Is this true or not regarding heads??

msheller

msheller

New member
Is this true or not regarding heads??

A couple people have told me that switching to vortec heads from stockers will reduce knock retard......Is this true???? You guys that switched to some heads that actually flow....did it reduce your knock?

I don't think this pte52 is ever gonna breathe right thru stock heads...true?

Matt
 
cloneman315

cloneman315

Active member
Re: Is this true or not regarding heads??

they will reduce knock because they have a better chamber,and u can add more timing with them ,but a 52 on a stock turbo can go into the mid to low 11s with stock heads cam etc.
 
MRKING

MRKING

New Parts for Old Trucks
Re: Is this true or not regarding heads??

Yes the combustion chamber design of the vortecs is less prone to knock . I believe p.long had a 52 on his stock head 10sec motor , so really its preference . If budget permits , they are well worth it ..
 
Skyhighsami

Skyhighsami

GMC Typhoon #1308
Re: Is this true or not regarding heads??

At what point is installing a cam make getting Vortec heads ness. What all do you need to do to use Vortec heads on one of these motors?
 
msheller

msheller

New member
Re: Is this true or not regarding heads??

cloneman315 said:
they will reduce knock because they have a better chamber,and u can add more timing with them ,but a 52 on a stock turbo can go into the mid to low 11s with stock heads cam etc.
Click to expand...

I know you helped me out b4 but, what do you think are the keys? I know you like the wb and the 2 step

I fouled out my wb sensor...do you know where to get an inexpensive replacement ntk or bosch wb sensor....my lm1 works great , but I fouled the sensor w/ lead

And i can't get the 2 step to launch w/ out bogging...any tips for that? where should I set the 2 step lower adjustable chip?

Matt
 
Tooky

Tooky

Serious about performance
Re: Is this true or not regarding heads??

To answer your question: No! I tuned a local truck that had a stock motor , with SMC alcohol and a PT54 at 23 PSI on the street with 93 octane. We could run about 18* timing. Then he got a new RPM motor with Vortecs and the 412 cam, and we went out to tune it, all ready to reap the gains of this extra Vortec timing I've heard so much about on SyTy.net for years..

Well on this truck, it never came true. We ran into knock retard any time we got near 20* and had to back the chip (Ultimate 50#) way down to get it back to 18*. The owner says he verified the timing at the balancer too.

Now I just converted my own truck to Vortecs and I tuned it to 21 PSI and guess what? I CANT RUN MORE TIMING EITHER! Do you see a trend? I do! And I verified TDC with the balancer when the heads were off, and with a timing light once the motor was running. Now I'm only talking about 2 trucks tuned by the same tuner (me) so it's not a very good test group. But take my experience for whatever it's worth to you..

msheller said:
I fouled out my wb sensor...do you know where to get an inexpensive replacement ntk or bosch wb sensor....my lm1 works great , but I fouled the sensor w/ lead
Click to expand...
Yes you can get the Bosch "LSU4" as cheap as $45, try searching around Google, I think a VWParts store had the cheapest price.
 
Foot Performance

Foot Performance

Donating Member
Re: Is this true or not regarding heads??

Are there better vortec than others(no exotic just facory take offs)?? I know on a v8 you wan the saw blade markings( /l/l/l ) is there any marking for the better ones or just casting numbers???
 
Tooky

Tooky

Serious about performance
Re: Is this true or not regarding heads??

I dont think anyone has determined a difference in performance between the earlier ~96-ish vortecs (#772) and the later (#113)s. The later ones are supposed to have stainless steel exhaust valves (if you're into using the stock valves.) Also the rocker studs can be different, I think. The 2000+ Vortecs have a smaller 8mm metric thread, but you'd have to check to be sure.
 
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