Limits of Vortec Heads

[Honky Kong jr]

Yeah that's true. Not sure it would need the self aligners with the heads set up for that cam though. But there's no excuse for the short valve covers, unless there are no tall covers available for the center bolt style. I personally wouldn't use that style head for performance, so I don't know what's available for them.

IMO Vortec are a good off the shelf slap on and go. If your building an engine with a solid roller then no. AFR or any number of good aluminum head comes to mind not a "truck" head. I've run them but I kept the cam sensible.

 

[SHOTROD81]

Here's a pic of the lifter, and one of the cam lobe taken with my newly acquired $12 ebay endoscope. That's the best I could do on the lobe for fear the ebay-special may fall apart if I probed around any more. The exhaust lifter roller looked smooth and solid, which was my main concern since it was under the blown rocker, but the intake didn't look flawless, as you can see in the pic. I could feel a very minute amount of roughness when running my fingernail across the marks, but it was roughness nonetheless. Is this grounds for replacement? Grounds for inspecting the all?

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[Honky Kong jr]

Here's a pic of the lifter, and one of the cam lobe taken with my newly acquired $12 ebay endoscope. That's the best I could do on the lobe for fear the ebay-special may fall apart if I probed around any more. The exhaust lifter roller looked smooth and solid, which was my main concern since it was under the blown rocker, but the intake didn't look flawless, as you can see in the pic. I could feel a very minute amount of roughness when running my fingernail across the marks, but it was roughness nonetheless. Is this grounds for replacement? Grounds for inspecting the all?

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How to they fit in the lifter bore and how does the bore look. That side wear tells me the geometry is off.

 

[crazy4offroad]

I think it would be grounds for replacement. Keep in mind it was running with the rocker out of alignment putting thrust against that rough area. A new lifter should be fine. And for good measure it would be worth checking them all while you're in there where you can do it.

 

[4WDKC]

I didn't modify them, I bought the whole package as-is, with about 1000 miles on the rebuild. The motor was built by a local builder called NVR Racing in Butler, Wisconsin. They have been very helpful, including a complimentary house call to make sure the valve lash was set correct this spring. They did not modify the heads though, they were provided by the previous owner when the engine was built. I can only assume they checked the heads for viability prior to the dyno runs. I was looking for a solid C10 with a fairly fresh plant for a little fun and for hauling. Had it a year now and I am getting a serious education in the trials and tribulations of having a motor that is a little more radical than I anticipated. Thanks to you guys and a couple of builder/racer friends, I am going at this with a lot of help.

Sounds like this this cam is all wrong for what you want. Can you put your camera in the spark plug hole so we can see if it has flat top or dished pistons.

 

[SHOTROD81]

Sounds like this this cam is all wrong for what you want. Can you put your camera in the spark plug hole so we can see if it has flat top or dished pistons.

I'll try to get a picture tomorrow. The build sheet says that they are SRP 4.040" Flat Tops part # 338563. I can't find that part on their website, so it may be an old number.

 

[SHOTROD81]

Do you think it would be wise to change the cam at this point? It seems the consensus is that this cam isn't a good fit for the application. Am I correct in thinking that a little less lift would make for less future problems if I keep the Vortecs in their current state?

 

[Honky Kong jr]

Do you think it would be wise to change the cam at this point? It seems the consensus is that this cam isn't a good fit for the application. Am I correct in thinking that a little less lift would make for less future problems if I keep the Vortecs in their current state?

That's what I would do. Solid roller is for racing and you will be adjusting them constantly. A nice torquey hydraulic roller would suite your needs.

 

[4WDKC]

Do you think it would be wise to change the cam at this point? It seems the consensus is that this cam isn't a good fit for the application. Am I correct in thinking that a little less lift would make for less future problems if I keep the Vortecs in their current state?

My vote is yes, according to the pic below that cam has a power band for 3-7K rpms, that is not goo for hauling and will feel like a slug unless you have a stall convertor. It is also more cam than i have in my 406 in my vette for street use. Something about 210/220 @.050 and .500 lift is my guess of what youre going to need if you put alot of weight behind the truck.

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