ZRATED

Finally got around to doing my vortec head swap, it took a while but it was well worth the wait. I started off with a brand new set of 062 casting vortec heads and topped it off with a marine vortec TBI intake without EGR. Heads were milled .030 but other than that they are completely stock. This is what my car needed, these heads really do wake up the 305 it pulls hard on the top end. As expected it is in need of a good tune, but it has a very noticeably louder idle

TonyC

iTrader: (1)

Very cool man, do you plan on spraying it more?

Pablo

iTrader: (1)

Sharp looking engine bay

DM91RS

Sounds like it worked out well.

The Vortec's made a good increase in power over (if I read your sig correctly) the stock TPI heads?

And is that a 14 x 2" breather that you have on there?

Later DM

ShiftyCapone

iTrader: (7)

Good to hear man. It is amazing how hard a little 305 can pull with vortec heads and an LT1 cam. Keep us posted on the tune.

dimented24x7

iTrader: (2)

I definatly concur. Wish mine was that clean

25THRSS

Where did you get that intake manifold?

ZRATED

The intake I found on Ebay some guy was selling them for 140$ plus shipping brand new. They have no EGR and already come with the 2" bore. http://cgi.ebay.com/ebaymotors/ws/eB...tem=4511959355
He has about 30 intakes left

I always try to keep my engine bay as clean as the outside

ShiftyCapone

iTrader: (7)

That intake is really great. I didn't know that they made that. Is that intake still produced at all? I bet it performs similar to their other performer intakes (including the performer TBI) but the application to vortec heads is what make it a nice option.

ZRATED

I was suprised when I saw it too and for 160$ shipped it beats the 330$ GM intake. I guess becuase its for marine applications it has not been seen around here, but its still made by edelbrock.

DM91RS Its a 14x3in OE and I did have 305 tpi heads on there before that I had ported my self

Im looking for at least mid-12s on the spray with this new setup, with tunning, bigger injectors, and a 3000 Edge stall cause this slp stall I have now is a little sloppy on nitrous

25THRSS

Do you know if they make the non egr manifold for standard centerbolt heads?

DM91RS

Thanks Z........I'm glad to hear those facts about the heads.

sunset92

also were you running the stock 1.84 valves on the tpi heads?
i was looking at buying a set of those that were ported and had the 1.94 valves. but if they aren't going to make a diffrence the i will go with vortecs?

Keith5

Can vortec heads take the lift of an LT1 cam? Of the corvette LT1 cam?

sunset92

they can if you put in beter springs.

ZRATED

Im running the stock vortec springs with my Lt1 cam its running great. The lt1 cam is at about the limit for the vortec head springs.

Keith5

Do you know if you have the F-body or the Corvette Cam? I've read that the Corvette cam has a little more lift.

ZRATED

I don't think there is any diff. in the vett. cam from the F-body cam. Basicly any production Lt1 cam is about the limit for vortec head springs.

BMmonteSS

The vortec head that I measured looked to be at the safe at .450 lift, so anything past that will be pushing it. Don't take my word for it, go measure your self, I had tons of valvtrain problems because I listened to what every one told me and just assumed they were correct (local guys). Low and behold when I actually went and measured my heads (not vortecs) I was kissing the valve seal every time the valve opened. My mysterious valve spring breaking problems went away, luckily none of the 4 valves that had broken springs droped, the damper held them open enough to keep them out of the pistons.

Keith5

https://www.thirdgen.org/techbb2/sho...threadid=81659

I found this thread, but I can't find the link that I used to go to, to find the cam specs.

The Corvette had a different cam because it didn't have an EGR vavle, the EGR effect happened with the cam, instead of with a valve.

My cam is the one with .450/.460 lift. That puts me a little over the .450 limit

So could I still get away with it?

Keith5

Ok, I found on the Jegs website, lift is ok up to .475

http://www.jegs.com/cgi-bin/ncommerc...42&prmenbr=361

# Material: Cast Iron
# Intake Runner Volume: 170cc
# Combustion Chamber Volume: 64cc
# Vale Diameter: 1.94'' Int./ 1.50'' Exh.
# Spark Plugs: Straight
# Special Note: Valve Springs - .475 Max Lift

z71stroker

kickass 305, man I really need one of those intakes! that xtremefi guy is selling a similar or the same intake on ebay for $279.99 pre-shipping!!!! and I was blocked from his auctions for asking him to lower shipping by $5 since I live 60 miles away, and I felt $20 for shipping a bored TB was alot... I paid $20 a piece to ship 53lb (each) heads across the country, so I'm not liking him too much right now lol.. nice build again bud

DM91RS

All this stated BS can cause you some problems. Some say they have no problems with that lift but all I know is that on mine (Yes I measured the lift and so should you) the retainer hit the seal at .465" of lift. I installed better springs, shimmed them up .060 and used offset keepers to get the lift to .515. That is what I have been using for 4 years with 1.6 rollers and an LT4 stock cam. .476/.480 lift.

Later DM

Keith5

The Pace Parts website says that they are good for .480 lift.

DM91RS

DM91RS

Believe everything you read eh?

Here's a cut and paste from the Vortec's for sale at good old SDPC

GM Performance Parts L31 Vortec Cylinder Heads. The best out-of-the-box head for the money. Excellent flow produces broad torque and killer power. Stock springs are good up to 0.450" lift. Requires special intake manifold to fit the Vortec bolt pattern. Price is per head.

It seems that the GM sites that sell these parts cannot get their facts straight.

Fast355

iTrader: (2)

Maybe Hot Rod was lucky a few years back. They took a pair of vortecs straight out of the box and bolted it to their Junkyard 350 short block with a Comp XE268 cam. That is way over .450" of lift. Its like .477" intake and .480" exhaust. They were running their engine to 6,000 without problems.

DM91RS

Yeah that's the article that convinced me to go Vortec back in the late 90ties....they was misleading in some of their articles...they later came back in 2002 and 2003 in Vortec articles that in which they stated:

"the safe valve lift is around .420"

and then went on to show how to cut down the guides. They may have had the retainer touching the seals on their dyno engine in which case it did not matter since it was just a dyno eng.

BMmonteSS

Hot Rod doesn't always tell you everything you need to know, it wouldn't surprise me if they didn't run the valve seals, that would give them the clearance they needed.

Keep in mind it's not the springs that are going to hit first, it's the retainer hitting the valve seal thats the problem. Trust me you really don't want to round a lobe off your brand new cam, the metal shavings make their way through the rest of your motor taking all the bearings with them, your left with a motor that won't cary any oil pressure and has no power, and if your lucky the shavings won't drop off the cam onto your cylinder walls, because then you'll also have to get it bored again. Ask me how I know.

Trust no one but yourself! when it comes to valvtrain geometry. Your dealing wth a casting and castings aren't perfect. There could be one guide that wasn't cut right or one seat thats a bit high that will totally funk up your motor.

Measure your self and know for sure. I used a piece of brake line carefully trimed to fit between the vale seat and the reatainer (without the spring in the way) then used it on the rest of the seats to quickly check for installed height. I then took that feeler guage and put my spring on a drill press and compressed it with the drill head till I got to my installed height, then just go another .450 or whatever the lift of your cam is and check for coil bind. Then make another feeler guage that is the max lift of your cam minus your installed height and check for seal to retainer clearance. If you want to see what your actuall installed pressure and open pressure of your spring is, barrow the bathroom scale and put it under the spring on the drill press.

Damon

ZRATED- a marine Vortec TBI intake, eh? Now THAT'S using your brain!! Good job on researching the entire combo before laying down the cash.

I've gone to marine parts on rare occasion when I just can't find exactly what I'm after in the automotive world. It's good to know that such an intake exists. Have fun with it!

RS Chris

SDPC sells modified Vortecs that can handle .525 and .600 lift cams for about a hundred bucks over the normal cost.

Keith5

I don't like SDPC, they charge more than Pace on just about everything it seems.

Those vortecs that can take .525 look tempting, but what about you guys that modified your own heads? How much did that cost you?

ShiftyCapone

iTrader: (7)

You will read a lot of different values for max lift on vortec heads. The castins of those heads were not consistant and some were as low as .420 while others were .500. As stated above you should always measure if you think you will be borederline. Most times magazines and such will measure their one set of heads to get their published values. The next magazine or parts place will do the same thing with a different year casting and report another value. This isn't really any different when dealing with any other stock GM head casting.

DM91RS

To get clearance for .480 lift I shimmed the springs and used crane offset (.050) locks. To get clearance for a ZZ4 cam with the 1.6 rollers I am going to have to cut down the guides and use the smaller seals. IE: 510/544 lift.

Cost; shims $25 I think and locks around $25. These are prob high but its been a while.

BMmonteSS

My shop only charged me 80$ to cut my guides, but I don't think thats tipical.