No Vortex Forum, but I have a question...

[murphylawe]

Hey everyone,

Apologies for posting in the Duramax forum, but there isn't a forum for Vortec and I have a question.

My engine is not running the way a 454 should and I have decided to build out a new engine. I have experience in building racing engines, decades ago. I have built out 350's, 426 Hemi's, a couple of 454's, and a 460 punched-out to 490. Some burned gas, and others methanol.

I know how to build a track-monster, been there done that. I need a torque-monster, and that is a different show entirely. Different torque bands, lower RPMs, just never built an engine for that type of performance.

SOooo... to make a long story shorter, I am here to pick your brains. I live on a pretty tight budget, like don't we all, but have a phenomenal aptitude for engines and have rebuilds that lasted for years.

I need to know how far to push the boring (or bore it out at all), piston suggestions, cam suggestions, etc.

I know a machine shop that does excellent work for me at a stunningly low price, so I have the cleaning and boring of the block covered. They will also deck, polish, and port the heads if I desire. I will assemble them and just about everything else to keep the costs manageable.

So, I await your towing engine wisdom.

Cheers everyone!

[Skip426]

I came from a drag racing background too , but jumped into RVing with the Dodge 8.0L , V-10 as my primary long distance tow vehicle. 305HP , 450 ftlb torque.
Partially because working on Dodge/Cummins all day didn't put me in a good frame of mind for owning one.

But on to your questions .
Cylinder wall taper will tell you how much boring you'll require , JMHO , don't go further than necessary.
454 truck engines were stout from the factory , I can't say if there would be a torque cam available , much better than factory grind.
Port/polish , works best on high RPM motors , my 426 liked it , but at 4,000 rpm , which will probably be top of the heap for your application , probably not worth the effort; unless your planning on headers , then port matching to the exhaust gaskets and header flange is in order.
You didn't give a year ? Are you dealing with a carb or EFI engine?
Have you done any diagnosing on your power issue ? Compression testing ?
You'll want be able to run regular gas , so compression ratio change probably not a good idea.

[Isaac-1]

You might try posting in the Workhorse forum since almost all Workhorse coaches had either the 7.4L Vortec or 8.1L Vortec engine.

[mikeintx]

Look at marine cams for a 454 they have an awesome flat torque band. Headers with dual exhaust and a good valve job.