POWER TIP

[Torquemonster]

Do you like it tight?

Don't we all.

Well here's how to pick up some serious hp gain without buying anything except labour and machine time - by simply making your engine tight in a key area....

the "quench area"

Actually I lie - you'll need adjustable valvetrain - roller rockers, but you wanted those anyway didn't you?

Assuming stock clearance is over 0.050" if you blue print the quench to around 0.035" you'll pick up more power than just about any popular bolt on goodie. CNC port the heads while the engine is out and compound the effort - just don't lose air speed at low to medium lifts!

With the cast pistons you can get the quench very tight as it has tighter bore clearances than the forged piston engines - which could still handle 0.035 piston to head clearance @ TDC - but that would be about the limit for them unless someone has found they can go tighter. The cast piston could possibly go under 0.030" but I'd not be game to be first. - I've seen 0.027" to 5500rpm before touching on a straight six. I'd go to 0.030" on cast pistons max - but 0.035" is safer for most - and should go to 7000rpm before looking like touching. I've seen a 440 Mopar run 0.035" to 7000rpm in road racing - no problems except no other 440 could keep up!

What about compression? As long as compression did not increase more than a point - no octane requirement change would result.

You can add an entire point in compression (i.e. go from 9.5:1 to 10.5:1) on the same octane by tightening the quench from 0.050" or more - to under 0.040" - FWIW.

Warning: 1) tight quench is the best hp trick - but you must blueprint EACH piston - do not assume all TDC heights are the same - you'll have to shave the highest pistons to match the lowest one, then deck the block and heads to get your desired quench. Its as basic a power trick as boring using a honing plate - but you'd be amazed how many "top" engine builders don't do it.... trust me ALL the top ones do it... even a Hemi (where the rules allow a tight quench) - now there's a challenge - hand finishing a Hemi piston crown to achieve a blueprinted clearance of 0.040" on the Hemi chamber... Ray Barton can do it. On a Viper with wedge heads its a piece of cake.... but

2) check the piston to valve clearances either side of TDC - worst case scenario would be a need for new pistons with deeper valve reliefs - but the power gain is worth it! You'll feel it seat of pants to drive - its that good, and it picks up response at all rpms - one of those rare power adders that has no downside other than cost.... even ecomomy will improve

 

[Daffy Duck Viper]

Fascinating. You got a big brain, Torquemonster.

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[Torquemonster]

Hope that brain doesn't need a big head to hold it in?

Thanks Daffy - but Nah - I'm just another person -

a very unique person of course -

just like everyone else!



Reminds me of the saying to the lonely...

"Are you alone? Don't worry, you are not alone.
And yet you are alone. So very alone!"



Did you know that I'm a handy mans *****.... it's true!

I wouldn't build a lawn mower engine - but I can give you a recipe to build 3000hp and it'll work! I got really good at recipes that work - but there's no money in that.... so it's just fun now.

So thank goodness for the tuners and builders out there that can actually build the stuff.

I go much further than the normal engine customer in some areas - and engine builders/tuners love that as it makes them think too... It's fun - and we all learn something as they always come up with something I never knew that adds another piece to the picture. They are the guys at the cutting edge - the ones building the winning engines.

you should have seen the look on one tuners face when his dyno analyzer showed zero bad emissions on my wifes car after we'd done a few mods to it! He was amazed - especially when he thought our gadget was funny before he tested it. It was funny too, but it worked.

What we don't know is infinitely more than what any of us do know - that's all I know.

I do know that if I got paid for all the time I spent here I could afford my Viper.... hey - maybe there's a lesson in that... time to go - I need to go earn my Viper

 

[Vic]

Torquey-

You're a trip! (Thats 60s lingo for you are way "out there")

You really know a lot about engines!

 

[joe117]

The LT-1 in my 96 Vette has 10.1 compression. I always wondered why my Viper wasn't made with that much. The Chevy V8s and the V10 seem to be about the same technology.

 

[Torquemonster]

Yes Joe - now you are catching on. The quench area is one reason many Chevy race engine builders have been able to compete with and beat Mopar engines - even though the Mopar engine always had several design advantages.

The Chrysler engine book - which was the Bible for many years - was saying up until only a few years ago that if you ran tighter than 0.055" you'd hit the head!

Only in their dreams. That belief put Chysler behind for decades from where they could have been.

Maybe if you had old tech aluminium rods, 0.008" bore clearance, and ran 10,000rpm - you MIGHT hit - but I can show you Pro Mod 500cube engines making 3000hp that do rpm to 10,000 at times - running a lot tighter than 0.055!!!

Consequently - the Mopar engines were always at least 30-50hp down on what they COULD have been! And in class racing that is the difference between win and lose!

When you build a Mopar engine right - with their excellent rod/stroke ratio, big lifter diameters, add decent heads, then a tight quench - you can go take on any of the Chevy and Ford boys cube for cube and win....at V8 level

The Viper V10 was never designed to take on big block racing V8's and it can't - you'll never get the V10 to do what you can get an aluminium big inch Hemi or Wedge to do - that's just the way it is - but - it's one hell of a street engine and has more than enough potential to satisfy any street application.

Think I'm exaggerating? For under $20,000 Ray Barton or Indy (there are others) will build you a wedge or Hemi that will spank the $84,000 racing V10 silly. Add another $20,000 for endurance bits and high tech bits, and you can have the reliability to run endurance events too. Everything is relative.

The stock Viper (just) beats the top Vette only because of its cubic capacity. The difference however is not 2 cylinders extra worth. But build the V10 to its design features and add tight quench however - and the Vette is history - it's no longer close cam for cam, cfm for cfm!! The Viper will pull all its 2 cylinder advantage in front and more.

oh yeah - What about Pro Stock the GM boys will say?

Well - let's put it this way - at Pro Stock level you could put any badge you wanted on those engines. Many of those blocks and heads come from the same casting shop - do you want yours drilled with a Chevy stud pattern? a Ford? a Mopar? Get the picture? The GM vs Ford vs Mopar at that level is just branding, the blocks and heads are basically the same. The GM and Ford Pro Stock engines also use 1" racing lifters and long rods and run deck heights well beyond anything factory - they're closer to Mopar than anything Ford or Chev in those 2 areas.