well i ordered my cam and lifter set from summit racing on 2/7 and estimated ship date was 2/20 well now it is 3/4

so i called and got a different cam i was oringinally going to use this cam. i had it worked out to .476 lift and car craft used the .477/.480 cam so i would be good.

http://www.summitracing.com/parts/HRS-CL110961-08/

but decided to go with this cam

http://www.summitracing.com/parts/LUN-00017LK/

after arguing with the tech guy. he wouldnt let me buy a cam near .470 lift because im using 1.52 rockers with gm performance heads.
(max lift .475)


my set up is 355, 9.35:1 compression, gm performance vortec heads, jegs dual plane vortec intake, magnum self aligning 1.52 rockers, holley 600 cfm carb(might be too small) v6 converter, built 700r4, auburn gear posi, 4.10 gears, and a 28" tall 275 street tire.

i believe with the lower duration that it will be better for low end torque and have better street manners, but can i still reach my goal of 375 hp at the flywheel? and did i sacrifice a great deal of top end power?

 

not a single person?

 

If those are stock Vortecs then anything over .450 is considered pretty dicey. Better springs and machine work or at least Comp beehive springs will be required. People on here smarter than me can give you exact numbers.

 

You can use one of the kits at alexsparts.com ... I have no first hand experience with them but they seem legit enough.

http://www.alexsparts.com/products/V...AT-TAPPET.html

They will get you a lot of extra clearance for lift on Vortecs if you have vortecs.

Do you have a roller block or a flat tappet block? Easiest, cheapest way to 375hp with vortecs is the LT4 hotcam.

Read about how to set up your heads here:
https://www.thirdgen.org/forums/tech...ne/index2.html

If you dont have a roller block then running a roller cam gets difficult, especially a factory roller cam. So if that's the case then dont bother with the hotcam idea.

In general, you may be better off with a split pattern cam with Vortecs. Something like the Lunati 60102. That should get you some healthy power numbers.

 

they are these heads

http://www.jegs.com/i/GM-Performance...oductId=749896

the ones, car craft used a .477/.480 lift cam on without issue

not vortecs from a junkyard

 

its a flat tappet block. am i able to use a lt4 hotcam with say lunati roller lifters? in a gen 1 block?

 

That's pretty cool!

 

You'll need a cam button and big dollar retro fit roller lifters.

 

And, I'm pretty sure, a new timing set.

 

ok sweet, these are the lifters my dad uses... but will i be fine with this cam and these vortecs?

 

Nevermind, i gotcha.

 

For Vortec heads, NEITHER of those cams is a very good choice.

The thing that makes Vortec heads so much better than others, is that they have all this phenomenal INTAKE PORT flow. GM accomplished this by moving the port; which is of course why you have to have the "special" intake.

However, they didn't do A DAMN THING about the exh port. They have the same sucky exh port as any other stock head. Very poor flow.

Therefore, the exh side needs a "crutch", to make its overall flow more nearly match the intake side. After all, you can't jam more INTO the cyl, unless what's left over from last time, gets OUT first. Don't outsmart yourself over something that simple.

Those heads therefore respnd DRAMATICALLY to a cam with a longer-duration exh lobe than int lobe. NOT a single-pattern cam, like either of the ones you posted; you will be leaving power on the table. NEITHER of them will come ANYWHERE CLOSE to 375 HP. I'd be surprised if they could crack 325 HP in the real world (as opposed to magazine world).

The Comp XE262 will give you about 360 HP or so in the RW, or the XE268 closer to 375 but will run the risk of needing either machine work or a different style of springs, so that the retainers don't smack into the top of the guides at full lift (that's the .477" / .480" cam that's so popular with those heads, for good reason). The Lunati Voodoo series (what Infernal posted about) is also a very good choice, is of the same general design, but may need the same sort of work. The old Bracket Master and Magnum cams are simply WRONG for the application.

600 CFM is probably too small... a 750 is a better choice.

 

Engine size x Engine rpm x Engine VE/3456

 

That has several oversimplifications...

The main one being, the airflow through the carb isn't a uniform smooth flow like your furnace blower or something; instead, it comes in pulses. Each time a cyl draws in air, the carb sees a pulse of flow. In between, nothing. The pulses may AVERAGE OUT to that formula, but the ACTUAL AIRFLOW during each pulse is MUCH HIGHER than the formula. What you end up with is, yeah, the flow rate might be say 650 CFM long-term average; but at the peaks of the pulses, which is what the carb has to be sized for, it might be 900 CFM. The smaller the plenum, the greater this difference is, since a large plenum tends to provide a "reservoir" of air to help smooth the pulses. A dual plane intake amplifies the effect even more, because with that, each half of the carb sees one of those same little short pulses of flow, followed by an even LONGER period of no-flow in between.

A 400 HP motor with a dual-plane intake needs at least a 750, regardless of what the "formula" works out to.

 

I've just been roaming around the internet planning a motor and trying to teach myself some things I came across that formula and thought it would help here.

 

Yup, pretty popular formula, and certainly correct and useful enough, within its limitations; which of course, you rarely see anybody mention. Surfing the Net is no substitute for experience in this regard.

Think of it, instead of "plug in my CID and crank the handle and out comes the carb size", as telling you the ABSOLUTE BARE MINIMUM carb size you need, assuming ALL ELSE IS ABSOLUTELY PERFECT; and then EVERY error or imperfection or violated assumption you come across, makes the carb need to be larger that what it gives. It's basically just a starting point for guesstimation.

 

From what I found out a few weeks ago about using a factory roller cam in a non roller block, the timing chain bolts are so close together there's no really any room to put a cam button unless you it all up and force it into a tiny spot. You'd have to buy one of those regular nylon ones, and carve it down until it fits. Which is doable, but Im not exactly sure it's recommended.

The differences between factory rollers and retro rollers are all in the cam snout. The snout has a step in it for the factory cam retainer and the timing chain bolts are closer together. Just those two small differences make it a pain to run them in a non roller block.

 

exactly what i needed to hear, thank you. i am calling the machine shop in the morning to see about getting the guides cut down. i AM sending that cam back and getting the xe 268.. with my 1.52 rockers lift will be .483/.486 and the little bit of added lift on the exhaust side should help get more exhaust out also. and down the road would a set of 1.6s on the exhaust be beneficial? i will try the 600 out first as it will be a daily for a while and should help on gas, but if its too bad, dad has a couple 750s laying around.

 

ok so i called my machine shop this morning, said they would charge 30 bucks to cut all the guides down. he also said i will want to get another set of springs and retainers. and obviously new seals.

so i want to keep it all as cheap as possible, i want to do the ls6 springs, comp retainers and seals i read i want to use the ones off a turbo daytona as they are viton and are a super tight fit. these are the links. i will be going to summit in the next week or so to get the parts and exchange cams. i want to know if these are the right parts?

http://www.rockauto.com/dbphp/x,cata...ER_ST2015.html

http://www.summitracing.com/parts/CCA-787-16/

http://www.summitracing.com/parts/NAL-12499224/

and will i be able to keep the stock keepers?

 

Here is 2 cents for whatever it is worth. I just finished a very similar build (355 10.1:1 forged, vortec 906's - port/polish/bowl worked myself, 525/525 lift 218/228 dur, perf built quadrajet 750) on a SUPER low budget. I didnt machine the heads - figured if I ever decided to sell them I would prob want to keep the hardware I bought, so like InfernalVortex has said, I purchased the kit through Alex's parts. They are a bit of a pain sometimes to get a hold of (small outfit) but I got springs,retainers,keepers and viton valve seals for under $125 - direct fit no machining. No complaints, they work great (they say to 550 lift but no need to push it). But be sure to check installed height or you will end up with valve float and hate your motor above about 5k.

And in my experience with 4 different cams, SofaKingdom is exactly correct. The vortecs have a much shittier exhaust design than intake and are restrictive. Adding to the exhaust duration is a huge advantage to these heads, not to mention a bit of porting and/or polishing.
Even though it isnt as big of a cam, I liked the Voodoo 60102 for the street. It gave that mean sounding idle without too much and good low end performance although I thought it was too small for what I was looking to do.. If you are looking for something a bit more aggressive, maybe check out the 60103 but watch your total lift if you will be using the 1.52. I ran this cam with a 1.5 and because of the added exhaust duration it really made the car come alive. It has a considerably more lopey idle but still ok to run vac acces. If you figure your lift to be ok and can get away with 1.6 on the exhaust go for it - that exhaust can use all the help it can get but the duration is where it will matter most.
As far as a carb, Fishook and SofaKingdom are really both right, but the formula to determine carb size generally doesnt work in the real world. It is based on the VE (volumetric efficiency) of an engine to be accurate. I ran a re-jetted 650 with mine originally and although it was ok for the street, it couldnt keep up. I have always loved the quadrajets, and a properly built and tuned quad can torch alot of carbs out there, both on the street and at the track (don't believe the hype about them being junk)

Even though I was pinching pennies toward the end of my build, I did kick out the cash for the dyno before I dropped the motor in. Now, I got lucky and ended up with a full forged setup because I wanted the best of both worlds - nice street manners and be able to kick it in the *** once a year at the track or when I had a rice burner roll up next to me. So I set it up with a 200hp nitrous kit. Nonetheless, just motor I started with 401hp and 396 lb-ft. Timing was a bit advanced (vortecs generally like a bit less, somewhere around 32-34, I started with 38 total) so we knocked it down to 36 and got 409hp and 402lb-ft. Dropped it down 2 more degrees to 34 and swapped needle and seat and jets in the carb and got 413hp@5600 and 423lb-ft @4400 which turned out to be the best combo. I was pleased with that, and the fact that it ate up the 200 shot and gave me 615hp and 580 lb-ft on the juice with no prob.

As far as the stock keepers - if you order the kit new keepers will come with it - if you machine the heads and use the same valves, then you should have no issue using the same keepers as long as the valve stem diameter isnt changing.
As far as swapping to a roller, you can get it done, but be prepared to shell out some cash to do it. With the right head/valvetrain setup you can get just as much out of a flat tappet if done correctly. I spent extra on a roller once, and even though they have a longer life due to less wear, I ended up swapping cams the next year anyway so it was a loss for me. Good luck and have fun with it. Like I said, I'm no pro engine builder, just learned from the 1.2 million mistakes ive made. Feel free to email me if I can help. I don't get on here that much

 

Just another note in case you had the seats machined already - make sure you know what outside diameter they cut your seats to and match springs accordingly, don't assume they cut to specific diameter unless you told them to do so. The ls6 springs are good along with the comp retainers etc, just get pricey. Alot of guys don't like Comp stuff, but I have used alot of their stuff and it has all been very good quality in my experience, just that there is alot of competition out there that has just as good quality for a smaller price tag. Take your time and shop, because believe me, you will always find something that you think you shouldve got instead that cost alot less.

Your top end power is going to come alot from stability in your valvetrain as well as your parts combo. The vortec's are not all that great above about 5k generally, but after i took the time to be sure my valvetrain was good above 5k rpm, and did a nice (although pretty amateur) port/polish job on them it really made a differnce in the higher ranges (above 5k-5500). I just can't stress enough to be sure you have a spring that will hold up and the correct installed height to avoid valve float

 

thats great to hear, i WILL buy those alex parts ones then. also since i will be doing a lot of street driving, what cam can all of you recommend since i wont be as limited now. if i can break 400hp out of my 355 that would be awesome. i want to run 12.50s in the 1/4. i will be eventually going with a 3k to 3500 stall to help squeeze every little bit out of the set up. and carb will most likely be a 750.

 

Old friend of mine ran a LT1 cam in a vortec headed 350 sbc with performer rpm intake. Swapped carbs from a 600cfm to a 750cfm double pumper and picked up power everywhere. Track times increased and this is in a 83 full size shortbed chevy truck. I agree, put a 750 on it and let it eat

Comp XE268 or the Lunati Voodoo equivalent are very popular with 350 sized motors. They work well. I'd run one of those with the vortec heads machined for the lift. Its been said here by a few ppl that LS6 springs or Beehives on stock vortecs brings max lift capability up well over .500", so a .470/.480 should be no problem but for 30 bucks, machining down the guides is well worth it.

 

http://www.lunatipower.com/Product.aspx?id=2325&gid=297

would i see more power with this cam than with the xe 268? i will make the trip to summit most likely this weekend. and i will use a 750 carb...

only problem i have with it... its an edelbrock and the 600 is a holley.
it came on a blueprint engine and the car fell flat on its face at wot. ill be using a wideband though so i should be able to get it straightened out and the tune better than most carbed set ups

 

What do you mean by "V6 converter"? S-10 converter?
If so, you're looking at too much cam with the XE 268, Voodoo 10103, etc. Either step up the converter or step back a notch or two on cam size, otherwise it's not going to be a snappy performer in daily use, and certainly not impressive at the track.
No sense in chasing a hp number without giving the car the supporting mods to make use of it.

 

look at post #22

you know back in the day people would take the converters out of vegas and put them behind their big powered sbc.. exactly what i did. i can only bring it up to about 1800 or so before my brakes give.

 

86LG is right on the money with it not being impressive at the track without a decent trans/converter/rear combo.

I could be wrong, but sounds to me like you want to do motor then work on trans/converter later. As long as you understand that the stuff talked about in this thread are mostly revolving around how to get a decent combo and performance out of your motor. Without any upgrades in trans/stall you will probably enjoy driving it on the street but will not achieve desired results at the track. You can do like I did, get the motor done and set, get it to where you like it, get shitty numbers at the track, then get the proper trans/converter/rear behind it and then see how your et's look.
If I had the money, sure I would re-do my trans and rear 15 different ways to get what I want out of it. But reality is, sometimes you have to do it in stages for what your budget allows. And if you have to, get the motor the way you want it, then go to the next step with trans etc.
Any good engine builder or cam tech will tell you to be realistic with what you expect to achieve and use it for and not dream on what you want to have some day. Having said that, if you feel that the rest of your drive train will be upgraded sometime soon, then go ahead and opt for the bigger cam. If you are going to be stuck with a stock type setup for a while, you can go with a smaller cam for now. Its not that bad of a job later down the road to swap a cam to match the upgrades you make.

 

355sleeper - Ive heard those stories of the vega converters - never knew anyone that actually did one - good info to know for down the road

 

i completely understand that the converter is not in the cams powerband. i do have drag radials, 4.10s and an auburn gear posi. and the trans was rebuilt and has less than 50 miles on it. it was built to handle the power. i want to just get it running as im stuck driving the wifes cobalt everywhere.

and for converter i plan on saving up the money for an edge or vigilante converter. around a 3k to 3500 stall.

it will be my only means of transportation for a while so after i can afford something else it will be a weekend/ summer car(depending on gas prices)

until then its all about power, then being able to put it down.

 

I'm with ya all the way brother. I know that feeling too well. And like I said, if I had the money - sure I would have whatever trans/rear etc I wanted. Truth is when you have so much to spend and are tired of not having some ooomph at the pedal, ya gotta do what you can.
I did it the same way - spent all the time in the world (and whatever little budget I had) to get my motor done and in. Just like you, the trans was built by a long time trans guy of my fathers - to handle whatever I could put to it. And I was running a 3.42 posi in the rear cuz I wanted to be able to cruise it and I didnt have the money to swap the rear at the time anyway.
Sure, I wished for a while I had a little better upgrades in certain things, but overall I was more than happy with the fact that I had done the motor myself on a skinny budget and was still hitting the 400hp mark cheap.
As long as you know what you are looking at go for it. You will have a blast with it, and will be able to better judge what mods make the most sense for your setup.
But most importantly - you will have something to put on the street!

 

I've always been the type to do motor first then worry about the other stuff later....I'm in the 9's on stock rear end...if it aint broke, dont fix it. My buddy drove his big cammed 360" motor around on stock "S10" type converter just fine. Only about 2000 stall and drove great. Lazy of the line tho but we expected it. 3600 stall woke it up but it wanted abit more

Upgrade converter later.

 

lunati 60103 it is then

 

I'm not sure that's the right cam, I can grind you whatever you need if you like, they're normally done in a couple of days. You'll benefit from more off the seat time than that offers.

Thanks
Mark

 

I liked the 60103 myself, but it wasnt in my daily driver either. It was right for the price I was looking for as far as cam/lifter set and gave me a good upgrade to the smaller cam I was running. But I was also running a larger stall and more in a car that was meant as a weekend warrior and a cruise every now and then. You also have to take into consideration your LSA depending on whether you would prefer it to be more street mannered and have a nice smooth idle or if you would prefer something a bit more aggressive and less well behaved at idle and low rpm

 

i will be degreeing the cam in, i will see how close it is out of the box. but i will install it to whatever the cam card says. i daily drove this cam and didnt mind it.

http://www.lunatipower.com/Product.aspx?id=1992&gid=290

this was with a 406 but its the same suspension and converter set up. it ran like crap until it was warmed up though

 

That is a pretty sizeable cam. Not to mention its a solid. I generally try to avoid a solid if its my daily driver. Don't mind adjusting lash if its my weekend warrior and I'm under the hood already. Just my opinion, but I don't know that you would be happy with that big of a cam with what you have in there right now.Thats a whole lotta cam and pretty high operating range with a stock converter. You won't be liking that one on the street with your current setup

 

it was with afr 220s so it pulled up top.

but this next set up will be geared towards street driving with many trips to the track

 

If you decide to go with the Lunati 60103 and the operating range works for you, then you could always just go to a 1.6 rocker as long as you are set up to handle the lift, and get more power in the same operating range. If you go to a bigger cam with more duration you will be moving the powerband up in the rpm range also, which is going to start affecting your streetability

 

good to know, this cam will stay in the car for a long time thanks for all your help

 

No prob man, hope there was some useful info through all of it. Let me know how it turns out

 

i ordered the alex parts springs, retainers, locks and viton seals. hopefully get these soon. im to summit racing saturday to exchange cams. in the next couple months i will be ordering a yank 4k stall i am hoping for high 11s with this set up on drag radials. i will be sure to take pics of the springs and everything when i get them. now i just need to get rid of my 6 inch cowl for a iroc z

 

i dont know about high 11's with that cam/heads, it will need compression and I think abit larger cam to have a shot unless you are really light weight. 3400lbs will need 340whp or so to have a shot at it. Thats a good bit of power for a stock vortec head. 4k stall definately will help get you there. Good choice.
750 carb and a good dual plane should do it.

 

glad to hear, i was hoping it would be possible. my goal is to crap on vettes light to light which with a 4k stall should be pretty easy