At last!! Got a Vortec long block...what are my options now?

[RootBreaker]

ok... so in that example.. do you know the general hp difference?
does a 40-50hp increase from cast to vortec sound about right?
thanks almighty motor "head" guy... /forums/images/icons/grin.gif

 

[Pure Insanity]

</font><blockquote><font class="small">In reply to:</font><hr />
thanks almighty motor "head" guy...

[/ QUOTE ] LOL! I dont know squat! /forums/images/icons/tongue.gif I just know what I have read. I only know what I do because I got the Vortec motor before the heads hit the magazines. I was originally told they were junk. Man was that guy wrong!

I did quite a bit of research before deciding to keep them, and those magazine build ups are what convinced me. When I got the motor I had intentions of tossing the heads and basicly just using the block and crank. The rods were "strange and unproven" too. I have taken the rods to close to 8 grand so far. My tach lite was burned out, it was dark and for some reason my shift lite didnt trigger. When I got back I hit recall and "flicked my Bic" in front of the tach. I would say that from about 6500-6800 up to where I shifted to 2nd, it was like Mr Toads Wild Ride at Disney. LOL!

As far as the expected gains, I have heard 40-50 Hp. All things being equal that is. Same cam, carb, and intake style. (Performer for example. The only difference being made for Vortec heads bolt pattern.) It may have been in a GM Performance catalog that I read that they out flow the Bowtie heads. They are what all the circle track guys seem to be running for the class where they have to run stock automotive production heads.

Now I dont think those gains can be expected over 2.02 or Bowtie heads. Think a more standard head.

One thing to remember is that the Vortecs have a 64cc (I think) chamber. It may be 68, Im not sure. And the have 1.94 1.50 valves. I would love to hear from someone that has JUST changed heads, everything else equal.

And IMO another beauty point to the heads is you gain the extra horses, but you dont HEAR them (so it makes for a great sleeper) and the motor is not overly radical, and "difficult" to drive.

 

[dyeager535]

40-50HP sounds about right with standard, "lo-po" (read, 70's-90's) stock heads compared to Vortecs.

Personally I think they did themselves, Vortecs, and TPI a disservice in this write-up http://www.sdpc2000.com/htm/vortec_tpi.html as the Vortec heads alone probably gave the HP boost, and almost nothing from the TPI. They should have done each component seperately, and measured torque. The results would have been much better I think. My 350 with Vortecs and TPI (through desktop dyno 2k) peaks out at just over 275HP, but over 400ftlbs of torque under 3000RPM, which is where the engine sits at cruise, and what I need to start moving with a manual transmission, 33" tires, and 3.42 gears.

Anyways, the Vortecs have a superior combustion chamber, and extremely (compared to earlier heads) clean castings in the intake/exhaust ports. Very smooth as cast, so they flow well.

All are 1.94/1.5 valves that I'm aware of, except *perhaps* the 305 Vortecs that I've never paid attention to. 350 Vortecs are 64CC, and 305's are 58CC.

 

[RootBreaker]

thanks for the info...
now if I was to change my heads later... after the motor is in.. do i have to change the rods too? just curious if they are a different length?
thanks..

 

[dyeager535]

nah, the vortec heads are a "bolt on" so it seems, but thats about as far as I can take it. I'd imagine pushrods are the same length, but Vortecs use "self aligning" (also known as rail) rockers, so you'd have to get new rockers as well.

Other than that, its the new intake, and any other problems related to the new intake, such as EGR if you were going to run it.