350 vortec 400+hp build

[v8nova64]

I know it possible to build a 5.7L vortec from a 96-2000 chevy truck to make 400+ hp with the change of a cam, rocker arms, valve springs, distributor, carb and a manifold with NO machine work required. I have some questions please do not reply to this thread if you cannot answer what i am asking. thank you

I will be buying a 5.7L vortec engine complete and runnig with the 64cc heads.

I have read that i can use a high lift cam by using LS6 valve springs, and comp cams 787-16 retainers.

i will be using the proper intake and a holley 750.

I need recommendations on a cam and rocker arms that will work for this engine.

I would like to know if these rockers will work?

I noticed that speedway and summit both have their own camshafts that are much cheaper than comp cams or the like. If possible i would like to use a summit racing or speedway camshaft under $150.

I would need to know what the specs of the camshaft i will need? I will not be doing any machining to the block so the camshaft must just slide in after the valve springs and rocker arms have been done.

If someone could give me a reccomendation on which rocker arms to use that would be great. trying to stay around a $100 for these also.

The stock engine with the 64cc heads has 9.4:1 compression. Will i need to up this compression to reach my 400+ horsepower goal?

If so will these flat top pistons fit without any troubles?If they do indeed fit they would give 10.14:1 compression.

Again PLEASE DO NOT POST IF YOU DONT HAVE AN ANSWER TO MY QUESTIONS. thanks

[BuiltFerComfort]

Don't worry, no one would even think of posting here if they didn't have an answer to your questions :-) The folks on the HAMB are good at doing what they are told.

[v8nova64]

i should get decent mpg out of it also.

[Sumfuncomet]

Hey wait a minute.......I never did like being told what to do! If you had a question about a flattie or hemi or y block I'm sur you would get lots of answers. I think if you post that question on Popular Chevy or super Truck you might get your answers to your belly button question!

[31Vicky with a hemi]

Lmao

[falcongeorge]

Originally Posted by BuiltFerComfort

Don't worry, no one would even think of posting here if they didn't have an answer to your questions :-) The folks on the HAMB are good at doing what they are told.

I like pistachios. No, really, I do.

[mastergun1980]

Originally Posted by falcongeorge

I like pistachios. No, really, I do.

So do I ... I 'm gonna got to the store and get some. mmmm. pistachios...

[alumslot]

If I had the right answer I would post it but since I don't I wont post on here.

Jim

[31Vicky with a hemi]

Where's the bunny with a pancake on his head ?

[283john]

Vortec's use different rockers than regular SBC's. One uses "self-aligning", one doesn't. Can't remember which is which.

[falcongeorge]

Originally Posted by 31Vicky with a hemi

Where's the bunny with a pancake on his head ?

I'm going for more of a "Canadiana" theme today...

[HamD]

Originally Posted by v8nova64

I know it possible to build a 5.7L vortec from a 96-2000 chevy truck to make 400+ hp with the change of a cam, rocker arms, valve springs, distributor, carb and a manifold with NO machine work required.

I have some questions please do not reply to this thread if you cannot answer what i am asking. thank you

Don't be this way or you won't get a tip.

5.7L vortec engine complete and runnig with the 64cc heads.

I have read that i can use a high lift cam by using LS6 valve springs, and comp cams 787-16 retainers.
I need recommendations on a cam and rocker arms that will work for this engine.

The issue is, some have gotten by with very close retainer to valve boss/guide clearance. Others have machined the heads to either gain clearance or peace of mind. Read this: http://www.chevyhiperformance.com/te...ift/index.html as it goes over the details.

The rockers you picked out are non-guided. Iron heads which have an opening that acts as a guide plate for the pushrod (or ones with guide plates) need non-guided rockers. Heads with a bigger opening that doesn't guide the pushrod need guided rockers.

www.kmjent.com/cart/product.php?productid=371&cat=20164562&page=1 are one set that would work. They make 1.6 ratio too.

If you want 400hp and mileage, you're going to want to go roller cam, since you already have the block, the lifters (re-use them,) and all the hardware for it. This way you can get higher lift and shorter duration than a flat tappet would necessitate.

I would need to know what the specs of the camshaft i will need?

Figure out your rear gear, tire size, stall of the converter and *THEN* contact a cam mfgr. Because they don't want to talk to you if you don't have an answer to their questions.

BTW, you're being cheap.

[rld14]

Originally Posted by mastergun1980

So do I ... I 'm gonna got to the store and get some. mmmm. pistachios...

Diamond has these almonds that have chocolate or something in them, pick some of them up while you're at it.

[falcongeorge]

Originally Posted by rld14

Diamond has these almonds that have chocolate or something in them, pick some of them up while you're at it.

And nuts are good for your prostate too...Pretty important, considering the median age of this group...

[v8nova64]

Originally Posted by HamD

Don't be this way or you won't get a tip.

The issue is, some have gotten by with very close retainer to valve boss/guide clearance. Others have machined the heads to either gain clearance or peace of mind. Read this: http://www.chevyhiperformance.com/te...ift/index.html as it goes over the details.

The rockers you picked out are non-guided. Iron heads which have an opening that acts as a guide plate for the pushrod (or ones with guide plates) need non-guided rockers. Heads with a bigger opening that doesn't guide the pushrod need guided rockers.

www.kmjent.com/cart/product.php?productid=371&cat=20164562&page=1 are one set that would work. They make 1.6 ratio too.

If you want 400hp and mileage, you're going to want to go roller cam, since you already have the block, the lifters (re-use them,) and all the hardware for it. This way you can get higher lift and shorter duration than a flat tappet would necessitate.

Figure out your rear gear, tire size, stall of the converter and *THEN* contact a cam mfgr. Because they don't want to talk to you if you don't have an answer to their questions.

BTW, you're being cheap.

Sorry guys I'm just in a bad mood I guess again I apoligize. I know all u great guys on the hamb are just trying to help out as best as u can.

If I may ask a few more questions just to recap.

Basically my parts list would be:

-complete running 1996+ 5.7L vortec block with 64cc heads (and remove all the computer stuff and efi along with the cam and rocker arms)
-ls6 valve springs with the comp cams retainers
-self aligning 1.6 roller rockers
-hei distributor
-edelbrock performer intake for vortec heads
-a 750 holley carb
- a camshaft that matches my drivetrain

Is there anything else I would need to add to my parts list?
Like u said I can reuse all my roller parts.

Also is there a difference between the vortec camshafts and sbc camshafts. When I search for camshafts they don't list vortec. Are there specific vortec camshafts? Also does the compression need to be upped from 9.4:1 in order produce atleast 400hp with the parts on my list? If so are there special pistons for the vortec or can I buy flat top pistons with a 4" bore for a 350 sbc?

Thanks in advance. Again sorry for my behavior earlier.

[nwbhotrod]

So how did we do

[falcongeorge]

Well, since you asked a little nicer (and I got a chance to post my "elk with a chair on his head " pic, I have been sitting on that one for a long time) If you machine the stud bosses down and install screw-in studs with guide plates, you dont need guided rockers. And google "Dirt Reynolds Ghetto grind". Cant believe I am being so helpful, it goes against my nature, as well as my better judgement...

[HamD]

Originally Posted by v8nova64

-complete running 1996+ 5.7L vortec block with 64cc heads (and remove all the computer stuff and efi along with the cam and rocker arms)
-ls6 valve springs with the comp cams retainers
-self aligning 1.6 roller rockers
-hei distributor
-edelbrock performer intake for vortec heads
-a 750 holley carb
- a camshaft that matches my drivetrain

Is there anything else I would need to add to my parts list?
Like u said I can reuse all my roller parts.

Also is there a difference between the vortec camshafts and sbc camshafts. When I search for camshafts they don't list vortec. Are there specific vortec camshafts? Also does the compression need to be upped from 9.4:1 in order produce atleast 400hp with the parts on my list? If so are there special pistons for the vortec or can I buy flat top pistons with a 4" bore for a 350 sbc?

Thanks in advance. Again sorry for my behavior earlier.

If you're on a budget, use your rocker money towards a nice roller cam; plan on staying 1.5 and include that in your discussion w/ cam mfgrs.

1986 to 2003 SBC bottom ends are the same except for the 86 block being non-roller valley. So the 5.7 iron head truck engine is a SBC. Same cam interchange applies.

The Vortec chambers are excellent and you can probably run a little higher compression on 87 octane. This depends on your cam and this is where engine builders near you are worth talking to even if you're not ready yet to buy and build.

Horsepower means jack. The amount of area under a torque curve matters. And you have heads already chosen which are optimal in a moderate RPM range. In short, you're not going to have a 7000rpm shift point from stock Vortec cast heads. Gearing matters heavily too. So you want to cam it to make excellent power where it matters. My DD spends a lot of time at 1800rpm with a SBC because of rear gear, the converter and shift points. So if I cammed it to make power starting at 3000rpm, it would be stupid and I'd hurt mileage.

Send me all the EFI crap for free. Thanks.

[brandon]

Ill have to find cam number...just did a 98ish vortec motor. Changed springs and cut guides...540ish lift hyd roller and airgap intake. Went 11.20's in 72 stock body nova a couple weeks ago

[Biscayner]

Here is what I have in my firebird. A 1997 Vortec 350 out of a 1 ton truck all stock except for the following items.

Air gap performer rpm intake
600 1405 eddy carb modified
1 5/8" headers and what you are looking for,

I used a LT4 hot cam, LT4 valve springs with the stock lifters and I took the
stock rockers and slotted them. Why you ask? I do not like to use the heavy roller tip
rockers on the street or roller rockers either. Too much extra weight on the tip floats the valves sooner. Was told this by an old time racer and you know what? it works. Besides stock rockers are cheap and work good. You just need to use a 1/8" die grinder with a good burr to do this.

This combo pulls to 6500 with out effort, boils the tires and get 17 mpg.

[v8nova64]

Originally Posted by brandon

Ill have to find cam number...just did a 98ish vortec motor. Changed springs and cut guides...540ish lift hyd roller and airgap intake. Went 11.20's in 72 stock body nova a couple weeks ago

Cool some cam specs would be awesome! Is that a quarter mile time? What tranny and rear gears? What size carb? What kind of valve springs? Did u used the stock rocker arms? Did you keep the stock pistons or upgrade for higher compression? Sorry for all the questions

[v8nova64]

Originally Posted by Biscayner

Here is what I have in my firebird. A 1997 Vortec 350 out of a 1 ton truck all stock except for the following items.

Air gap performer rpm intake
600 1405 eddy carb modified
1 5/8" headers and what you are looking for,

I used a LT4 hot cam, LT4 valve springs with the stock lifters and I took the
stock rockers and slotted them. Why you ask? I do not like to use the heavy roller tip
rockers on the street or roller rockers either. Too much extra weight on the tip floats the valves sooner. Was told this by an old time racer and you know what? it works. Besides stock rockers are cheap and work good. You just need to use a 1/8" die grinder with a good burr to do this.

This combo pulls to 6500 with out effort, boils the tires and get 17 mpg.

Awesome what do u think u have for hp? Is is stock compression?

[Race@Rockets]

Good combo listed above....11.20's is movin for a full weight street car I would like to hear more about the rest of his combo...mine is wayyyy nastier than that and it doesn't run that deep into the elevens.

[brandon]

Originally Posted by Race@Rockets

Good combo listed above....11.20's is movin for a full weight street car I would like to hear more about the rest of his combo...mine is wayyyy nastier than that and it doesn't run that deep into the elevens.

I totally goofed on that post....the car is my nephews...and forgot its now a fastburn headed 98 vortec 350. The old vortec headed motor with 488/292 hyd cam went 11.80's....sorry for the confusion....though i doubt there would be much more than 20/30 hpdifference between fastburns and steel vortecs

[brandon]

Originally Posted by Race@Rockets

Good combo listed above....11.20's is movin for a full weight street car I would like to hear more about the rest of his combo...mine is wayyyy nastier than that and it doesn't run that deep into the elevens.

Effiency is the key to vortec stuff....dont need crazy big stuff to go fast. I know that a 330/350 "crate" motor ihra stocker. 465 Lift and 262 @ 50....went 10.80's in a 79super malibu

[Biscayner]

Originally Posted by v8nova64

Awesome what do u think u have for hp? Is is stock compression?

Yes it is stock compression and I est. it is 420 to 440 hp. I am thinking of trying some Bow tie Vortec heads I just bought as they flow 260ish out of the box and the heads I have flowed 231. Should be good for some extra hp. The eddy 600 1405 is the best combo I have tried on this engine. Had to modify it a little to get rid of the dreaded flat spot when putting the pedal all the way down fast, but now it just flies.

[v8nova64]

Originally Posted by Biscayner

Yes it is stock compression and I est. it is 420 to 440 hp. I am thinking of trying some Bow tie Vortec heads I just bought as they flow 260ish out of the box and the heads I have flowed 231. Should be good for some extra hp. The eddy 600 1405 is the best combo I have tried on this engine. Had to modify it a little to get rid of the dreaded flat spot when putting the pedal all the way down fast, but now it just flies.

awesome thats exactly the kind of power i want. do you have a 1/4 mile ET and weight of the car you ran it in so i can estimate hp? Also what kind of tranny and rear gears? Is there any chance you would be getting that combo dynoed before you put on the new heads you wanna try? I guess running a large 750 holley may not be the best choice. Do the LT4 valve springs just drop in place of the stock vortec springs or do they require any other parts? thanks alot!

[k9racer]

I am not running a vortec engine but I have a set of the vortec heads on a 355 engine in a circle track car . I can tell the difference in power . The next think I will add I also have the same engine as you in storage. mine has cast number that ends with 880.. I bought mine at what I thought was a very fair price of 400 dollars with trans. from a running but wrecked unit with less than 80K miles. This means I am looking forward to seeing how your build up does as I have been thinking along the same lines as you.. Good Luck on the build... Keep us posted.. Thank You Bobby.

[v8nova64]

does anyone know if the edelbrock performer air gap will work with a stock quadrajet? What kind of cfm do they pull? Do you think thestock vortec with lt4 hot cam and lt4 springs combo that "Biscayner" has pulls 420-440 hp?

[indyjps]

I like Q Jets but you should consider a Holley for the hp goal youre going for. check out http://www.performancetrucks.net/forums/ they are always building these engines and selling parts, you will find vortec specific info there.

checking summit racing, there isnt a spread bore performer RPM, with or without air gap. Performer is the only edelbrock offered with vortec and spread bore.

square bore carb edelbrock performer rpm air gap http://www.summitracing.com/parts/EDL-7516/

square bore carb edelbrock performer rpm NO air gap http://www.summitracing.com/parts/EDL-7116/

spread bore (Q Jet) edelbrock performer
http://www.summitracing.com/parts/EDL-2116/

[Mr. Sinister]

I'm making just about 425hp, on a Vortec 350 block and bottom end (motor had 10,000 miles on it, so it didn't need any cylinder work or bearings, but I re-assembled with ARP fasteners, since it sees 6500rpm occasionally), Keith Black 10.8:1 pistons, cleaned up 70cc Performer RPM heads, upgraded springs, solid pushrods, scorpion 1.5 full rollers, Comp XR294HR cam, Performer RPM Air Gap intake, tweaked Holley 670 carb, full MSD ignition (box, coil, distributor), Hooker Super Comps, and a few other goodies. It's a little lazy down low, but pulls like a freight train from 3500 to 6000 rpm. It begins to nose over around 6300. Compression is just a hair under 11:1, and it runs just fine on 93 octane. It's been a really great motor for the street, and has decent manners in traffic.

Do what you will with that info. Personally, I think expecting north of 400hp from that combo is pushing it. Upgrade the heads, and use a good cam in the 2500-6500 rpm range, and you'll get there. You're pretty limited on lift with the Vortec heads unless you do some machining, and you'd be better off with a 2.02/1.60 head anyway. But for a budget build, it should still run pretty well.

[Race@Rockets]

Originally Posted by brandon

I totally goofed on that post....the car is my nephews...and forgot its now a fastburn headed 98 vortec 350. The old vortec headed motor with 488/292 hyd cam went 11.80's....sorry for the confusion....though i doubt there would be much more than 20/30 hpdifference between fastburns and steel vortecs

Sounds alot closer...you had me feelin like a slacker pretty bad on this one! My old small block with a 507 lift Isky stick with 265 @.050 10.5-1 Dart Iron Eagle heads and killer valvetrain stuff, a Victor and a 750 carb was good for an 11.90 timeslip. Dynoed just under 400 horse to the wheels... I always liked superstock stuff those guys know all the tricks! Race

[v8nova64]

does anyone know of a free dyno software so i can enter all the parts and specs and come up with the perfect engine?

[brandon]

Originally Posted by Race@Rockets

Sounds alot closer...you had me feelin like a slacker pretty bad on this one! My old small block with a 507 lift Isky stick with 265 @.050 10.5-1 Dart Iron Eagle heads and killer valvetrain stuff, a Victor and a 750 carb was good for an 11.90 timeslip. Dynoed just under 400 horse to the wheels... I always liked superstock stuff those guys know all the tricks! Race

Wont mention what my throw together 355 iron eagle runs then....lol. but will say, bullet cams make power ....

Just out of curiousity, are your 60' in the low 1.60's? The @50 on you cam seems huge

[v8nova64]

i played around with desktop dyno 2003 and came up with this:

-stock vortec with stock heads and stock 1.5 ratio rockers
-Lt4 Hot cam
-750cfm carb
-dual plane high flow manifold
-large tube headers with mufflers
-flat top pistons and .015 gasket to up compression to 10.14:1

this combo would give me 375hp and 358 torque (at the flywheel) at 5500 rpm. with open large tuibe headers its 391hpand 374 torque.

Does anyone have any other suggestions to bump up the hp. Dont wanna do any machine work and want to avoid changing heads. Any suggestions on a better cam?

[HamD]

Since you have DD, keep screwing around with roller cam profiles to up the torque curve a bit without raising powerband.

[v8nova64]

Having a really hard time finding full cam specs needed for DD for certain cams on summit racing.

would anyone happen to know the valve event timing specs at 0.050" timing for this cam:

Howards Cams 110245-14

[HamD]

That's what the Howard catalog or contacting Howard is for.

Originally Posted by HamD

contact a cam mfgr.

Originally Posted by HamD

your discussion w/ cam mfgrs.

[31Vicky with a hemi]

Try the 1.6 rockers on the lt4 hot cam.

[brandon]

Originally Posted by 31Vicky with a hemi

Try the 1.6 rockers on the lt4 hot cam.

Is the cam the 492 (or something like that)on lift and 525 with 1.6 rockers? Like the hot cam kit?

[v8nova64]

Originally Posted by 31Vicky with a hemi

Try the 1.6 rockers on the lt4 hot cam.

it only gives me 2hp extra. Although by swapping the dual plane for a tunnel ram and using 1.6 rockers i can make 408hp with mufflers and 419 hp open headers. No luck so far finding vortec tunnel ram though

[Shaner's74]

One of the car mags (I think CC) had a 355 build called "Danger Mouse" using vortec heads, RPM airgap, Comp Cam Extreme Energy, 1.6 rockers and a 750 carb that made around 409 hp. I built the exact combo but in a 383 using a one step larger cam and a 800 carb. We both used the vortec heads from S-D with the higher lift springs.

[v8nova64]

so it doesn't look like i am going to find a tunnel ram. But i can get 390hp if i use a single plane high flow intake instead of a dual plane.

I also need to up the compression to 10.14:1. I can do that if i use +6cc flat top 4 valve relief pistons and 0.015 head gaskets.

Do these pistons fit a stock vortec 350?

What size rings i need? will these work?

These pistons are less than a $100 bucks and will get my compression to 10.14. I was looking to get my compression to 11:1 that would allow me to make 408 hp but dont think i can do that for the price of these pistons that will get me 10.14.

If anyone knows how i can get my compression to 11:1 for around 100 bucks let me know.

I believe these will be the last questions i will ask. I think i have all the info i need. I will try and document the whole build when i gather the parts. thanks a ton

[v8nova64]

forget about those pistons i listed above.

I really need to know if these will work with the stock vortec 350 and which rings i need? These willl get me a 10.81:1 compression. Which is perfect. They are dish with 4 valve reliefs

[Race@Rockets]

Originally Posted by brandon

Just out of curiousity, are your 60' in the low 1.60's? The @50 on you cam seems huge

I lied too..recheched my cam card 250 duratiuon @ .050 108 lobe separation My 60' was 1.65 on average...never better than 1.63... The cam is an old isky Z50 solid grind,my favorite street cam. When I throw a small block together for a new kid I usually use a Z30 isky with stock diameter Kmotion springs. I usually make a newbie who wants to get into racing run a solid cam so they can learn the importance of valve adjustment. I like Isky stuff because he keeps conservative on the lift so you dont have to run crazy spring pressure and it keeps the valvetrain light.

[Race@Rockets]

Originally Posted by v8nova64

so it doesn't look like i am going to find a tunnel ram. But i can get 390hp if i use a single plane high flow intake instead of a dual plane.

I also need to up the compression to 10.14:1. I can do that if i use +6cc flat top 4 valve relief pistons and 0.015 head gaskets.

Do these pistons fit a stock vortec 350?

What size rings i need? will these work?

These pistons are less than a $100 bucks and will get my compression to 10.14. I was looking to get my compression to 11:1 that would allow me to make 408 hp but dont think i can do that for the price of these pistons that will get me 10.14.

If anyone knows how i can get my compression to 11:1 for around 100 bucks let me know.

I believe these will be the last questions i will ask. I think i have all the info i need. I will try and document the whole build when i gather the parts. thanks a ton

Dont worry too much about advertised compression ratio numbers, get with a good machinist and have him check the piston depth in the hole..also dont be afraid to deck the heads to arrive at your final compression ratio. I spent alot of time hanging out at my local machine shop asking lots of questions before I built my first engine. There wern't forums full of desktop heroes back then! I would recomend a dual plane intake and if you don't want to have to warm the thing up forever I would run a gmpp intake rather than an airgap...I know it sounds crazy coming from a guy building a blown injected Hemi to drive on the street! Just my 2 cents....Race, Desktop Hero

[v8nova64]

Originally Posted by Race@Rockets

Dont worry too much about advertised compression ratio numbers, get with a good machinist and have him check the piston depth in the hole..also dont be afraid to deck the heads to arrive at your final compression ratio. I spent alot of time hanging out at my local machine shop asking lots of questions before I built my first engine. There wern't forums full of desktop heroes back then! I would recomend a dual plane intake and if you don't want to have to warm the thing up forever I would run a gmpp intake rather than an airgap...I know it sounds crazy coming from a guy building a blown injected Hemi to drive on the street! Just my 2 cents....Race, Desktop Hero

thanks for the advice. Even if i dont go with these pistons. I just basically need to know if they work in a stock (non bored) vortec block. Just so i know. Why is it that a dual plane manifold will decrease over 25hp when compared to the single plane?

PS whats the hemi going in?

[Race@Rockets]

As far as I know (not much aout later blocks) 350's a 350....4" bore is 4" bore. As far as the dual plane single plane debate.....I guess Ill give my .02...even if it is going to cause a fight, a single plane will make more peak horsepower than a dual plane...great on a dyno. A dual plane will make more broad curve, better on the street..Again this from a guy who never bought anything less than a Victor jr. or Team G sinleplane and ran 4.56 gears every day on the street. What are you doing with the car? How fast do you want it to go? Are you going to race it? how much do you want to spend? These are the questions you need to ask yourself, dont worry about horsepower numbers for now....Race

[jeff/21]

last year using a circle track crate 602 350/350 this motor comes with a dual plane intake,adding an adapter, two barrel holley one inch carb spacer timing at 32* retarded cam 4* 9.2 compression small tube header 1 5/8" x3"x18" made 380hp at 5500 flat torque from 3500 to 5500. on reg gas not high test. lost horse power with stepped headers recommended by GM may be because of the two brl carb. stock out of the crate with the stepped headers no spacer and no miles on motor made 355HP this is a non roller cam motor so your 400HP is very doable

[Gotzy]

You'd benefit from reading a couple of articles, one done by stock car racing magazine, google 500hp for $2500 and you'll find it. 2nd is popular hot roddings budget sledgehammer build, google and read

[Motorbreath]

Originally Posted by v8nova64

... I will not be doing any machining to the block so the camshaft must just slide in after the valve springs and rocker arms have been done.

How do you plan on doing that? To have the rocker arms done (as in installed im guessing) the pushrods and lifters would be in as well... no cam will slide in at that point....

[v8nova64]

will the old muncie, saginaws, th350, th400s fit the vortec without modification? Thinking of getting an M20 4 speed from a 68 chevelle.

[31Vicky with a hemi]

Originally Posted by v8nova64

thanks for the advice. Even if i dont go with these pistons. I just basically need to know if they work in a stock (non bored) vortec block. Just so i know. Why is it that a dual plane manifold will decrease over 25hp when compared to the single plane?

PS whats the hemi going in?

The single plane does a better job at delivering fuel and air evenly at higher RPM than a dual plane. However the single plane is not as efficient as the dual plane at delivering fuel at lower RPM. Look at the torque curve on the different Desktop Dyno builds. That curve will tell you how fun it will be to drive .
The flatter & highest the earliest will be the most fun on the street . stop light to stop light seat mount tests should be a blast and higher MPG even if the peak HP is lower.

A curve that's peaked, highest the latest is going to be the better/best for a all out max effort race car. This will decrease your low end torque so you don't over power the tires on launch. Let you stay on the curve during high rpm shifts and thru the lights.
This curve would be aggravating on the street even if the peak HP is higher.

[unkledaddy]

This is what I used for a guideline on my Vortec build.

Click here: Vortec Small-Block Build - Popular Hot Rodding Magazine

[v8nova64]

Originally Posted by 31Vicky with a hemi

The single plane does a better job at delivering fuel and air evenly at higher RPM than a dual plane. However the single plane is not as efficient as the dual plane at delivering fuel at lower RPM. Look at the torque curve on the different Desktop Dyno builds. That curve will tell you how fun it will be to drive .
The flatter & highest the earliest will be the most fun on the street . stop light to stop light seat mount tests should be a blast and higher MPG even if the peak HP is lower.

A curve that's peaked, highest the latest is going to be the better/best for a all out max effort race car. This will decrease your low end torque so you don't over power the tires on launch. Let you stay on the curve during high rpm shifts and thru the lights.
This curve would be aggravating on the street even if the peak HP is higher.

Thanks for the advice. This car will be a weekend strip car so based on what you said I should probly go with a dual plane even though it will bring my hp down by over 25hp. I really wanted 400+ horses which I would get with a single plane. Anyhow, would carb spacers on the dual plane help bump up the horsepower or kind of work like a tunnel ram. According to DD a tunnel ram would bump me up to 420hp too bad they don't make them for vorects

[Mr. Sinister]

Originally Posted by unkledaddy

This is what I used for a guideline on my Vortec build.

Click here: Vortec Small-Block Build - Popular Hot Rodding Magazine

That's amazing power given the parts. I'm beginning to wonder if my 670 carb is holding me back.....

[unkledaddy]

Originally Posted by Mr. Sinister

That's amazing power given the parts. I'm beginning to wonder if my 670 carb is holding me back.....

Like I said I used it for a guideline.

I have a flat tappet cam and a 650 cfm carb.
Might be around 370 hp.

[Mr. Sinister]

Originally Posted by unkledaddy

Like I said I used it for a guideline.

I have a flat tappet cam and a 650 cfm carb.
Might be around 370 hp.

Well, figuring my 2.02/1.60 Edelbrock heads are at least as good as the Vortecs (should be better, especially considering the mild port work) in that article, my Air Gap intake is pretty much the same, my cam should make more peak power, and I have more compression......

I see some dyno tuning in my future.....

Sorry to hijack.

[v8nova64]

would a home porting job on the stock 64cc heads up the compression and increase hp and torque without changing pistons? If so to what?

If i do home port should i still change the pistons to the KB 1470-std?

I have a dremel? and a box of accessories for it they are cheapies though? What do you guys recommend i use and how should i go about doiing it?

[pottsie454]

Vortec heads will draw you back on lift. For one, if you trying to gain lift then go with the Beehive springs comp cam offers. They are built for this intended purpose. Personally I would have the spring pockets machined to accept high lift and use high performance springs. High lift cams tend to drop valves if you dont have enough spring pressure.

Also, you really need to look into screw in studs and guide plates. With a high lift/high pressure cams, those press in studs will pull right out causing engine failure.

I am no expert on the performance side of things but have built a few gasoline and large diesel engines, but just recently built a 383 stroker. 450 hp 510 tq. I can attest that everything you do will lead to changing something else if you dont start with a solid game plan from the start.

Compression ratio, stall converter, tire size, transmission, gear ratios and intake type will all dictate what kind of cam will give you most power. You can start with any of those listed above and then build around it.

[v8nova64]

Found a reman Lt4 Hot cam for $160. Here is the link. Do i need the long pin? I assume i dont need the optispark or feul pump lobe?

[Roothawg]

I didn't read all of the replies, but look up Car Craft Feb 2009. It will answer all of your questions.

[Motorbreath]

Originally Posted by v8nova64

would a home porting job on the stock 64cc heads up the compression and increase hp and torque without changing pistons? If so to what?

If i do home port should i still change the pistons to the KB 1470-std?

I have a dremel? and a box of accessories for it they are cheapies though? What do you guys recommend i use and how should i go about doiing it?

No, it will not affect compression, done wrong you will loose power, and a die grinder would be much more effective than the dremel.

[HamD]

Originally Posted by v8nova64

Found a reman Lt4 Hot cam for $160. Here is the link. Do i need the long pin? I assume i dont need the optispark or feul pump lobe?

The step-down on the front face of the cam is for a factory retainer plate on an 87-up block. That's compatible with your 96-up retainer plate.

The LT1 and LT4 had a couple different pin lengths due to changes in the optical distributor. If you're not running a distributor off the front of the cam, you can remove or drive in the pin.

Choose the cam that will make the best torque under the curve in the useful rpm level. The LT4 HOT is a fun cam but if a custom grind can gain you torque across useful rpm, why compromise?