Well, I apologize for disseminating what was apparently erroneous information.

I'll check my facts more closely next time.

To the poster that said "Comparing a 4" X 3" engine and a 3.40" X 4.125" engine is ridiculous" (or, something like that) was right; there IS no comparison, because of practical valve size limitations. That was my point.

Having a 170 that makes 1.5 hp/cu.in vs. a 225 that makes 1.33 hp cu.in.....

Well, on the street the 225 would be the faster car, but in class racing (where they classify cars by lbs./cu.in) the 170 would prevail.

You pays your money and you takes your choice....

Hey Bill, the 302 head, 186 casting # was great for its time compared to the 461 castings that everone thinks hung the moon of that same era. Just not that good.....

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There's no such thing as too much cam....only not enough engine!

Chevvy guys........

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Wrong Zilla,I built MY motor,Wyane had his built.Jefferies did my head and guided me but I built it.From my calculations its about 305 hp at the flywheel and 275ish at the rear wheels.Guzzi Mark

Mark, the fact remains that you and Wayne have very similar parts in your motors. No replacement for displacement unless you turn it to the sky.

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Official Cookie and Mater Tormentor.

There may be no replacement for displacement, but a turbocharger is a pretty good "crutch." The two guys I personally know of running 225 turbos have no "heroic measures" inside their engines (no offset ground strokers or .100"+ bore jobs, roller cams, offset valve guides, or even EFI) and they both make in the neighborhood of 500 horsepower. It takes a fairly well-built small block to exceed that figure without breaking the bank.

Considering all the problems associated with the breathing limitations foisted upon the 225 by that 170 head it has to deal with, forced induction would seem to make an end run around those restrictive flow problems, and be worth whatever complexity and extra expense that it brings with it (and, it DOES arrive with "baggage," believe me.)

Turbocharging is just like conventional hop-up methods in this respect; you can go mild, wild, or anything in between; it all depends on how much you want to spend.

I personally feel like a mild (10-pound boost) turbo setup on a nearly stock /6 engine could be the cheapest way to the 13's in fairly light A-body.....

Definitely cheaper than swapping in a 360, with the necessary parts to put it into the same e.t. range.

Getting a normally-aspirated /6 into the 13's requires several mods, I believe, some not cheap.

Just sayin'....

Mark,

Just a comment. If you are calculating 275 RWHP (I think I get a bit higher by my calculator), I believe you are around 340 HP at the flywheel. An auto (904) loses a lot. Tilley chassis dyno'ed at about 280 HP and then engine dyno'ed and got around 345. That was with a 2800 RPM converter and yours is 4000, right?

You have done some amazing work, my friend!!

Lou

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Home of Slant6-powered fun machines since 1988

"You have done some amazing work, my friend!!"

I second that!!! Mark's car is SO impressive!!!

Bill

Back in '61 they were pulling 184hp from the 170's in NASCRAP with the Hyperpaks.

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

You can DO that with a 170; that's the size engine the head's valves and ports were designed to feed. Add 55 cubic inches (or, put another way, 33%) and it's a different story.

The 225 slant six did a great job of hauling around 3,600-pound cars on the street.

Trying to get it to breathe like a racing motor is an uphill battle.

It can be done, to some extent, but the easy way out is forced induction.

My 2-cents...

Bill

Most of us came to that very same conclusion about 5 years ago. Welcome to the party.

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Official Cookie and Mater Tormentor.

and it`s a really good party with lots of special guests

Thanks for the confirmation.

That said, I think that the slant 6's REAL strengths lie in its unusually robust construction (block and head stiffness,) and the short, forged crank with 426 Hemi sized bearings.

I believe that its robust block and head construction owe their existence to the fact that Ma intended it to be an aluminum engine, from the git-go, and when that didn't work out, the changes in construction that WERE implemented (in the changeover to cast iron) were cheaper to change minimally; the least amount of things possible, were modified.

So, what we end up with, is a basic engine that is strong almost like a Diesel, and can withstand boost levels that would destroy my 360 Magnum in a New York minute!

I go to breakfast every Saturday, with about 6 or 8 cronies... all of whom own Buicks with turbos. They tell me that using factory blocks and cranks, they dare not exceed 22-24 pounds of boost, or egregious engine damage WILL occur. They just come apart.

I think a slant 6 will handle a LOT more than that, properly assembled with forged rods and pistons.

Hopefully we're going to find out.

Both Tom Wolfe and Ryan Peterson have taken their engines to the high 20's, boost-wise, and we're eventually going to see what comes apart after that, with our effort.

At least, that's the plan...

Thanks for your interest!

Bill, in Conway, Arkansas

I hope we get to see you at a Slant 6 race with this machine.

Happy building, Lou

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Home of Slant6-powered fun machines since 1988

The 184hp was being spun at 7000+? Lots of breathing going on.

How much air they were pumping? I can't do the math.

Bill are you Frank's friend in Little Rock?

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick