HELP - Vortec head question
Thread Starter
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
HELP - Vortec head question
I'm building a 383 for my 77 and I'm using new Vortec heads with a Comp Cams grind # CS XE262H-10. The cam specs include .469 lift on intake and exhaust. I read an article in Car Craft that said Vortec heads can't be used with more than .450 lift. Does anyone know why and how can the heads be modified? Thanks guys.
Pro
Joined: Jun 2001
Posts: 672
Likes: 0
From: Quebec
Re: HELP - Vortec head question (BKbroiler)
I have a pair of Vortec too. There is two things that I know of that need to be done to get .500 lift and more. First you will need stiffer spring and they require some machining to fit the head. The spring are bigger so the inner radius and exterior radius have to be widder. The second thing is where you put the valve seal. This part have to be shave to prevent the valve lock to hit it. I think I read that on chevyhiperformance.com.
It's a little pain but these head sure kick ****. :cool:
The flow is impressive from 0.200 lift to 0.500. Have you thought on having your valve work. They claim that a simple 30 degrees backcutting is well worth.
Stephan
It's a little pain but these head sure kick ****. :cool:
The flow is impressive from 0.200 lift to 0.500. Have you thought on having your valve work. They claim that a simple 30 degrees backcutting is well worth.
Stephan
Racer
Joined: Sep 2000
Posts: 485
Likes: 1
From: Dallas Texas
Re: HELP - Vortec head question (BKbroiler)
You need stiffer springs. There is one other option on the springs without having to cut the seats bigger. I think it is comp cams that sell a spring that is the stock diameter at the seat but wider at the top that will do up to 0.500. Don't know anything about them but just thought I would throw it out as an option.
Navigator
Joined: Aug 2002
Posts: 9
Likes: 0
From: Denton TX
Re: HELP - Vortec head question (BKbroiler)
I have ran the Vortecs on a circletrack motor with a solid lifter cam with .525 lift with NO machine work.
I ran the generic Z/28 valve springs and removed the inner damper spring, you MUST do this. It will coil bind because it doesn't sit down properly due to the large o.d. of the valve guide boss.
This motor saw 6200 rpm extended every weekend.
I used positive valve guide seals and the retainer would just clear the seals.
I ran the generic Z/28 valve springs and removed the inner damper spring, you MUST do this. It will coil bind because it doesn't sit down properly due to the large o.d. of the valve guide boss.
This motor saw 6200 rpm extended every weekend.
I used positive valve guide seals and the retainer would just clear the seals.
Melting Slicks
Joined: Mar 2001
Posts: 3,365
Likes: 5
From: Lake Villa IL
Cruise-In IV Veteran
Cruise-In V Veteran
St. Jude Contributor
Re: HELP - Vortec head question (BKbroiler)
I'm having Vortec's installed, well, when my builder feels like it. Anyway, I bought my heads online, as a kit, from Scoggin Dickey. They offer them two ways, you can get the standard kit, with the heads assembled with standard parts. Or you can get the high lift kit, for a little more. Check it out. The kits come with everything you need.
Le Mans Master
Joined: Aug 2000
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From: Semper ubi, sub ubi
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Cruise-In VII Veteran
Re: HELP - Vortec head question (BKbroiler)
Pace performance told me that standard Z-28 springs without the damper would work fine (and are really cheap) they will work perfectly well with the XE262. I was planning on using them on my Vortec heads, (which are now for sale!)
Comp also makes a couple of cutters and a guide rod so you can widen the spring pockets and cut down the height and width of the guides. The whole set of tools will set you back about $100. You can use a 3/8" drill to do it yourself if you want to use really big springs. But if you are going to go with much stiffer springs you better have a set of threaded rocker studs put it.
Comp also makes a couple of cutters and a guide rod so you can widen the spring pockets and cut down the height and width of the guides. The whole set of tools will set you back about $100. You can use a 3/8" drill to do it yourself if you want to use really big springs. But if you are going to go with much stiffer springs you better have a set of threaded rocker studs put it.
Intermediate
Joined: Apr 2002
Posts: 29
Likes: 0
From: Brewster New York
Re: HELP - Vortec head question (Wightnite)
I am running the vortec heads with .490 gross lift all I had done was to put screw in studs and had posi lock seals installed. I am running the Z28 springs with the damper and comp self allign. roller tip rockers...no problems as of yet. I was told by the machine shop I took the heads to that they can handle .500 lift without any machining but he did the valve guides for me when he put the seals on so I can have a safty margin.
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Instructor
Joined: Aug 2000
Posts: 216
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From: Sacramento CA
Re: HELP - Vortec head question (joeveto)
joeveto-
I checked all over Scoggin Dickey website and could not find the high lifet version your talking about. Did you see it there or do I just have to call them? Also, how much $$ if you dont mind me asking.
I checked all over Scoggin Dickey website and could not find the high lifet version your talking about. Did you see it there or do I just have to call them? Also, how much $$ if you dont mind me asking.
Melting Slicks
Joined: Oct 1999
Posts: 2,581
Likes: 14
From: Tolar Texas
Re: HELP - Vortec head question (Wightnite)
Do the vortec heads have a GM mark or # on them?
10239906...96-up...350...."Vortec 5700", "L31", 64cc chamber, 170cc intake port, 1.94"/1.5" valves.
12552520...97-up...305....Vortec, truck
12558062...98......350...L31 Vortec, truck, 64cc chambers, 1.94/1.5, 170cc intake port.
It is a well known fact that the L31 Vortec heads are great for the price. IF your application calls for greater than the 0.450 lift limit, you should carefully analyze the TOTAL COST of the new Vortec heads, springs, machine work, and a Vortec specific intake so that you can make an informed decision between these heads and some of the commonly available aftermarket heads. The difference in price might be smaller than you think.
Burning Brakes
Joined: Aug 2000
Posts: 1,063
Likes: 0
From: Monument Colorado
Re: HELP - Vortec head question (BKbroiler)
There is an article in this month's Chevy High Performance on just this modification. I didn't read it in depth, but if you'd like, I can scan it for you.
Thread Starter
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
Re: HELP - Vortec head question (Tex71BB)
Sorry for not replying sooner - I could use the info in that article if you don't mind scanning it. Thanks for your help.
Thread Starter
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
Re: HELP - Vortec head question (BKbroiler)
My brother in law and machinist measured the clearance from the bottom of the retainer to the top of the seal on one valve. It measured .470 - not good for my .469 lift cam. He will cut the top of the guides to lower the seals by .050, giving me .520 clearance. We will also change to heavier springs. That should do it. Thanks to everyone who offered advice.
