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Author Topic:   Vortec head question
STICK01
Member
posted December 21, 2001 09:43 AM
I have a set of GM takeoff Vortec heads. I was told that they do not have one piece valves and would need a three angle valve job. Does anyone know if this is true and what cost am I looking at to fix them up?



istock59
Member
posted December 22, 2001 08:59 PM
Stick01, I've raced the stock Vortec valves (and seats) for 2 years in the IMCA Stock class. Not a problem with mine. I'm using Crane H11 valve springs on these.

And the seat is already 3 angle. The margin could be a little narrower, but it's worked fine so far.

race8k
Member
posted December 23, 2001 10:09 AM
Watch those stock 2 piece valves they will pop the head off and kill the block, heads, and all.Midwest and JR motorsports both sell a one piece stainless valve for less than $6.00 a piece. Seen more engines die from stock valves than from not being balanced.


istock59
Member
posted December 23, 2001 10:47 AM
Yeah, I figure 2 years on them is enough. Replacing them this winter with a set of SS Manley's from Scoggin-Dickey.

In claimer stuff, you can get away with the stock 2-piece valves, as long as your not over agressive on the seat pressures.

coop25
Member
posted December 23, 2001 12:54 PM
[/B][/QUOTE]I GMC tech. I Know a mod. driver that runs up front with a 358 vortec engine with vortec rods and heads. We turn engine 7500to8000 with a set of new stock replacement valves Manley from Competition Products 69.95. The springs are a set of cheap solid springs with about 125lb of seat and around 350lb open. Engine has about 1250 laps of hard running. Only problems I have had is stock guides after 750laps wore out. Would be happy to help with any Questions.
Xtreme Racing Engines by Josh.


coop25
Member
posted December 23, 2001 01:01 PM

[This message has been edited by coop25 (edited December 23, 2001).]

STICK01
Member
posted December 23, 2001 02:54 PM
So what you are all saying is that these heads are not going to take much money to be a good set of heads for a backup engine and it can turn 7000 + if necessary.

Sounds like valves and springs and a set of covers I'm in for under $300.00, Merry Christmas to me....

WPP
Member
posted December 23, 2001 05:40 PM
I am interested in these heads how big of valves can you put in them and how many rpms are they good for


sdhnc29
Member
posted December 23, 2001 07:07 PM
You can go as large as 2.055"/1.600" , but the flow numbers are not as good as with the 2.020"/1.600" combo , if your using them on a small bore block (4.00-4.060"). With the 2.055" intake valve , the valve ends up being shrouded by the chamber wall and you will lose about 5% of flow at all valve lifts . If you are going to use these heads with 2.055" valves on a big bore block (4.125"-4.185") , then you can unshroud the chamber to match a 400 head gasket . This will then make the 2.055/1.600 combo out flow the smaller valves . The Vortec's flow very well up to .550" lift with either valve combo , after that they drop off rapidly . As for RPM's , I have customers who are using these heads on engines that turn between 7,800-8,000 RPM's with no problems . But by that point , the engine is out of air and power will drop off rapidly . I usually recommend staying right around 7,200-7,500 RPM . These heads are an excellent choice for the average racer who can not afford after market heads , or if your rules require an OEM casting .

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


WPP
Member
posted December 24, 2001 09:31 AM
I am thinking about putting these heads on a 377 with 6.125 or 6.2 rods 13 to 14 com in a mod and wondering what size valves i should have. I also was needing information on if a cast crank will live and what brand


sdhnc29
Member
posted December 24, 2001 11:27 AM
Since your going with a big bore combo , I'd open the heads up for the 2.055/1.600 valves and unshroud the chambers . As far as cast cranks , I'd use a stock GM crank ! I have not seen any of the after market cast cranks go any farther in total life span than an stock crank . If it's in your budget , you might want to invest in an inexpensive 4340 crank perhaps a Cola or a Callies Dragon Slayer . One of these cranks , good US made rods , and good pistons will last you for a long time . Warning though ! You are on the right track with your compression ratio , but you will start having to worry about main webs and main caps . If you are using a stock block and if it is also in your budget , I would have good caps put on . Just keep on eye on your main webs , the second main back is your problem area , and that's where you'll find a cracking problem 75% of the time . Good luck !

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


WPP
Member
posted December 24, 2001 07:47 PM
Thats for the information it will be a 2-bolt with the good studs and bolts from arp It will be alittle while before i started gathering all my parts up and i would like to do a little dealing with you guys if possible Thanks again hendren


istock59
Member
posted December 26, 2001 09:44 PM
From what I've read, unless you go with a TON of portwork in these heads, you're just as well off sticking with 194/150 valves. Only with extensive portwork was the 202/160 and bigger valves worth spending the $$.

[This message has been edited by istock59 (edited December 26, 2001).]

sdhnc29
Member
posted December 26, 2001 10:15 PM
By simply opening up the pockets for the 2.02/1.60 valves , and then hand blending the bowls , you will pick up enough CFM to achieve 100 more horse power , mathematically . On average , you will spend about $200.00 for blending the bowls . The bowl area is where your largest gains come from on these heads .So spending a ton of money and time on the intake runners , will only get you minimal gains as compared to the bowls . You are right though , with the 1.94/1.5 valves , they already flow better than any other OEM casting . So it just depends on what your looking for , and what your budget will allow .

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


istock59
Member
posted December 27, 2001 12:59 PM
When your feeding these heads with a 350 cfm Holley, like I have to, 194/150 are probably plenty...

[This message has been edited by istock59 (edited December 27, 2001).]

willie
Member
posted December 27, 2001 03:34 PM
quote:
Originally posted by sdhnc29:
You can go as large as 2.055"/1.600" , but the flow numbers are not as good as with the 2.020"/1.600" combo , if your using them on a small bore block (4.00-4.060"). With the 2.055" intake valve , the valve ends up being shrouded by the chamber wall and you will lose about 5% of flow at all valve lifts . If you are going to use these heads with 2.055" valves on a big bore block (4.125"-4.185") , then you can unshroud the chamber to match a 400 head gasket . This will then make the 2.055/1.600 combo out flow the smaller valves . The Vortec's flow very well up to .550" lift with either valve combo , after that they drop off rapidly . As for RPM's , I have customers who are using these heads on engines that turn between 7,800-8,000 RPM's with no problems . But by that point , the engine is out of air and power will drop off rapidly . I usually recommend staying right around 7,200-7,500 RPM . These heads are an excellent choice for the average racer who can not afford after market heads , or if your rules require an OEM casting .

will the vortech head work with a j&e
13 t0 1 piston or do you have to use flat tops?



sdhnc29
Member
posted December 27, 2001 08:59 PM
Yes the JE's will work , but you must modify the dome a little to clear the spark plug boss .

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


WPP
Member
posted December 28, 2001 05:42 AM
I will be running a 400 block 377 with 6.2 rods with a new pair of vortec heads.What deck height and pistons will i need to get 13.5 compression. The vavles size are ??? What do i need to do


sdhnc29
Member
posted December 28, 2001 12:02 PM
You can use a JE piston , Part # 115961 (it's a +.030" piston) . This piston has a CD of 1.062" , so with a 9" deck , you will be .002" out of the hole . Using this piston , with a 1034 head gasket , and a 64cc chamber , .002" out of the hole , you will be at roughly 13.2:1 - 13.5:1 . knock the heads down to 58cc's and you'll be at 14:1 or a little better . of coarse you will have to juggle these numbers around a little after modifying the domes to clear the plug boss , but with only a 8cc dome , your machine work should be minimal . I'd go ahead and open the heads up for 2.055"/1.600" valves , and use an Edelbrock Super Victor intake that's designed for the vortec heads . Sounds like your on your way to a good running motor !!!

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


WPP
Member
posted December 29, 2001 07:45 AM
Hendren Motor I talked to a machinst last night and he knows everything to do to the heads the only thing he id not like was the longer rod he said i would have to really turn the motor up with the 6.2 rod I would like to here your reply on this Thanks again


sdhnc29
Member
posted December 29, 2001 12:14 PM
No , you wont have to spin the engine any higher than normal . The longer rod will raise your toque band a couple hundred RPM , but the torque band will now be much broader . The key to getting back the minimal amount of torque lost with the longer rod is compression ratio . We build our alky engines with a minimum compression ratio of 15:1 . I would definitely shoot for at least 14:1 with your combination . I just got off the phone with you now , and we talked about all of this ....LOL Kind of weird , me writing this , and you calling at the same time . Any way , I'm looking forward to doing business with you !

Thanks ,
Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


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