engine with intercooler? lol

[Guest nosz350]

IF YOU ARE WANTING TO KNOW YOUR 1/4 MILE TIME THERE IS A NEW GAME OUT(NIRA IMPORT DRAG RACING) AND IT IS VERY CLOSE TO REAL LIFE.BUT IT IS ONLY A GAME BUT,WE BUILT MY FRIENDS HONDA ON THERE AND IT IS ONLY A 1/10 OFF OF HIS TIME IN REALLY LIFE.AND BETTER THAN THAT IT HAS A 1974 DATSUN 240Z,HELL THE GAME IS ONLY $15.00.

[Modern Motorsports Ltd]

Some v. quick comments as I'm off to bed..

 

No matter what carb you pick make sure the floats etc/fuel bowls will work well with your intended use...(ie. in general side hung for straight line and fore/aft for lateral). I prefer edelbrock for same reasons your mech does.

 

Additional comments on your listed combo; all just as my opinion (if you weren't looking for them, I apologize, but we're generally pretty straight up around here so figured you (or others lurking) might welcome the feedback:

-why increase your intake greater than your exhaust duration? If anything I'd think you'd want to help out the 1-5/8's headers (borderline OK for that power). Are you thinking intake will be restricted (milling V.Jr.). Lower your motor to gain that intake clearance/space Xmember below frame and if necessary/notch oilpan. For that intake you WANT the height and a carb spacer if you can fit it. As well if you are buying a pan get a v. good one (Canton) as most others don't give you the xtra torque a good pan should with oil control if you're bucking up.

-268H is an old cam design, they've improved a lot, the XE256H-10 or XE262-10 have quicker ramps and a dual pattern (you can adjust as you know w/ your rockers)

 

-how much will those heads set you back? as well the flow you quoted isn't relevant to what lift this cam will operate in....(you'll hit .484 with the 268H and 1.6 rocker you propose), you need max flow in the .3-.5 range, those ports you mentioned would IMO make it fall on its face with your 'mid' lift cam (aluminum heads will REALLY help your weight distribution, and give you a free .5 point on compression with pump gas). I ran cheap iron first till my pennies grew, then aluminum and balance/steering were greatly improved (and moved battery at same time:-)

 

-268H in my catalog is a 110 LCA, you getting a custom grind to 108? that's narrow IMO for a street cam of the range you're looking at. Your torque curve (does your book have the dyno curve) sure won't be the flattest.

-were those iron heads? do you want to run pump gas at 10:1? with sbc's power is so cheap it pays off quick IMO at your power levels to build for pump gas

 

all just curiousities and not meant to offend, just seems the parts might have some room for 'optimizing' your bang/buck

 

PS if you can alter the budget to include roller lifters and a cam (cam's can be had in your range/used/great shape/cheap) we can build you same or MORE power with far better manners:-)

 

FWIW, I've got a 280ZX roller 350sbc w/ a ~.519/.522 lift cam and it's an easy 400hp flywheel (seen 420 dynosheets for same) setup with easy manners d/2 it's roller design with a FLAT torque curve their all over.

 

------------------

Of all the things I've lost, I miss my mind the most.

[Scottie-GNZ]

Jeff,

 

having used both carbs, I would recommend the Edelbrock, which looks suspiciously like the old Carter AFBs.

 

As for 1/4-mile projections, let me take a stab at that with a lot of guesswork. The projection is 408hp at the flywheel and an actual of 13.7 @ 105 in a 80 Camaro. If we speculate the Camaro with slicks would run 13.2 @ 106 and weigh 3500 (w/driver), my formula spits out 327 RWHP and 409hp at the flywheel using an 80% factor.

 

I am guessing that your 280ZXT weighs 3000lbs w/driver, so with 327 RWHP, I project 12.40 @ 110-111MPH. Now, put that puppy in a 2600lb 240Z and you are in the 11.80s

 

Is'nt bench racing fun?

 

------------------

Scottie

71 240GN-Z

http://www.mindspring.com/~vscott911/gnz.html

[Andrew Bayley]

I guess I'll try to defend the old Holley's here.

 

This past summer I was at a local track and I was having (what I thought was) carb troubles. Within five minutes, I had the entire carb pulled apart, then rebuilt with different components. Took a run... nope, didn't fix it. Tore it apart, put different components in again, took another run... nope. I must have done this six or seven times that day (problem turned out to be the distributor was loose and retarded itself 20 degrees). All the parts I used for the carb were from friends, or total strangers that I met that day at the track.

 

I guess my argument is that the Holley is such a widely used aftermarket carb, one could rebuilt a dozen of these thing from scratch at any local race track. The main reason people talk about "tearing them down" in order to do maintanence is because there's only a few parts in these units. Holley's are very module and can have parts swapped from all across the product board. However, this means that "dialing" these things in requires a lot more dedication and patience. It's not impossible, it just takes time.

 

Good luck with whatever you choose.

 

-Andy

[Guest Anonymous]

Most test I have seen where they ran both carbs on a dyno were withing a few HP of each other. The Holley tended to give slightly more peak power by a few HP. That being said, IMHO, the edelbrock (which Scottie-GNZ pointed out is nearly if not totally identical to the Carter AFB) is a little more trouble free for street use and won't disappoint. The difference in power isn't much, and if its a concern, you could always squeeze on it with some N02 since your using forged stuff, an extra 100-150 Hp should be no problem. Hook up 500+ Hp in a Z and your flying.

 

Have a good flight Capt.,

 

Lone

[Guest Anonymous]

heres the story... I want more power "like everyone" I love my L28 turbo but... this is a cheap fix and Im going to keep the ECU AFM and wires so later on if I want to build it back up as a 500+BHP turbo engine I can

 

"most people say I wont"

 

anyways I have the block waiting for me to pull it apart

 

other then my dirt bike and tons of R/C engines when it comes to valves cams CR intakes and so on I have no idea another reason for this engine build is to learn as much as I can

 

may take a month or two to build the engine but the more time I take to do it the more I will learn

 

everything I listed was from a book since I have no idea what do work with as far as what lift and what kinda valve job...

 

Im looking at it as let them do the guess work I just want to build it for my first motor

 

but Im looking more and more "reading ALOT" and Im thinking about droping to a lower BHP engine for now

 

this way when I mess up I wont blow alot of money "I hope I don't"

also I wont have as many problems with my rear end and body holding the power

 

so far Im pretty set on getting 750cfm carbs since later on I could use the extra fuel flow

 

victor JR intake since I keep hearing good things about it

 

stock cast crank stock cast rods "both run thu the mech shop"

 

forged pistons/cast if you think they can hold around 350BHP

 

I want to talk to the mech shop about my heads

or if any of you guys know of any good priced heads

 

I would like a CR of around 9:1

 

350BHP is my goal

 

if I need forge pistons rods or crank I will work with that but if not I might as well keep this engine on the safe side just in case...

 

has anyone had any problems running a 350 trans? I can get one of them for 50 700r4 is not as cheap but I know some people that I can get them from

 

would the 700R4 be a drop in replacment for the 350? if so I will just go with the 350 for now and later on move to a 700R4 or nice 5/6 speed if I get rich anytime soon

 

Im guessing the engine will be around 700-1200 bucks "with out labor other then mech shop" thats with carbs and headers "hoping I can pull that off"

if not I will just dig deeper in the pockets lol

 

2 1/2 exhaust maybe 3" if you guys think its worth it

 

anyone know of a good webpage that list engine setups and what power they put out?

 

I wish it was as easy as a crank rod piston and sleeve "O.S engine" =)

 

btw if any wants a L28Turbo with intercooler 118K miles on it let me know

 

thanks for the replys

 

I love learning about this stuff

 

Jeff

[Modern Motorsports Ltd]

Sounds like you got a great attitude Jeff:-)

 

Some reading I highly recc'd (money v. well spent IMNSHO)

 

John Lingenfelter on modifying sbc engines, he discusses quite well how the different parts/designs relate and includes dyno sheets of his proven combos with listing's of all parts in those combos.

 

as well Vizards: how to rebuild your small block chevy, and any of his other books

 

I rec'd JL's book 1st if you can find it (if you were here I'd have an armful for you to borrow:-)

 

and, order as many free catalogs as you can as they offer a lot of good info on combo's

edelbrock/comp cams etc etc, comp cam's catalog is a wealth of info, you also get good ideas from some info in summit on characteristics as well

 

I'm not sure but a 700R4 may swap in place of TH350 IF the shorter TH350 tailhousing is used on the 700...ask your shops, I'm not sure anyone here as done that so we'd appreciate hearing back on it:-)

 

 

 

------------------

Of all the things I've lost, I miss my mind the most.

[Guest Anonymous]

I have two of Vizard books "thats where my specs/combos are coming from

 

I have tons of summit books and jegs

 

alots of import mags too=)

 

I work 5 days a week then work as soon as I get home on music then I fit school into it too on top of that I have hobbies 2 cars 4 R/C cars "3 gas powered" and I have to keep track of a girl lol

 

on top of that Im 17 so time is hard to come by but Im hoping that I start this new project in the next week

 

my mech has a 76 280Z he made his own motor mounts Im thinking about having him make some since MSA are around 200 bucks

 

also when my engine is out Im going to do all the rust work in the engine bay "battery tray" one frame rail needs to be sanded then Im going to shoot it with paint and get my body ready=) its taking awhile but my babys getting there! =)

 

btw I saw a Interga Type R today with a supercharger "found out the guy works with me" he runs 12.2s on slicks 13.5s on street tires thats not to bad for a 4 banger

p.s yes it was a type R not just a sticker lol I checked

 

back to the engine building

 

any other tips for me before I jump into this project? first thigns first taking everything apart and checking the block to make sure its good for making power and no cracks

 

I just wish it was warm out=( ohwell lucky for my my mech says I can use his shop with all of his tools YA! hehe everything needed will be right there for me

 

I love having good friends lol

 

Jeff

[pparaska]

Jeff, I was your age when I built my first motor. Did a bunch of reading as you are. One of the books I read was a Chevrolet Overhaul manual. Good for learning some mundane stuff not in the "Hipo" books. A great book is the Engine Blueprinting one that's out there (HP books I think).

 

BTW, all older Chevy rods are forged or some of the later ones are powdered metal (don't laugh, this is pretty good stuff). The forged ones are resizeable on the big end though.

 

If all you want is 350hp, then cast pistons would be fine. I agree with Ross on getting the Comp Cams Xtreme hydraulic cam. For the budget you're talking about, that'd be the hydraulic flat tappet type. I might go to the 268 cam for that grind type on a 350. A little loss of super low end torque is not a bad thing for a tire-challenged V8Z.

 

Same on the Victor Jr. That intake doesn't really match your cam/rpm/power(350hp) choice well (it's more of a higher rpm design), so you'd gain more low end torque with a dual plane (Performer RPM -I'd spring for the air gap version, or a 300-36 Holley hi rise dual plane). But the dual planes will have nicer low end/mid-rpm throttle response as well, so you ought to consider that.

 

The heads you are talking about are decent old design heads. Not sure you want to bring the chamber volume down to any though, as to get 9:1 compression (I'd suggest going to 9.5:1) without a really dished piston and possibly a thick head gasket and alot of negative deck height. The thing I'd suggest is trying to limit head gasket thickness and deck height (piston top below the block surface) to get the smallest possible head to piston clearance in the quench area. This is somewhere around 0.045", if I recall.

 

With the knowledge you already have and some more Chevy specific reading, and the help of your (SBC experienced?) friend this ought to be pretty easy to do to get a reliable motor with that power level.

 

Jeff, aren't you in Annapolis? I'm in Laurel. If you're in the area, let's hook up!

 

------------------

Pete Paraska - 73 540Z - Marathon Z Project

pparaska@home.com

Pete's V8 Datsun 240Z Pages

[Guest Anonymous]

I work right out side of annapolis

 

some times Im over at the ice gardens I forgot what road its off somthing barral? hmm

 

I was just looking at the engine heads and my mech was showing me around them with porting "home port jobs lol" i've ported 2 stroke engines before not the heads but the intake/exhaust port/headers "nice gain in power=)"

 

if we meet I will need to take my baby out let you see all the homemade things on her lol K&N intake Intercooler piping my waste gate lol hey it works

I raced a mustang 5.0 "89 gt" blew him away you should of seen his face after we pulled over and I poped my hood=)

 

anyways back to the engine building

 

"performer RPM "company Im guessing" intake air gap version

 

aim for 9.5:1 CR

 

Comp Cams Xtreme hydraulic cam "cam kit with spings and rocker arms" atlest I think it would be smart

 

Im hoping I can get the bill of sale tomorrow for the engine so I can start on it

 

how long do you think this will take? 2-3 months? =)

 

pparaska just wondering did your first engine last or will we just not go there lol

30 mins later... boom

 

thanks for all the help

 

Jeff

[pparaska]

quote:

---

Originally posted by Jeff 280ZXT:

I work right out side of annapolis

 

some times Im over at the ice gardens I forgot what road its off somthing barral? hmm

---

 

Not sure where that is.

 

quote:

---

"performer RPM "company Im guessing" intake air gap version

---

 

Company is Edelbrock (look in your Summit Racing or Jegs catalogs), the intake is the "Performer RPM Air gap"

 

quote:

---

Comp Cams Xtreme hydraulic cam "cam kit with spings and rocker arms" atlest I think it would be smart

---

 

Yes, the Xtreme cams need a bit more spring than the older grinds due to the faster ramps.

 

quote

how long do you think this will take? 2-3 months? =)

 

Sounds about right. Could be shorter depending one the machine shop's turn around. Not something I'd hurry through though!

 

quote

pparaska just wondering did your first engine last or will we just not go there lol

 

I ran it for 5 years, sold it to my boss and put it in his work truck for him - he drove it another 5 years and sold the truck. Still running great (sweet little 327 with the fuelie heads, 10:1, 327/350 cam) Loved that motor. I ran against a friend's GT500 Shelby from a roll of about 15 mph and pulled on him until about 90, where the 428 Cobra Jet showed me what cubes could do.) Fun car! (70 Camaro)

 

 

------------------

Pete Paraska - 73 540Z - Marathon Z Project

pparaska@home.com

Pete's V8 Datsun 240Z Pages

[Guest Anonymous]

well today I bought the engine its a 350 2 bolt main for 50 bucks running cond "but smoked"

 

if I can Im going to start on things sat

 

wish me luck

[Guest zfan]

BEST OF LUCK!!!!!

JUST REMEMBER TO MOST IMPORTANTLY TAKE YOUR TIME. WHEN I RUSH I USUALLY MAKE THE STUPID MISTAKES.

Z/FAN...MIKE

[Guest Anonymous]

with anything in life if you rush it your in other words halfassing the job

 

too bad I can't wait to get this in and I know Im going to try and rush but I will hold back as much as I can=) atlest when it comes to building the engine

 

first part sat is taking everything apart to get it ready for the mech shop

after that order needed parts then put it all together then I can rig up my Z to hold the engine lol this should be fun ohyaeh... I need to get my 350 trans now doh

 

Jeff

[pparaska]

Jeff, make sure you mark the rods and caps, and main caps as per the position and direction that they are now. A center punch can be used to put 1-8 dots on each rod and rod cap (on the same side of the rod, before you unbolt them). If you have access to number punches, even better.

 

------------------

Pete Paraska - 73 540Z - Marathon Z Project

pparaska@home.com

Pete's V8 Datsun 240Z Pages

[Guest Anonymous]

yup yup on top of that =) talking to some one about that it sounds like its should be done but it does not matter if your going to send the rods out to have them redone I guess I will do it anywhys just for the sake of it

 

Im thinking that Im going to get 8 boxes #1-8 and keep parts from each cly in them

 

I've torn everything up in my room/house trying to find the how to rebuild SBC book but... no luck =( I really would love to look thu it again ohwell it will show up once I bolt the engine into the engine bay lol it always works that way

 

Jeff

[Guest Anonymous]

Day 1

 

I get to my shop and well its closed doh so I go home and change the oil in my honda since its over due

 

2-3 hours later I go back and hes there woohoo

 

first things first putting the engine stand together

 

after doing that I took some pictures of the engine sitting there and then hooked it up the the cherry picker

 

I asked him for some bolts to mount the engine... um you don't have any? man....

 

its 3:55pm he wants me to get some sodas since Im going out to get some bolts first place I go to I missed my turn so I said to myself I will just hit them on the way back and try the other stores before that just in case they have them

 

both of the other stores just closed hmmm ohwell I will just hit the other store since the open sign was on when I missed the turn

 

I drive back there and what the... the open sign was turned off AGH!

 

so I drove down to the beach and found a open shop lucky me...

 

1 hour later...

 

I hook the engine up get it on the stand and take some more pictures then I start to have fun

 

valve train... GREAT looking the only thing bad was a push road had the top messed up "rocker arm came lose" my mech hes guessings thats why it smoked

 

I get the heads off and the clys look GREAT!

I flip it over and pull the cam out the cam is in 5X better shape then my Z cam lol

 

I take the pistons out and they look great too other then the one that I droped and it broke a skirt off oops.... "was going to replace them anyways=)"

 

the crank looks great too

 

all in all this moter only needed a new timing chain and push road and it would of been fine not bad for 50 bucks

 

btw the timing gear was had so much slack that I could of taken it off by turning the engine over with something under the chain to pull it off

 

atlest I know the enigng was and is in good shape now its waiting for me to take it to the mech shop for diping and boring

rods/crank redone

 

then its time to put it all back together

 

total time from "after enigne was on stand with bolts" to bare block was 3 hours thats not to bad for a first time

 

if I did it again I think I could do it in 2 hours easy

 

I only asked my mech little dumb thingsl ike wheres do you keep this tool or when something did not come off like the cam sproket I asked if there was something else holding it on

 

so Im happy that things worked out the way they did

 

he said a guy has a working turbo 350 for sell for 100 bucks I need to look into that becuase it might just work out for me =)

 

Im way ahead of my plans=) I might have everything ready to go by the end of this month if I can keep the money coming =)

 

too bad my funds look kinda low after I get the trans and the mech work done ohwell thats why we have 1 loans and 2 credit "same thing=)"

 

as long as I don't go over kill with things lol

 

 

I will keep you guys updated with things and tell you how long it tanks to blow it up

 

btw I found out tonight that my ZXT was running bad under full throttle becuase some how Im hitting 16LBS of boost... hmmm something blow thu and opened her up =) such a kick in the butt to run 1/2 throttle at 10LBS boost and FLY!

 

lol I will miss turbos

 

atlest untell I can get rich "lol" and build a twin turbo 350

 

Z Ya p.s rich/tt350 thats what I call a dream and thats all it will be

 

Jeff