I'm looking for the next level with my Vortec headed 353.
The time has come for a new cam (I've made a few inquiries).
I'd like to know what other ETs are like compared to my own.
All the good stuff is in my signature.
Best time is 12.74 @ 108 w/1.7 60' (3700lbs).
Anyone else?
These heads are unported by the way. Original valves (1.94 and 1.5) with an OEM valve job.

 

tci 10" 3600 stall--flashed to 3800
4.11 9" with spool
28x9 et drag
11.90@115 I believe, it's been years and years since I ran the combo

super victor
750 quick fuel double pumper
cam similar to a XE274 except it was solid flat tappet out of the circle track catalog with a 106lsa

 

Nice time for a little iron head I'd say. Was that with a 700R4? That would be a TON of 1st gear.

 

th350, 700R4 sucks for for that 1-2 gear spread

 

I would have thought there were more Vortec small blocks than just 2 of us.

 

there's an old thread on here on this subject and there was a guy with a 406 that went mid 11's with vortecs. a good solid cam setup will do you a lot of good

 

Found it.
https://www.thirdgen.org/forums/orga...aded-cars.html

 

Well when I went I was dealing with a lot of teething issues with my new build and still learning how to drive a stick on the street, much less at the strip.

I got an awful 60 ft time... something like 2.7 seconds I think? Ended up running a 14.5 at 101.8 mph.

That was pretty much with my holley right out of the box, and distributor just set... "in the ballpark".

I did two more runs that afternoon but the engine flooded itself between the 2-3 shifts both times due to a boiling fuel issue I was having after letting the car sit between runs.

Anyway I've gotten the car in a much better state of tune these days and I've been meaning to go out to see what it can really do, but I may end up getting my 3.70's in the 9-bolt before that happens.

But I think my 218/224 xe262 cam is a bit small for the rest of my combo. Makes for a well-mannered car with an amazing torque curve, but I think I'm leaving a lot of top end power on the table as it quits at about 5500 RPM. But it seems like with a modern xtreme energy grind like I have, I'm not sure a bigger cam would really make as big of a difference as im hoping, even if I go roller. The costs involved are enormous for the horsepower gains I would get I think... am I wrong? New springs, retainers, and lifter/cam set if I go with beehives, or new springs and machinework on my valveguides. And then there's the extra cost of doing a retrofit roller swap if I go for a roller cam.. then hardened pushrods to deal with my guideplates. Not really sure for the $500-$1000 involved I will really see that much of a power gain.

I mean what really is the reasonable limit for rwhp from Vortec heads in a 350? 350hp? 375hp? And how do I get there? As far as streetability... as long as I can run my power brakes Im fine.

I still think that 102mph isn't bad, hopefully there's more in it. Car was 3550 lbs with me in it that day.

 

I've made all the mods you've listed: Beehive springs, screw in studs, guide plates, hardened push rods, retro fit roller cam with thrust button as well as a cast aluminum timing cover with end play adjuster.
The XR276HR pulls 11 -12 inches of vacuum at idle (800+/-).
Calculated 10:1 SCR with a DCR of 8:1
20 plus mpg at hiway speeds.
3750 lbs.
107 mph in the quarter.
Probably 350 rwhp.

 

Seems like that might be around the limit for these heads in normal situations.

 

Funny you should say that. After my last trip to the track, I was thinking the same thing.
The operative phrase is "in normal situations".
I'm SURE I could get another 1/2 second or more out of it but I'd lose the drivability and mileage I talk about so much.
I've been studying camshaft theory alot lately and engine dynamics in general. While the stock Vortecs are excellent cylinder heads by most standards (and possibly the best head in a true street application where power is made well below 6000 rpm) they are limited in horsepower potential. I think it's a safe bet to say 450 chp from 350 cid is about it.
If my trap speed vs weight is any indication, I'm close to 420 as it stands now. Another 30 hp is going to be hard to come by without some wholesale changes.
That said my target is 110mph. With a decent launch, I should be 12.5 or less.

 

Is this a limitation due to port volume?

450fwhp is still pretty damned impressive. How much of an increase would, for instance, some AFR "Vortec" 190s or regular 195s or 210's make in comparison? When are we starting to knock on the door of the limit of a naturally aspirated Gen I 350 sbc?

 

Not so much port volume as it is flow.
Using port flow as a hp guide, the Vortecs with a max cfm of 239 have the potential to make 450 hp from 353 cubes. That's at 7100 rpm.
More head flow equals more hp. What makes the Vortecs impressive is the amount they flow at values below peak lift. Check out flow values for ANY head at lifts from .050 up to about .300 and the Vortecs covers them all.
That builds more overall torque, not neccesarily peak hp.
NA Gen 1 SBCs hp limit...put on a big set of 12 degree canted valve heads, a ridiculously large solid roller and induction/exhaust matched and tuned and my calculator says 950 hp at....12 000rpm. You won't be using an OEM block to do that.

 

You say you trapped at 107 with a 3750 lb car.
The crappy calculator Im using says:
359RWHP

I trapped at 101.8 with a 3550 lb car:
292RWHP

If I were making 359RWHP I could trap at 109MPH. That's moving... maybe it's worth the trouble to upgrade and keep the heads after all. I'm leaning towards cheaping out with another flat tappet cam though. Maybe an XE274, I ownder if that could get me to the same 359 rwhp mark. 359 rwhp would get me to 109mph theoretically since Im 200 lbs lighter. Theoretically.

If I did it with an xe274 Id have $200 in cam/lifters, then money in the valve springs and retainers... not too shabby.

 

how much better is the LT1 head? i was thinking the ports and stuff were similar between the 2.... and if thats the case i would think porting could pick up a ton. my LT1 heads flow around 290 on the intake and the car makes ~425ish rwhp through a th400/9"/slicks. 350cid.

 

nascar boys pretty much do that with a 358 using a bowtie block. ~9,000 rpms with some sb2.2 heads setup for roundy round. i bet 1000hp+ would be completely do-able with a dragstrip minded combo. and still using 358 cubes.

 

The heads have enough flow to support your goal however the real trick is the right cam. The problem with a flat tappet design is that the lift values needed to keep the flow active require duration numbers that kill vacuum. Roller cams solve that problem. If you study cam design deep enough you can probably spec a flat tappet that will offer something similar to a roller but that could mean a lot of research.
Way back in my college days my engines professor said roller cams were the way to go but back then (30+ years) rollers where in the realm of race cars only.



As far as I know the Vortec port IS the LT1 port. I don't have ported Vortec numbers off the top of my head but I do know that 290 cfm is impressive. That's an improvement of 20%. 290 cfm out of 358 buzzing to 8500 rpm will net you 550 hp. (These are maximum horsepower potentials I'm tossing out here).

I thought about that after I posted. They're supposed 900 hp 355's more or less aren't they? 9000 rpm redline. I wouldn't think that's something you could do with any reliability with an OEM block. Drag racing does let you hide from the laws of physics for a little while though. That's the only way my more or less stock bottom end does what it does. I may spin to 6500 now and again, but not for long. It would interesting to know how far they DID go back in the day when stock blocks and heads were all they had,

 

If any flat tappet cams could get close... wouldnt the XE series be it? THey're the most flat tappet modern lobes in Comp's catalog. Very fast ramp and close rates from what I understand. Should I go for a 114 LSA or something? Maybe a solid flat tappet would get closer? $600 in cam and lifters is just... a LOT. If I have to spend $600 plus another $300 in valve train parts, I'd rather just do a Gen III swap.

 

if thats the case, a set of ported vortecs would fly. im using an off the shelf "nitrous" hydro roller, and it peaks around 6700 on the chassis dyno. by no means a full blown race cam, it pulls around 11in. of vacuum at idle. stock shortblock.


i believe i have read where they dyno'd some cars after a 500 mile race and they were still making 850 at the wheels. im pretty sure the rotating assemblies are good for well over 10k rpms, but you would need to adjust the valvetrain accordingly. they were running a bowtie (high performance) block from gm in previous years, not sure what they are running now. high rpms seem to kill a block just as easily as big torque #s. personally, i would like to see them throw carbs and restrictor plates in the trash and run a factory engine like the old days. let em do whatever they wanted, but use the factory castings. i figure a 3.8 v6 with the majic touch could still make some crazy power.

 

As far as I know, it's the XFI series of lobes that are the latest in technology.
Check out the lobe index on page 428 of the latest downloadable Comp catalouge and compare it to the lobes on you XE262 (page 138). I'm assuming you have the 2-238-2 grind. More lift per degrees of duration and "more area under the curve" to use Comps advertising lingo. Also consider that carbed 350's in general for NA use, prefer a 108 LSA combined with the now typical 104 ICL angle (4 degrees advanced).
Keep in mind that any change you make beyond your current lift will mean a change to accomodate the increased lift on your Vortecs (if you haven't already).

 

Nitrous is a different beast altogether and is very dependent on a properly spec'd cam, particularly on the exhaust side. I suspect your "off the shelf grind" compensates for this.
11" of vacuum is pretty good for a cam that peaks at 6700 rpm. What rpm do you idle at?

 

Rpms are what kill engines more than anything as you suggest. Build lots of low rpm torque and let the hp take care of itself. That's what makes the Vortec (or LT1) cylinder head such an excellent piece. In a high performance street sense that is.
As for running factory engines....I'd like to see that too. As well as stock bodies that we can actually identify. I guess it wouldn't be Cup racing though.

 

Im going to look into the xfi cam line and see if I can see anything useful to me, but Im guessing without the need to deal with EFI, I wont find any advantages there. Oh well.

Im well aware of vortec lift limitations, been doing research all day to work around them. That's the reason I only had the xe262. An xe274 still has fairly tame lifts compared to roller cams, which makes it a little easier to accomodate in my build. Seems like I should be able to run some beehive retainers, some LS3 yellow springs, and be fine with the xe274. I just have to figure out whether the LS3 springs have enough closed seat pressure, and if not, whether I can shim them to get closer. But the xe274 being .487/.490 will be pretty easy to find a good spring for. If all that fails I may just end up ghetto grinding the valve guides...

If I end up going for a roller setup, I'm probably just gonna find a cheap used LT4 hotcam somewhere and try to make that owrk, but the retro-roller costs and returns aren't so great compared to just buying a Gen III truck motor and using that as a base.

 

The XFI lobes don't mean that you have to run fuel injection. I was thinking more along of the lines of building a custom grind with your lobe choices and LSA, etc. What I had forgotten was that you were attempting to stay with a flat tappet design and as such, I don't think the XFI lobe profiles are suitable. You could still spec your own cam from the XE flat tappet profiles.
Have you considered the Beehive/retainers as an alternative to getting more lift out of the Vortecs? No machining required but they do cost a bit. You would have to upgrade springs over the stockers with any more cam than you already have anyway. I learned that lesson the hard way.
If it's just a clearence issue to accomodate a little more lift and you're not concerned with valve float or bounce then the "ghetto grind" of the RETAINERS has proven to be effective. I don't have any personal experience with it myself.
As for an LS engine.....I would if I could but I have too much invested in what I have already.

 

Sorry this is going to get wordy... I decided maybe some other people with Vortecs will see this in a search one day and find some interesting info, so I figured I'd be a little more detailed. I did a LOT of searching to find what I have.

The springs I have are mystery springs I got on my original set of junk vortec heads years ago. Long story short I got screwed on some heads with some REALLY nice stuff on it. The intake valves were junk, but I kept the 1.60 exh valves and they're in my Vortecs now. The springs I have are roughly equivalent to Comp 981 springs, but my springs were at a 1.8 inch installed height, not 1.7 as those are. So whatever they are, they may be more analogous, or even the same, as Comp 986 springs. I was told by the seller that the heads would be good to .550 lift. My machine shop said they certainly were not, so either the seller was lying, or .550 was the coil bind height on those springs. Crapshoot.

After I realized my heads had more holes in them than swiss cheese, I just went to my machine shop with all my parts and told them to set me up as affordably as possible with some new Vortecs (I was broke from the original build already! LOL), and we decided on leaving the stock intake valves, using my 1.60 exh valves, guideplates, and screw in studs from the old heads. But I have absolutely NO idea what the spring installed height is on these... I just dont want to tear it apart just for investigative purposes. I dont even know if it's still at a 1.800 inch installed height.

It's conceivable I could have my valve guides machined down and use the springs I have, but I cant find anything on line mentioning the cost of machining down the valve guides.

Scenario A: I get my valve guides machined down, current springs are adequate, save cost on springs and beehives and only bill is the machine shop. Worst case scenario I can have them cut the valve seats for the more affordable 986 springs which comp recommends for the XR276.
$85+machine shop costs

Scenario B: GM LS3 yellow springs(12499224, good to .550-.580 lift allegedly. Beyond .550 is dubious but I will be nowhere near that), same new retainers(787-16) , new locks(648-16).
$150

Scenario C: 26918 Beehive springs, new retainers(787-16), new locks(648-16).
$300


Grinding the retainers? So what is it about the beehives that allow so much more clearance? Is it just that the retainers themselves are so much smaller (shorter)? Allegedly those beehive retainers can take you from .470->.550 allowable lift... Whats that? Something around a 16th of an inch I guess? Wonder if I can just grind my retainers and eschew all of it.... I'll look into that. I've heard about it, but I had been under hte impression they were grinding down the valve guide which I wasnt really comfortable iwth.

And I have a decent amount invested, but nothing radical. I dont have a $1600 set of AFR heads or a $600 forged crank. It was a pretty well done budget build. It's surpassed my expectations, really. But Im at the point where I can either make it a super serious motor, or go to a Gen III platform for the money I would have invested. If I dump $500-$750 into cams/valvetrain the Gen III thing will have to wait. But if I'm trapping near 110 MPH I'll be more than satisfied.

For the record, if I can just grind down the retainers... I'll get my current springs checked out. Maybe I can run an XR276 with them. If nothing else I at least need to know what size my spring pockets are, they may not even be stock.

What else is needed for the roller cam swap? A new timing cover, new lifters, and new pushrods? Aside from the locks/retainers/springs dilemma is that everything else?

And I already have guideplates and screw in studs. There's no pressing need for any other machinework. I'm also running some of the older Comp Pro Magnum roller rockers too, so even my rocker arms are very over the top for what I have. ARP waveloc bolts in SCAT I-beam rods too, so nothing fancy, but it should handle 6k RPM.

By the way, thank you very much for all the advice, sorry to hijack your thread.

 

you cant really say the heads are good to .550 without listing the spring, so thats kinda worthless info. you might be able to stick a stock spring in there and compress it .550 without coil bind, but it will float the valves since it isnt strong enough. if you had a spring with thicker wire, you may not be able to get .550 out of it.
i BARELY squeezed a .590" lift cam into an LT1 using a set of comp 978's. i had to use +.050" locks, and it was REALLY pushing it on the safety margin. heads still had stock valves with no valve job. spring pockets werent cut, either.

 

If I say a spring is good to .550 lift, I do mean only the spring. Im not saying the spring, installed in my heads, is good to .550 lift. The LS3 springs are beehive springs and use the beehive retainers, which give me more retainer to guide clearance. Springs themselves are more than good enough for my application it seems. I was illustrating that I would hit the lift limit of my heads before I would get to the limit of those springs, but that setup would still yield me more clearance.

 

[QUOTE=InfernalVortex;5065178]
For the record, if I can just grind down the retainers... I'll get my current springs checked out. Maybe I can run an XR276 with them. If nothing else I at least need to know what size my spring pockets are, they may not even be stock.

What else is needed for the roller cam swap? A new timing cover, new lifters, and new pushrods? Aside from the locks/retainers/springs dilemma is that everything else?

And I already have guideplates and screw in studs. There's no pressing need for any other machinework. I'm also running some of the older Comp Pro Magnum roller rockers too, so even my rocker arms are very over the top for what I have. ARP waveloc bolts in SCAT I-beam rods too, so nothing fancy, but it should handle 6k RPM.

QUOTE]

Check the springs like you suggested. Get them tested at a machine shop to determine pressures.
Do you know the spring o.d.?
Google "Vortec head ghetto grind". That will give you an idea of the mod. You may be able upgrade on the cheap.
It all depends on what springs you have.
If the pockets haven't been cut past the OEM 1.25" , the Beehives seem far and away the simplest and least expensive way to get lift capability well past what I'd ever need. At .540" I'm approaching the limit of what's effective on an unported head.

 

I'd be highly suspect of the calculator you're using there. I'd buy 292fwhp, but not RWHP based on your mph. My car dynoed at 250RWHP and trapped at 101.18mph a week later.

 

Im not too hung up on whether it's rwhp or fwhp. I've tried a bunch of different calcs and half of them say rear wheel, have say flywheel, but the actual numbers are pretty consistent so I use it more as a frame of reference to see what kind of hp increases I need to hit different trap speeds/ET's.

 

Back to the original topic at hand, just for anyone who searches at some point.

My xe262 cammed Vortec 350 setup went back to the track last weekend and I made two passes. I knew I had new gears going in 2 days later, so I just wanted to get a new baseline and to be honest Im pretty inexperienced with the drag racing and my car is just hard to launch... So after 2 passes i figured that was enough. I didnt crash the car or blow it up so I considered it a victory.

First pass I botched my 2-3 shift. Nerves all frayed, bad driving, etc.

2.2 60 ft

Second pass went okay, but I bogged it awful off the line, nearly stalled it.

2.37 60 ft
14.1
101.94mph

The new 3.70s I just put in make the car feel SOOOO much better, it's unbelievable. Those 3.27s were like driving around without a first gear and having to use second. I think it'll be MUCH easier to get into the mid 13's now.

Timing is only at 32 degrees, I didnt want to push it just to be safe, next time I take some fresh plugs and start checking plugs and upping the timing and see what it's really got in it.

What a blast... I had a lot more fun than my first trip which was more of a shakedown day, the car was a pretty fresh build. For the record, it went 101.98@14.5 then.

 

Best mine ever did was 8.601 on the on the 1/8th.

 

What do you have for rear tires?

 

Regular skreet tires^^

 

Goodrich drag radials...cuts a 2.01 60'

 

?

 

As an average, and we're not talking about sophisticated race machinery here, 1/10 in the 60' is worth about about 2/10's in the quarter.
I can testify to that.

 

how big of a stall do you run with yours?

 

InfernalVortex is running regular old skreet tires...and a t56

 

Street tires. Some BFG G-force sports. They didn't slip but I wasnt doing any 5k RPM clutch dumps either. I almost stalled it my second run.

The main issue with the car now is between the steering wheel and the seat. Hopefully I'll find a way to pull some drag radials out of nowhere next year. Otherwise maybe I can work some magic and pull a 2 second 60 foot out of it on the street tires.

 

Lemme know when you're ready Kyle, I'm sure I can come up with something.

 

A local guy that goes by the internet moniker "Honk If Parts Fall Off" has been 8's with Vortec heads in a 4-door Chevelle. I've seen it with my own eyes and funny enough first pass I witnessed at the track his hood flew off...

http://www.chevelles.com/forums/showthread.php?t=248388

 

I run a TCI Street Fighter which flashes to almost 4000. I can't foot brake much past 2500 though as the brakes won't hold and I creep out of the staging beams.