Gm vortec heads cracking

A very low percentage of cylinder head s manufactured with an embossed castech logo may develop a porosity crack in a very specific area. Chevy truck forum silverado sierra gmc truck forums. Anything i should know about installing vortec heads. I would run from the front of the engine to the heater.

I know i will be buying a pair myself for 100 bucks just to have them however i am concern about which casting number is prone to cracking. May 09, 2005 the first test called for a baseline run using the oe vortec heads. Please discard corporate bulletin number 060601019a section 06 enginepropulsion system. Jan 01, 2003 these production vortec heads were used in the new vortec 350ci engine intended for. Modifying and test fitting chevy 350 vortec heads for thread in rocker studs.

Seals, springs, retainers or keepers need not be included as we replace these. During the 2001 to 2006 silverado model years, gm had several different suppliers making the cast cylinder heads for the vortec 4. We use the new, chevrolet mexico produced casting for. Reinforced castings make these heads more durable and less susceptible to cracking, should your vehicle overheat. I seen some heads online that are 862 but dont have no logo on them. Some cylinder heads, made by the supplier castech, began to crack, allowing coolant to seep into the oil. Agreed with jake, l31 vortec heads are prone to cracking, that is one of their achilles heels, and the major issue that got addressed with the release years back of the bow tie vortecs. Everything ive been reading has been pointing to the issue of cracked heads. Small block chevy heads have been manufactured since 1955, and have.

Features include fast burn combustion chambers, and a highvelocity lt1 port design. The vortec combustion chamber is a kidneyshaped design that promotes better combustion and will have the spark plug located near the center of the chamber. Oct 12, 2017 modifying and test fitting chevy 350 vortec heads for thread in rocker studs. Step 2 valve lifters and camshaft noise and damage. The truth is they do not crack any more than any modern lightweight production head, although there have been problems associated with leaking intake gaskets on vortec engines that may have caused more than the usual number of cracked heads. Bolt on a set of fully assembled heads for instant power gains or custom build your engines topend. Vortec heads require a vortec style intake manifold due to an improved manifold mounting flange and gasket design and raised intake ports. Vortec bowtie cylinder heads come with bigger valves, a thicker deck surface and 66cc combustion chambers. Performance cylinder heads enhance the airflow into your engine, giving you improved power and torque.

I have often wondered if the intake gaskets commonly blowing out of these engines and overheating could be one of the causes of the cracking. Chevy cylinder head identification small block casting numbers, big block cylinder head, camel back heads, double hump heads. Modifying the heads to accept early intake manifolds is not. The only drawback to these heads is that they suffer from a little more valve shrouding see fig 61 than is necessary, and sometimes chamber cracking details on cracking later in his chapter. You do not have the required permissions to view the files attached to this post. Im planning on changing my heads with some non castech heads because i currently have the castech 706 and are cracked. The 193 tbi heads dont seem to crack nearly as much as the vortec heads do. The first test called for a baseline run using the oe vortec heads. How to find and fix cracks engine builder magazine. Every time ive gone in there they had a few l31s in the cracked head area. Can i run the casting numbers anywhere to find out if they ar.

I just bought a 400 sbc and it has the 333882 factory heads. Vortec heads outflow bow tie heads right out of the box and are a 20 to 40 horsepower bolton increase over earlier cast iron small block heads. How i diagnosed a cracked head on my 2005 gmc sierra with a 5. Chevy cylinder head identification small block casting. Vortec heads require a vortecstyle intake manifold due to an improved manifold mounting flange and gasket design and raised intake ports. All of our upgraded heads are professionally assembled with 1. The complete cylinder head guide for chevy small block engines. The cast iron vortec head was in development six months longer than the aluminum head, and during that time, gm engineers tweaked the intake and exhaust ports for additional flow. Valve lifter noise is a light, rapid metallic clicking. Sd8060a2 vortec sbc cylinder head with valve spring upgrade. However, it is difficult to find a set of good, used factory nonmexican vortec heads that are not cracked. Unfollow vortec heads to stop getting updates on your ebay feed. After our undercover porting or sst porting modifications, a modified mexican vortec head will flow the same as a modified nonmexican vortec head. Earlier and more durable heads did not have these scallops.

Chevy cylinder head identification small block casting numbers. I had the heads off two years ago to replace leaking head gaskets and had the heads tested and no cracks. Chevrolet performance 12558060 cast iron l31 vortec sb. Minor head bolt hole cracking can be fixed by drilling and reaming the hole oversize usually 58 past the end of crack, about 1 18 deep. Fully assembled as pictured, ready to ship and ready to plug and play. Use these casting numbers to identify the heads you have. Now, i see milky colored oilgunk at my oil cap now. Cracks in cylinder heads or blocks except in the main bore or web area are. If the budget means earlystyle heads as opposed to the later vortec heads then closed chamber heads are definitely the ones to look for. My understanding is that the 906 and 062 vortec castings are virtually the same. These upgraded production cylinder heads are ideal for 400450 horsepower street and racing great for circle track applications engines. Jun 29, 2018 how i diagnosed a cracked head on my 2005 gmc sierra with a 5. I am not racing my car, but want a strong running impala when i am finish.

I bought mine from a local core yard that gets vortec engines in all the time. Dec 05, 2007 my understanding is that the 906 and 062 vortec castings are virtually the same. The two fluids are always segregated into separate chambers and passageways. Any one elts see this on the gm service site or experience it. Dec 18, 2010 the vortec heads need a lot of port work to really flow well, i did a set a few years ago, and i swore id never do another. How to tell if your cylinder head is bad or cracked. Gm fast burn 62 cc 210 cc intake runner angle plug vortec.

Rhs patented clean cast technology and close tolerance machining provide exceptional finish quality for superior performance and reliability, and the revised water jacket design helps prevent cracking. Vortec heads cab be drilled and tapped for the 5586 style intake mainifolds. They are prone to heads cracking due to overheating. A guide to vortec vs oe small block chevy heads onedirt.

Also valve size plays a big roll in how the engine will perform. The cast iron vortec heads was one of the first to purposely integrate tumble instead of large swirl numbers in the design. Patterned from the design of the lt1 cylinder heads from the 199296 corvette, the vortec iron heads were first used on the fuel injected 1996 pickup truck rp0 code l31. Cylinder heads are responsible for containing and directing the internal combustion of an engines cylinders, meaning if that ability. They are off of a 1997 suburban with 5k miles on it. Nov 04, 2011 hey guys, just figured i would post my personal experience with bad casting on my sierra heads to inform and hopefully help someone out that might run into the same issue. Pro torker vortec heads are designed as a stock replacement for the popular gm 906 casting but flow far better and are much more powerful. These heads usually crack from the center exhaust seats to the nearest cooling crossover or center head bolt hole. Gm introduced its vortec line of engines in the mid1990s, in i4, i5, i6, v6 and three v8 configurations in various displacements from 2. The returned cylinder heads must be from a late 1998 or newer engine as prior to mid1998, gm used smaller valvespring pilot seats and the heads were prone to cracking at these locations.

Unless you getting the vortec heads for 50 bucks a piece than i think it is better saving the extra bucks. With our upgraded vortec heads, you have a great selection of options to meet your needs. Head gaskets leaking or a cracked casting that lets coolant into the combustion. You can recognize the valve, cause they have 4 hose connections vs 2. Well, i bought a used pair of vortec heads and theres a tiny crack at the edge of the combustion chamber, its just big enough that i can barely hook my finger nail in it. These heads are quite beefy and unless you overheated your rig or had a major meltdown 99% sure your looking at a head gasket. Chevrolet performance vortec cylinder heads 12558060. Vortec heads have gotten a reputation for cracking easily.

Some vehicles may experience a gradual coolant loss over time. It is a simple job, if you want to utilize an older intake. Chevy performance sbc cast iron vortec cylinder heads jegs. Vortec l31 cylinder head crankshaft coalition wiki. A magnetic test for cracks on chevy heads with an explanation of the 305 head. The trouble with junk yard vortec heads is the whole reason they ended up in the junk yard instead of being rebuilt with the original vortec motor and put back into service is they got cracked in the original trucks. The newly redesigned vortec cylinder heads were intended to replace the swirlport throttle body injection heads that were previously used on gm 350 trucks. If you are looking for a replacement set of stock heads, try to avoid the latermodel iron nonvortec heads that are lighter castings and prone to cracking. The heads provide outstanding lowlift flow numbers the more air you flow, the more potential power and fast burn performance all in an affordable, castiron head. Is there any way to tell if i have castech heads other than removing the rockers and the rail they are sitting on. The core heads must include valves and be in rebuildable condition. With thousands of sdpc upgraded vortec heads on streets and tracks around the world, you can feel confident that you will be getting the best product available.

Streetstyle vortec head test tech article chevy high. I always recommend starting with new gm 062 or 906 castings for a vortec head buildup. Flowbench numbers on various sbc heads chevy message. Chevrolet performance vortec cylinder heads 12558060 free.

Guide to chevy smallblock production heads chevy diy. Also, there looks like something hit the top of the chamber between the intakeexhaust valves, like theres a little piece of it missing, though it doesnt. The intake valve seat of the vortec head has a threeangle grind straight from the factory and the combustion chamber design is a radical departure from former gm heads utilized in the market. If you get too wild with porting, you run into overheating and cracking issues. The vortec heads come with various intake and exhaust valve sizes to complement the highvelocity port design and your performance needs. Inspect the cylinder head assembly to determine if the casting was manufactured by castech. Whether you race pro stock, super comp, or just want to rebuild your old chevy 350 small block, there are cylinder heads just for you. I have 862s on my 99 which i have owned since 01 and never have had problems. What is the gm vortec engine and why is it goodbetter. Vortec bowtie cylinder heads are the most powerful castiron heads offered by chevrolet performance. When the vortec heads made their v8 appearance in the late 90s. These cast iron vortec cylinder heads will fit 1958 and later small block chevy engines, and offer a 20 to 40 hp increase over earlier cast iron small block heads. When enthusiasts speak of vortec engines, theyre typically referring t.

The scallops around the lower row of head boltholes can quickly identify these heads. Apparently the castech heads have a tendency to crack, allowing coolant to mix into the oil. Gm has issued a tsb for the issue, but provides no help funding the millions of necessary repairs. Also, the mexican vortec head is brand new and are much less prone to cracking. What is the gm vortec engine and why is it goodbetter than. Apr 25, 2016 gm introduced its vortec line of engines in the mid1990s, in i4, i5, i6, v6 and three v8 configurations in various displacements from 2. The casting on a set of oe vortec heads, are thin, and are pron to cracking, also the studs in the oe heads are pressed into the head, so if you bump up the hp, these studs will pull out. What got the power merchants attention was the increase in horsepower from 200 to 255 solely based on the power generated by these heads.