New performance Slant article in Hot Rod
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New? that article is from 2006.But I must say the owner of that engine has been racing it for the last 11 years and it is still going strong.With a mild set up it has run in the 12.90's in a 67 Dart.
Missed that it was an old article - just showed up in my feed, and I hadn't seen that one before - so new to me, at least.
I think it's an interesting article, too, It was written to illustrate the many ways that performance can be improved by conventional hop-up methods, such as increasing displcement by boring and stroking, increasing the compression ratio, installing bigger valves and porting the head to take advantage of those valves; opening up the intake to more flow, through the use of a bigger carburetor, and optimizing exhaust flow through the use of a header, to move more exhaust, efficiently. All this is aided by the installation of a camshaft that lifts the valves further off their seats and holds them open longer.
The engine builder even went so far as to fabricate a fuel injection system; this engine was built by a knowledgeable, professional team that left no stone unturned (within reason,) in getting the absolute max out of this naturally-aspirated 225 motor.
I think, after lots of time and effort, this excellently-prepared motor made just a little over 300 horsepower.
This project was NOT a "budget-build." It represented the max you could reasonably expect from a naturally-aspirated slant six on gasoline, that had been treated to virtually all of the conventional bells and whistles we commonly use to make these things go fast...
Just a shade over 300 horsepower.
That's about 1.3 horsepower-per-cubic-inch; enough to put an A-body into the twelves.
There is, however, another train of thought that wants a little more from the leaning tower of power, and at this point, there are a couple of examples that have shown us that 300 horsepower is nowhere near the maximum potential for this engine if forced induction is utilized.
Two FABO members, Tom Wolfe and Ryan Peterson have built near-identical 225's with turbo's that each demonstrate 500+horsepower capability and do it without any exotic, state-of-the-art components nor stratospheric rpms. They are both redlined at 5,500 rpm.
Neither has a roller cam nor fuel injection. They both use 1 4bbl Holley carburetor and an automatic transmission.
Here are their videos...
[ame="https://www.youtube.com/watch?v=EAxRmoDgsdY"]Turbo charged Slant 6 11.02 @ 120.56 - YouTube[/ame] 1970 Dart 3,200 pounds
and
[ame="https://www.youtube.com/watch?v=7QzUfV8iTpQ"]Turbo Slant Six 10.74 @ 127 mph 7-19-10 - YouTube[/ame] 1966 Valiant 2,800 pounds
Those cars were both running 28 pounds of boost.
Adding a turbo to the motor appears to be good for about another 200 horsepower in this case.
That the people who built that slant six motor and spared no expense to get a little over 300 horsepower, didn't go a little further and add forced induction (supercharging or turbocharging; there's not much difference,) is really too bad, because they might have made even more power than these two private efforts.
The fact is, the astounding performance available from turbocharging a slant six is a too-well-kept secret. I think that needs to be changed.... :cheers:
Agreed!
BTW, found a link yesterday with Kenny Duttweiler commenting on turbo'ing slants - have you seen this one, Bill (go about halfway down to find the Duttweiler part)?
What do you think of his cam and compression ratio suggestions?
http://www.hotrod.com/how-to/engine/hrdp-0803-1965-plymouth-slant-six-engine/
I read the Hot Rod article and found it interesting. I'm always trying to learn more. What I learned was that they put a lot of time, MONEY and effort into that thing. The head work by Angie was beautiful. The nicely done FI info was great and it points out the discrepancy between the intake runners on a /6, +20HP.
A 300 HP slanty built to the hilt is nice but...
Reverend Dedman and Brother Pishta are making more and more sense. Preach it brothers!
A 300 HP slanty built to the hilt is nice but...
Reverend Dedman and Brother Pishta are making more and more sense. Preach it brothers!
I think that Kenny Duttweiler is the expert and I am a know-nothing wannabe, johnny-come-lately, with a big mouth.
I LOVE talking about turbo slants, but the truth us, I don't REALLY know what I am talking about because I have very limited experience with these motors. My car is the only blown slant I have ever worked on and I only started this project 6 years ago... and, when you're 77 years old. 6 years isn't very long... :banghead:
SO, my opinion doesn't mean much, but, I keep running my mouth, anyway.
My motor has a measured 9:1 compression ratio and it sems to like it; that's all I know...
And, that is with 15 pounds of boost. Soon to be 20, then 25 if everything goes well (and, when did THAT ever happen???)
My only argument is with Duttweiler's cam duration specs for turbo slants. He seems to like duration @ .050" of 220 degrees for the intake and 230 for the exhaust, while my experience (HA!) is that 210/210 works well, and more just isn't necessary; more just causes more power-robbing overlap. I HAVE a Comp cam I have never tried that is ground to his specs and IF I am around long-enough, I will probably get around to trying it for a comparison. We'll see...
rayer:rayer:rayer:Shaker223
Boost Rules
Just a quick correction...3500lbs race weight @ 22PSI.
Thanks for the kind words Bill!
Thanks for the kind words Bill!
The numbers don't lie.... 300+ vs. 500+ tells me all I need to know about naturally-aspirated vs. boosted slant six motors. I am not the least bit masochistic when it comes to choosing an induction system (N/A vs. forced-induction,) so, if you're staring from ground-zero with a "build," why not take the more effective road to performance? N/A is simpler. cheaper and the learning curve is a lot more user-friendly, but, in the end, the odds are that the turbo car will be a LOT faster, and that's what appeals to me... (TOO MANY YEARS AT THE DRAG STRIP!)
Boosted slants are just too good a deal to pass up... :blob:
I talk about it, but PISHTA makes it all possible with his J-Pipe!:cheers:
Well, one could argue that dropping a stroked SB w/quality pieces and adding a snail to it
would produce waaay more hp/$. So whats the point? Again, you'll find no bigger proponent
of turbos above all else for output combined w/efficiency, than myself. But,I am strictly in the
do it with EFI or don't bother w/it camp, and that road ain't cheap. Just sayin'...
A friend/customer of mine purchased an AAR that had a Rotomaster turbo kit installed on
it, orig. T/A eng. & all. In the early '90's, it had been set up to run alky, which didn't suit him
so we switched it to gas w/water/alky inj.. We made mods to the kit, and had it running well,
but it was primarily designed to "wake-up" dead *** smog engines. Eventually we ran against
the systems limits,the shaft speeds were getting too high, then the inj. system crapped out
on a pass that looked like a hi 11 sec pass. It broke a ring land out of one of the blower pis-
tons, and that was the end of that,as he vowed to put it back to 6bbl form if he had to buy
said pistons ever.
It became a 9.7:1 6bbl 340 w/a 292 purple shaft,9.5" converter, that ran bests in the 12.3s
and no drama. Clever kit that Rotomaster tho', w/the right cam there was ZERO lag.
would produce waaay more hp/$. So whats the point? Again, you'll find no bigger proponent
of turbos above all else for output combined w/efficiency, than myself. But,I am strictly in the
do it with EFI or don't bother w/it camp, and that road ain't cheap. Just sayin'...
A friend/customer of mine purchased an AAR that had a Rotomaster turbo kit installed on
it, orig. T/A eng. & all. In the early '90's, it had been set up to run alky, which didn't suit him
so we switched it to gas w/water/alky inj.. We made mods to the kit, and had it running well,
but it was primarily designed to "wake-up" dead *** smog engines. Eventually we ran against
the systems limits,the shaft speeds were getting too high, then the inj. system crapped out
on a pass that looked like a hi 11 sec pass. It broke a ring land out of one of the blower pis-
tons, and that was the end of that,as he vowed to put it back to 6bbl form if he had to buy
said pistons ever.
It became a 9.7:1 6bbl 340 w/a 292 purple shaft,9.5" converter, that ran bests in the 12.3s
and no drama. Clever kit that Rotomaster tho', w/the right cam there was ZERO lag.
One thing that was said about the Hot Rod article was the owner wanted it to be N/A with no boost or nitrous. Goal was to reach 300 to 325 HP N/A. Rich Nedbal who wrote the article also built the engine as a challenge.He is well known as the go to guy for fuel injection and building mostly Gen 2 Hemi's. they did the fuel injection even though the engine would be raced with a carburetor.A 500 AFB was used knowing a 600-750 Holley would make more power.To this day it still has a 500 AFB on it.Also a Offenhauser intake. Many Slant racers feel that the Clifford is a better manifold and makes more power.
Well, i understand your friend's displeasure at the circumstances; a piston-failure is never easy-to-take.... but, hot rodding is not an "exact-science" and particularly, with forced induction and, particularly, with slants. Detonation is a strict headmistress, and is exceedingly demanding of tuning issues. If he broke a ring-land, it was likely, due to detonation, whixh can come from several sources. I am playing with fire (literally), attempting to raise my boost-level from 15 to 20 pounds in an effort to pick up a few tenths, but, I know the dangers... and, am willing to take the chance.
My car is JUST a race car though, and is trailered to the strip, so, if it breaks something, I'll just winch it back up on the trailer and haul it home and hope it won't be too-expensive to fix... one more time. :banghead:
Looks like he achieved his goal. I just never wanted that uphill battle that the builder of a n/a slant six, faces with that difficult to work with cylinder head.
I use an Aussiespeed Hurricane manifold which may, or may not, be better than a Clifford, with a turbo. I am not sure if it makes much difference. When I bought this long-runnner manifold, Aussiespeed had not yet, released the short-runner version, but I'd like to try one. Right now, I don't have $550.00 burning a hole in my pocket, though...
ale:I'm with you Bill,Use what ya got.That $550 can be useful for other parts.My budget is in the 3 figure range most of the time.Saving now to build my last slant racer and it will be in a "B" body. Got the header, the intake and carb,a 64 225,a 71 904, 4.10 rear.and a 63 Belvedere to put it in.Plan is to have it done for 2018.Shooting for a consistent 15 second bracket racer.Budget no more than $7000 total.Biggest expense with be a special built converter and long block work. Only time will tell.
Darter, I don't know where you plan on racing that car, but, Las vegas is at about 2,500-ft. above sea level and if you run there, that will definitely slow you down.You lose 3% horsepower for every 1,000-foot above sea level, so that's about 15 hp at the strip, on a 200 hp motor. I think it may be somewhat difficult to get a B-body into the 15's at Vegas, naturallly-aspirated.
What do you think?
Sarter,
Here is some better information for you...
Oops, the formatting is screwy...
Anyway, Las Vegas (the drag strip) is not 2,500-feet above sea level; it's only 2,100 feet... a difference of 12%... significant.
No, not likely, definitely due to detonation. As I stated, the inj. system crapped out.
With no water/alky & pump premium only, the 15psi was too much to take,and no inter-
cooler all sealed it's fate. We had temporarily ran 21psi,"just to see" :twisted:, but backed
it down to 15psi of reality, w/the inj. working of course.
As I also stated,the system wasn't designed for all-out,and we also ran against the
rpm limit of the turbo,resulting in one rebuld & an all-out shaft failure.
Yes,his car is & was a street car,but the value and originality played a larger role in
returning the AAR back to 6bbl form.This included scaring up an orig. hood, as the turbo
kit sat up as high as a tunnel ram, and it had a custom hood to match. All in all, it was
fun while it lasted,but He made the right decision.
For 24 years, I lived in the San Francisco Bay Area (sea level) and visited Las Vegas once or twice a year. I could tell a drop in performance when I arrived there, and it was pretty noticable. I once drove a 1962 Dodge Lancer which had a Hyper Pak 4bbl setup and cam, but a stock exhaust manifold, It had a 904, 13-inch Bucrons, and ran 16.88 at sea level. 88 miles-per-hour.
Sixteens out of a 225 N/A in a B-Body at 2,500-feet altitude is asking a lot, I think.
Charrlie_S
Well-Known Member
Charrlie, Time will tell on what combo of parts I will actually use. The 64 engine was given to me. A guy in Vegas has a bunch of different years that I can get too, I just got to pull them.
Bill, Normal density alt during race time in Vegas is in the 3000 to 4000 D.A. Anyway I like to run with the Slant racers back east during the summer anyway.Vegas,,Too damn hot and they race during the night(I don't see that well in the dark anymore.)
Bill, Normal density alt during race time in Vegas is in the 3000 to 4000 D.A. Anyway I like to run with the Slant racers back east during the summer anyway.Vegas,,Too damn hot and they race during the night(I don't see that well in the dark anymore.)
So.... that's why my 3.3-liter V-6 Dodge minivan was "lazy" at Vegas...
You could just put a hairdryer on the slant and race at home... :blob:
I sure like mine...
I hear ya,Again only time will tell.I use 2018 as a dead line.Maybe some other parts will show up between now and then.Many think I am nuts as I have a 500 inch RB carb to pan that has been waiting for it's day in the sun for over 10 years now that will be perfect for the Belvedere.Along with all the other parts for it too in boxes.BUT I guess I'm not over the SLANT SICKNESS as of yet...........Who knows, maybe I can trade my 79 Chrysler 300 for a nice little "A" Body to build instead."Dare to be different" as they say..
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