valvetrain question re: vortec

go_faster

go_faster

New member
I have been doing some searching here but have found conflicting info.

I have just done a vortec conversion on a stock engine. I am looking to buy a cam, possibly the 415. The heads are the 2001 shaft mounted rocker type. I have done the intake, redrilled the heads and 'squared' the head ports only.

Some posts state that I cannot use the the factory springs but must use the beehive type? Will the factory valvetrain (pushrods, rockers, springs etc.) not work? What is the reason for the beehive spring conversion? Is it only required on cams with greater lift?

I also need suggestions on head gaskets and my cam selection. My goal is mid 12's with an injector, turbo and converter upgrade. Does this sound reasonable?
 
dgoodhue

dgoodhue

BuSTeD 4.3
Re: valvetrain question re: vortec

go_faster said:
I have been doing some searching here but have found conflicting info.

I have just done a vortec conversion on a stock engine. I am looking to buy a cam, possibly the 415. The heads are the 2001 shaft mounted rocker type. I have done the intake, redrilled the heads and 'squared' the head ports only.

Some posts state that I cannot use the the factory springs but must use the beehive type? Will the factory valvetrain (pushrods, rockers, springs etc.) not work? What is the reason for the beehive spring conversion? Is it only required on cams with greater lift?

I also need suggestions on head gaskets and my cam selection. My goal is mid 12's with an injector, turbo and converter upgrade. Does this sound reasonable?
Click to expand...


The beehive springs are need for cams with more lift. You can measure the spring if you want but typically most stock GM springs need to be replace when using cams with than .460 Lift.
 
turbodig

turbodig

Active member
Re: valvetrain question re: vortec

The "need" for springs will be dictated by the amount of total lift you have. You don't want to bind coils.
You also don't want the retainers getting too close to the guide bosses either, although this shouldn't be a problem with your heads.

All the same, check your springs for bind, and compressed height.

Since you're changing lift, you'll also want to verify that the rocker geometry is correct, also.

There's a lot of guys who slap different cams/rockers/lifters in without checking this stuff.
It'll bite ya if you don't.
 
go_faster

go_faster

New member
Re: valvetrain question re: vortec

Ok, I called Comp Cams and told them my set up and that I was going with their 415 cam which has .500 lift. I told them that what I learned here; that the springs would likely bind past .470 or so and that I needed springs that would work (even if I have to machine). He had no idea what to sell me or even if I would have to machine the seats? There are many 'beehive' numbers and rates etc. Does anyone know which part number I should use with this head and cam combo? I need room for the .500 lift and a margin of error.

Thanks in advance for your comments!
 
TYHOGG

TYHOGG

Active member
Re: valvetrain question re: vortec

I believe its comp cams 982 kit that will work a .500 lift cam and no machining on the vortec heads.
 
go_faster

go_faster

New member
Re: valvetrain question re: vortec

no machining? That would save some time and money. Are they beehive type?
 
Quickstop [UK]

Quickstop [UK]

Combating adversyty.
Re: valvetrain question re: vortec

Read Tooky's vortec head swap thread - it'll set it out for you AND save some pennies. All in his swap was around $1500 or so - awesome.
 
NecroWolf

NecroWolf

lost marbles member
Re: valvetrain question re: vortec

hey tooky i bet i came in under your vortec swap cost if you discount the random extras
 
Tooky

Tooky

Serious about performance
Re: valvetrain question re: vortec

Post your results and prove it. Check my spreadsheet too, the price of just the heads came to something like $960, the $1500 includes the custom turbo camshaft, rockers, everything.
 
NecroWolf

NecroWolf

lost marbles member
Re: valvetrain question re: vortec

i got my entire engine for 425.... with the vortecs, but i'll do it up in a seperate thread
 
TYHOGG

TYHOGG

Active member
Re: valvetrain question re: vortec

I checked today the 982 springs will support a .500 lift cam. You can save some money on the machining.
 
Big Mike

Big Mike

New member
Re: valvetrain question re: vortec

Your goal was to run mid 12's. An ultimate chip and some tuning should get you there, SY-1193 had done it with his truck, if your changing all those parts you might want to set your goal higher. You do not have much of a goal if it can be obtained with not much more than a chip change and a good running truck.
 
Don W.

Don W.

Stab it and steer it
Re: valvetrain question re: vortec

Just finished this conversion so some thoughts: I had the heads machined for oversize springs (Comp 987-12), also for the correct seals. Because the rockers are NOT adjustable I spent quite a bit of time with a dial indicator (I'm slow:)) confirming lifter pre-load and then ordered a set of custom pushrods. In the end, rocker geometry was OK, not perfect. Clearance between the valve retainer and underneath side of rockers was close with non beehive springs.

Having done only mine I can't swear to it but I doubt your pushrods will work. I wanted chromoly ones anyway. As mentioned geometry is important but so is correct preload.

Because there is no adjustment make sure when the heads come back from the machine shop that the valves are all the same height.

Personally I would install hardened exhaust seats but I guess a lot of people don't and seem to do fine. As I understand it the factory seats are induction hardened for only a very shallow depth and once through that with any kind of valve job the seats won't hold up with unleaded gas.

End of rant... :roll:
 
SY2455

SY2455

70's Veteran
Re: valvetrain question re: vortec

Don W. said:
I spent quite a bit of time with a dial indicator (I'm slow:)) confirming lifter pre-load and then ordered a set of custom pushrods. In the end, rocker geometry was OK, not perfect. Clearance between the valve retainer and underneath side of rockers was close with non beehive springs.End of rant... :roll:
Click to expand...

Don, How long would your custom pushrods have to be to make the rocker geometry perfect?
 
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